ARROWHEAD PHARMACEUTICALS, INC. - Quarter Report: 2008 March (Form 10-Q)

Table of Contents

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 10-Q

(Mark One)

For the quarterly period ended March 31, 2008.

Commission file number 000-21898

ARROWHEAD RESEARCH CORPORATION

(Exact name of registrant as specified in its charter)

201 S. Lake Avenue, Suite 703

Pasadena, California 91101

(626) 304-3400

(Address and telephone number of principal executive offices)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Exchange Act 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 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

The number of shares outstanding of the issuer’s classes of common equity, as of the latest practicable date is 38,765,777 shares of common stock as of May 5, 2008.

Table of Contents

Table of Contents

Arrowhead Research Corporation and Subsidiaries

(A Development Stage Company)

Consolidated Balance Sheets

As of March 31, 2008 and September 30, 2007

(unaudited)

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

1

Table of Contents

Arrowhead Research Corporation and Subsidiaries

(A Development Stage Company)

Consolidated Statements of Operations

(unaudited)

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

2

Table of Contents

Arrowhead Research Corporation and Subsidiaries

(A Development Stage Company)

Consolidated Statement of Stockholders Equity

from inception to March 31, 2008

(unaudited)

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

3

Table of Contents

Arrowhead Research Corporation and Subsidiaries

(A Development Stage Company)

Consolidated Statements of Cash Flows

For the six months ended March 31, 2008 and 2007 and from inception through March 31, 2008

(Unaudited)

SUPPLEMENTAL NON CASH TRANSACTIONS

On March 23, 2005, Arrowhead purchased 7,375,000 shares of Insert Therapeutics, Inc. common stock from two minority stockholders of Insert for 502,260 newly issued shares of Arrowhead Common Stock valued at $2,000,000 based on the closing market price of Arrowhead Common Stock on NASDAQ on the date of the closing.

On March 31, 2006, Arrowhead purchased 964,000 shares of Calando Pharmaceuticals, Inc. common stock from minority stockholders of Calando for $1,928,000 consisting of 208,382 newly issued shares of Arrowhead Common Stock valued at $1,077,333 plus $850,667 in cash. The 208,382 shares of Arrowhead common stock were valued based on the average closing price of Arrowhead’s Common Stock on NASDAQ during the last ten days prior to the date of the closing.

On April 20, 2007, Arrowhead purchased the Series E Preferred Stock of Carbon Nanotechnologies, Inc. in exchange for 1,431,222 shares of Arrowhead Common Stock with an estimated fair market value of $5,400,000.

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

4

Table of Contents

Arrowhead Research Corporation

Notes to Consolidated Financial Statements

March 31, 2008

Unless otherwise noted, (1) the term “Arrowhead Research” refers to Arrowhead Research Corporation, a Delaware corporation, (2) the terms “Arrowhead,” the “Company,” “we,” “us” and “our” refer to the ongoing business operations of Arrowhead and its subsidiaries, whether conducted through Arrowhead Research or a subsidiary of the Company, (3) the term “Common Stock” refers to Arrowhead Research’s Common Stock, (4) the term “Warrant” refers to warrants to purchase Company Common Stock, and (5) the term “stockholder(s)” refers to the holders of Common Stock, Warrants and any other security convertible into Common Stock.

NOTE 1. ORGANIZATION AND SIGNIFICANT ACCOUNTING POLICIES

Nature of Business

Arrowhead is a development stage nanotechnology company commercializing new technologies in the areas of life sciences, electronics and energy. Arrowhead’s mission is to build value through the identification, development and commercialization of nanotechnology-related products and applications. The Company works closely with universities to source early stage deals and to generate rights to intellectual property covering promising new nanotechnologies. Arrowhead takes a portfolio approach by operating multiple subsidiaries (each a “Subsidiary,” and collectively the “Subsidiaries”) which allows the pursuit of multiple opportunities and diversifies risk. Arrowhead operates five majority-owned Subsidiaries commercializing nanotech products and applications, and has funded a number of prototype development efforts in leading university labs in exchange for the right to license the technology developed in such labs.

Arrowhead owns a majority interest in each of its Subsidiaries, securing substantial participation in any success. Each Subsidiary is staffed with its own technical and business team that focuses on its specific technology and markets while Arrowhead provides financial, strategic and administrative resources. The Company’s majority-owned Subsidiaries are commercializing a variety of nanotech products and applications, including anti-cancer drugs, RNAi therapeutics, fullerene-based anti-oxidents, carbon-based electronics and compound semiconductor materials. Arrowhead’s business plan includes adding to its portfolio through selective acquisition and formation of new companies.

