Cartesian Therapeutics, Inc. - Quarter Report: 2025 June (Form 10-Q)

Accounts receivable Prepaid expenses and other current assets Total current assets Non-current assets:Property and equipment, net Right-of-use asset, net In-process research and development assets Goodwill Long-term restricted cash Investments Other assets Total assets$ $ Liabilities and stockholders’ deficit Current liabilities: Accounts payable$ $ Accrued expenses and other current liabilities Lease liability Contingent value right liability Total current liabilities Non-current liabilities:Lease liability, net of current portion Warrant liabilities, net of current portion Contingent value right liability, net of current portion Deferred tax liabilities, net Total liabilities

Commitments and contingencies (Note 17)

Stockholders’ deficit:

Series A Preferred Stock, $ par value; shares authorized as of June 30, 2025 and December 31, 2024; shares issued and outstanding as of June 30, 2025 and December 31, 2024

Series B Preferred Stock, $ par value; shares authorized as of June 30, 2025 and December 31, 2024; shares issued and outstanding as of June 30, 2025 and December 31, 2024

Preferred stock, $ par value; shares authorized as of June 30, 2025 and December 31, 2024; shares issued and outstanding as of June 30, 2025 and December 31, 2024

Common stock, $ par value; shares authorized as of June 30, 2025 and December 31, 2024; and shares issued and outstanding as of June 30, 2025 and December 31, 2024, respectively

Additional paid-in capital Accumulated deficit()()Accumulated other comprehensive loss()()Total stockholders’ deficit()()Total liabilities and stockholders’ deficit$ $

The accompanying notes are an integral part of these unaudited consolidated financial statements.

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Cartesian Therapeutics, Inc. and Subsidiaries

Consolidated Statements of Operations and Comprehensive Income (Loss)

(Amounts in thousands, except share and per share data)

)


	Three Months Ended June 30,								Six Months Ended June 30,
	2025				2024				2025		2024
Revenue:
Collaboration and license revenue	$				$				$		$
Grant revenue
Total revenue
Operating expenses:
Research and development
General and administrative
Total operating expenses
Operating (loss) income	()								()
Interest income



Change in fair value of warrant liabilities					()						()
Change in fair value of contingent value right liability											()
Change in fair value of forward contract liabilities											()
Other (expense) income, net	()								()


Net income (loss)	$				$				$	()	$	()

Other comprehensive income:
Foreign currency translation adjustment

()			$	()			$	()

		—				—



()			$	()			$	()

		—				—





()			$	()			$	()

— — — ()()) )— ()$()$()

The accompanying notes are an integral part of these unaudited consolidated financial statements.

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Cartesian Therapeutics, Inc. and Subsidiaries

Consolidated Statements of Cash Flows

(Amounts in thousands)


	2025		2024
Cash flows from operating activities
Net loss	$	()	$	()
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization

Non-cash lease expense
Loss on disposal of property and equipment
Stock-based compensation expense

Warrant liabilities revaluation	()
Contingent value right liability revaluation	()
Forward contract liabilities revaluation



Changes in operating assets and liabilities:
Accounts receivable			()
Unbilled receivable			()
Prepaid expenses, deposits and other assets	()
Accounts payable			()

Deferred revenue			()

Accrued expenses and other liabilities	()		()
Net cash used in operating activities	()		()
Cash flows from investing activities




Purchases of property and equipment	()		()


Net cash used in investing activities	()		()
Cash flows from financing activities









Equity offering costs	()
Proceeds from exercise of common warrants
Proceeds from issuance of Series A Preferred Stock, gross in private placement

Proceeds from exercise of stock options

Payments of contingent value rights distributions	()
Net cash (used in) provided by financing activities	()
Effect of exchange rate changes on cash
Net change in cash, cash equivalents, and restricted cash	()
Cash, cash equivalents, and restricted cash at beginning of period
Cash, cash equivalents, and restricted cash at end of period	$		$


Non-cash investing and financing activities




Purchase of property and equipment not yet paid	$		$

The accompanying notes are an integral part of these unaudited consolidated financial statements.

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Cartesian Therapeutics, Inc. and Subsidiaries

Notes to Consolidated Financial Statements

shares of the common stock, par value $ per share, of the Company, or the common stock, and shares of the newly designated Series A Non-Voting Convertible Preferred Stock, par value $ per share, or the Series A Preferred Stock. The Series A Preferred Stock is intended to have economic rights similar to the common stock, but with only limited voting rights. Additionally, the Company assumed all outstanding stock options of Old Cartesian. The common stock and Series A Preferred Stock related to the Merger were issued on December 5, 2023.

In connection with the Merger, the Company entered into a definitive agreement, or the 2023 Securities Purchase Agreement, for a private investment in public equity transaction, or the 2023 Private Placement, with the Investors (as defined below). The 2023 Securities Purchase Agreement provides for the issuance to the Investors of an aggregate of shares of Series A Preferred Stock for an aggregate purchase price of approximately $ million. See Note 11 to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 for further discussion of the 2023 Private Placement.

In connection with the Merger, a contractual contingent value right, or CVR, was distributed to the holders of record of the Company’s common stock and 2022 Warrants (as defined below) as of the close of business on December 4, 2023, but was not distributed to holders of shares of common stock or Series A Preferred Stock issued to stockholders of Old Cartesian or the Investors in the transactions. Holders of the CVRs will be entitled to receive certain payments from proceeds received by the Company, if any, related to the disposition or monetization of the Company’s legacy assets following the issuance of the CVRs. For additional information, see Note 7 to these unaudited consolidated financial statements.

On March 27, 2024, the Company’s stockholders approved the conversion of shares of Series A Preferred Stock into shares of common stock. For additional information, see Note 11 to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024.

Additionally, on March 27, 2024, the Company’s stockholders approved an amendment to the Company’s restated certificate of incorporation, as amended, or the Charter, to effect a reverse stock split of the Company’s issued and outstanding common stock, at a ratio in the range of 1-for-20 and 1-for-30, with such ratio to be determined at the discretion of the Company’s board of directors, or the Board of Directors. The Board of Directors subsequently approved a final reverse stock split ratio of 1-for-30, and the Company effected the Reverse Stock Split on April 4, 2024. As a result of the Reverse Stock Split, all figures in this Quarterly Report on Form 10-Q relating to shares of the Company’s common stock (such as share amounts, per share amounts, and conversion rates and prices), reflect the Reverse Stock Split for all periods presented, including reclassifying an amount equal to the reduction in par value of common stock to additional paid-in capital. Shares of common stock underlying outstanding stock options, restricted stock units and warrants were proportionately reduced and the respective exercise prices, if applicable, were proportionately increased in accordance with their terms. Additionally, the conversion ratio of the Company’s Series A Preferred Stock was proportionally adjusted. Stockholders entitled to fractional shares as a result of the Reverse Stock Split received a cash payment in lieu of receiving fractional shares.

On July 2, 2024, the Company entered into a securities purchase agreement, or the 2024 Securities Purchase Agreement, for a private investment in public equity financing, or the 2024 Private Placement, which provided for the issuance of shares of common stock and shares of Series B Non-Voting Convertible Preferred Stock, par value $ per share, or the Series B Preferred Stock, each at a purchase price of $ per share. The 2024 Private Placement resulted in gross proceeds of approximately $ million before deducting placement agent fees and other offering expenses. On September 20, 2024, the Company’s stockholders approved the conversion of shares of Series B Preferred Stock into shares of

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million, of which $ million was restricted cash related to lease commitments. The Company believes the cash, cash equivalents and restricted cash as of June 30, 2025 will enable it to fund its current planned operations for at least the next 12 months from the date of issuance of these financial statements, though it may pursue additional cash resources through public or private equity or debt financings or by establishing collaborations with other companies. Management’s expectations with respect to its ability to fund current and long term planned operations are based on estimates that are subject to risks and uncertainties. If actual results are different from management’s estimates, the Company may need to seek additional strategic or financing opportunities sooner than would otherwise be expected. However, there is no guarantee that any of these strategic or financing opportunities will be executed on favorable terms, and some could be dilutive to existing stockholders. Further, the liability associated with the CVR Agreement (as defined below) will be settled solely through cash flow received under the Company’s License and Development Agreement, or as so amended, the Sobi License, with Swedish Orphan Biovitrum AB (publ.), or Sobi, and any other Gross Proceeds (as defined in the CVR Agreement) net of certain agreed deductions. Under the CVR Agreement, % of all milestone payments, royalties and other amounts paid to the Company or controlled entities under the Sobi License, and any

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million. The Company anticipates operating losses to continue for the foreseeable future due to, among other things, costs related to research and development of its product candidates and its administrative organization.

operating segment, which prior to the Merger related to the research and development of nanoparticle immunomodulatory drugs for the treatment and prevention of human diseases and subsequent to the Merger relates to the research and development of cell therapy product candidates. The Company’s CODM function is fulfilled by its Chief Executive Officer. The CODM function assesses performance for the segment and decides how to allocate resources based on consolidated net income (loss) that is also reported on the consolidated statements of operations and comprehensive income (loss). The CODM function uses net income (loss) to monitor budget versus actual results to assess performance of the segment. Segment assets are the same as total assets on the Company’s consolidated balance sheets. All long-lived assets are located in the United States. Long-lived assets consist of property and equipment, net, and operating lease right-of-use assets.

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million. There were no changes to the carrying value of the Company’s goodwill during the six months ended June 30, 2025.

Intangible Assets

$ $

shares of Cyrus’ Series B Preferred Stock, par value $ per share, at a purchase price of $ per share, for $ million.

In accordance with ASC 810, the Company has a variable interest in Cyrus resulting from its equity investment. The Company will share in Cyrus’ expected losses or receive a portion of its expected returns and absorb the variability associated with changes in the entity’s net assets. However, the Company is not the primary beneficiary as it does not have the power to direct the activities most significant to Cyrus, and therefore it is not required to consolidate Cyrus. The Company has recognized the $ million investment of Cyrus’ Series B Preferred Stock at cost on the purchase date.

As of June 30, 2025 and December 31, 2024, no impairment indicators were present and there were no observable price changes. Therefore, the carrying value of the investment in Cyrus is $ million on the accompanying consolidated balance sheets. The Company’s maximum exposure to loss related to this variable interest entity is limited to the carrying value of the investment. The Company has not provided financing to Cyrus other than the amount contractually required by the Series B Preferred Stock Purchase Agreement.

