ALNYLAM PHARMACEUTICALS, INC. - Quarter Report: 2016 June (Form 10-Q)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

For the quarterly period ended June 30, 2016

OR

For the transition period from                      to                     

Commission File Number 001-36407

ALNYLAM PHARMACEUTICALS, INC.

(Exact Name of Registrant as Specified in Its Charter)

(617) 551-8200

(Registrant’s Telephone Number, Including Area Code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

At July 29, 2016, the registrant had 85,724,637 shares of Common Stock, $0.01 par value per share, outstanding.

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INDEX

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ALNYLAM PHARMACEUTICALS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands, except share and per share amounts)

(Unaudited)

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

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ALNYLAM PHARMACEUTICALS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS

(In thousands, except per share amounts)

(Unaudited)

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

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ALNYLAM PHARMACEUTICALS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

(Unaudited)

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

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ALNYLAM PHARMACEUTICALS, INC.

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation and Principles of Consolidation

The accompanying condensed consolidated financial statements of Alnylam Pharmaceuticals, Inc. are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP, applicable to interim periods and, in the opinion of management, include all normal and recurring adjustments that are necessary to state fairly the results of operations for the reported periods. Our condensed consolidated financial statements have also been prepared on a basis substantially consistent with, and should be read in conjunction with, our audited consolidated financial statements for the year ended December 31, 2015, which were included in our Annual Report on Form 10-K that was filed with the Securities and Exchange Commission, or SEC, on February 12, 2016. The year-end condensed consolidated balance sheet data was derived from our audited financial statements, but does not include all disclosures required by GAAP. The results of our operations for any interim period are not necessarily indicative of the results of our operations for any other interim period or for a full fiscal year.

The accompanying condensed consolidated financial statements reflect the operations of Alnylam and our wholly-owned subsidiaries. All significant intercompany accounts and transactions have been eliminated.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Net Loss Per Common Share

We compute basic net loss per common share by dividing net loss by the weighted-average number of common shares outstanding. We compute diluted net loss per common share by dividing net loss by the weighted-average number of common shares and dilutive potential common share equivalents then outstanding. Potential common shares consist of shares issuable upon the exercise of stock options (the proceeds of which are then assumed to have been used to repurchase outstanding stock using the treasury stock method). Because the inclusion of potential common shares would be anti-dilutive for all periods presented, diluted net loss per common share is the same as basic net loss per common share.

The following table sets forth for the periods presented the potential common shares (prior to consideration of the treasury stock method) excluded from the calculation of net loss per common share because their inclusion would be anti-dilutive, in thousands:

Public Offering

In January 2015, we sold an aggregate of 5,447,368 shares of our common stock through an underwritten public offering at a price to the public of $95.00 per share. As a result of the offering, which included the full exercise of the underwriters’ option to purchase additional shares, we received aggregate net proceeds of $496.4 million, after deducting underwriting discounts and commissions and other offering expenses of $21.1 million.

Fair Value Measurements

The fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. In general, fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities. Fair values determined by Level 2 inputs utilize data points that are observable, such as quoted prices (adjusted), interest rates and yield curves. Fair values determined by Level 3 inputs utilize unobservable data points for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. The fair value hierarchy level is determined by the lowest level of significant input.

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Investments in Marketable Securities and Cash Equivalents

We invest our excess cash balances in short-term and long-term marketable debt and equity securities. We classify our investments in marketable debt securities as either held-to-maturity or available-for-sale based on facts and circumstances present at the time we purchased the securities. At each balance sheet date presented, we classified all of our investments in debt and equity securities as available-for-sale. We report available-for-sale investments at fair value at each balance sheet date and include any unrealized holding gains and losses (the adjustment to fair value) in accumulated other comprehensive income (loss), a component of stockholders’ equity. At June 30, 2016, the balance in our accumulated other comprehensive loss was composed primarily of activity related to our available-for-sale marketable securities, including our investment in equity securities of Regulus Therapeutics Inc., or Regulus. Realized gains and losses are determined using the specific identification method and are included in other income (expense). We recognized $1.0 million and $6.1 million of realized gains from sales of our Regulus available-for-sale securities as other income on our condensed consolidated statements of comprehensive loss during the three and six months ended June 30, 2016, respectively. If any adjustment to fair value reflects a decline in the value of the investment, we consider all available evidence to evaluate the extent to which the decline is “other than temporary,” including our intention to sell and, if so, mark the investment to market through a charge to our condensed consolidated statements of comprehensive loss. We did not record any impairment charges related to our fixed income marketable securities during the six months ended June 30, 2016 or 2015. Our marketable securities are classified as cash equivalents if the original maturity, from the date of purchase, is 90 days or less, and as marketable securities if the original maturity, from the date of purchase, is in excess of 90 days. Our cash equivalents are composed of commercial paper, corporate notes, U.S. government-sponsored enterprise securities and money market funds.

We account for our investment in Regulus as an available-for-sale marketable security. Intraperiod tax allocation rules require us to allocate our provision for income taxes between continuing operations and other categories of earnings, such as other comprehensive income. In periods in which we have a year-to-date pre-tax loss from continuing operations and pre-tax income in other categories of earnings, such as other comprehensive income, we must allocate the tax provision to the other categories of earnings. We then record a related tax benefit in continuing operations. Upon sales of our available-for-sale marketable securities, we apply the aggregate portfolio approach to recognize the related tax provision or benefit into income (loss) from continuing operations. As a result, the disproportionate tax effect remains in accumulated other comprehensive income (loss) as long as we maintain an investment portfolio.

Recent Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board, or FASB, issued a new revenue recognition standard which amends revenue recognition principles and provides a single, comprehensive set of criteria for revenue recognition within and across all industries. The new standard provides a five step framework whereby revenue is recognized when promised goods or services are transferred to a customer at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard also requires enhanced disclosures pertaining to revenue recognition in both interim and annual periods. In August 2015, the FASB deferred the effective date of the new revenue standard from January 1, 2017 to January 1, 2018. In March 2016, the FASB issued amendments to clarify the implementation guidance on principal versus agent considerations. In April 2016, the FASB issued amendments to clarify the guidance on accounting for licenses of intellectual property and identifying performance obligations. In May 2016, the FASB issued amendments related to collectibility, non-cash consideration, the presentation of sales and other similar taxes collected from customers and transition. Early adoption is permitted any time after the original effective date, which for us is January 1, 2017. The standard allows for adoption using a full retrospective method or a modified retrospective method. We are currently evaluating the timing and method of our adoption as well as the expected impact that the standard could have on our condensed consolidated financial statements and related disclosures.