In exchange for the right to license the resultant technology developed in sponsored laboratories, Arrowhead sponsors university research. Arrowhead has worked with some of the most highly-regarded academic institutions in the country, including the California Institute of Technology (Caltech), Stanford University, Duke University and the University of Florida, in critical areas such as stem cell research, carbon electronics and molecular diagnostics.

Arrowhead is incorporated in Delaware and its principal executive offices are located in Pasadena, California.

From its inception until the acquisition of Carbon Nanotechnologies, Inc. (“CNI”) in April 2007, neither Arrowhead nor its Subsidiaries derived revenue from product sales. Arrowhead and its Subsidiaries fund research and operations from cash on hand, government grants and license royalties. In April 2007, Arrowhead acquired CNI by CNI’s merger with and into Arrowhead’s consolidated Subsidiary, Unidym, Inc. (“Unidym,” formerly known as NanoPolaris, Inc.) Unidym manufactures carbon nanotubes for the primary purpose of using them in research and development activities and derives revenues from the sale of carbon nanotubes for research and commercial applications.

Summary of Significant Accounting Policies

Basis of Presentation— This report on Form 10-Q for the quarter ended March 31, 2008, should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended September 30, 2007, filed with the SEC on December 14, 2007. The accompanying unaudited consolidated financial statements have been prepared in accordance with generally accepted accounting principles for interim financial statements and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all the information and footnotes required by generally accepted accounting principles for complete financial statements. Certain prior period amounts have been reclassified to conform to the current period’s presentation. In the opinion of management, all normal recurring adjustments considered necessary for a fair presentation have been included. Operating results for the three month and six month periods ended March 31, 2008 are not necessarily indicative of the results that might be expected for the year ending September 30, 2008.

Principles of Consolidation—The consolidated financial statements of the Company include the accounts of Arrowhead and its Subsidiaries Insert Therapeutics, Inc. (“Insert”), Calando Pharmaceuticals, Inc. (“Calando”), Unidym, Tego BioSciences Corporation (“Tego”) and Aonex Technologies, Inc. (“Aonex”). Nanotechnica, Inc. (“Nanotechnica”) is included in the results as Loss from Discontinued Operations. All significant intercompany accounts and transactions are eliminated in consolidation, and minority interests are accounted for in the consolidated statements of operations and the balance sheets.

5

Table of Contents

Use of Estimates—The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in the accompanying financial statements. Significant estimates made in preparing these financial statements include valuing of the stock of the Subsidiaries, assumptions to calculate the value of stock options, stock-based compensation expense, allowance for doubtful accounts, deferred tax asset valuation allowance, patents, minority-interest Common Stock and useful lives for depreciable and amortizable assets. Actual results could differ from those estimates.

Cash and Cash Equivalents—For purposes relating to the statement of cash flows, the Company considers all liquid debt instruments purchased with a maturity of three months or less to be cash equivalents.

Credit Risk—The Company extends credit to its customers in the normal course of business and generally does not require collateral or other security. The Company performs ongoing credit evaluations of its customers’ financial condition and historically has not incurred significant credit losses.

Concentration of Credit Risk—The Company maintains checking accounts for Arrowhead and separate accounts for each Subsidiary at either of two financial institutions. These accounts are insured by the Federal Deposit Insurance Corporation (FDIC) for up to $100,000. The Company has four wealth management accounts at the same financial institution that invest in higher yield money market accounts and in government securities. At March 31, 2008, the Company had uninsured cash deposits totaling $19,758,045. The Company has not experienced any losses in such accounts and management believes it has placed its cash on deposit with financial institutions that are financially stable.

Property and Equipment—Property and equipment are recorded at cost. Depreciation of property and equipment is recorded on the straight-line method over the respective useful lives of the assets ranging from 3 to 7 years. Leasehold improvements are amortized over the initial term of the leases.

Intellectual Property—At March 31, 2008, intellectual property consisted of patents and patent applications licensed or purchased in the gross amount of $570,983. A portion of the consideration paid for Insert has been allocated to the patents held by Insert. The Insert patents, in the gross amount of $3,301,190, are being amortized over the life of these patents. The accumulated amortization of patents totaled $1,141,642 at March 31, 2008. Patents are being amortized over 3 years to 20 years unless a patent is determined to have no foreseeable commercial value and is written down to $1. The weighted average original amortization period is 13 years. The weighted average remaining amortization period is 11 years.