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$ $()$() Less: Undistributed earnings allocable to participating securities()()

Net income (loss) allocable to shares of common stock - basic and diluted

$ $ $()$()Denominator: Weighted-average common shares outstanding - basic Dilutive effect of employee equity incentive plans Weighted-average common shares outstanding - diluted

Net income (loss) per share:

Basic$ $ $()$() Diluted$ $ $()$()

Warrants to purchase common stock Series A Preferred Stock Series B Preferred Stock Total

$ $ $ Total assets$ $ $ $ Liabilities: Warrant liabilities$ $ $ $ Contingent value right liability$ $ $ $ Total liabilities$ $ $ $

December 31, 2024

Total

Level 1

Level 2

Level 3

Assets:

Money market funds (included in cash equivalents)

Total assets

Liabilities:

Warrant liabilities

Contingent value right liability

Total liabilities

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transfers within the fair value hierarchy during the six months ended June 30, 2025 or the year ended December 31, 2024.

Cash, Cash Equivalents, and Restricted Cash

As of June 30, 2025 and December 31, 2024, money market funds were classified as cash and cash equivalents on the accompanying consolidated balance sheets as they mature within 90 days from the date of purchase.

As of June 30, 2025, the Company had restricted cash balances relating to secured letters of credit in connection with its real estate leases.

$ Long-term restricted cash Total cash, cash equivalents, and restricted cash$ $ Change in fair value()

Fair value as of June 30, 2025

Contingent Value Right

On December 6, 2023, as contemplated by the Merger Agreement, the Company entered into a contingent value rights agreement, or the CVR Agreement, pursuant to which each holder of common stock or a 2022 Warrant as of December 4, 2023 was distributed a CVR, issued by the Company for each share of common stock held directly or underlying a 2022 Warrant held by such holder as of December 4, 2023. Holders of warrants other than the 2022 Warrants will be entitled to receive, upon exercise of such warrants and in accordance with the terms of the warrants, CVRs per each share of common stock underlying such warrants.

Each CVR entitles its holder to distributions of the following, pro-rated on a per-CVR basis, during the period ending on the date on which the Royalty Term (as defined in the Sobi License) ends, or the Termination Date:

•% of all milestone payments, royalties and other amounts paid to the Company or its controlled affiliates, or the Company Entities, under the Sobi License or, following certain terminations of the Sobi License, any agreement a Company Entity enters into that provides for the development and commercialization of SEL-212; and

•% of all cash consideration and the actual liquidation value of any and all non-cash consideration of any kind that is paid to or is actually received by any Company Entity prior to the Termination Date pursuant to an agreement relating to a sale, license, transfer or other disposition of any transferable asset of the Company existing as of immediately prior to the Merger, other than those exclusively licensed under the Sobi License or which the Company Entities are required to continue to own in order to comply with the Sobi License.

The distributions in respect of the CVRs will be made on a semi-annual basis, and will be subject to a number of deductions, subject to certain exceptions or limitations, including for (i) certain taxes payable on the proceeds subject to the CVR distribution, (ii) certain out of pocket costs incurred by the Company Entities, including audit and accounting fees incurred in connection with reporting obligations relating to the CVRs and other expenses incurred in the performance of their obligations and other actions under the CVR Agreement, (iii) a fixed semi-annual amount of $ million for general and administrative overhead, (iv) payments made and remaining obligations on lease liabilities of Selecta immediately prior to the Merger and (v) amounts paid and remaining obligations with regard to the Xork product candidate. Each of the deductions described in (iv) and (v) will be made only if certain milestone payments under the Sobi License are made and are also subject to certain adjustments as contemplated in the CVR Agreement. Upon the achievement of a development milestone in June 2024, Sobi became obligated to make a $ million payment to the Company and made such payment in July 2024. The proceeds from this payment, net of deductions specified in the CVR Agreement, were included in the scheduled distribution to the holders of the CVR in March 2025.

The CVRs represent financial instruments that are accounted for under the fair value option election in ASC 825, Financial Instruments, or ASC 825. Under the fair value option election, the CVRs are initially measured at the aggregate estimated fair value of the CVRs and will be subsequently remeasured at estimated fair value on a recurring basis at each reporting period date. The liability was recorded at the date of approval, November 13, 2023, as a dividend. The estimated fair value of the CVR liability was determined using a Monte Carlo simulation model to estimate future cash flows associated with the legacy assets, including the expected milestone and royalty payments under the Sobi License, net of deductions. Changes in fair value of the CVR liability are presented in the consolidated statements of operations and comprehensive income (loss). The liability value is based on significant inputs not observable in the market such as estimated cash flows, estimated probabilities of success, and

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% - %

Expected volatility of future revenues%%

Distributions() Change in fair value()

Fair value as of June 30, 2025

Forward Contract Liabilities

The Company entered into a contract for the issuance of shares of Series A Preferred Stock as part of the 2023 Private Placement which was settled in multiple tranches. The Company determined the obligation to issue shares of Series A Preferred Stock to Dr. Timothy A. Springer, a member of the Company’s Board of Directors, and TAS Partners LLC, an affiliate of Dr. Springer, represented a forward contract. See Note 11 to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024. The initial fair value of the forward contract liability on November 13, 2023 was insignificant as the fair value of the underlying Series A Preferred Stock was equal to the purchase price of the Series A Preferred Stock as agreed upon in the 2023 Private Placement. Subsequent measurement of the fair value of the forward contract liability was based on the market price of the Company’s common stock, which represented the redemption and conversion value of the Series A Preferred Stock, less the purchase price, on an as-converted basis. The non-cash settlement of a portion of the liability occurred on December 13, 2023 with the issuance of the first tranche of the Series A Preferred Stock for $ million. The non-cash settlement of the remaining second and third tranches occurred on January 12, 2024 and February 11, 2024, respectively, for a total of $ million.

$ Computer equipment and software Leasehold improvements Furniture and fixtures Office equipment Construction in process Total property and equipment Less: Accumulated depreciation()()Property and equipment, net$ $

million and $ million for the three months ended June 30, 2025 and 2024, respectively, and $ million and $ million for the six months ended June 30, 2025 and 2024, respectively.

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$ Accrued patent fees Accrued external research and development costs Accrued professional and consulting services Property and equipment Other Accrued expenses$ $

10.

leasable square feet of integrated manufacturing and office space. The lease commenced on May 1, 2024 which was the date the Landlord delivered full possession of the premises to the Company. The Frederick Lease Agreement will terminate approximately years following the commencement date. The Company will have option to extend the term of the Frederick Lease Agreement for a period of at a cost of % of the then-fair market value, not to exceed % of the then-current base rent.

Base rent, which was due beginning on July 1, 2024, is $ million annually and is subject to an annual upward adjustment of % of the then-current rental rate. In addition, the Company is obligated to pay its share of operating costs and taxes related to the property. The Company paid the first month’s rent of $ million upon execution of the Frederick Lease Agreement.

The Company assessed the classification of the lease at the commencement date and concluded it should be accounted for as an operating lease. The Company recorded a lease liability and right-of-use asset of $ million and $ million, respectively, on the commencement date. The Frederick Lease Agreement includes a tenant improvement allowance of up to $ million which was recognized as a reduction in the right-of-use asset and lease liability at the commencement date as the Company was reasonably certain to incur reimbursable costs related to alterations equal to or exceeding the amount. Additionally, the prepaid rent was included as an adjustment to the right-of-use asset. The discount rate of % was determined based on the Company’s incremental borrowing rate adjusted for the lease term, including any reasonably certain renewal periods.

Effective May 7, 2024, the Company and the Landlord entered into the first amendment to the Frederick Lease Agreement, or the First Frederick Lease Agreement Amendment, providing for the expansion of the premises leased pursuant to the Frederick Lease Agreement by approximately square feet. In connection with the expansion of the leased premises, the Company is obligated to pay $ million in additional annual base rent for the first year of the term, which is subject to an annual upward adjustment of % of the then-current rental rate, as well as its share of operating costs and taxes. The lease commenced on May 7, 2024 which was the date the Landlord delivered full possession of the premises to the Company and will be coterminous with the Frederick Lease Agreement. The rent commencement date was September 1, 2024.

The Company assessed the classification of the lease at the commencement date and concluded it should be accounted for as an operating lease. The Company recorded a lease liability and right-of-use asset each of $ million on the commencement date. The First Frederick Lease Agreement Amendment includes a tenant improvement allowance of up to $ million which was recognized as a reduction in the right-of-use asset and lease liability at the commencement date as the Company was reasonably certain to incur reimbursable costs related to alterations equal to or exceeding the amount. The discount rate of % was determined based on the Company’s incremental borrowing rate adjusted for the lease term.

Effective August 30, 2024, the Company and the Landlord entered into the second amendment to the Frederick Lease Agreement, or the Second Frederick Lease Agreement Amendment, providing for the expansion of the premises leased pursuant to the Frederick Lease Agreement and First Frederick Lease Agreement Amendment by approximately square feet. In connection with the expansion of the leased premises, the Company is obligated to pay $ million in additional annual base rent for the first year of the term, which is subject to an annual upward adjustment of % of the then-current rental rate, as well as its share of operating costs and taxes. The lease commenced on September 1, 2024, which was the date the Landlord

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million on the commencement date. The discount rate of % was determined based on the Company’s incremental borrowing rate adjusted for the lease term.

On March 13, 2025, the Company and the Landlord entered into the third amendment to the Frederick Lease Agreement, or the Third Frederick Lease Agreement Amendment, providing for the expansion of the premises leased pursuant to the Frederick Lease Agreement by approximately square feet. In connection with the expansion of the leased premises, the Company is obligated to pay $ million in additional annual base rent for the first year of the term, which is subject to an annual upward adjustment of % of the then-current rental rate, as well as its share of operating costs and taxes. The initial term of the Third Frederick Lease Agreement Amendment is expected to commence on September 1, 2025 once the Landlord delivers full possession of the premises to the Company and will be coterminous with the Frederick Lease Agreement, the First Frederick Lease Agreement Amendment and the Second Frederick Lease Agreement Amendment.

The Company secured a letter of credit from Silicon Valley Bank, a division of First-Citizens Bank & Trust Company (successor by purchase to the Federal Deposit Insurance Corporation as Receiver for Silicon Valley Bridge Bank, N.A. (as successor to Silicon Valley Bank)), or SVB, for $ million for the Frederick Lease Agreement, the First Frederick Lease Agreement Amendment and the Second Frederick Lease Agreement Amendment, which is recognized as long-term restricted cash as of June 30, 2025 and December 31, 2024 and renews automatically each year.

65 Grove Street Lease

In July 2019, the Company entered into a lease with BRE-BMR Grove LLC for square feet of laboratory and office space located at 65 Grove Street, Watertown, Massachusetts, or the Watertown Lease Agreement. As part of the Watertown Lease Agreement, the Company incurred $ million in on-reimbursable construction costs. The lease began in March 2020, when the Company took control of the office space, and the lease term is . The discount rate of % was determined based on the Company’s incremental borrowing rate adjusted for the lease term, including any reasonably certain renewal periods.