In January 2016, the FASB issued new guidance on recognition and measurement of financial assets and financial liabilities. The new guidance will impact the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. All equity investments in unconsolidated entities (other than those accounted for under the equity method of accounting) will generally be measured at fair value with changes in fair value recognized through earnings. There will no longer be an available-for-sale classification (changes in fair value reported in other comprehensive income (loss)) for equity securities with readily determinable fair values. In addition, the FASB clarified the need for a valuation allowance on deferred tax assets resulting from unrealized losses on available-for-sale debt securities. In general, the new guidance will require modified retrospective application to all outstanding instruments, with a cumulative effect adjustment recorded to opening retained earnings. This guidance will be effective for us on January 1, 2018. We are currently evaluating the expected impact that the standard could have on our condensed consolidated financial statements and related disclosures.

In February 2016, the FASB issued a new leasing standard that requires that all lessees recognize the assets and liabilities that arise from leases on the condensed consolidated balance sheet and disclose qualitative and quantitative information about its leasing arrangements. The new standard will be effective for us on January 1, 2019. Early adoption is permitted. We are currently evaluating the expected impact that this standard may have on our condensed consolidated financial statements and related disclosures.

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In March 2016, the FASB issued guidance that will update the accounting for certain aspects of share-based payments to employees, including the income tax consequences, classification of awards as either equity or liabilities and classification on the condensed consolidated statement of cash flows. The new standard will be effective for us on January 1, 2017. Early adoption is permitted. We are currently evaluating the expected impact that this standard may have on our condensed consolidated financial statements and related disclosures.

2. COLLABORATION AGREEMENTS

The following table summarizes our total consolidated net revenues from collaborators, for the periods indicated, in thousands:

Product Alliances

Sanofi Genzyme Collaboration

In January 2014, we entered into a global, strategic collaboration with Sanofi Genzyme, the specialty care global business unit of Sanofi, or Sanofi Genzyme, to discover, develop and commercialize RNAi therapeutics as Genetic Medicines to treat orphan diseases. The 2014 Sanofi Genzyme collaboration superseded and replaced the previous collaboration between us and Sanofi Genzyme entered into in October 2012 to develop and commercialize RNAi therapeutics targeting transthyretin, or TTR, for the treatment of TTR-mediated amyloidosis, or ATTR amyloidosis, including patisiran and revusiran, in Japan and the Asia-Pacific region.

2012 Sanofi Genzyme Agreement

Under the 2012 Sanofi Genzyme agreement, Sanofi Genzyme paid us an upfront cash payment of $22.5 million. We were also entitled to receive certain milestone payments under the 2012 Sanofi Genzyme agreement. In the fourth quarter of 2013, we earned a milestone of $7.0 million based upon the completion of a successful patisiran Phase 2 clinical trial and a milestone of $4.0 million based upon the initiation of the Phase 3 clinical trial for patisiran.

Under the 2012 Sanofi Genzyme agreement, the parties agreed to collaborate in the development and commercialization of licensed products, with Sanofi Genzyme assuming primary responsibility in the Sanofi Genzyme territory, which included Japan and the Asia-Pacific region, and us retaining primary responsibility in the rest of the world.

We determined that the deliverables under the 2012 Sanofi Genzyme agreement included the license, a joint steering committee and any additional TTR-specific RNAi therapeutic compounds that comprised the ALN-TTR program. We also determined that, pursuant to the accounting guidance governing revenue recognition on multiple element arrangements, the license and undelivered joint steering committee and any additional TTR-specific RNAi therapeutic compounds did not have standalone value due to the specialized nature of the services to be provided by us. In addition, while Sanofi Genzyme had the ability to grant sublicenses, it could not sublicense all or substantially all of its rights under the 2012 Sanofi Genzyme agreement. The uniqueness of our services and the limited sublicense right were indicators that standalone value was not present in the arrangement. Therefore the deliverables were not separable and, accordingly, the license and undelivered services were treated as a single unit of accounting. We were unable to reasonably estimate the period of performance under the 2012 Sanofi Genzyme agreement, as we were unable to estimate the timeline of our deliverables related to the deliverable for any additional TTR-specific RNAi therapeutic compounds. Through December 31, 2013, we had deferred all revenue, or $33.5 million, under the 2012 Sanofi Genzyme agreement.

2014 Sanofi Genzyme Collaboration

In January 2014, we entered into the 2014 Sanofi Genzyme collaboration. As noted above, the 2014 Sanofi Genzyme collaboration superseded and replaced the 2012 Sanofi Genzyme agreement.

The 2014 Sanofi Genzyme collaboration is structured as an exclusive relationship for the worldwide development and commercialization of RNAi therapeutics in the field of Genetic Medicines, which includes our current and future Genetic Medicine programs that reach Human Proof-of-Principle Study Completion (as defined in the Sanofi Genzyme master agreement), or Human POP, by the end of 2019, subject to extension to the end of 2021 in various circumstances. We will retain product rights in North America and Western Europe, referred to as the Alnylam Territory, while Sanofi Genzyme will obtain exclusive rights to develop and

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commercialize collaboration products in the rest of the world, referred to as the Sanofi Genzyme Territory, together with certain broader co-development/co-promote or worldwide rights for certain products. Sanofi Genzyme’s rights, described in detail below, are structured as an opt-in that is triggered upon achievement of Human POP. We maintain development control for all programs prior to Sanofi Genzyme’s opt-in and maintain development and commercialization control after Sanofi Genzyme’s opt-in for all programs in the Alnylam Territory.