Revenue Recognition—Revenue from product sales is recognized when the related goods are shipped and all significant obligations of the Company have been satisfied. The Company recognizes license fee revenue on a straight-line basis over the term of the license. Development fees, milestone fees, collaboration fees and grant revenues are recognized upon the completion and payment of services or achievement of the mutually agreed milestones.

The Company generated revenues of $729,766 and a reversal of $(3,697) for the three months ended March 31, 2008 and 2007, respectively and revenues of $1,132,627 and $7,394 for the six months ended March 31, 2008 and 2007, respectively. The revenue for the three months ended March 31, 2008 consists of $557,471 from grants to fund research for the development of carbon nanotube applications, $158,795 from the sale and delivery of carbon nanotubes to third parties, $8,500 for shipping charges and $5,000 for services performed at Aonex. The revenue for the first six months of fiscal 2008 consists of $748,487 from grants to fund research for the development of carbon nanotube applications, $362,740 from the sale and delivery of carbon nanotubes to third parties and $16,400 for shipping charges and $5,000 for services performed at Aonex. The $7,394 of revenue in the prior year’s six months resulted from a National Institute of Health grant at Calando.

Cost of Goods Sold—The Company includes direct materials, production labor and direct plant production cost (excluding depreciation) in cost of goods sold.

Research and Development—Costs and expenses that can be identified as research and development are charged to expense as incurred in accordance with Financial Accounting Standards Board (“FASB”) statement No. 2, “Accounting for Research and Development Costs”.

Earnings (Loss) per Share—Basic earnings (loss) per share is computed using the weighted-average number of common shares outstanding during the period. Diluted earnings (loss) per share are computed using the weighted-average number of common shares and dilutive potential common shares outstanding during the period. Dilutive potential common shares primarily consist of stock options issued to employees and consultants and warrants of the Company.

Recently Issued Accounting Standards—Management does not believe that any recently issued, but not yet effective, accounting standards, if currently adopted, would have a material effect on the accompanying financial statements.

6

Table of Contents

NOTE 2. BASIS OF CONSOLIDATION

The consolidated financial statements for the three month and six month periods ended March 31, 2008 and 2007, respectively, include the accounts of Arrowhead and its Subsidiaries Insert, Calando, Unidym, Tego and Aonex. All significant intercompany accounts and transactions are eliminated in consolidation and minority interests were accounted for in the consolidated statements of operations and the balance sheets.

NOTE 3. ALLOWANCE FOR DOUBTFUL ACCOUNTS

The Company accrues an allowance for doubtful accounts based on estimates of uncollectible revenues by analyzing historical collections, accounts receivable aging and other factors. Accounts receivable are written off when all collection attempts have failed. The allowance for doubtful accounts applicable to Unidym as of March 31, 2008 was $46,031.

NOTE 4. INVESTMENT IN SUBSIDIARIES

Insert Therapeutics, Inc.

On June 4, 2004, Arrowhead purchased 24,496,553 shares of Series B Preferred Stock, representing a 62% controlling interest of Insert, a Subsidiary based in Pasadena, California, for $1,000,000. Arrowhead also agreed to pay an additional $4,000,000 in consideration contingent upon the attainment of certain milestones in the development of Insert’s business. Since its initial investment of $1,000,000 on June 4, 2004, Arrowhead has provided $9,150,000 of additional capital to Insert, including $4,000,000 of contingent consideration.

Developing new drugs for market is a long process expected to last for years. At the time of Arrowhead’s initial purchase of Insert securities in June 2004, Insert was in the process of developing unique intravenous drug delivery technologies for cancer therapeutics. The delivery system enables Insert to develop its own pharmaceutical products and provide customized drug delivery solutions for others. In addition to intravenous use, the delivery system may also be effective for use in tablets, topical ointments and inhalants. At the time of purchase, the primary assets of Insert were 14 patents and/or patent applications filed with the United States Patent and Trademark Office, as well as foreign counterparts in Europe, Japan and other countries. Insert’s initial patent was issued in January 2003 for a linear cyclodextrin copolymer drug delivery technology. Two additional US patents have since been issued covering the compositions of matter, methods of use, manufacturing and purification processes and routes of delivery. The initial payment of $1,000,000, the additional contingent consideration of $4,000,000 and the purchase of shares from the minority shareholders for $2,000,000 in March 2005 have been accounted for under Statement of Financial Accounting Standards (“SFAS”) 141. In accordance with paragraphs 26 and 27 of SFAS 141, the $4,000,000 of contingent consideration was accounted for as an additional cost of the acquired entity. The purchase price was allocated to the assets acquired and liabilities assumed based on their estimated fair values. The primary assets acquired are patents, which have alternative use.