On September 1, 2022, the Company entered into an amendment to the Watertown Lease, or the Watertown Lease Agreement Amendment, to expand the Company’s laboratory and office space located at 65 Grove Street, Watertown, Massachusetts by approximately square feet. The lease term began on September 1, 2022, consistent with when the Company took control of the office space and expected lease term is years. The discount rate of % was determined based on the Company’s incremental borrowing rate adjusted for the lease term including any reasonably certain renewal periods. Rent payments began in November 2022, and the base rent for the first year is $ million per month. The Company recorded the right-of-use asset and operating lease liabilities of $ million during the year ended December 31, 2022 as control of the premises was transferred to the Company during such year.

On October 6, 2022, the Company entered into a sublease agreement to sublease square feet of space currently rented by the Company at 65 Grove Street, Watertown, Massachusetts. The sublease commenced on October 24, 2022. The term of the sublease expired on March 31, 2024 with no option to extend the sublease term. Sublease income is included within other (expense) income, net in the consolidated statements of operations and comprehensive income (loss).

As a result of the sublease agreement, rent payments to BRE-BMR Grove LLC for the lease of the office space increased. The change of consideration in the contract was accounted for as a lease modification and the right-of-use asset and lease liability were remeasured at the modification date of October 24, 2022. The discount rate of % was determined based on the Company’s incremental borrowing rate adjusted for the lease term including any reasonably certain renewal periods as of October 24, 2022, resulting in a decrease of less than $ million to both the right-of-use asset and lease liabilities.

In May 2023, the Company received notice from BRE-BMR Grove LLC that the requirements to reduce the amount of the letter of credit for the Watertown Lease had been met. In connection therewith, in June 2023, the Company secured a letter of credit from JPMorgan Chase Bank, N.A. for $ million, which is recognized as long-term restricted cash as of June 30, 2025 and December 31, 2024, and renews automatically each year.

On October 31, 2023, in connection with entering into Amendment No. 1 to the Sobi License as described in Note 13, the Company entered into a sublease agreement with Sobi to sublease approximately square feet of space currently rented by the Company at 65 Grove Street, Watertown, Massachusetts for which Sobi paid $ million upfront rental payment. The sublease commenced on November 6, 2023. The term of this sublease expired on November 5, 2024. Sublease income is included within other (expense) income, net in the consolidated statements of operations and comprehensive income (loss).

As a result of the expiration of the sublease to Sobi in November 2024 and the Company’s decision to cease use of its office and laboratory space at 65 Grove Street, Watertown, Massachusetts, the Company assessed the right-of-use assets and related furniture and fixtures associated with the Watertown Lease Agreement and Watertown Lease Agreement Amendment for impairment. The carrying value of each asset group was compared against the future net undiscounted cash flows projected to be generate over the remaining lease terms. These projections included management’s estimates of cash inflows from

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million was recognized during the year ended December 31, 2024, $ million of which related to the right-of-use assets and $ million related to property and equipment.

704 Quince Orchard Road Leases

In connection with the Merger, the Company acquired operating leases for office and laboratory space in Gaithersburg, Maryland. The leases expire in January 2027 and do not contain any renewal rights. The discount rate of % was determined based on the Company’s incremental borrowing rate adjusted for the lease term.

$ $ $ Variable lease cost Short-term lease cost Less: Sublease income () ()Total lease cost$ $ $ $

2026 2027 2028 2029 Thereafter Total future minimum lease payments Less: Imputed interest Total operating lease liabilities$

Other than the initial recording of the right-of-use assets and lease liabilities for the Frederick Lease Agreement and Amended Frederick Lease Agreement, which were non-cash, the changes in the Company’s right-of-use assets and lease liabilities for the six months ended June 30, 2025 and 2024 are reflected in the non-cash lease expense and accrued expenses and other liabilities, respectively, in the consolidated statements of cash flows.

years yearsWeighted-average discount rate%%

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11.

shares of common stock and shares of Series B Preferred Stock, inclusive of shares of Series B Preferred Stock purchased by directors and executive officers of the Company, and related parties thereto, each at a price per share of $. The 2024 Private Placement resulted in gross proceeds of approximately $ million before deducting placement agent fees and other offering expenses.

“At-the-Market” Offering

On December 13, 2024, the Company entered into a Sales Agreement, or the Sales Agreement, with Leerink Partners LLC to sell shares of the Company’s common stock, from time to time, through an “at the market” equity offering program under which Leerink Partners LLC will act as sales agent. The shares of common stock sold pursuant to the Sales Agreement will be issued pursuant to the Company’s shelf registration statement on Form S-3 (File No. 333-283803), filed on December 13, 2024 with the SEC, and related prospectus supplement, filed on January 8, 2025 with the SEC, for aggregate gross sales proceeds of up to $ million.

During the six months ended June 30, 2025 and the year ended December 31, 2024, the Company sold shares of its common stock pursuant to the Sales Agreement.

Warrants

During the six months ended June 30, 2025, there were warrants issued, exercised, or cancelled.

See Note 12 to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 for further discussion of the terms related to the Company’s warrants.

Common Stock

On April 4, 2024, the Company implemented the Reverse Stock Split. The Reverse Stock Split became effective at 4:30 p.m. Eastern Time on April 4, 2024. On April 5, 2024, the Company’s common stock began trading on The Nasdaq Global Market on a split-adjusted basis under the symbol “RNAC” with a new CUSIP number, 816212302. As a result of the Reverse Stock Split, every 30 shares of common stock outstanding were combined, automatically and without any action on the part of the Company or its stockholders, into one share of common stock. Stockholders entitled to fractional shares as a result of the Reverse Stock Split received a cash payment in lieu of receiving fractional shares. The Reverse Stock Split did not change the number of authorized shares or par value of the Company’s common or preferred stock.

Preferred Stock

As of June 30, 2025, the Company had shares of Series A Preferred Stock and shares of Series B Preferred Stock issued and outstanding, respectively, which are convertible into shares of common stock.

Reserved Shares

Shares available for future stock incentive awards Unvested restricted stock units Outstanding common stock options Series A Preferred Stock Series B Preferred Stock Total

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12.

shares of common stock for future issuance under the 2016 Plan and the Company ceased granting awards under the 2008 Plan. Upon the effective date of the 2016 Plan, awards issued under the 2008 Plan remained subject to the terms of the 2008 Plan. Awards granted under the 2008 Plan that expired, lapsed or terminated became available under the 2016 Plan as shares available for future grants.

Additionally, pursuant to the terms of the 2016 Plan, the Board of Directors is authorized to grant awards with respect to common stock, and may delegate to a committee of one or more members of the Board of Directors or executive officers of the Company the authority to grant options and restricted stock units. On December 9, 2020, the Board of Directors established a Stock Option Committee authorized to grant awards to certain employees and consultants subject to conditions and limitations within the 2016 Plan. In June 2024, the Company’s stockholders approved an amendment and restatement of the 2016 Plan to reserve an additional shares of the Company’s common stock for issuance. In January 2025, the number of shares of common stock that may be issued under the 2016 Plan was increased by . As of June 30, 2025, shares remain available for future issuance under the 2016 Plan.

In September 2018, the Company’s 2018 Employment Inducement Incentive Award Plan, or the 2018 Inducement Incentive Award Plan, was adopted by the Board of Directors without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Stock Market LLC listing rules, which authorized shares of its common stock for issuance. In March 2019, the Board of Directors approved an amendment and restatement of the 2018 Inducement Incentive Award Plan to reserve an additional shares of the Company’s common stock for issuance thereunder. In December 2023, the Board of Directors approved an amendment and restatement of the 2018 Inducement Incentive Award Plan to reserve an additional shares of the Company’s common stock for issuance thereunder. In June and December 2024, the Board of Directors approved amendments and restatements of the 2018 Inducement Incentive Award Plan to reserve an additional and shares, respectively, of the Company’s common stock for issuance thereunder. As of June 30, 2025, there are shares available for future grant under the 2018 Inducement Incentive Award Plan.

In accordance with the Merger Agreement, the Company assumed Old Cartesian’s 2016 Stock Incentive Plan, or the Old Cartesian Plan. The Old Cartesian Plan permits the granting of options or restricted stock to employees, officers, directors, consultants and advisors to the Company. The unvested common stock options and Series A Preferred Stock options assumed by the Company in connection with the Merger generally vest over a period. Additionally, the stock options granted have a contractual term of and only full shares can be exercised as per the individual award agreements. As of June 30, 2025, there are shares available for future grant under the Old Cartesian Plan.

In connection with the Merger, the outstanding stock options to purchase Old Cartesian common stock were converted into stock options to purchase shares of common stock and shares of Series A Preferred Stock of the Company. These replacement awards were revalued at their acquisition-date fair value and then attributed to pre- and post-combination service. This resulted in $ million attributed to post-combination service to be recognized as stock-based compensation expense over the remaining terms of the replacement awards, of which $ million and $ million was recognized during the three months ended June 30, 2025 and 2024, respectively, and $ million and $ million was recognized during the six months ended June 30, 2025 and 2024, respectively, as research and development expense in the consolidated statements of operations and comprehensive income (loss). Following the stockholder approval of the conversion of the Series A Preferred Stock into shares of common stock, the options exercisable for shares of Series A Preferred Stock became exercisable for shares of common stock.

Stock-Based Compensation Expense

In April 2025, the Company entered into a separation agreement and release, or the Separation Agreement, with the Company’s former Chief Technology Officer, Metin Kurtoglu. Dr. Kurtoglu’s employment with the Company ended effective May 2025, and Dr. Kurtoglu will serve as a consultant to the Company from May 2025 through April 2026, or the Consulting Period. Pursuant to the Separation Agreement, certain of Dr. Kurtoglu’s stock options and restricted stock unit awards were modified to accelerate the vesting of a portion of the awards, continue the vesting of the remaining awards during the Consulting Period, and extend the post-termination exercise period of the modified stock options. The services performed during the Consulting Period do not qualify as substantive services under ASC 718 and therefore, the continued vesting of these awards represents a modification to the original award. The modification resulted in the recognition of $ million of stock-compensation expense during the three and six months ended June 30, 2025 which is reflected in research and development expenses on the consolidated statements of operations and comprehensive income (loss).

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$ $ $ General and administrative Total stock-based compensation expense$ $ $ $

Stock Options

%%%%Dividend yield Expected term (in years)Expected volatility%%%%Weighted-average fair value of common stock$ $ $ $

The expected term of the Company’s stock options granted has been determined utilizing the “simplified” method for awards that qualify as “plain-vanilla” options. Under the simplified method, the expected term is presumed to be the midpoint between the vesting date and the end of the contractual term. The Company utilizes this method due to lack of historical exercise data and the plain nature of its stock-based awards. Expected volatilities are based on the Company’s historical volatility.