Specifically, in addition to its regional rights for our current and future Genetic Medicine programs in the Sanofi Genzyme Territory, Sanofi Genzyme has the right to either (i) co-develop and co-promote fitusiran for the treatment of hemophilia and other rare bleeding disorders in the Alnylam Territory, with us maintaining development and commercialization control, or (ii) obtain a global license to ALN-AS1 for the treatment of hepatic porphyrias. Sanofi Genzyme may exercise this selection right upon the completion of Human POP for both the fitusiran and ALN-AS1 programs. Finally, Sanofi Genzyme has the right for a global license to a single, future Genetic Medicine program that was not one of our defined Genetic Medicine programs as of the effective date of the 2014 Sanofi Genzyme collaboration. We will retain global rights to any RNAi therapeutic Genetic Medicine program that does not reach Human POP by the end of 2019, subject to certain limited exceptions. We retain full rights to all current and future RNAi therapeutic programs outside of the field of Genetic Medicines, including the right to form new collaborations.

Under the 2014 Sanofi Genzyme collaboration, Sanofi Genzyme’s specific license rights and the programs into which Sanofi Genzyme has opted include the following:

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Due to the uncertainty of pharmaceutical development and the high historical failure rates generally associated with drug development, we may not receive any additional milestone payments or any royalty payments from Sanofi Genzyme under the 2014 Sanofi Genzyme collaboration.

Under the master agreement, the parties will collaborate in the development of option products, with us leading development for all programs prior to Sanofi Genzyme’s opt-in and also leading development and commercialization for all programs in the Alnylam Territory after Sanofi Genzyme’s opt-in. If Sanofi Genzyme does not exercise its option to license rights to a particular program, we will retain the exclusive right to develop and commercialize such program throughout the world, including the right to sublicense to third parties.

The 2014 Sanofi Genzyme collaboration is governed by an alliance joint steering committee that is comprised of an equal number of representatives from each party. There are additional committees to manage various aspects of each regional, co-developed/co-promoted and global program. We and Sanofi Genzyme intend to enter into supply agreements to provide for supply of collaboration products to Sanofi Genzyme for clinical studies, and, at Sanofi Genzyme’s request, commercial sales. Sanofi Genzyme also has certain rights to manufacture collaboration products. Additionally, Sanofi Genzyme has certain limited opt-out rights, as specified in the master agreement, upon which products revert fully back to us with no further obligations to Sanofi Genzyme.

The master agreement (including the license terms appended thereto) contains certain termination provisions, including for material breach by the other party. Unless terminated earlier pursuant to its terms, the master agreement will terminate upon the last to expire of any of the option periods under the master agreement or the license terms appended thereto.

Upon the closing of the equity transaction in February 2014, we sold to Sanofi Genzyme 8,766,338 shares of our common stock and Sanofi Genzyme paid $700.0 million in aggregate cash consideration to us. As a condition to the closing of the equity transaction, Sanofi Genzyme entered into an investor agreement with us. Under the investor agreement, until the earlier of the fifth anniversary of the expiration or earlier termination of the 2014 Sanofi Genzyme collaboration and the date on which Sanofi Genzyme and its affiliates cease to beneficially own at least 5% of our outstanding common stock, Sanofi Genzyme and its affiliates are bound by certain “standstill” provisions. The standstill provisions include agreements not to acquire more than 30% of our outstanding common stock, call stockholder meetings, nominate directors other than those approved by our board of directors, subject to certain limited exceptions, or propose or support a proposal to acquire us. Further, Sanofi Genzyme has agreed to vote, and cause its affiliates to vote, all shares of our voting securities they are entitled to vote, up to a maximum of 20% of our outstanding common stock, in a manner either as recommended by our board of directors or proportionally with the votes cast by our other stockholders, except with respect to certain change of control transactions or our liquidation or dissolution. Until Sanofi Genzyme owns less than 7.5% of our outstanding common stock, subject to Sanofi Genzyme’s limited right to maintain its ownership percentage as described below, if we issue common stock or securities convertible into or exercisable for common stock to a third party that holds at least 30% of our outstanding common stock or, in connection with a collaboration or license transaction, to a third party that will initially hold at least the percentage of our outstanding common stock represented by the shares purchased by Sanofi Genzyme at the closing of the equity transaction, we will offer Sanofi Genzyme an opportunity to amend the standstill and voting provisions in the investor agreement to be consistent with the terms provided to such third party.

Under the investor agreement, Sanofi Genzyme has also agreed not to dispose of any shares of common stock beneficially owned by it immediately after the closing of the stock purchase until the earlier of (i) December 31, 2019 (subject to extension by up to two years if Sanofi Genzyme’s option to select additional compounds under the master agreement is extended beyond December 31, 2019) and (ii) six months after the expiration or earlier valid termination of the collaboration, in each case subject to earlier termination in the event certain clinical activities under the collaboration fail to occur. Following the expiration of this lock-up period, Sanofi Genzyme will be permitted to sell such shares of common stock subject to certain limitations, including volume and manner of sale restrictions. Notwithstanding the foregoing, following the two-year anniversary of the closing of the stock purchase, in the event that the market price per share of our common stock is at least 100% higher than the market price per share of our common stock at closing of the stock purchase (in each case based upon a ten-day trailing average), Sanofi Genzyme may sell up to 25% of its initial shares, subject to certain restrictions on post-lock-up period dispositions as described above.

Under the investor agreement, following the lock-up period, Sanofi Genzyme will have three demand rights to require us to conduct a registered underwritten public offering with respect to the shares of common stock beneficially owned by Sanofi Genzyme immediately after the closing of the stock purchase, subject to certain conditions. In addition, following the lock-up period, subject to certain conditions, Sanofi Genzyme will be entitled to participate in registered underwritten public offerings by us if other selling stockholders are included in the registration.

The investor agreement provides that, until Sanofi Genzyme owns less than 7.5% of our outstanding common stock, subject to Sanofi Genzyme’s limited right to maintain its ownership percentage as described herein, in connection with new issuances of common stock, subject to certain exceptions, Sanofi Genzyme will be entitled to a right of first offer to participate proportionally to

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maintain its then-current ownership percentage of our common stock. If Sanofi Genzyme is not entitled to a right of first offer with respect to a new issuance, Sanofi Genzyme will have the opportunity, on a post-transaction basis, to purchase additional shares sufficient to maintain its pre-transaction ownership percentage of our common stock (subject to the same 7.5% ownership threshold).

Finally, in the event Sanofi Genzyme and its affiliates acquire at least 20% or more of our outstanding common stock, Sanofi Genzyme will be entitled to appoint one individual to our board of directors. Sanofi Genzyme will also be entitled to certain information rights, including with respect to financial information in the event Sanofi Genzyme or its affiliates require such information for its own financial reporting purposes. The rights and restrictions under the investor agreement are subject to termination upon the occurrence of certain events.