On March 23, 2005, Arrowhead purchased 7,375,000 shares of Insert common stock from two minority stockholders of Insert for 502,260 newly issued shares of Arrowhead Common Stock. The additional investment increased Arrowhead’s net ownership of Insert by approximately 7%, from approximately 62% to approximately 69% of Insert’s outstanding voting securities. The Arrowhead Common Stock issued in the transaction was valued at $2,000,000 based on the closing market price of Arrowhead Common Stock on the NASDAQ Capital Market on the date of the purchase. The additional consideration paid for the 7,375,000 common shares was allocated among the assets of Insert, primarily patents.

On March 29, 2005, Arrowhead exchanged 4,000,000 shares of the Series B Preferred Stock of Insert for 4,000,000 shares of Series C Preferred Stock of Insert.

On March 31, 2005, Arrowhead sold 2,640,000 shares of its Insert Series C Preferred Stock to qualified investors for $1.00 per share. Net proceeds of the sale were $2,424,924. Arrowhead recognized a gain of $2,292,800 on the sale.

In October 2006, Insert completed a $10.3 million private placement to qualified investors, including a $5.15 million follow-on investment by Arrowhead. The private placement sold 10,341,681 units at $1.00 per unit, each unit consisting of a share of Series C-2 Preferred Stock and 40% warrant coverage to purchase shares of Series D Preferred Stock at an exercise price of $1.25 per share. The warrants became callable by Insert after July 1, 2007. Arrowhead owned 68.3% of the outstanding voting stock prior to the transaction and 64.5% immediately thereafter.

The $10.3 million raised by Insert in October 2006 resulted in a change in Arrowhead’s proportionate share of Insert’s equity value. In accordance with Staff Accounting Bulletins Topic 5.H, Arrowhead’s proportionate share of Insert’s equity value was recorded in consolidation as an equity transaction, increasing additional paid-in capital by $2,401,394. On October 27, 2006, Insert repaid Arrowhead $2,500,000 of working-capital loans and $42,501 of interest incurred while the loans were outstanding.

As of March 31, 2008, Arrowhead had loans outstanding to Insert totaling $1,600,000, payable upon demand. Each loan bears simple interest at 6%. Arrowhead owned 64.2% of the outstanding, voting securities of Insert or 57% on a fully diluted basis as of March 31, 2008.

7

Table of Contents

On April 17, 2008, Insert merged with Arrowhead subsidiary Calando Pharmaceuticals, Inc. Please refer to Note 12 Subsequent Events.

Calando Pharmaceuticals, Inc.

On February 22, 2005, Arrowhead purchased 4,000,000 shares of common stock in a newly-formed entity, Calando, for $250,000 cash and entered into a contribution agreement to provide up to $3,750,000 of additional capital over time. In exchange for 480,000 shares of common stock, royalty and license fees, Insert granted to Calando a license agreement, pursuant to which Calando has exclusive rights to Insert’s technology for the delivery and therapeutic use of RNAi in Calando’s research, development and business efforts. Arrowhead has provided a total of $8,000,000 in capital to Calando consisting of the original $4,000,000 investment, $3,000,000 paid for Series A Preferred Stock of Calando and $1,000,000 under the terms of the March 31, 2006 agreement to provide additional capital.

On March 31, 2006, Arrowhead purchased 5,000,000 newly issued shares of Calando’s Series A Preferred Stock for $3,000,000 from Calando and purchased 964,000 shares of common stock for $2.00 per share from minority stockholders. The $1,928,000 payment for the purchase of Calando common stock from selling stockholders consisted of $850,667 in cash and 208,382 shares of Arrowhead Common Stock with an estimated value of $1,077,333 or $5.17 per share based on the average closing price of Arrowhead’s Common Stock during the last ten trading days immediately preceding the transaction closing.