The weighted-average grant date fair value of stock options granted during the three months ended June 30, 2025 and 2024 was $ and $, respectively, and $ and $ during the six months ended June 30, 2025 and 2024, respectively.

As of June 30, 2025, total unrecognized compensation expense related to unvested common stock options was $ million, which is expected to be recognized over a weighted average period of years.

$ $ Granted $ Exercised()$ Forfeited()$ Outstanding at June 30, 2025 $ $ Vested at June 30, 2025 $ $ Vested and expected to vest at June 30, 2025 $ $

Restricted Stock Units

During the six months ended June 30, 2025, the Company granted restricted stock unit awards with a weighted-average fair value of $ per share based on the closing price of the Company’s common stock on the date of grant under the 2016 Plan, which generally vest over a term. Forfeitures are estimated at the time of grant and are adjusted, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The Company has estimated a forfeiture rate of % for restricted stock unit awards based on historical experience.

Unrecognized compensation expense related to the restricted stock units was $ million as of June 30, 2025, which is expected to be recognized over a weighted-average period of years.

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$ Granted Vested() Forfeited()

Unvested at June 30, 2025

13.

million upfront payment to the Company upon signing of the Astellas Agreement, and the Company was entitled to receive up to $ million in future additional payments over the course of the partnership that were contingent on the achievement of various development and regulatory milestones and, if commercialized, sales thresholds for annual net sales where Xork is used as a pre-treatment for an Astellas investigational or authorized product. The Company was also eligible for tiered royalty payments ranging from low to high single digits. Any proceeds received from milestone payments or royalties relating to Xork would have been required to be distributed to holders of CVRs, net of certain deductions. A more detailed description of the Astellas Agreement and the Company's evaluation of this agreement under ASC 606 can be found in Note 14 to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024.

In March 2024, the Company was notified by Astellas of its intention to terminate the Astellas Agreement, which occurred effective June 6, 2024.

As of June 30, 2025, there were unsatisfied performance obligations and receivable related to the Astellas Agreement. As of December 31, 2024, the Company recorded a receivable of $ million, representing billings for the Xork Development Services (as defined in the Astellas Agreement) that are subject to reimbursement by Astellas. revenue related to the Astellas Agreement was recognized during the three and six months ended June 30, 2025. During the three and six months ended June 30, 2024, revenue of $ million and $ million, respectively, related to the Astellas Agreement was recognized, inclusive of $ million of revenue recognized from performance obligations related to prior periods as a result of the change in transaction price during the six months ended June 30, 2024.

Swedish Orphan Biovitrum AB (publ.)

License and Development Agreement

In June 2020, the Company and Sobi entered into the Sobi License, which was subsequently amended in October 2023. Pursuant to the Sobi License, the Company agreed to grant Sobi an exclusive, worldwide (except as to Greater China) license to develop, manufacture and commercialize the SEL-212 drug candidate, which is currently in development for the treatment of chronic refractory gout. The SEL-212 drug candidate is a pharmaceutical composition containing a combination of SEL-037, or the Compound, and ImmTOR. Pursuant to the Sobi License, in consideration of the license, Sobi agreed to pay the Company a one-time, upfront payment of $ million. Sobi has also agreed to make milestone payments totaling up to $ million to the Company upon the achievement of various development and regulatory milestones and, if commercialized, sales thresholds for annual net sales of SEL-212, and tiered royalty payments ranging from the low double digits on the lowest sales tier to the high teens on the highest sales tier. A more detailed description of the Sobi License and the Company’s evaluation of this agreement under ASC 606 can be found in Note 14 to the consolidated financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024. Any proceeds received from milestone payments or royalties relating to the Sobi License would be required to be distributed to holders of CVRs, net of certain deductions.

On June 28, 2024, Sobi initiated a rolling biologics license application to the FDA for SEL-212 for the potential treatment of chronic refractory gout which resulted in the achievement of a development milestone and a $ million payment obligation from Sobi to the Company. As a result, the development milestone was no longer constrained and $ million was

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million, representing billings for the Phase 3 DISSOLVE program that are subject to reimbursement by Sobi. Additionally, as of June 30, 2025 and December 31, 2024, there was no unbilled receivable outstanding. revenue was recognized during the three and six months ended June 30, 2025. Revenue of $ million, inclusive of the $ million development milestone, related to the Sobi License was recognized during each of the three and six months ended June 30, 2024.

Transaction Price Allocated to Future Performance Obligations

Remaining performance obligations represent the transaction price of contracts for which work has not been performed, or has been partially performed. As of June 30, 2025 and December 31, 2024, there were unsatisfied performance obligations from contracts with customers.

Grant revenue

National Institute of Neurological Disorders and Stroke of the National Institutes of Health

In June 2024, the Company received funding approval from the National Institute of Neurological Disorders and Stroke of the National Institutes of Health, or NINDS, for an award of $ million granted for the budget period, which ran from June 2024 through May 2025. In June 2025, the Company received funding approval from NINDS for an additional award of $ million granted for the budget period that runs from June 2025 through May 2026. The funding was provided by NINDS to further the Company’s use of RNA-based CAR-T cells to combat autoantibody-associated autoimmune disorders. Grant funding is to be used solely for manufacturing of RNA-based CAR-T cells and analysis of samples to inform mechanism of action. The award period runs through May 31, 2026. The Company will recognize grant revenue when expenses reimbursable under the grant have been incurred.

As of June 30, 2025 and December 31, 2024, the Company recorded a receivable of $ million and $ million, respectively, that is subject to reimbursement by NINDS. The Company recognized grant revenue of $ million and $ million during the three and six months ended June 30, 2025, respectively. The Company recognized grant revenue of $ million during the three and six months ended June 30, 2024.

14.

shares of Series A Preferred Stock for an aggregate purchase price of $ million. See Note 11 to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024 for further discussion of the 2023 Private Placement. $

Exercise of Amended 2019 Warrants

On March 26, 2024, TAS Partners LLC exercised Amended 2019 Warrants, paid the per-share exercise price of $ in cash for an aggregate exercise price of $ million, and received shares of common stock and CVRs.

During the three and six months ended June 30, 2025, there were no related party transactions.

15.

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days if the Company fails to pay a fee owed to Biogen or for any other material breach of the agreement. The Biogen Agreement will otherwise expire when all claims of all issued patents within the patents and patent applications licensed to the Company under the Biogen Agreement have expired or been finally rendered revoked, invalid or unenforceable by a decision of a court or government agency.

The Biogen Agreement encompasses patents and patent applications in the PCT/US2010/026825 patent family, which was filed March 10, 2010. In general, all patents that issue in this family have an expected expiration date of March 10, 2030, subject to potential patent term adjustments and/or extensions. For the U.S. patents and applications in this family, U.S. Patent 9,034,324 was awarded 677 days of patent term adjustment, which would extend the expiration date of this patent to January 16, 2032, absent any challenges to the patent term. The other issued patent in this family was not awarded any patent term adjustment, so its expected expiration date is March 10, 2030.

National Cancer Institute of the National Institutes of Health

Effective September 16, 2019, the Company entered into a nonexclusive, worldwide license agreement, or the NCI Agreement, with the U.S. Department of Health and Human Services, represented by the National Cancer Institute of the National Institutes of Health, or NCI.

Under the NCI Agreement, the Company was granted a license under certain NCI patents and patent applications designated in the agreement, to make, use, sell, offer and import products and processes within the scope of the patents and applications licensed under the NCI Agreement when developing and manufacturing anti-BCMA CAR-T cell products for the treatment of myasthenia gravis, pemphigus vulgaris, and immune thrombocytopenic purpura according to methods designated in the NCI Agreement.

In connection with the Company’s entry into the NCI Agreement, Old Cartesian paid to NCI a one-time $ million license royalty payment. Under the NCI Agreement, the Company is further required to pay NCI a low five-digit annual royalty. The Company must also pay earned royalties on net sales in a low single-digit percentage and pay up to $ million in benchmark royalties upon the Company’s achievement of designated benchmarks that are based on the commercial development plan agreed between the parties.

Under the NCI Agreement, the Company must use reasonable commercial efforts to bring licensed products and licensed processes to the point of Practical Application (as defined in the NCI Agreement). Upon the Company’s first commercial sale, the Company must use reasonable commercial efforts to make licensed products and licensed processes reasonably accessible to the United States public. After the Company’s first commercial sale, the Company must make reasonable quantities of licensed products or materials produced via licensed processes available to patient assistance programs and develop educational materials detailing the licensed products. Unless the Company obtains a waiver from NCI, the Company must have licensed products and licensed processes manufactured substantially in the United States. Prior to the first commercial sale, upon NCI’s request, the Company is obligated to provide NCI with commercially reasonable quantities of licensed products made through licensed processes to be used for in vitro research.

Additionally, the Company must use reasonable commercial efforts to initiate a Phase 3 clinical trial of a licensed product by the fourth quarter of 2024, submit a BLA with respect to a licensed product by the fourth quarter of 2026, and make a first commercial sale of a licensed product by the fourth quarter of 2028.

The NCI Agreement terminates upon the expiration of the last to expire of the patent rights licensed thereunder, if not sooner terminated. The NCI Agreement encompasses patents and patent applications in the PCT/US2013/032029 patent family, which was filed March 15, 2013. In general, all patents that issue in this family have an expected expiration of March 15, 2033, subject to potential patent term adjustments and/or extensions. For the U.S. patents and applications in this family, only two patents were awarded patent term adjustments. U.S. Patent 9,765,342 was awarded 297 days of patent term adjustment, which would extend the expiration date of this patent to January 6, 2034, absent any challenges to the patent term. The other patent, U.S. Patent 10,876,123, was awarded three days of patent term adjustment, but this patent is subject to terminal disclaimers filed against other family members, so this patent will not extend beyond the March 15, 2033 date. The other issued patents in this family were not awarded any patent term adjustment, so the expected expiration date for these patents also remains March 15, 2033. There is also a pending patent application which, if issued, will expire on March 15, 2033, but could also be subject to patent term adjustment and to any potential future terminal disclaimers.

NCI has the right to terminate the NCI Agreement, after giving written notice and providing a cure period in accordance with its terms, if the Company is in default of a material obligation. The Company has the unilateral right to terminate the agreement in any country or territory by giving NCI days’ written notice. The Company agreed to indemnify NCI against any liability arising out of the Company’s, sublicensees’ or third parties’ use of the licensed patent rights and licensed products or licensed processes developed in connection with the licensed patent rights.

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million payment to Genovis as a result of the sublicense of Xork to Astellas. See Note 13 to these unaudited consolidated financial statements for further discussion on the Astellas Agreement.

In March 2024, the Company notified Genovis of its intention to terminate the Genovis Agreement, which occurred effective September 13, 2024.