We recorded the issuance of 8,766,338 shares of our common stock under the stock purchase agreement using the price of our common stock on the date the shares were issued to Sanofi Genzyme. Based on the common stock price of $85.72, the fair value of the shares issued was $751.5 million, which was $51.5 million in excess of the proceeds received from Sanofi Genzyme for the issuance of our common stock. This $51.5 million is being amortized on a straight-line basis over the performance period, which is currently approximately six years as described below. In addition, due to intraperiod tax allocation rules, upon closing of the equity transaction we recorded a benefit from income taxes of $15.2 million due to the Sanofi Genzyme equity purchase being recorded in additional paid-in capital, net of tax.

In accordance with the investor agreement, as a result of our issuance of shares in connection with our acquisition of Sirna Therapeutics, Inc., in March 2014, Sanofi Genzyme exercised its right to purchase an additional 344,448 shares of our common stock for $23.0 million. In addition, in January 2015, in connection with our public offering, Sanofi Genzyme exercised its right to purchase directly from us, in concurrent private placements, 744,566 shares of common stock at the public offering price resulting in $70.7 million in proceeds to us. The sales of common stock to Sanofi Genzyme were not registered as part of the public offering, though they were consummated simultaneously with the public offering.

Sanofi Genzyme also has the right at the beginning of each year to purchase a number of shares of our common stock based on the number of shares we issued during the previous year for compensation-related purposes. Sanofi Genzyme exercised this right to purchase directly from us 196,251 shares of our common stock on January 22, 2015 for $18.3 million and 205,030 shares of our common stock on February 1, 2016 for $14.3 million. The sales of these shares to Sanofi Genzyme were consummated as private placements.

In each instance, the purchase by Sanofi Genzyme described above allowed Sanofi Genzyme to maintain its ownership level of our common stock of approximately 12%.

We determined that the deliverables for the programs on which Sanofi Genzyme was collaborating with us upon initiation of the 2014 collaboration included the licenses to our patisiran and revusiran clinical programs, which licenses were delivered to Sanofi Genzyme upon the closing date of the transaction, and the associated development activities, joint steering committee participation and information exchange for these clinical programs. We also determined that, pursuant to the accounting guidance governing revenue recognition on multiple element arrangements, the license and associated undelivered development activities, joint steering committee participation and information exchange activities did not have standalone value due to the specialized nature of the services to be provided by us. In addition, while Sanofi Genzyme has the ability to grant sublicenses, it cannot sublicense all or substantially all of its rights under the 2014 Sanofi Genzyme collaboration. The uniqueness of our services and the limited sublicense rights are indicators that standalone value is not present in the arrangement. Therefore the deliverables are not separable and, accordingly, the license and undelivered services were treated as a single unit of accounting. When multiple deliverables are accounted for as a single unit of accounting, we base our revenue recognition model on the final deliverable. Under the 2014 Sanofi Genzyme collaboration, the last deliverables for patisiran and revusiran are expected to be completed within approximately six years from the closing date of the transaction and the last deliverables for fitusiran are expected to be completed within approximately five years from the date Sanofi Genzyme elected to opt into our fitusiran clinical development program under the regional license terms. We determined that the total cash received from Sanofi Genzyme under the now superseded 2012 Sanofi Genzyme agreement reflects consideration for certain of the performance obligations for ALN-TTR programs included in the 2014 Sanofi Genzyme collaboration. Therefore we are recognizing the $33.5 million of deferred revenue under the 2012 Sanofi Genzyme agreement on a straight-line basis over the period of performance of the ALN-TTR programs, which, as noted above, is currently approximately six years. As consideration is achieved, including any milestones or reimbursement for development activities, we recognize as revenue a portion of these payments equal to the percentage of the performance period completed when the milestone or activities have been satisfied, multiplied by the amount of the payment. We recognize the remaining portion of consideration received over the remaining performance period on a straight-line basis.

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The following table presents information related to the 2014 Sanofi Genzyme collaboration, in thousands:

We determined that the opt-in rights that Sanofi Genzyme has for future Genetic Medicine programs represent separate and additional deliverables that Sanofi Genzyme may receive from us in future periods. Upon each opt-in by Sanofi Genzyme, we have determined that each program and the related activities will represent a single unit of accounting and, consistent with our accounting policies, we will base our revenue recognition period on the final deliverable associated with each future opt-in.

3. FAIR VALUE MEASUREMENTS

The following tables present information about our assets that are measured at fair value on a recurring basis at June 30, 2016 and December 31, 2015, and indicate the fair value hierarchy of the valuation techniques we utilized to determine such fair value, in thousands:

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During the six months ended June 30, 2016, there were no transfers between Level 1 and Level 2 financial assets. The carrying amounts reflected in our condensed consolidated balance sheets for cash, billed and unbilled collaboration receivables, other current assets, accounts payable and accrued expenses approximate fair value due to their short-term maturities. The fair value of our long-term debt at June 30, 2016, computed pursuant to a discounted cash flow technique using a market interest rate, was $150.2 million and is considered a Level 3 fair value measurement. The effective interest rate reflects the current market rate.

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4. MARKETABLE SECURITIES

The following tables summarize the fair value, accumulated other comprehensive income (loss) and intraperiod tax allocation regarding our investment in Regulus available-for-sale marketable securities at June 30, 2016 and 2015, and for the activity recorded for the three months ended June 30, 2016 and 2015, in thousands:

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The following tables summarize the fair value, accumulated other comprehensive income (loss) and intraperiod tax allocation regarding our investment in Regulus available-for-sale marketable securities at June 30, 2016 and 2015, and the activity for the six months ended June 30, 2016 and 2015, in thousands:

We obtain fair value measurement data for our marketable securities from independent pricing services. We perform validation procedures to ensure the reasonableness of this data. This includes meeting with the independent pricing services to understand the methods and data sources used. Additionally, we perform our own review of prices received from the independent pricing services by comparing these prices to other sources and confirming those securities are trading in active markets.