On March 31, 2006, Arrowhead entered into an agreement with Calando to provide up to $7,000,000 of additional capital to Calando subject to the attainment of certain milestones in its preclinical testing, clinical testing and related approval processes. Arrowhead had provided $1,000,000 to Calando pursuant to this agreement. Should Arrowhead elect not to make any additional capital contributions, the conversion ratio of Calando’s Series A Preferred Stock to common stock would be adjusted to a conversion ratio from 1 to 1 (Series A Preferred to common stock) to approximately 2.5 to 1.

On August 14, 2006, Arrowhead purchased 240,000 shares of Calando common stock from a minority stockholder for an aggregate purchase price of $480,000 or $2.00 per share.

In October 2006, two of Calando’s founders exercised warrants for Calando common stock reducing Arrowhead’s combined direct and indirect ownership from 85.1% to approximately 69.8% of the outstanding voting securities of Calando, or 63.9% of Calando’s outstanding securities on a fully diluted basis.

As of March 31, 2008, Arrowhead had loans outstanding to Calando totaling $4,450,000, payable on demand. Each loan bears simple interest at 6%. Arrowhead owned 69.8% of the outstanding, voting securities of Calando, or 63.9% on a fully diluted basis as of March 31, 2008.

On April 17, 2008, Calando merged with Arrowhead subsidiary Insert Therapeutics, Inc. Please refer to Note 12 Subsequent Events for additional detail regarding the merger of Insert and Calando.

Unidym, Inc. (formerly NanoPolaris, Inc.)

On April 4, 2005, Arrowhead founded NanoPolaris, Inc. (“NanoPolaris”) as a wholly-owned subsidiary of Arrowhead. NanoPolaris was initially capitalized with $1,000.

On June 13, 2006, NanoPolaris acquired substantially all of the net assets and the name “Unidym” from Unidym’s founding scientist. Unidym develops carbon nanotube-based electronics. The net assets acquired included Unidym’s intellectual property, prototypes and equipment, for a purchase price consisting of $25,000 in cash, the assumption of $75,000 of liabilities and shares of NanoPolaris common stock, with an estimated value of $154,350. At the time of the purchase, the shares issued for the purchase represented 11.9% (10% on a fully diluted basis) of NanoPolaris’ outstanding voting stock. Concurrently with the purchase, Arrowhead agreed to provide up to $4,000,000 in additional capital contributions over the next two years. In August 2006, NanoPolaris changed its name to Unidym, Inc.

On April 20, 2007, a wholly owned subsidiary of Unidym merged with CNI, a Texas-based company involved in the development, manufacture and marketing of carbon nanotubes (the “Merger”). The combined company operates under the Unidym name, has an expansive portfolio of carbon nanotube-related patents and is one of the largest manufacturers of carbon nanotubes in the world.

In connection with the Merger, Arrowhead agreed to accelerate the $4,000,000 capital contribution to Unidym and made payment on April 23, 2007. In aggregate consideration for the acceleration of the additional capital to Unidym and the transfer from Arrowhead to Unidym of rights and obligations under two sponsored research agreements, Unidym issued 448,000 shares of Unidym common stock to Arrowhead.

Prior to the Merger, certain shareholders of CNI assumed all of CNI’s outstanding debt, a total of $5,400,000, in exchange for 1,080,000 shares of Series E Preferred Stock of CNI. On the date of the Merger, Arrowhead purchased the Series E Preferred

8

Table of Contents

Stock in exchange for 1,431,222 shares of Arrowhead Common Stock with an estimated fair market value of $5,400,000. The CNI Series E Preferred Stock was exchanged in the merger for 2,784,252 shares of newly authorized Unidym Series B Preferred Stock. The 2,889,000 shares of Unidym Series A Preferred Stock owned by Arrowhead were exchanged for 2,889,000 shares of Unidym Series B Preferred Stock.

In exchange for all the outstanding shares of CNI common stock, Unidym issued 5,000,000 shares of newly authorized Unidym Series A Convertible Preferred Stock with an estimated total value of $4,200,000. The Series A Preferred Stock is convertible into 8,400,482 shares of Unidym common stock under certain conditions. Unidym also assumed CNI’s 2007 Restricted Stock Unit Plan subject to which 1,104,010 shares and a warrant for 64,000 shares of Unidym common stock is issuable on the later of March 31, 2008, or an initial public offering by Unidym.

The consolidated statement of operations includes the results of the merged companies since April 21, 2007.

Prior to the Merger, Arrowhead owned 88.1% of the outstanding voting securities of Unidym. Immediately following the Merger, Arrowhead’s ownership of the outstanding voting securities was 60.1%. If all options were awarded and exercised, all common stock subject to restricted stock units was issued and all preferred stock was converted, Arrowhead’s interest would be 42.1% immediately following the Merger.

In December 2007, Unidym completed a private financing with strategic and financial investors, pursuant to which Unidym issued and sold an aggregate of 5,764,778 shares of its Series C Preferred Stock for $1.80 per share. The private placement generated net cash proceeds of $10,013,897, including $3,000,000 invested by Arrowhead.

Immediately following the private financing, Arrowhead’s ownership of the outstanding, voting securities was 51.2%. If at that point in time all options were awarded and exercised, all common stock subject to restricted stock units was issued and all preferred stock was converted, Arrowhead’s interest would be 39.2%. The ownership interest remained the same at March 31, 2008.

On March 13, 2008, the Unidym’s wholly owned subsidiary, Unidym Acquisition LLC that merged with CNI was itself merged into Unidym and ceased to exist.

In addition to other licensing agreements on March 14, 2008, Unidym sub-licensed certain of its intellectual property to Ensysce BioSciences Inc. (“Ensysce’) that will focus on research into the medical therapeutic applications of carbon nanotubes. Ensysce is both funded and effectively controlled by a related party to Unidym who also serves as a director of Unidym.

Terms of the licensing arrangement between Unidym and Ensysce include a $25,000 up-front sub-licensing fee, ongoing royalties, and an initial 50% equity position for Unidym in Ensysce. Unidym also provides contract services to Ensysce, including supplies of research grade nanotubes, back-office and accounting support. Ensysce is accounted for on the equity basis.

Aonex Technologies, Inc.

On April 20, 2004, Arrowhead acquired 1,000,000 shares of Series A Preferred stock in a newly-formed entity, Aonex, for $2,000,000. The 1,000,000 shares of Series A Preferred stock represent 80% of the outstanding voting shares of Aonex. To date, Arrowhead has provided $3,000,000 of additional capital to Aonex.

As of March 31, 2008, Arrowhead had loans outstanding to Aonex totaling $975,000, payable upon demand. Each loan bears simple interest at 6%. As of March 31, 2008, Arrowhead owned 80.0% of the outstanding voting securities of Aonex or 50% on a fully diluted basis.

On May 6, 2008, Aonex merged with a wholly owned subsidiary of AmberWave Systems Corporation and Arrowhead’s loan to Aonex were converted to equity. Please refer to Note 12 Subsequent Events.

Tego BioSciences Corporation

On April 20, 2007, Tego, a newly formed, wholly-owned Subsidiary of Arrowhead, acquired the assets of C Sixty, Inc., a Texas-based company developing pharmaceuticals based on the unique biochemical properties of modified fullerenes, for $1,000. On July 3, 2007, Arrowhead capitalized Tego with a purchase of 5,000,000 shares of Tego Series A Preferred Stock for $100,000. The Company is evaluating opportunities for Tego’s technology.

On October 25, 2007, Arrowhead provided $2.4 million in additional capital to Tego, in exchange for 15 million shares of Series A-2 Preferred Stock. The $2.4 million is to be used for developing and commercializing pharmaceuticals based on modified fullerenes. Arrowhead owns 100% of the outstanding voting securities of Tego and 93% of the outstanding voting securities on a fully diluted basis.

NOTE 5. STOCKHOLDERS’ EQUITY

The Company had a total of 75,000,000 authorized shares at March 31, 2008, consisting of 70,000,000 authorized shares of Common Stock, par value $0.001, and 5,000,000 shares of authorized Preferred Stock.

9

Table of Contents

At March 31, 2008, 38,765,777 shares of Common Stock were outstanding. At March 31, 2008, 1,559,000 shares and 4,738,310 shares were reserved for issuance upon exercise of options granted under Arrowhead’s 2000 Stock Option Plan and 2004 Equity Incentive Plan, respectively. On December 3, 2007, an inducement grant of options to purchase 2,000,000 shares of Common Stock was made outside of Arrowhead’s equity incentive plans to the Company’s newly hired CEO. Arrowhead’s Compensation Committee is negotiating the final terms of this grant to be memorialized in a Stock Option Agreement. Through March 31, 2008, options to purchase 1,559,000 shares were outstanding under the 2000 Stock Option Plan and options to purchase 3,909,370 shares were outstanding under the 2004 Equity Incentive Plan.

On January 24, 2006, the Company completed a private placement of 5,590,000 shares of restricted Common Stock at $3.50 per share that generated $19.6 million in total proceeds. The purchasers received warrants, exercisable after July 25, 2006, to purchase an additional 1,397,500 shares of restricted Common Stock at $5.04 per share. The warrants may be called by the Company any time after July 25, 2006, if the closing price of the Company’s Common Stock is $6.50 or above for the previous 30 trading days.

On May 29, 2007, the Company completed a private placement of 2,849,466 shares of restricted Common Stock at $5.78 per share that generated $15.2 million in net proceeds. The purchasers received warrants to purchase an additional 712,362 shares of Common Stock at $7.06 per share. The warrants may be called by the Company any time after May 29, 2008, if the closing price of the Company’s Common Stock is $8.47 or above for the previous 20 trading days.

The following table summarizes information about warrants outstanding at March 31, 2008:

On January 30, 2008, Arrowhead’s Form S-3 Registration Statement, originally filed on December 20, 2007, was declared effective. The prospectus allows Arrowhead to issue, from time to time in one or more offerings, shares of Common Stock and warrants to purchase common stock for an aggregate dollar amount of up to $50 million.

It is the Company’s intent to use the net proceeds from the sale of the securities and received upon exercise of the warrants for general corporate purposes, which may include one or more of the following: working capital, research and clinical development activities, potential future acquisitions of companies and/or technologies, and capital expenditures.

NOTE 6. LEASES

The Company leases the following facilities:

The Company has no plans to own any real estate and expects that all facility leases will be operating leases.

10

Table of Contents

At March 31, 2008, the future minimum commitments remaining under leases were as follows:

Facility and equipment rent expense for the three months ended March 31, 2008 and 2007 was $272,272 and $232,999 respectively. Facility and equipment rent expense for the six months ended March 31, 2008 and 2007 was $555,784 and $420,089 respectively. From inception to date, rent expense has totaled $2,772,469.

NOTE 7. COMMITMENTS AND CONTINGENCIES—SUBSIDIARIES AND SPONSORED RESEARCH

Subsidiaries

As of March 31, 2008, Arrowhead held a majority interest of each of the following five operating Subsidiaries:

Arrowhead has entered into two separate funding agreements to provide future additional capital to Calando. One is fully funded and terminated. At March 31, 2008, there existed an agreement giving Arrowhead the right to provide additional capital to Calando or to forfeit a specified portion of its interest in lieu of additional future funding. On April 17, 2008 Calando merged with Insert Therapeutics See Note 12 Subsequent Events.

In deciding whether to make an additional capital contribution, the Company looks at such factors as progress toward a milestone and the spending plan. Because the Company works closely with the senior management of each Subsidiary, the decision regarding funding milestones is made well in advance of the milestone date or event. Should Calando meet its milestones and the Company decides not to fund further, the Company would still own a majority of the outstanding voting securities of Calando.

The following table summarizes the terms and status of these additional capital contributions as of March 31, 2008:

11

Table of Contents

With the merger of Insert and Calando, approved by the stockholders of Insert and Calando and effectuated on April 17, 2008, the Calando Agreement to Provide Additional Capital between Calando and the Company, entered into in March 2006, was amended and terminated to accelerate the payment of the remaining $6,000,000 against receipt of the repayment in principal on loans extended by the Company to either Insert or Calando. The combined principal and interest on all loans extended by the Company to either Insert or Calando totaled $6,187,663 as of April 17, 2008.

Sponsored Research

By funding university research, Arrowhead has the opportunity to ascertain the technical success at low research cost and, if warranted, continue cost effective development at the university by leveraging the already existing resources available to scientists at universities, such as laboratories and equipment and a culture that encourages the exchange of ideas. Moreover, the cultivation of relationships in the academic community provides an additional window into other promising technologies. The Company normally obtains the exclusive license to the technology developed by the research it sponsors. If such technology has commercial potential, the Company can form a majority-owned subsidiary to develop the technology and provide stock in the subsidiary to the scientist and the university, in order to give them an economic interest in the success of the subsidiary. Should the related technology prove to be too difficult or too expensive to commercialize, Arrowhead may terminate the license agreement and return the licensed intellectual property to the university.