Shenyang Sunshine Pharmaceutical Co., Ltd

In May 2014, the Company entered into a license agreement, or the 3SBio License, with Shenyang Sunshine Pharmaceutical Co., Ltd., or 3SBio. The Company has paid to 3SBio an aggregate of $ million in upfront and milestone-based payments under the 3SBio License as of June 30, 2025. The Company is required to make future payments to 3SBio contingent upon the occurrence of events related to the achievement of clinical and regulatory approval milestones of up to an aggregate of $ million for products containing the Company’s ImmTOR platform.

16.

17.

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18.

% reduction of the Company’s headcount as of April 2023. $ $()$ December 31, 2024ChargesCash PaymentsJune 30, 2025Severance liability$ $ $()$

restructuring charges. For the six months ended June 30, 2024, the Company recognized $ million in research and development expenses and $ million in general and administrative expenses. Payments for the restructuring plan were completed in the first quarter of 2025.

19.

$ $ Grant revenue Total revenue LessOperating expenses:Legacy Selecta programs Descartes-08 for MG Early stage programs Research and development employee expenses Research and development stock-based compensation expense Research and development facilities and other expenses General and administrative Other (income) expense, net (1)()()

Net income (loss)

$ $ ()$()

(1) Includes interest income; foreign currency transaction, net; change in fair value of warrant liabilities; change in fair value of contingent value right liability; change in fair value of forward contract liabilities; and other (expense) income, net.

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20.

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our unaudited consolidated financial statements and related notes appearing elsewhere in this Quarterly Report and with our audited financial statements and the notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2024, which we filed with the SEC on March 13, 2025. In addition, you should read the “Risk Factors” and “Information Regarding Forward-Looking Statements” sections of this Quarterly Report and our Annual Report on Form 10-K for the year ended December 31, 2024 for a discussion of important factors that could cause actual results to differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis.

Overview

We are a clinical-stage biotechnology company pioneering cell therapy for the treatment of autoimmune diseases. Unlike DNA cell therapies, our cell therapy method degrades naturally over time without integrating into the cell’s genetic material. Therefore, our cell therapy is distinguished by its capacity to be dosed repeatedly like conventional drugs, administered in an outpatient setting, and given without pre-treatment chemotherapy required with many conventional cell therapies. In our Phase 2b clinical trial in patients with myasthenia gravis, or MG, a chronic autoimmune disease that causes disabling muscle weakness and fatigue, we observed that our lead product candidate, Descartes-08, generated a deep and durable clinical benefit, with 83% of participants maintaining improvements in MG severity scales considered clinically meaningful by expert consensus at six months and sustained improvements in MG severity scales considered clinically meaningful by expert consensus at 12 months. Durability of response in MG is commonly measured over a period of 26 to 52 weeks, and maintenance of response over that period is considered durable.

Merger

On November 13, 2023, the Company (formerly known as Selecta Biosciences, Inc., or Selecta) merged with the private Delaware corporation which, immediately prior to the Merger (as defined below), was known as Cartesian Therapeutics, Inc., or Old Cartesian, in accordance with the terms of an Agreement and Plan of Merger, or the Merger Agreement, by and among

Selecta, Sakura Merger Sub I, Inc., a wholly owned subsidiary of Selecta, or First Merger Sub, Sakura Merger Sub II, LLC, a wholly owned subsidiary of Selecta, or Second Merger Sub, and Old Cartesian. Pursuant to the Merger Agreement, First Merger Sub merged with and into Old Cartesian, pursuant to which Old Cartesian was the surviving corporation and became a wholly owned subsidiary of Selecta, or the First Merger. Immediately following the First Merger, Old Cartesian merged with and into Second Merger Sub, pursuant to which Second Merger Sub was the surviving entity, or the Second Merger and, together with the First Merger, the Merger. In connection with the Second Merger, Old Cartesian changed its name to Cartesian Bio, LLC. In connection with the Merger and pursuant to the Merger Agreement, the Company changed its corporate name to Cartesian Therapeutics, Inc. See Note 4 of the notes to the consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2024 for additional information regarding the Merger.

Financial Operations

To date, we have financed our operations primarily through public offerings and private placements of our securities, funding received from research grants, collaboration and license arrangements and a credit facility. We do not have any products approved for sale and have not generated any product sales.

We have incurred significant operating losses since our inception. We incurred a net loss of $1.8 million and $43.0 million for the six months ended June 30, 2025 and 2024, respectively. As of June 30, 2025, we had an accumulated deficit of $693.9 million. We expect to continue to incur significant expenses and operating losses for the foreseeable future as we:

•continue to advance Descartes-08 for MG through Phase 3 development;

•continue to develop our preclinical and clinical-stage product candidates;

•seek regulatory approvals for any product candidates that successfully complete clinical trials;

•maintain, expand and protect our intellectual property portfolio, including through licensing arrangements;

•hire additional staff, including clinical, scientific and management personnel; and

•incur additional costs associated with continuing to operate as a public company.

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The following table presents our research and development expenses for the three and six months ended June 30, 2025 and 2024 (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
Legacy Selecta programs	$	—	$	3,570	$	—	$	6,347
Descartes-08 for MG	5,035		2,945		12,071		4,211
Early stage programs	1,715		528		2,705		655
Research and development employee expenses	4,254		2,184		7,956		5,425
Research and development stock-based compensation expense	1,810		776		3,085		1,488
Research and development facilities and other expenses	2,055		2,658		3,726		4,273
Total research and development expenses	$	14,869	$	12,661	$	29,543	$	22,399

Until we can generate substantial product revenues, we expect to finance our cash needs through a combination of equity offerings, debt financings, and license and collaboration agreements. We may be unable to raise capital when needed or on reasonable terms, if at all, which would force us to delay, limit, reduce or terminate our product development or future commercialization efforts. We will need to generate significant revenues to achieve profitability, and we may never do so.

Concurrently with the closing of the Merger, we entered into a securities purchase agreement, or the 2023 Securities Purchase Agreement, pursuant to which we agreed to issue 149,330.115 shares of Series A Non-Voting Convertible Preferred Stock, par value $0.0001 per share, or the Series A Preferred Stock, in exchange for aggregate gross proceeds of $60.25 million, or the 2023 Private Placement. We granted customary registration rights to investors in connection with the 2023 Private Placement.

On July 2, 2024, we entered into a securities purchase agreement, or the 2024 Securities Purchase Agreement, for a private investment in public equity financing, or the 2024 Private Placement, which provided for the issuance of 3,563,247 shares of common stock and 2,937,903 shares of Series B Non-Voting Convertible Preferred Stock, par value $0.0001 per share, or the Series B Preferred Stock, each at a purchase price of $20.00 per share. The 2024 Private Placement resulted in gross proceeds of approximately $130.0 million before deducting placement agent fees and other offering expenses. We granted customary registration rights to investors in connection with the 2024 Private Placement.

We believe that our existing cash, cash equivalents, and restricted cash as of June 30, 2025 will enable us to fund our operating expenses and capital expenditure requirements into mid-2027. We have based this estimate on assumptions that may prove to be wrong, and we could use our capital resources sooner than we currently expect.

The consolidated financial information presented below includes the accounts of Cartesian Therapeutics, Inc. and our wholly owned subsidiaries, Selecta (RUS) LLC, a Russian limited liability company, or Selecta (RUS), Selecta Biosciences Security Corporation, a Massachusetts securities corporation which was dissolved in December 2024, and Cartesian Bio, LLC, a Delaware limited liability company, which is a variable interest entity for which we are the primary beneficiary. All intercompany accounts and transactions have been eliminated.

Components of our Results of Operations

Collaboration and license revenue

To date, we have not generated any revenue from product sales. Our revenue consists primarily of collaboration and license revenue, which includes amounts recognized related to upfront and milestone payments for research and development funding under collaboration and license agreements. We expect that any revenue we generate will fluctuate from quarter to quarter because of the timing and amounts of fees, research and development reimbursements and other payments from collaborators. We do not expect to generate revenue from product sales for at least the next several years. If we or our collaborators fail to complete the development of our product candidates in a timely manner or fail to obtain regulatory approval as needed, our ability to generate future revenue will be harmed, and will affect the results of our operations and financial position. For further descriptions of the agreements underlying our collaboration and license revenue, see Note 13 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Grant revenue

Additionally, we generate grant revenue which consists of funding received to perform specific research and development services under grant arrangements.

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Research and development

Our research and development expenses consist of internal and external research and development costs, which primarily include fees paid to contract research organizations, internal manufacturing and quality related expenses, process development costs, internal research and development expenses, as well as fees paid to contract manufacturing organizations. These costs are primarily associated with compensation expenses for our research and development employees, capital equipment and supplies for our process development and manufacturing process, and other related expenses. Our internal research and development employees as well as our indirect costs are shared across multiple development programs and are not solely dedicated to individual programs.

We expense research and development costs as incurred. Conducting a significant amount of research and development is central to our business model. Product candidates in clinical development generally have higher development costs than those in earlier stages of development, primarily due to the size, duration and cost of clinical trials. The successful development of our clinical and preclinical product candidates is highly uncertain. Clinical development timelines, the probability of success and development costs can differ materially from our expectations. For example, if the FDA or another regulatory authority were to require us to conduct clinical trials beyond those which we currently expect will be required for the completion of clinical development of a product candidate, or if we experience significant delays in enrollment in any of our clinical trials, we could be required to expend significant additional financial resources and time to complete any clinical development.

General and administrative

General and administrative expenses consist primarily of salaries and related benefits, including stock-based compensation, related to our executive, finance, business development and support functions. Other general and administrative expenses include facility-related costs not otherwise allocated to research and development expenses, travel expenses for our general and administrative personnel and professional fees for auditing, tax and corporate legal services, including intellectual property-related legal services.

Impairment of long-lived assets

Impairment of long-lived assets consists of impairment charges on our long-lived assets.

Interest income

Interest income consists primarily of income earned on our cash, cash equivalents and marketable securities.

Other (expense) income, net

Other (expense) income, net consists of non-operating income and non-operating expenses.

Change in fair value of warrant liabilities

Common warrants classified as liabilities are remeasured quarterly at fair value with the change in fair value recognized as a component of earnings.

Change in fair value of contingent value right liability

The contingent value right liability is remeasured quarterly at fair value with the change in fair value recognized as a component of earnings.

Change in fair value of forward contract liabilities

The forward contract liabilities associated with the delayed issuance of the Series A Preferred Stock related to the Merger and 2023 Private Placement are remeasured quarterly and upon settlement at fair value with the change in fair value recognized as a component of earnings.