The following tables summarize our marketable securities, other than our holdings in Regulus noted above, at June 30, 2016 and December 31, 2015, in thousands:

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We classify our debt security investments based on their contractual maturity dates. The following table summarizes our available-for-sale debt securities by contractual maturity, at June 30, 2016, in thousands:

5. COMMITMENTS AND CONTINGENCIES

Manufacturing Facility

On February 10, 2016, we entered into an agreement with 20 Commerce LLC to purchase 12 acres of undeveloped land in Norton, Massachusetts for approximately $8.0 million for the land and related acquisition costs. We completed the purchase and closed this transaction on April 4, 2016. We have commenced construction of a manufacturing facility at this site for drug substance, including siRNAs and siRNA conjugates, for clinical and commercial use. At June 30, 2016, property and equipment, net on our condensed consolidated balance sheets reflects $17.1 million of land and associated costs related to the construction of our drug substance manufacturing facility.

Credit Agreeements

On April 29, 2016, we entered into (i) a Credit Agreement, or the BOA Credit Agreement, with Alnylam U.S., Inc., our wholly-owned subsidiary, as the borrower, us, as a guarantor, and Bank of America N.A., or BOA, as the lender and (ii) a Credit Agreement, or the Wells Credit Agreement, together with the BOA Credit Agreement, the Credit Agreements, by and among Alnylam U.S., Inc., as the borrower, us, as a guarantor, and Wells Fargo Bank, National Association, or Wells, as the lender. The Credit Agreements were entered into in connection with the planned build out of our new drug substance manufacturing facility.

The BOA Credit Agreement provides for a $120.0 million term loan facility and matures on April 29, 2021. The Wells Credit Agreement provides for a $30.0 million term loan facility and matures on April 29, 2021. The proceeds of the borrowing under each of the BOA Credit Agreement and the Wells Credit Agreement are to be used for working capital and general corporate purposes. Interest on borrowings under the Credit Agreements is calculated based on LIBOR plus 0.45 percent, except in the event of default. The borrower may prepay loans under each of the BOA Credit Agreement and the Wells Credit Agreement at any time, without premium or penalty, subject to certain notice requirements and LIBOR breakage costs.

The obligations of the borrower under each Credit Agreement are guaranteed by us. The obligations of the borrower and us under each Credit Agreement are secured by cash collateral in an amount equal to, at any given time, at least 100% of the principal amount of all term loans outstanding under such Credit Agreement at such time. At June 30, 2016, we have recorded $150.0 million of cash collateral in connection with the Credit Agreements as restricted investments on our condensed consolidated balance sheets. Each of the lenders and the borrower have agreed to consider the appropriateness of a change in the type of approved collateral on a periodic basis throughout the term of the Credit Agreements; provided that any such change to the type of such approved collateral shall be made only upon each of the lender’s and the borrower’s consent.

Each Credit Agreement contains limited representations and warranties and limited affirmative and negative covenants, including quarterly reporting obligations. Each Credit Agreement also contains certain customary events of default, including nonpayment of principal or interest, material inaccuracy of representations, failure to comply with covenants, cross-defaults to certain other indebtedness, invalidity of any loan document relating to such Credit Agreement, judgments having a material adverse effect, insolvency events and change of control. If an event of default occurs and is continuing under either Credit Agreement, the entire outstanding balance under such Credit Agreement may become immediately due and payable.

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Several of the lenders under each of the Credit Agreements, as well as their affiliates, have various relationships with us and our subsidiaries involving the provision of financial services, such as investment banking, commercial banking, advisory, cash management, custody and corporate credit card services for which they receive customary fees and may do so in the future.

During the three and six months ended June 30, 2016, we recorded $0.7 million of interest expense related to the Credit Agreements that are reflected in other income (expense) on our condensed consolidated statements of comprehensive loss.

Litigation

University of Utah Litigation

On March 22, 2011, The University of Utah, or Utah, filed a civil complaint in the United States District Court for the District of Massachusetts, or the MA District Court, against us, Max Planck Gesellschaft Zur Foerderung Der Wissenschaften e.V. and Max Planck Innovation GmbH, the Whitehead Institute for Biomedical Research, the Massachusetts Institute of Technology and the University of Massachusetts, claiming a professor at Utah is the sole inventor or, in the alternative, a joint inventor, of the Tuschl patents. Utah was seeking changes to the inventorship of the Tuschl patents, unspecified damages and other relief. After several years of court proceedings and discovery, on September 28, 2015, the MA District Court granted both of our motions for summary judgment, finding that there was no collaboration between Dr. Bass and Dr. Tuschl, which is a pre-requisite for co-inventorship, and dismissing Utah’s state law damages claims as well. On October 28, 2015, Utah filed a notice of appeal to the United States Court of Appeals for the Federal Circuit, or the CAFC. On December 18, 2015, the CAFC entered an order dismissing Utah’s appeal following a joint motion filed by us and Utah seeking dismissal of the appeal with prejudice. This disposed of Utah’s inventorship claims and its state law claims for damages.

On October 14, 2015, we filed a motion with the MA District Court seeking reimbursement of costs and fees associated with defending this action in the amount of approximately $8.0 million. On November 30, 2015, the MA District Court denied our motion and on December 15, 2015, we filed a notice of appeal of this ruling with the CAFC. On February 16, 2016, we filed our appeal brief with the CAFC. Utah filed a response on April 11, 2016 and our reply was filed May 9, 2016. While we believe a fee award is merited in this case, such awards are not customary and are made at the discretion of the court. We anticipate a ruling on our appeal by the end of the fourth quarter of 2016, however, the timing will be determined by the CAFC.

Dicerna Litigation

On June 10, 2015, we filed a trade secret misappropriation lawsuit against Dicerna Pharmaceuticals, Inc., or Dicerna, in the Superior Court of Middlesex County, Massachusetts, seeking to stop misappropriation by Dicerna of our confidential, proprietary and trade secret information related to the RNAi assets we purchased from Merck Sharp & Dohme Corp., including certain GalNAc conjugate technology. In addition to permanent injunctive relief, we are also seeking monetary damages from Dicerna. On July 10, 2015, Dicerna filed its answer to our complaint, in which it denied our claims, along with initial discovery requests, to which we responded in a timely fashion. On July 27, 2015, Dicerna filed a motion seeking removal of the case to the Business Litigation Session of the Superior Court of Suffolk County, which we opposed. On August 31, 2015, the Court denied Dicerna’s motion. We and Dicerna agreed to a protective order, which was entered by the Court on November 12, 2015. Discovery is ongoing and we now expect discovery to close on November 21, 2016.