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Results of Operations

Comparison of the Three Months Ended June 30, 2025 and 2024


	Three Months Ended June 30,				Increase (Decrease)
	2025		2024
	(in thousands, except percentages)
Revenue:
Collaboration and license revenue	$	—	$	33,271	$	(33,271)	(100)	%
Grant revenue	298		174		124		71	%
Total revenue	298		33,445		(33,147)		(99)	%
Operating expenses:
Research and development	14,869		12,661		2,208		17	%
General and administrative	7,240		7,027		213		3	%

Total operating expenses	22,109		19,688		2,421		12	%
Operating (loss) income	(21,811)		13,757		(35,568)		(259)	%
Interest income	1,748		1,195		553		46	%


Change in fair value of warrant liabilities	654		(3,908)		4,562		(117)	%
Change in fair value of contingent value right liability	35,300		2,500		32,800		1,312	%

Other (expense) income, net	(5)		292		(297)		(102)	%


Net income	$	15,886	$	13,836	$	2,050	15	%

Collaboration and license revenue

During the three months ended June 30, 2025, we recognized no collaboration and license revenue, compared to $33.3 million for the three months ended June 30, 2024, a decrease of $33.3 million. The decrease was primarily due to revenue recognized under the Sobi License resulting from the $30.0 million unconstrained development milestone recognized during the three months ended June 30, 2024.

Grant revenue

During the three months ended June 30, 2025, we recognized $0.3 million of grant revenue, compared to $0.2 million for the three months ended June 30, 2024, an increase of $0.1 million. The increase was primarily due to increased expenses reimbursable under the grant from the National Institute of Neurological Disorders and Stroke of the National Institutes of Health, or NINDS, incurred during the three months ended June 30, 2025, for which we received funding approval during the three months ended June 30, 2024.

Research and development expenses

The following is a comparison of research and development expenses for the three months ended June 30, 2025 and 2024 (in thousands, except percentages):


	Three Months Ended June 30,				Increase (Decrease)
	2025		2024
Legacy Selecta programs	$	—	$	3,570	$	(3,570)	(100)	%
Descartes-08 for MG	5,035		2,945		2,090		71	%
Early stage programs	1,715		528		1,187		225	%
Research and development employee expenses	4,254		2,184		2,070		95	%
Research and development stock-based compensation expense	1,810		776		1,034		133	%
Research and development facilities and other expenses	2,055		2,658		(603)		(23)	%
Total research and development expenses	$	14,869	$	12,661	$	2,208	17	%

For the three months ended June 30, 2025, our research and development expenses were $14.9 million, compared to $12.7 million for the three months ended June 30, 2024, an increase of $2.2 million. The decrease in expenses for legacy Selecta programs was primarily related to decreased expenses for Xork as a result of the termination of the License and Development Agreement, or the Astellas Agreement, with Audentes Therapeutics, Inc., doing business as Astellas Gene Therapies, or

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Astellas in 2024. The increase in expenses for Descartes-08 for MG was primarily related to the expenses for the ongoing Phase 3 AURORA trial. The increase in our expenses for early stage programs was primarily related to increased discovery expenses and manufacturing operations expenses. The increases in our research and development employee expenses and stock-based compensation expense were primarily a result of headcount growth.

General and administrative expenses

For the three months ended June 30, 2025, our general and administrative expenses were $7.2 million, compared to $7.0 million for the three months ended June 30, 2024, an increase of $0.2 million. The increase in cost was primarily the result of increased facilities expenses.

Interest income

Interest income for the three months ended June 30, 2025 was $1.7 million, compared to $1.2 million for the three months ended June 30, 2024, an increase of $0.5 million. The increase in interest income was due to increased cash and cash equivalents balance.

Change in fair value of warrant liabilities

For the three months ended June 30, 2025, we recognized $0.7 million of income from the decrease in the fair value of warrant liabilities, compared to $3.9 million charge from the increase in the fair value of warrant liabilities for the three months ended June 30, 2024, an increase of $4.6 million. Fair value of warrant liabilities was determined utilizing the Black-Scholes valuation methodology. The decrease in warrant value was primarily driven by a decrease in the per-share price of our common stock and the expiration of the warrants we issued in 2019 during the year ended December 31, 2024.

Change in fair value of contingent value right liability

For the three months ended June 30, 2025, we recognized $35.3 million of income from the decrease in the fair value of the CVR liability, compared to $2.5 million of income from the decrease in the fair value of the CVR liability for the three months ended June 30, 2024, an increase of $32.8 million. The fair value of the CVR liability was determined utilizing a Monte Carlo simulation model. The decrease in the fair value of the CVR liability was primarily due to changes in the timing of anticipated payments.

Other (expense) income, net

During the three months ended June 30, 2025, we recognized less than $0.1 million other expense, net, compared to $0.3 million other income, net for the three months ended June 30, 2024. The decrease was primarily due to a decrease in sublease income. The terms of our subleases expired during the year ended December 31, 2024.

Net income (loss)

Net income for three months ended June 30, 2025 was $15.9 million as compared to net income of $13.8 million for the three months ended June 30, 2024, an increase of $2.1 million The change was primarily due to income associated with the change in the fair value of the CVR liability and the change in the fair value of the warrant liabilities, partially offset by the decrease in collaboration revenue during the three months ended June 30, 2025.

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Comparison of the Six Months Ended June 30, 2025 and 2024


	Six Months Ended June 30,				Increase (Decrease)
	2025		2024
	(in thousands, except percentages)
Revenue:
Collaboration and license revenue	$	400	$	39,111	$	(38,711)	(99)	%
Grant revenue	998		174		824		474	%
Total revenue	1,398		39,285		(37,887)		(96)	%
Operating expenses:
Research and development	29,543		22,399		7,144		32	%
General and administrative	15,555		16,477		(922)		(6)	%

Total operating expenses	45,098		38,876		6,222		16	%
Operating (loss) income	(43,700)		409		(44,109)		(10,785)	%
Interest income	3,763		2,359		1,404		60	%


Change in fair value of warrant liabilities	2,472		(2,866)		5,338		(186)	%
Change in fair value of contingent value right liability	35,646		(36,800)		72,446		(197)	%
Change in fair value of forward contract liabilities	—		(6,890)		6,890		(100)	%
Other (expense) income, net	(5)		800		(805)		(101)	%


Net loss	$	(1,824)	$	(42,988)	$	41,164	(96)	%

Collaboration and license revenue

During the six months ended June 30, 2025, we recognized $0.4 million of collaboration and license revenue, compared to $39.1 million for the six months ended June 30, 2024, a decrease of $38.7 million. The decrease was primarily due to a decrease in revenue recognized under the Sobi License resulting from the $30.0 million unconstrained development milestone recognized during the six months ended June 30, 2024 and a decrease for revenue recognized under the Astellas Agreement upon notice of termination during the six months ended June 30, 2024.

Grant revenue

During the six months ended June 30, 2025, we recognized $1.0 million of grant revenue, compared to $0.2 million for the six months ended June 30, 2024, an increase of $0.8 million. The increase was primarily due to increased expenses reimbursable under the grant from NINDS incurred during the six months ended June 30, 2025, for which we received funding approval during the six months ended June 30, 2024.

Research and development expenses

The following is a comparison of research and development expenses for the six months ended June 30, 2025 and 2024 (in thousands, except percentages):


	Six Months Ended June 30,				Increase (Decrease)
	2025		2024
Legacy Selecta programs	$	—	$	6,347	$	(6,347)	(100)	%
Descartes-08 for MG	12,071		4,211		7,860		187	%
Early stage programs	2,705		655		2,050		313	%
Research and development employee expenses	7,956		5,425		2,531		47	%
Research and development stock-based compensation expense	3,085		1,488		1,597		107	%
Research and development facilities and other expenses	3,726		4,273		(547)		(13)	%
Total research and development expenses	$	29,543	$	22,399	$	7,144	32	%

For the six months ended June 30, 2025, our research and development expenses were $29.5 million, compared to $22.4 million for the six months ended June 30, 2024, an increase of $7.1 million. The decrease in expenses for legacy Selecta programs was primarily related to decreased expenses for Xork as a result of the termination of the Astellas Agreement in 2024. The increase in expenses for Descartes-08 for MG was primarily related to the expenses for the ongoing Phase 3 AURORA

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trial. The increase in our expenses for early stage programs was primarily related to increased discovery expenses and manufacturing operations expenses. The increases in our research and development employee expenses and stock-based compensation expense were primarily a result of headcount growth.

General and administrative expenses

For the six months ended June 30, 2025, our general and administrative expenses were $15.6 million compared to $16.5 million for the six months ended June 30, 2024, a decrease of $0.9 million. The decrease in cost was primarily the result of expenses incurred for professional fees incurred in connection with the Merger.

Interest income

Interest income for the six months ended June 30, 2025 was $3.8 million, compared to $2.4 million for the six months ended June 30, 2024. The increase in interest income was due to increased cash and cash equivalents balance.

Change in fair value of warrant liabilities

For the six months ended June 30, 2025, we recognized $2.5 million of income from the decrease in the fair value of warrant liabilities, compared to $2.9 million charge from the increase in the fair value of warrant liabilities for the six months ended June 30, 2024, an increase of $5.4 million. Fair value of warrant liabilities was determined utilizing the Black-Scholes valuation methodology. The decrease in warrant value was primarily driven by a decrease in the per-share price of our common stock.

Change in fair value of contingent value right liability

For the six months ended June 30, 2025, we recognized $35.6 million of income from the decrease in the fair value of the CVR liability, compared to $36.8 million charge from the increase in the fair value of the CVR liability for the six months ended June 30, 2024, an increase of $72.4 million. The fair value of the CVR liability was determined utilizing a Monte Carlo simulation model. The increase in the fair value of CVR liability was primarily due to changes in the timing of anticipated payments during the six months ended June 30, 2025.

Change in fair value of forward contract liabilities

The remaining Series A Preferred Stock forward contract liability was settled during the six months ended June 30, 2024. As such, no change in the fair value of the Series A Preferred Stock forward contract liability is reflected in our unaudited consolidated financial statements for the six months ended June 30, 2025.

Other (expense) income, net

During the six months ended June 30, 2025, we recognized less than $0.1 million of other expense, net, compared to $0.8 million other income, net for the six months ended June 30, 2024, a decrease of $0.8 million, or 100%. The decrease was primarily due to a decrease in sublease income. The terms of our subleases expired during the year ended December 31, 2024.

Net income (loss)

Net loss for the six months ended June 30, 2025 was $1.8 million as compared to net loss of $43.0 million for the six months ended June 30, 2024, a decrease of $41.2 million or 96%. The change was primarily due to income associated with the change in the fair value of the CVR liability and warrant liabilities during the six months ended June 30, 2025, partially offset by revenue recognized under the Sobi License during the six months ended June 30, 2025.