Although we believe we have meritorious claims in this matter, litigation is subject to inherent uncertainty and a court could ultimately rule against us. In addition, litigation and related matters are costly and may divert the attention of our management and other resources that would otherwise be engaged in other activities.

Our accounting policy for accrual of legal costs is to recognize such expenses as incurred.

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ITEM 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS.

This Quarterly Report on Form 10-Q contains forward-looking statements that involve risks and uncertainties. The statements contained in this Quarterly Report on Form 10-Q that are not purely historical are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended and Section 21E of the Securities Exchange Act of 1934, as amended. Without limiting the foregoing, the words “may,” “will,” “should,” “could,” “expects,” “plans,” “intends,” “anticipates,” “believes,” “estimates,” “predicts,” “potential,” “continue,” “target,” “goal” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these words. All forward-looking statements included in this Quarterly Report on Form 10-Q are based on information available to us up to, and including, the date of this document, and we expressly disclaim any obligation to update any such forward-looking statements to reflect events or circumstances that arise after the date hereof. Our actual results could differ materially from those anticipated in these forward-looking statements as a result of certain important factors, including those set forth in this Item 2 — “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” as well as under Part II, Item 1A — “Risk Factors” and elsewhere in this Quarterly Report on Form 10-Q. You should carefully review those factors and also carefully review the risks outlined in other documents that we file from time to time with the Securities and Exchange Commission, or SEC.

Overview

We are a biopharmaceutical company developing novel therapeutics based on RNA interference, or RNAi. RNAi is a naturally occurring biological pathway within cells for selectively silencing and regulating the expression of specific genes. Since many diseases are caused by the inappropriate activity of specific genes, the ability to silence genes selectively through RNAi could provide a new way to treat a wide range of human diseases. We believe that drugs that work through RNAi have the potential to become a broad new class of innovative medicines, and that this potential new drug class is similar to the opportunity created with other major biological discoveries such as recombinant DNA and monoclonal antibodies. Using our intellectual property and expertise, we are developing what we believe to be a reproducible and modular platform to develop RNAi therapeutics for a variety of human diseases.

Our research and development strategy is focused primarily on use of our proprietary N-acetylgalactosamine, or GalNAc-conjugate strategy for delivery of small interfering RNAs, or “siRNAs” — the molecules that mediate RNAi — toward genetically validated, liver-expressed genes involved in the cause or pathway of human diseases. We are also focused on clinical indications where there are high unmet medical needs, early biomarkers for the assessment of clinical activity in Phase 1 clinical studies, and a definable path for drug development, regulatory approval and commercialization.

Specifically, our pipeline of investigational RNAi therapeutics is focused in three Strategic Therapeutic Areas, or “STArs:” Genetic Medicines, with a broad pipeline of RNAi therapeutics for the treatment of rare diseases; Cardio-Metabolic Diseases, with a pipeline of RNAi therapeutics toward genetically validated, liver-expressed disease targets for unmet needs in cardiovascular and metabolic diseases, such as dyslipidemia, non-alcoholic steatohepatitis, type 2 diabetes, hypertension and other major diseases; and Hepatic Infectious Diseases, with a pipeline of RNAi therapeutics designed to address the major global health challenges of hepatic infectious diseases, beginning with hepatitis B and hepatitis D viral infections. We continue to make progress towards our Alnylam 2020 guidance, launched in January 2015, for the advancement and commercialization of RNAi therapeutics as a whole new class of innovative medicines. Specifically, by the end of 2020, we expect to achieve a company profile with three marketed products and ten RNAi therapeutic clinical programs, including four in late stages of development, across our three STArs.

Based on our expertise in RNAi therapeutics and broad intellectual property estate we have formed alliances with leading pharmaceutical and life sciences companies, including Ionis Pharmaceuticals, Inc., or Ionis (formerly Isis Pharmaceuticals, Inc.), Novartis Pharma AG (which assigned its rights and obligations to Arrowhead Pharmaceuticals, Inc., or Arrowhead (formerly Arrowhead Research Corporation), in early 2015), or Novartis/Arrowhead, F. Hoffmann-La Roche Ltd (which assigned its rights and obligations to Arrowhead in 2011), or Roche/Arrowhead, Takeda Pharmaceutical Company Limited, or Takeda, Kyowa Hakko Kirin Co., Ltd., Cubist Pharmaceuticals, Inc., or Cubist (now a wholly-owned subsidiary of Merck & Co., Inc.), Monsanto Company, or Monsanto, Sanofi Genzyme, the specialty care global business unit of Sanofi, or Sanofi Genzyme, and The Medicines Company, or MDCO.

We have incurred significant losses since we commenced operations in 2002 and expect such losses to continue for the foreseeable future. At June 30, 2016, we had an accumulated deficit of $1.44 billion. Historically, we have generated losses principally from costs associated with research and development activities, acquiring, filing and expanding intellectual property rights, and general administrative costs. As a result of planned expenditures for research and development activities relating to our drug development programs, clinical trial and manufacturing costs, the establishment of late-stage clinical and commercial capabilities, including European operations, continued management and growth of our patent portfolio, collaborations and general corporate activities, we expect to incur additional operating losses for the foreseeable future. We also anticipate that our operating results will fluctuate for the foreseeable future. Therefore, period-to-period comparisons should not be relied upon as predictive of the results in future periods.

Although we currently have programs focused on a number of therapeutic areas, we are unable to predict when, if ever, we will successfully develop or be able to commence sales of any product. To date, a substantial portion of our total net revenues has been

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derived from collaboration revenues from strategic alliances with Roche/Arrowhead, Takeda, Cubist, Novartis/Arrowhead, Monsanto, Sanofi Genzyme and MDCO. We expect our sources of potential funding for the next several years to be derived primarily from existing and new strategic alliances, which may include license and other fees, funded research and development and milestone payments, and proceeds from the sale of equity or debt.