Liquidity and Capital Resources

We have incurred recurring net losses since our inception. We expect that we will continue to incur losses and that such losses will increase for the foreseeable future. We expect that our research and development and general and administrative expenses will continue to increase and, as a result, we will need additional capital to fund our operations, which we may raise through a combination of equity offerings, debt financings, third-party funding, potential royalty and/or milestone monetization transactions and other collaborations and strategic alliances.

Our cash, cash equivalents, and restricted cash were $162.1 million as of June 30, 2025, of which $1.7 million was restricted cash related to lease commitments.

In addition to our existing cash equivalents, we from time to time have received and may receive in the future research and development funding pursuant to our collaboration and license agreements. Currently, funding from payments under our collaboration agreements represent our only source of committed external funds.

The liability associated with the contingent value rights agreement, or CVR Agreement, entered into on December 6, 2023, will be settled solely through cash flow received under the Sobi License and any other Gross Proceeds (as such term is defined in the CVR Agreement) net of certain agreed deductions. Under the CVR Agreement, 100% of all milestone payments, royalties, and other amounts paid to us or our controlled entities under the Sobi License, and any other Gross Proceeds, in each

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case net of certain agreed deductions, will be distributed to holders of the CVRs. There is no contractual obligation for us to fund any amount related to the CVR liability.

Collaboration and License Agreements

In-licenses

In September 2023, we entered into a non-exclusive, sublicensable, worldwide, perpetual patent license agreement, or the Biogen Agreement, with Biogen MA, Inc., or Biogen, to research, develop, make, use, offer, sell and import products or processes containing or using an engineering T-cell modified with an mRNA comprising, or encoding a protein comprising, certain sequences licensed under the Biogen Agreement for the prevention, treatment, palliation and management of autoimmune diseases and disorders, excluding cancers, neoplastic disorders, and paraneoplastic disorders. We are not obligated to pay Biogen any expenses, fees, or royalties. For further description of the Biogen Agreement, see Note 15 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Effective September 2019, we entered into a non-exclusive, worldwide license agreement, or the NCI Agreement, with the U.S. Department of Health and Human Services, represented by the National Cancer Institute of the National Institutes of Health, or NCI. Under the NCI Agreement, we were granted a license under certain NCI patents and patent applications designated in the agreement, to make, use, sell, offer and import products and processes within the scope of the patents and applications licensed under the NCI Agreement when developing and manufacturing anti-BCMA CAR-T cell products for the treatment of MG, pemphigus vulgaris, and immune thrombocytopenic purpura according to methods designated in the NCI Agreement. In connection with our entry into the NCI Agreement, we paid to NCI a one-time $0.1 million license royalty payment. Under the NCI Agreement, we are further required to pay NCI a low five-digit annual royalty. We must also pay earned royalties on net sales in a low single-digit percentage and pay up to $0.8 million in benchmark royalties upon our achievement of designated benchmarks that are based on the commercial development plan agreed between the parties. For further description of the NCI Agreement, see Note 15 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Out-licenses

In January 2023, we entered into the Astellas Agreement with Astellas. Under this agreement, Astellas obtained the sole and exclusive right to commercialize Xork for use in Pompe disease in combination with an Astellas gene therapy investigational or authorized product, with a current focus on AT845. In connection with entry into this agreement, we received a $10.0 million upfront payment and were eligible to receive $340.0 million for certain additional development and commercial milestones plus royalties on any potential commercial sales where Xork is used as a pre-treatment for AT845. As a result of the sublicense of Xork to Astellas, we made a $4.0 million payment to Genovis in February 2023. The Astellas Agreement was terminated effective June 6, 2024. For further description of the Astellas Agreement, see Note 13 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report. Amounts paid and remaining obligations with regard to the Xork product candidate not reimbursed by Astellas through the Astellas Agreement were subject to potential reimbursement through deductions to CVR distributions as described in Note 7 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report and were reimbursed in the March 2025 CVR distribution.

In June 2020, we entered into the Sobi License. Sobi paid us a one-time, upfront payment of $75 million, and upon the closing of a private placement of our common stock to Sobi at a price of $138.468 per share, we received an additional $25 million from Sobi. We are eligible to receive $630.0 million in milestone payments upon the achievement of various development and regulatory milestones and sales thresholds for annual net sales of SEL-212, and tiered royalty payments ranging from the low double digits on the lowest sales tier to the high teens on the highest sales tier. Sobi has agreed to fund the Phase 3 clinical program of SEL-212, which commenced in September 2020. In July 2022, we received $10.0 million for the completion of the enrollment of the DISSOLVE II trial. In July 2024, we received $30.0 million for the milestone associated with the initiation of a rolling biologics license application to the FDA for SEL-212 for the potential treatment of chronic refractory gout by Sobi. Proceeds from milestone payments and royalties on sales of SEL-212, if any, are required to be distributed, net of certain agreed deductions, to holders of the CVRs. For further description of the Sobi License, see Note 13 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Financings

On December 13, 2024, we and Leerink Partners LLC entered into a Sales Agreement, or the Sales Agreement. Under the Sales Agreement, we may issue and sell shares of our common stock, from time to time, through Leerink Partners LLC or aggregate gross sales proceeds of up to $100.0 million. During the six months ended June 30, 2025, we sold no shares of our common stock pursuant to the Sales Agreement.

On November 13, 2023, we entered into the 2023 Securities Purchase Agreement with (i) Dr. Timothy A. Springer, a member of our Board of Directors; (ii) TAS Partners LLC, an affiliate of Dr. Springer, and (iii) Seven One Eight Three Four Irrevocable Trust, a trust associated with Dr. Murat Kalayoglu, a co-founder and the former chief executive officer of Old

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Cartesian, who joined our Board of Directors effective immediately after the effective time of the Merger, providing for the 2023 Private Placement. In the 2023 Private Placement, we issued and sold an aggregate of 149,330.115 shares of Series A Preferred Stock for an aggregate purchase price of $60.25 million, of which 50,189.789 shares of Series A Preferred Stock were issued and sold in the year ended December 31, 2023 for gross proceeds of $20.25 million, and 99,140.326 shares of Series A Preferred Stock were issued and sold during the three months ended March 31, 2024 for gross proceeds of $40.0 million.

On July 2, 2024, we entered into the 2024 Securities Purchase Agreement for the 2024 Private Placement with certain institutional and accredited investors, or the Purchasers. In the 2024 Private Placement, we issued and sold an aggregate of 3,563,247 shares of common stock and 2,937,903 shares of Series B Preferred Stock for which we generated gross proceeds of approximately $130.0 million.

Future funding requirements

As of the date of this Quarterly Report, we have not generated any revenue from product sales. We do not know when, or if, we will generate revenue from product sales. We will not generate significant revenue from product sales unless and until we obtain regulatory approval and commercialize one of our current or future product candidates. Our primary uses of capital are, and we expect will continue to be, compensation and related expenses, third-party clinical research and development services, laboratory and related supplies, clinical costs, legal and other regulatory expenses, milestone and royalty payments for in-licenses, and general overhead costs. We expect that we will continue to generate losses for the foreseeable future, and we expect the losses to increase as we continue the development of, and seek regulatory approvals for, our product candidates, and begin to commercialize any approved products. We are subject to risks in the development of our products, and we may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. We expect that we will need substantial additional funding to support our continuing operations.

As of June 30, 2025, we had an accumulated deficit of $693.9 million. We anticipate operating losses to continue for the foreseeable future due to, among other things, costs related to research, development of our product candidates, conducting preclinical studies and clinical trials, and our administrative organization. We will require substantial additional financing to fund our operations and to continue to execute our strategy, and we will pursue a range of options to secure additional capital.

We regularly evaluate various potential sources of additional funding such as strategic collaborations, license agreements, debt issuance, potential royalty and/or milestone monetization transactions and the issuance of equity instruments to fund our operations. If we raise additional funds through strategic collaborations and alliances, which may include existing collaboration partners, we may have to relinquish valuable rights to our technologies or product candidates, or grant licenses on terms that are not favorable to us. To the extent that we raise additional capital through the sale of equity instruments, the ownership interest of our existing stockholders will be diluted, and other preferences may be necessary that adversely affect the rights of existing stockholders.

We believe that our existing cash, cash equivalents, and restricted cash as of June 30, 2025 will enable us to fund our operating expenses and capital expenditure requirements into mid-2027. We may pursue additional cash resources through public or private equity or debt financings, by establishing collaborations with other companies or through the monetization of potential royalty and/or milestone payments pursuant to our existing collaboration and license arrangements. Management’s expectations with respect to our ability to fund current and long-term planned operations are based on estimates that are subject to risks and uncertainties. If actual results are different from management’s estimates, we may need to seek additional strategic or financing opportunities sooner than would otherwise be expected. However, there is no guarantee that any of these strategic or financing opportunities will be executed on favorable terms, and some could be dilutive to existing stockholders. If we are unable to obtain additional funding on a timely basis, we may be forced to significantly curtail, delay, or discontinue one or more of our planned research or development programs or be unable to expand our operations, meet long-term obligations or otherwise capitalize on our commercialization of our product candidates.

Our future capital requirements will depend on many factors, including:

•the scope, progress, results and costs of our clinical trials, preclinical development, manufacturing, laboratory testing and logistics;

•the number of product candidates that we pursue and the speed with which we pursue development;

•our headcount growth and associated costs;

•the costs, timing and outcome of regulatory review of our product candidates;

•the costs and timing of future commercialization activities, including manufacturing, marketing, sales and distribution, for any of our product candidates for which we receive marketing approval;

•the revenue, if any, from commercial sales of our product candidates for which we receive marketing approval;

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•the costs and timing of preparing, filing and prosecuting patent applications, maintaining and enforcing our intellectual property rights and defending any intellectual property-related claims;

•the effect of competing technological and market developments; and

•the extent to which we acquire or invest in businesses, products and technologies, including entering into licensing or collaboration arrangements for product candidates.

Cash Requirements due to Contractual Obligations and Other Commitments

We are under agreement to lease approximately 32,294 square feet of laboratory and office space in Watertown, Massachusetts through May 2028. Remaining lease payments from June 30, 2025 through the end of the lease term total approximately $8.3 million. Payments made and remaining obligations on this lease liability were subject to potential reimbursement through deductions to CVR distributions as described in Note 7 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report and were reimbursed in the March 2025 CVR distribution.

In November 2023, in connection with the Merger, we acquired two leases for office and laboratory space in Gaithersburg, Maryland, which expire in January 2027. Annualized rent is approximately $0.3 million and remaining lease payments from June 30, 2025 through the end of the lease term total approximately $0.5 million.