In addition, in April 2016, our subsidiary, Alnylam U.S., Inc., entered into an aggregate of $150.0 million of term loan agreements with Bank of America N.A., or BOA, and Wells Fargo Bank, National Association, or Wells, for which we are the guarantor, related to the build out of our new drug substance manufacturing facility, that mature in April 2021. See Note 5 to our condensed consolidated financial statements included in Item 1, “Financial Statements (Unaudited),” of this quarterly report on Form 10-Q for a description of these credit agreements.

Recent Development

Lease Extension

On August 2, 2016, we entered into an amendment to our non-cancelable real property lease agreement, or the BMR-665 Concord Avenue Lease, with BMR-Fresh Pond Research Park LLC for our manufacturing facility for patisiran formulated bulk drug product. Under the BMR-665 Concord Avenue Lease, we lease approximately 15,000 square feet of office and laboratory space located at 665 Concord Avenue, Cambridge, Massachusetts. Pursuant to the amendment, we extended the term, which was set to expire in August 2017, for an additional five years, through August 31, 2022. We have the option to extend the BMR-665 Concord Avenue Lease for one additional five-year period.

Research and Development

Since our inception, we have focused on drug discovery and development programs. Research and development expenses represent a substantial percentage of our total operating expenses. In early 2015, we launched our guidance for the advancement and commercialization of RNAi therapeutics as a whole new class of innovative medicines. Specifically, by the end of 2020, we expect to achieve a company profile with three marketed products and ten RNAi therapeutic clinical programs, including four in late stages of development, across our three STArs: Genetic Medicines; Cardio-Metabolic Diseases; and Hepatic Infectious Diseases.

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The following is a summary of our product development programs in each of our STArs as of July 31, 2016, that identifies those programs in which we have achieved human proof of concept by demonstrating target gene knockdown and/or additional evidence of activity in clinical studies:

During the second quarter of 2016 and recent period, we reported the following updates from our clinical-stage programs:

Genetic Medicine STAr:

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Cardio-Metabolic Disease STAr:

Hepatic Infectious Disease STAr:

There is a risk that any drug discovery or development program may not produce revenue for a variety of reasons, including the possibility that we will not be able to adequately demonstrate the safety and effectiveness of the product candidate. Moreover, there are uncertainties specific to any new field of drug discovery, including RNAi. The successful development of any product candidate we develop is highly uncertain. Due to the numerous risks associated with developing drugs, we cannot reasonably estimate or know the nature, timing and estimated costs of the efforts necessary to complete the development of, or the period, if any, in which material net cash inflows will commence from, any potential product candidate. These risks include the uncertainty of:

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Any failure to complete any stage of the development of any potential products in a timely manner could have a material adverse effect on our operations, financial position and liquidity. A discussion of some of the risks and uncertainties associated with completing our projects on schedule, or at all, and the potential consequences of failing to do so, are set forth in Part II, Item 1A below under the heading “Risk Factors.”

Strategic Alliances

Our business strategy is to develop and commercialize a broad pipeline of RNAi therapeutic products directed towards our three STArs. As part of this strategy, we have entered into, and expect to enter into additional, collaboration and licensing agreements as a means of obtaining resources, capabilities and funding to advance our investigational RNAi therapeutic programs.

Our collaboration strategy is to form alliances that create significant value for ourselves and our collaborators in the advancement of RNAi therapeutics as a new class of innovative medicines. Specifically, with respect to our Genetic Medicine pipeline, we formed a broad strategic alliance with Sanofi Genzyme in 2014 pursuant to which we retain development and commercial rights for our current and future Genetic Medicine products in North America and Western Europe, and Sanofi Genzyme has the right to develop and commercialize our current and future Genetic Medicine products principally in territories outside of North America and Western Europe, subject to certain broader rights. With respect to our Cardio-Metabolic and Hepatic Infectious Disease pipelines, we intend to seek future strategic alliances for these programs, while retaining significant product development and commercialization rights in the United States and European Union, or EU. We currently have a global alliance with MDCO for the development and commercialization of our ALN-PCSsc program.

We also seek to form or advance new ventures and opportunities in areas outside our primary focus on RNAi therapeutics. In 2007, we and Ionis formed Regulus Therapeutics Inc., or Regulus, to capitalize on our technology and intellectual property in the field of microRNA therapeutics. Currently, we own approximately 9% of Regulus’ outstanding common stock.

We have entered into license agreements with Ionis, Max Planck Innovation GmbH (formerly known as Garching Innovation GmbH), or Max Planck Innovation, Cancer Research Technology Limited, or CRT, and Whitehead Institute for Biomedical Research, or Whitehead, as well as a number of other entities, to obtain rights to intellectual property in the field of RNAi. In addition, because delivery of RNAi therapeutics has historically been an important objective of our research activities, we have also evaluated potential collaboration and licensing arrangements with other companies and academic institutions to gain access to delivery technologies. For example, we entered into agreements with Arbutus Biopharma Corporation, or ABC (formerly Tekmira Pharmaceuticals Corporation), Protiva Biotherapeutics, Inc., a wholly owned subsidiary of ABC, and together with ABC, referred to as Arbutus, The University of British Columbia and Acuitas Therapeutics Inc. (formerly AlCana Technologies, Inc.), among others, related to various lipid nanoparticle, or LNP, delivery technologies. Finally, we have sought, and may seek in the future, funding for the development of our proprietary RNAi therapeutics pipeline from the government and foundations.

Intellectual Property

The strength of our intellectual property portfolio relating to the development and commercialization of siRNAs as therapeutics is essential to our business strategy. We own or license issued patents and pending patent applications in the United States and in key markets around the world claiming fundamental features of siRNAs and RNAi therapeutics as well as those claiming crucial chemical modifications and promising delivery technologies. Specifically, we have a portfolio of patents, patent applications and other intellectual property covering: fundamental aspects of the structure and uses of siRNAs, including their use as therapeutics, and RNAi-related mechanisms; chemical modifications to siRNAs that improve their suitability for therapeutic and other uses; siRNAs directed to specific targets as treatments for particular diseases; delivery technologies, such as in the fields of carbohydrate conjugates and cationic liposomes; and all aspects of our specific development candidates.