In February 2024, we entered into an agreement to lease approximately 19,199 square feet of integrated manufacturing and office space in Frederick, Maryland. In May 2024, we entered into an amendment to lease an additional approximately 7,842 square feet at the same site. In August 2024, we entered into a second amendment to lease an additional approximately 2,009 square feet at the same site. In March 2025, we entered into a third amendment to lease an additional approximately 6,439 square feet at the same site. The leases expire coterminously in June 2031. Annualized base rent under the leases is approximately $1.2 million and is subject to annual increases in accordance with the terms of the lease agreement. The leases provide for a tenant improvement allowance of $0.8 million. Remaining lease payments total $9.4 million through the end of the lease term.

We are also party to certain license and collaboration agreements with Biogen, NCI, and Shenyang Sunshine Pharmaceutical Co., Ltd., or 3SBio. We may be obligated to make certain future payments which are contingent upon future events such as our achievement of specified regulatory and commercial milestones, or royalties on net product sales under these agreements. As of June 30, 2025, we were unable to estimate the timing or likelihood of achieving these milestones or generating future product sales. Payments made and remaining obligations on the license agreement with 3SBio are subject to potential reimbursement through deductions to CVR distributions as described in Note 7 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Summary of Cash Flows


	2024
Cash (used in) provided by:
(40,629)			$	(30,363)
		(2,189)
		43,151
		9
(52,220)			$	10,608

Operating activities

Net cash used in operating activities for the six months ended June 30, 2025 was $40.6 million compared to $30.4 million for the six months ended June 30, 2024. The increase in cash used in operating activities of $10.2 million was primarily due to $32.0 million of net loss, adjusted for non-cash items, and $8.6 million of cash used in changes in operating assets and liabilities, in each case during the six months ended June 30, 2025 compared to $8.1 million of net loss, adjusted for non-cash items, and $38.5 million of cash used in changes in operating assets and liabilities during the six months ended June 30, 2024.

Investing activities

Net cash used in investing activities for the six months ended June 30, 2025 was $3.7 million compared to $2.2 million in the same period in 2024, a decrease of $1.5 million. The net cash used in investing activities for the six months ended June 30, 2025 and 2024 consisted primarily of purchases of property and equipment.

Financing activities

Net cash used in financing activities for the six months ended June 30, 2025 was $8.0 million compared to net cash provided by financing activities of $43.2 million for the six months ended June 30, 2024, a decrease of $51.2 million. The net

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cash used in financing activities in the six months ended June 30, 2025 was primarily the result of payments for the CVR distribution. The net cash provided by financing activities in the six months ended June 30, 2024 was primarily the result of proceeds of the 2023 Private Placement.

Recent Accounting Pronouncements

For a discussion of recently adopted or issued accounting pronouncements refer to Note 3 to our unaudited consolidated financial statements included elsewhere in this Quarterly Report.

Off-Balance Sheet Arrangements

As of June 30, 2025, we did not have any off-balance sheet arrangements as defined in the rules and regulations of the SEC.

Critical Accounting Policies and Use of Estimates

Our management’s discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements, which have been prepared in accordance with accounting principles generally accepted in the United States of America, or U.S. GAAP. The preparation of these consolidated financial statements requires us to make estimates and judgements that affect the reported amounts of assets, liabilities, revenues and expenses, and disclosure of contingent assets and liabilities in our consolidated financial statements. Actual results may differ from these estimates under different assumptions or conditions. During the three and six months ended June 30, 2025, there were no material changes to our critical accounting policies from those described in our Annual Report on Form 10-K for the year ended December 31, 2024.

Smaller Reporting Company

We qualify as a “smaller reporting company” under the rules of the Securities Act and the Exchange Act. As a result, we may choose to take advantage of certain scaled disclosure requirements available specifically to smaller reporting companies. We will remain a smaller reporting company until the last day of the fiscal year in which the aggregate market value of our common stock held by non-affiliated persons and entities, or our public float, is more than $700 million as of the last business day of our most recently completed second fiscal quarter, or until the fiscal year following the year in which we have at least $100 million in revenue and at least $250 million in public float as of the last business day of our most recently completed second fiscal quarter.

Item 3. Quantitative and Qualitative Disclosures About Market Risk

The market risk inherent in our financial instruments and in our financial position represents the potential loss arising from adverse changes in interest rates. As of June 30, 2025 and December 31, 2024, we had cash, cash equivalents, and restricted cash of $162.1 million and $214.3 million, respectively, consisting of non-interest and interest-bearing money market accounts. Our primary exposure to market risk is interest rate sensitivity, which is affected by changes in the general level of U.S. interest rates. Due to the short-term and the low risk profile of our money market accounts and marketable securities, and our current policy to hold marketable securities to maturity, an immediate 100 basis point change in interest rates would not have a material effect on the fair market value of our cash equivalents or short-term marketable securities.

Item 4. Controls and Procedures

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our Chief Executive Officer and Chief Financial Officer, evaluated, as of the end of the period covered by this Quarterly Report, the effectiveness of our disclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act). Based on that evaluation, our Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures were effective at the reasonable assurance level as of June 30, 2025.

Inherent Limitations on Effectiveness of Controls

There are inherent limitations to the effectiveness of any system of internal control over financial reporting. Accordingly, even an effective system of internal control over financial reporting can only provide reasonable assurance with respect to financial statement preparation and presentation in accordance with U.S. GAAP. Our internal controls over financial reporting are subject to various inherent limitations, including cost limitations, judgments used in decision making, assumptions about the likelihood of future events, the soundness of our systems, the possibility of human error, and the risk of fraud. Moreover, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may be inadequate because of changes in conditions and the risk that the degree of compliance with policies or procedures may deteriorate over time.

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Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during the three months ended June 30, 2025 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

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PART II. OTHER INFORMATION

Item 1. Legal Proceedings

None.

Item 1A. Risk Factors

See the risk factors previously disclosed in Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2024. There have been no material changes from the risk factors previously disclosed in such filings.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds

Not applicable.

Item 3. Defaults Upon Senior Securities

None.

Item 4. Mine Safety Disclosures

None.

Item 5. Other Information

, , our , a trading plan intended to satisfy the conditions under Rule 10b5-1(c) of the Exchange Act. Dr. Miljkovic’s plan provides for the exercise of vested stock options and the potential associated sale of up to shares of our common stock and the potential sale of up to an additional shares of our common stock until and including March 31, 2026. The foregoing exercises or sales, if any, will be made in accordance with the prices and formulas set forth in the plan and such plan terminates on the earlier of the date all the shares under the plan are sold and .

Other than as set forth above, during the fiscal quarter ended June 30, 2025, no officer or director, as defined in Rule 16a-1(f) of the Exchange Act, informed us of the , modification or of any “Rule 10b5-1 trading arrangement” or a “non-Rule 10b5-1 trading arrangement,” as those terms are defined in Item 408 of Regulation S-K .

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Item 6. Exhibits

EXHIBIT INDEX


		Incorporated by Reference
Exhibit Number	Exhibit Description	Form	File No.	Exhibit	Filing Date
2.1*	Agreement and Plan of Merger, dated November 13, 2023, by and among Selecta Biosciences, Inc., Sakura Merger Sub I, Inc., Sakura Merger Sub II, LLC, and Cartesian Therapeutics, Inc.	8-K	001-37798	2.1	11/13/2023
3.1(a)	Restated Certificate of Incorporation of Selecta Biosciences, Inc.	8-K	001-37798	3.1	6/29/2016
3.1(b)	Certificate of Amendment to the Restated Certificate of Incorporation of Selecta Biosciences, Inc., dated June 21, 2022	8-K	001-37798	3.1	6/21/2022
3.1(c)	Certificate of Amendment to the Restated Certificate of Incorporation of Selecta Biosciences, Inc., dated November 13, 2023	8-K	001-37798	3.3	11/13/2023
3.1(d)	Certificate of Amendment to the Restated Certificate of Incorporation, as amended, of Cartesian Therapeutics, Inc., dated March 28, 2024.	8-K	001-37798	3.2	3/28/2024
3.2	Amended and Restated By-laws of Cartesian Therapeutics, Inc.	10-Q	001-37798	3.2	11/13/2023
4.1(a)	Certificate of Designation of Preferences, Rights and Limitations of Series A Non-Voting Convertible Preferred Stock	8-K	001-37798	3.4	11/13/2023
4.1(b)	Certificate of Amendment to the Certificate of Designation of Series A Non-Voting Convertible Preferred Stock, dated March 26, 2024.	8-K	001-37798	3.1	3/28/2024
4.2	Certificate of Designation of Preferences, Rights and Limitations of Series B Non-Voting Convertible Preferred Stock	8-K	001-37798	3.1	7/2/2024





10.1	Fourth Amendment to Lease Agreement by and between 7495 RP, LLC and Cartesian Therapeutics, Inc. dated June 26, 2025	-	-	-	Filed herewith
31.1	Certification of Principal Executive Officer pursuant to Rule 13a-14(a) or Rule 15d-14(a) of the Securities Exchange Act of 1934, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002	-	-	-	Filed herewith
31.2	Certification of Principal Financial Officer pursuant to Rule 13a-14(a) or Rule 15d-14(a) of the Securities Exchange Act of 1934, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002	-	-	-	Filed herewith
32.1	Certification of Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002	-	-	-	Furnished herewith
101.INS	Inline XBRL Instance Document (the Instance Document does not appear in the interactive data file because its XBRL tags are embedded within the Inline XBRL document)	-	-	-	Filed herewith
101.SCH	Inline XBRL Taxonomy Extension Schema Document	-	-	-	Filed herewith
101.CAL	Inline XBRL Taxonomy Extension Calculation Linkbase Document	-	-	-	Filed herewith
101.DEF	Inline XBRL Taxonomy Extension Definition Linkbase Document	-	-	-	Filed herewith
101.LAB	Inline XBRL Taxonomy Extension Label Linkbase Document	-	-	-	Filed herewith

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101.PRE	Inline XBRL Taxonomy Extension Presentation Linkbase Document	-	-	-	Filed herewith
104	Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101)	-	-	-	Filed herewith

* Certain annexes, schedules and exhibits have been omitted pursuant to Item 601(a)(5) of Regulation S-K. The Company agrees to furnish supplementally a copy of any omitted attachment to the SEC on a confidential basis upon request.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed by the following persons on behalf of the registrant in the capacities and on the dates indicated.


	CARTESIAN THERAPEUTICS, INC.

Date: August 7, 2025	By:	/s/ Carsten Brunn, Ph.D.
		Carsten Brunn, Ph.D.
		President and Chief Executive Officer, and Director
		(Principal Executive Officer)


Date: August 7, 2025	By:	/s/ Blaine Davis
		Blaine Davis
		Chief Financial Officer
		(Principal Financial Officer)

Cartesian Therapeutics, Inc. - Quarter Report: 2025 June (Form 10-Q)

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