We believe that no other company possesses a portfolio of such broad and exclusive rights to the patents and patent applications required for the commercialization of RNAi therapeutics. Our intellectual property estate for RNAi therapeutics includes over 2,000 active cases and over 1,100 granted or issued patents, of which over 400 are issued or granted in the United States, the EU, including by the European Patent Office, or EPO, and Japan. We continue to seek to grow our portfolio through the creation of new technology in this field. In addition, we are very active in our evaluation of third-party technologies. To that end, in January 2014, we acquired the RNAi assets of Sirna Therapeutics, Inc., or Sirna, including an extensive patent estate, from Merck Sharp & Dohme Corp., or Merck. The granted patents, applications and know-how obtained through this acquisition further strengthened the breadth and depth of our intellectual property portfolio.

Given the importance of our intellectual property portfolio to our business operations, we intend to vigorously enforce our rights and defend against challenges that have arisen or may arise in this area.

Critical Accounting Policies and Estimates

There have been no significant changes to our critical accounting policies since the beginning of this fiscal year. Our critical accounting policies are described in the “Management’s Discussion and Analysis of Financial Condition and Results of Operations” section of our Annual Report on Form 10-K for the year ended December 31, 2015, which we filed with the SEC on February 12, 2016.

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Results of Operations

The following data summarizes the results of our operations for the periods indicated, in thousands:

Net revenues from collaborators

We generate revenues through research and development collaborations. The following table summarizes our total consolidated net revenues from collaborators, for the periods indicated, in thousands:

Net revenues from collaborators during the three months ended June 30, 2016 were consistent with the three months ended June 30, 2015 and represented increased services performed in connection with our performance obligations under our alliances during the three months ended June 30, 2016, offset by the completion of our revenue amortization under the Takeda agreement in May 2015. Net revenues from collaborators decreased during the six months ended June 30, 2016 as compared to the six months ended June 30, 2015 due primarily to the completion of our performance obligations under the Monsanto agreement in February 2015 and the completion of our revenue amortization under the Takeda agreement in May 2015, partially offset by services performed in connection with our performance obligations under our agreement with Sanofi Genzyme. In addition, net revenues from other collaborators during the six months ended June 30, 2016 as compared to the six months ended June 30, 2015 decreased due to the achievement of certain non-recurring milestones from other sources during the three months ended March 31, 2015. We expect net revenues from collaborators to increase during the second half of 2016 due to an expected increase in expense reimbursement from Sanofi Genzyme. Given the updated timeline with respect to the start of Phase 3 clinical trials for fitusiran, we now expect to receive our next milestone payment from Sanofi Genzyme in 2017.

We had $73.7 million of deferred revenue at June 30, 2016, which consists primarily of payments we have received from collaborators, primarily Sanofi Genzyme, MDCO, Kyowa Hakko Kirin and Monsanto, but have not yet recognized pursuant to our revenue recognition policies.

For the foreseeable future, we expect our revenues to be derived primarily from our alliances with Sanofi Genzyme, MDCO and other strategic alliances, as well as new collaborations and licensing activities.

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Operating expenses

The following tables summarize our operating expenses for the periods indicated, in thousands and as a percentage of total operating expenses, together with the changes, in thousands and percentages:

Research and development. The following tables summarize the components of our research and development expenses for the periods indicated, in thousands and as a percentage of total research and development expenses, together with the changes, in thousands and percentages:

Research and development expenses increased during the three months ended June 30, 2016 as compared to the three months ended June 30, 2015 due primarily to additional compensation and related expenses and non-cash stock-based compensation expenses during the three months ended June 30, 2016 as a result of a significant increase in headcount during the period as we expand and advance our development pipeline. In addition, clinical trial and manufacturing and external services increased during the three months ended June 30, 2016 as compared to the three months ended June 30, 2015 as a result of the significant advancement of our Genetic Medicine pipeline.

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Research and development expenses increased during the six months ended June 30, 2016 as compared to the six months ended June 30, 2015 due primarily to additional compensation and related expenses and non-cash stock-based compensation expenses as a result of a significant increase in headcount during the period as we expand and advance our development pipeline, as well as the vesting of certain performance-based stock option awards during the first quarter of 2016 upon completion of enrollment in our patisiran Phase 3 clinical trial. In addition, clinical trial and manufacturing and external services increased during the six months ended June 30, 2016 as compared to the six months ended June 30, 2015 as a result of the significant advancement of our Genetic Medicine pipeline.

We expect to continue to devote a substantial portion of our resources to research and development expenses, including for the advancement of our Genetic Medicine, Cardio-Metabolic Disease and Hepatic Infectious Disease STArs, to support our goal of three marketed products and ten programs in clinical development, including four late stage programs, by 2020. We expect that research and development expenses during the second half of 2016 will increase compared to the first half of 2016 as we continue to develop our pipeline and advance our product candidates into clinical trials, but that such expenses will be variable on a quarterly basis depending on the timing of manufacturing batches, clinical trial enrollment and results, regulatory review of our product candidates and non-cash stock-based compensation expenses.

A significant portion of our research and development costs are not tracked by project as they benefit multiple projects or our technology platform. However, certain of our collaboration agreements contain cost-sharing arrangements pursuant to which certain costs incurred under the project are reimbursed. Costs reimbursed under the agreements typically include certain direct external costs and a negotiated full-time equivalent labor rate for the actual time worked on the project. As a result, although a significant portion of our research and development expenses are not tracked on a project-by-project basis, we do track direct external costs attributable to, and the actual time our employees worked on, our collaborations.

General and administrative. The following tables summarize the components of our general and administrative expenses for the periods indicated, in thousands and as a percentage of total general and administrative expenses, together with the changes, in thousands and percentages:

General and administrative expenses increased during the three months ended June 30, 2016 as compared to the three months ended June 30, 2015 due primarily to an increase in non-cash stock-based compensation expense resulting from an increase in headcount, partially offset by lower consulting and professional services, primarily legal activities.

General and administrative expenses increased during the six months ended June 30, 2016 as compared to the six months ended June 30, 2015 due primarily to an increase in non-cash stock-based compensation expense resulting from an increase in headcount, as well as the vesting of certain performance-based stock option awards during the first quarter of 2016 upon completion of enrollment in our patisiran Phase 3 clinical trial, partially offset by lower consulting and professional services, primarily legal activities. We expect that general and administrative expenses during the second half of 2016 will remain relatively consistent with the first half of 2016.

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Liquidity and Capital Resources

The following table summarizes our cash flow activities for the periods indicated, in thousands: