Vertex Pharmaceuticals Incorporated

Condensed Consolidated Balance Sheets

(unaudited)

(in thousands, except share and per share amounts)

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

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

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

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements

(unaudited)

A. Basis of Presentation and Accounting Policies

Basis of Presentation

        The accompanying condensed consolidated financial statements are unaudited and have been prepared by Vertex Pharmaceuticals Incorporated ("Vertex" or the "Company") in accordance with accounting principles generally accepted in the United States of America ("GAAP").

        The condensed consolidated financial statements reflect the operations of (i) the Company, (ii) its wholly-owned subsidiaries and (iii) Alios BioPharma, Inc. ("Alios"), a collaborator that is a variable interest entity (a "VIE") for which the Company is deemed under applicable accounting guidance to be the primary beneficiary. All material intercompany balances and transactions have been eliminated. The Company operates in one segment, pharmaceuticals.

        Certain information and footnote disclosures normally included in the Company's annual financial statements have been condensed or omitted. These interim financial statements, in the opinion of management, reflect all normal recurring adjustments (including accruals) necessary for a fair presentation of the financial position and results of operations for the interim periods ended June 30, 2012 and 2011.

        The results of operations for the interim periods are not necessarily indicative of the results of operations to be expected for the full fiscal year. These interim financial statements should be read in conjunction with the audited financial statements for the year ended December 31, 2011, which are contained in the Company's Annual Report on Form 10-K for the year ended December 31, 2011 that was filed with the Securities and Exchange Commission (the "SEC") on February 22, 2012 (the "2011 Annual Report on Form 10-K").

Use of Estimates and Summary of Significant Accounting Policies

        The preparation of condensed consolidated financial statements in accordance with GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements, and the amounts of revenues and expenses during the reported periods. Significant estimates in these condensed consolidated financial statements have been made in connection with the calculation of revenues, inventories, research and development expenses, stock-based compensation expense, restructuring expense, the fair value of intangible assets, noncontrolling interest (Alios), income tax provision, derivative instruments and debt securities. The Company bases its estimates on historical experience and various other assumptions, including in certain circumstances future projections, that management believes to be reasonable under the circumstances. Actual results could differ from those estimates. Changes in estimates are reflected in reported results in the period in which they become known.

        The Company's significant accounting policies are described in Note A, "Nature of Business and Accounting Policies," in the 2011 Annual Report on Form 10-K.

Recent Accounting Pronouncements

        For a discussion of recent accounting pronouncements please refer to Note A, "Nature of Business and Accounting Policies—Recent Accounting Pronouncements," in the 2011 Annual Report on

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements (Continued)

(unaudited)

A. Basis of Presentation and Accounting Policies (Continued)

Form 10-K, as supplemented below. The Company did not adopt any new accounting pronouncements during the six months ended June 30, 2012 that had a material effect on the Company's condensed consolidated financial statements.

        In the first quarter of 2012, the Company retrospectively adopted amended guidance issued in June 2011 by the Financial Accounting Standards Board ("FASB") that resulted in two separate, but consecutive, statements of operations and comprehensive income (loss) that affected the presentation of the Company's condensed consolidated financial statements.

        In July 2012, the FASB issued amended guidance applicable to annual impairment tests of indefinite-lived intangible assets. The FASB added an optional qualitative assessment for determining whether an indefinite-lived intangible asset is impaired. Prior to this guidance, companies were required to perform an annual impairment test that included a calculation of the fair value of the asset and a comparison of that fair value with its carrying value. If the carrying value exceeded the fair value, an impairment was recorded. The amended guidance allows a company the option to perform a qualitative assessment, considering both negative and positive evidence, regarding the potential impairment of the indefinite-lived intangible asset. If, based on the qualitative analysis, the company determines that it is more likely than not that the fair value of such an asset exceeds its carrying value, the company would be permitted to conclude that the indefinite-lived intangible asset was not impaired without a quantitative calculation of the fair value of the asset. Otherwise, the company would perform the quantitative calculation of the fair value and the comparison with the carrying value. This amended guidance will be effective for annual impairment tests performed by the Company for fiscal years beginning on January 1, 2013 and early adoption is permitted.

B. Product Revenues, Net

        The Company sells its products principally to a limited number of major wholesalers, as well as selected regional wholesalers and specialty pharmacy providers (collectively, its "Distributors"), that subsequently resell the products to patients and health care providers. The Company recognizes net revenues from product sales upon delivery as long as (i) there is persuasive evidence that an arrangement exists between the Company and the Distributor, (ii) collectibility is reasonably assured and (iii) the price is fixed or determinable.

        The Company has written contracts with its Distributors and delivery occurs when a shipment of a product is received. The Company evaluates the creditworthiness of each of its Distributors to determine whether revenues can be recognized upon delivery, subject to satisfaction of the other requirements, or whether recognition is required to be delayed until receipt of payment. In order to conclude that the price is fixed or determinable, the Company must be able to (i) calculate its gross product revenues from sales to Distributors and (ii) reasonably estimate its net product revenues. The Company calculates gross product revenues based on the wholesale acquisition cost that the Company charges its Distributors. The Company estimates its net product revenues by deducting from its gross product revenues (a) trade allowances, such as invoice discounts for prompt payment and distributor fees, (b) estimated government and private payor rebates, chargebacks and discounts, such as Medicaid reimbursements, (c) reserves for expected product returns and (d) estimated costs of incentives offered to certain indirect customers, including patients.

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements (Continued)

(unaudited)

B. Product Revenues, Net (Continued)

         Trade Allowances:     The Company generally provides invoice discounts on product sales to its Distributors for prompt payment and pays fees for distribution services, such as fees for certain data that Distributors provide to the Company. The payment terms for sales to Distributors generally include a 2% discount for payment within 30 days. The Company expects that, based on its experience, its Distributors will earn these discounts and fees, and deducts the full amount of these discounts and fees from its gross product revenues and accounts receivable at the time such revenues are recognized.

         Rebates, Chargebacks and Discounts:     The Company contracts with Medicaid, other government agencies and various private organizations (collectively, its "Third-party Payors") so that products will be eligible for purchase by, or partial or full reimbursement from, such Third-party Payors. The Company estimates the rebates, chargebacks and discounts it will provide to Third-party Payors and deducts these estimated amounts from its gross product revenues at the time the revenues are recognized. For each product, the Company estimates the aggregate rebates, chargebacks and discounts that it will provide to Third-party Payors based upon (i) the Company's contracts with these Third-party Payors, (ii) the government-mandated discounts applicable to government-funded programs and (iii) information obtained from the Company's Distributors and other third parties regarding the payor mix for such product.

         Product Returns:     The Company estimates the amount of each product that will be returned and deducts these estimated amounts from its gross revenues at the time the revenues are recognized. The Company's Distributors have the right to return unopened unprescribed packages beginning six months prior to the labeled expiration date and ending twelve months after the labeled expiration date. Based on the inventory levels held by its Distributors and its distribution model, the Company believes that returns of its products will be minimal.

         Other Incentives:     Other incentives that the Company offers to indirect customers include co-pay mitigation rebates provided by the Company to commercially insured patients who have coverage and who reside in states that permit co-pay mitigation programs. The Company's co-pay mitigation program is intended to reduce each participating patient's portion of the financial responsibility for a product's purchase price to a specified dollar amount. Based upon the terms of the Company's co-pay mitigation programs, the Company estimates average co-pay mitigation amounts for each of its products in order to establish its accruals for co-pay mitigation rebates and deducts these estimated amounts from its gross product revenues at the later of the date (i) the revenues are recognized or (ii) the incentive is offered. The Company's co-pay mitigation rebates are subject to expiration.

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C. Collaborative Arrangements

Janssen Pharmaceutica, N.V.

        In 2006, the Company entered into a collaboration agreement with Janssen Pharmaceutica, N.V. ("Janssen") for the development, manufacture and commercialization of telaprevir, which Janssen began marketing under the brand name INCIVO™ in certain of its territories in September 2011. Under the collaboration agreement, Janssen agreed to be responsible for 50% of the drug development costs incurred under the development program for the parties' territories (North America for the Company, and the rest of the world, other than certain countries in Asia, for Janssen) and has exclusive rights to commercialize telaprevir in its territories including Europe, South America, the Middle East, Africa and Australia.

        Janssen pays the Company a tiered royalty averaging in the mid-20% range as a percentage of net sales of INCIVO in Janssen's territories. Janssen is required under the agreement to use diligent efforts to maximize net sales of INCIVO in its territories through its commercial marketing, pricing and contracting strategies. In addition, Janssen is responsible for certain third-party royalties on net sales of INCIVO in its territories.

        Janssen made a $165.0 million up-front license payment to the Company in 2006. The up-front license payment is being amortized over the Company's estimated period of performance under the collaboration agreement. As of June 30, 2012, there were $49.7 million in deferred revenues related to this up-front license payment that the Company expects to recognize over the remaining estimated period of performance.

        Under the collaboration agreement, Janssen agreed to make contingent milestone payments for successful development, approval and launch of telaprevir as a product in its territories. At the inception of the agreement, the Company determined that all of these contingent milestones were substantive and would result in revenues in the period in which the milestone was achieved. The Company has earned $350.0 million of these contingent milestone payments, including a $50.0 million milestone payment earned in the first quarter of 2011 in connection with the European Medicines Agency's acceptance of the marketing authorization application for INCIVO. The Company does not expect to receive any further milestone payments under this agreement.

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements (Continued)

(unaudited)

C. Collaborative Arrangements (Continued)

        Under the Janssen collaboration agreement, each party incurs internal and external reimbursable expenses related to the telaprevir development program and is reimbursed by the other party for 50% of these expenses. The Company recognizes the full amount of the reimbursable costs it incurs as research and development expenses on its condensed consolidated statements of operations. The Company recognizes the amounts that Janssen is obligated to pay the Company with respect to reimbursable expenses, net of reimbursable expenses incurred by Janssen, as collaborative revenues. In the three and six months ended June 30, 2012 and 2011, Janssen incurred more reimbursable costs than the Company, and the net amounts payable by the Company to reimburse Janssen were recorded as a reduction of collaborative revenues.

        Each of the parties is responsible for drug supply in its territories. In the three and six months ended June 30, 2011 and the three months ended March 31, 2012, the Company provided Janssen certain services through the Company's third-party manufacturing network for telaprevir. Reimbursements from Janssen for these manufacturing services were recorded as collaborative revenues.

        Janssen may terminate the collaboration agreement upon the later of (i) one year's advance notice and (ii) such period as may be required to assign and transfer to the Company specified filings and approvals. The agreement also may be terminated by either party for a material breach by the other, subject to notice and cure provisions. Unless earlier terminated, the agreement will continue in effect until the expiration of Janssen's royalty obligations, which expire on a country-by-country basis with the last-to-expire patent covering telaprevir. In the European Union, the Company has a patent covering the composition-of-matter of telaprevir that expires in 2021 and expects to obtain extensions to the term of this patent through 2026.

        During the three and six months ended June 30, 2012 and 2011, the Company recognized the following revenues attributable to the Janssen collaboration:

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements (Continued)

(unaudited)

C. Collaborative Arrangements (Continued)

Mitsubishi Tanabe Pharma Corporation

        The Company has a collaboration agreement (the "MTPC Agreement") with Mitsubishi Tanabe Pharma Corporation ("Mitsubishi Tanabe") pursuant to which Mitsubishi Tanabe has a fully-paid license to manufacture and commercialize TELAVIC™ (the brand name under which Mitsubishi Tanabe is marketing telaprevir) in Japan and other specified countries in Asia. In September 2011, Mitsubishi Tanabe obtained approval to market TELAVIC in Japan.

        The parties entered into the MTPC Agreement in 2004 and amended it in 2009. Pursuant to the MTPC Agreement, Mitsubishi Tanabe provided financial and other support for the development and commercialization of telaprevir, made a $105.0 million payment in connection with the 2009 amendment of the collaboration agreement and made a $65.0 million commercial milestone payment in the fourth quarter of 2011 related to the commercialization of TELAVIC in Japan. There are no further milestone payments under this collaboration agreement. Mitsubishi Tanabe is responsible for its own development and manufacturing costs in its territory.

        Mitsubishi Tanabe may terminate the MTPC Agreement at any time without cause upon 60 days' prior written notice to the Company. The MTPC Agreement also may be terminated by either party for a material breach by the other, subject to notice and cure provisions. Unless earlier terminated, the MTPC Agreement will continue in effect until the expiration of the last-to-expire patent covering telaprevir in Mitsubishi Tanabe's territories. In Japan, the Company has a patent covering the composition-of-matter of telaprevir that expires in 2021.

        The $105.0 million payment that the Company received in the third quarter of 2009 in connection with the amendment is a nonrefundable, up-front license fee, and revenues related to the 2009 payment were recognized on a straight-line basis over the period of performance of the Company's obligations under the amended agreement. In connection with the amendment to the MTPC Agreement, the Company supplied manufacturing services to Mitsubishi Tanabe, until April 2012, through the Company's third-party manufacturing network for telaprevir. The final $3.2 million in deferred revenues related to the 2009 up-front license payment was recognized in April 2012.

        During the three and six months ended June 30, 2012 and 2011, the Company recognized the following collaborative revenues attributable to the Mitsubishi Tanabe collaboration:

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements (Continued)

(unaudited)

C. Collaborative Arrangements (Continued)

Cystic Fibrosis Foundation Therapeutics Incorporated

        In April 2011, the Company entered into an amendment (the "April 2011 Amendment") to its existing collaboration agreement with Cystic Fibrosis Foundation Therapeutics Incorporated ("CFFT") pursuant to which CFFT agreed to provide financial support for (i) development activities for VX-661, a corrector compound discovered under the collaboration, and (ii) additional research and development activities directed at discovering new corrector compounds.

        The Company entered into the original collaboration agreement with CFFT in 2004 and amended it several times to, among other things, provide partial funding for its cystic fibrosis drug discovery and development efforts. In 2006, the Company received a $1.5 million milestone payment from CFFT. There are no additional milestones payable by CFFT to the Company pursuant to the collaboration agreement, as amended. Under the April 2011 Amendment, CFFT agreed to provide the Company with up to $75.0 million in funding over approximately five years for corrector-compound research and development activities. The Company retains the right to develop and commercialize KALYDECO™ (ivacaftor), VX-809, VX-661 and any other compounds discovered during the course of the research collaboration with CFFT. The Company recognized collaborative revenues from this collaboration of $4.5 million and $8.5 million, respectively, during the three and six months ended June 30, 2012 and $5.9 million during both the three and six months ended June 30, 2011.

        In the original agreement, as amended prior to the April 2011 Amendment, the Company agreed to pay CFFT tiered royalties calculated as a percentage, ranging from single digits to sub-teens, of annual net sales of any approved drugs discovered during the research term that ended in 2008, including KALYDECO, VX-809 and VX-661. The April 2011 Amendment provides for a tiered royalty in the same range on net sales of corrector compounds discovered during the research term that began in 2011. The Company also is obligated to make two one-time commercial milestone payments upon achievement of certain sales levels for a potentiator compound such as KALYDECO and two one-time commercial milestone payments upon achievement of certain sales levels for a corrector compound such as VX-809 or VX-661. The Company began marketing KALYDECO in the United States in January 2012 and received approval to begin marketing KALYDECO in the European Union in July 2012.

        The Company has royalty obligations to CFFT for each compound commercialized pursuant to this collaboration until the expiration of patents covering that compound. The Company has patents in the United States and European Union covering the composition-of-matter of ivacaftor that expire in 2027 and 2025, respectively, subject to potential patent life extensions. CFFT may terminate its funding obligations under the collaboration, as amended, in certain circumstances, in which case there will be a proportional adjustment to the royalty rates and commercial milestone payments for certain corrector compounds. The collaboration also may be terminated by either party for a material breach by the other, subject to notice and cure provisions.

Alios BioPharma, Inc.

License and Collaboration Agreement

        On June 13, 2011, the Company entered into a license and collaboration agreement (the "Alios Agreement") with Alios, a privately-held biotechnology company. The Company and Alios are

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements (Continued)

(unaudited)

C. Collaborative Arrangements (Continued)

collaborating on the research, development and commercialization of two HCV nucleotide analogues discovered by Alios, ALS-2158 and ALS-2200, which are designed to act on the HCV polymerase. Alios and the Company began clinical development of these two HCV nucleotide analogues in December 2011. The Company is responsible for all costs related to development and commercialization of the compounds incurred after the effective date of the Alios Agreement, and manufacturing costs for the supply of ALS-2158 and ALS-2200 used after the effective date, and is providing funding to Alios to conduct the Phase 1 clinical trials for ALS-2158 and ALS-2200 and a research program directed to the discovery of additional HCV nucleotide analogues that act on the HCV polymerase.

        Under the terms of the Alios Agreement, the Company received exclusive worldwide rights to ALS-2158 and ALS-2200, and has the option to select additional compounds discovered in the research program. The Company paid Alios a $60.0 million up-front payment, and Alios is eligible to receive research and development milestone payments of up to $715.0 million if two compounds are approved and commercialized. As of June 30, 2012, Alios had received $35.0 million of these research and development milestones. Alios also is eligible to receive commercial milestone payments of up to $750.0 million, as well as tiered royalties on net sales of approved drugs.

        The Company may terminate the Alios Agreement (i) upon 30 days' notice to Alios if the Company ceases development after both ALS-2158 and ALS-2200 have experienced a technical failure and/or (ii) upon 60 days' notice to Alios at any time after the Company completes specified Phase 2a clinical trials. The Alios Agreement also may be terminated by either party for a material breach by the other, and by Alios for the Company's inactivity or if the Company challenges certain Alios patents, in each case subject to notice and cure provisions. Unless earlier terminated, the Alios Agreement will continue in effect until the expiration of the Company's royalty obligations, which expire on a country-by-country basis on the later of (a) the date the last-to-expire patent covering a licensed product expires or (b) ten years after the first commercial sale in the country.

        Alios is continuing to operate as a separate entity, is engaged in other programs directed at developing novel drugs that are not covered by the Alios Agreement and maintains ownership of the underlying patent rights that are licensed to the Company pursuant to the Alios Agreement. Under applicable accounting guidance, the Company has determined that Alios is a VIE, that Alios is a business and that the Company is Alios' primary beneficiary. The Company based these determinations on, among other factors, the significance to Alios of the two licensed compounds and on the Company's power, through the joint steering committee for the licensed compounds established under the Alios Agreement, to direct the activities that most significantly affect the economic performance of Alios.

        Accordingly, the Company consolidated Alios' statements of operations and financial condition with the Company's consolidated financial statements beginning on June 13, 2011. However, the Company's interests in Alios are limited to those accorded to the Company in the Alios Agreement. In particular, the Company did not acquire any equity interest in Alios, any interest in Alios' cash and cash equivalents or any control over Alios' activities that do not relate to the Alios Agreement. Alios does not have any right to the Company's assets except as provided in the Alios Agreement.

        The initial consolidation of a VIE that is determined to be a business is accounted for as a business combination. As a result, as of June 13, 2011 the Company recorded all of Alios' assets and

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements (Continued)

(unaudited)

C. Collaborative Arrangements (Continued)

liabilities at fair value on the Company's condensed consolidated balance sheet. The Company continues to consolidate Alios' financial statements by (A) eliminating all intercompany balances and transactions and (B) allocating the noncontrolling interest in Alios between redeemable noncontrolling interest (Alios) and noncontrolling interest (Alios) on the Company's condensed consolidated balance sheet and reflecting net income (loss) attributable to noncontrolling interest (Alios) in the Company's condensed consolidated statement of operations.

Intangible Assets and Goodwill

        As of June 30, 2012 and December 31, 2011, the Company had $250.6 million of intangible assets and $4.9 million of goodwill related to Alios. The Company tests Alios' intangible assets and goodwill for impairment on an annual basis as of October 1, and more frequently if indicators are present or changes in circumstance suggest that impairment may exist. In connection with each annual impairment assessment and any interim impairment assessment, the Company compares the fair value of the asset as of the date of the assessment with the carrying value of the asset on the Company's condensed consolidated balance sheet. No impairment has been found with respect to these intangible assets or goodwill since the effective date of the collaboration.

Noncontrolling Interest (Alios)

        The Company records noncontrolling interest (Alios) on two lines on its condensed consolidated balance sheets. The noncontrolling interest (Alios) is reflected on two separate lines because Alios has both common shareholders and preferred shareholders that are entitled to redemption rights in certain circumstances. The Company records net income (loss) attributable to noncontrolling interest (Alios) on its condensed consolidated statements of operations, reflecting Alios' net income (loss) for the reporting period, adjusted for changes in the fair value of contingent milestone and royalty payments, which are evaluated each reporting period. A summary of net income (loss) attributable to noncontrolling interest (Alios) for the three and six months ended June 30, 2012 and 2011 is as follows:

        The Company uses present-value models to determine the estimated fair value of the potential contingent milestone and royalty payments, based on assumptions regarding the probability of achieving the relevant milestones, estimates regarding the time to develop the Alios HCV nucleotide analogues, estimates of future cash flows from potential product sales and assumptions regarding the appropriate discount rates. In the three and six months ended June 30, 2012, the fair value of contingent milestone

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements (Continued)

(unaudited)

C. Collaborative Arrangements (Continued)

and royalty payments increased by $56.2 million and $55.2 million, respectively, primarily because the Company received positive clinical data from a Phase 1 clinical trial evaluating ALS-2200, which increased the probability that Alios will earn future payments from the Company under the Alios Agreement. If the Alios HCV nucleotide analogues continue to advance in clinical development, the Company expects it will record additional increases in the fair value of the contingent milestone and royalty payments in future periods. Any such increase will reduce net income attributable to Vertex in the period of adjustment, and any such reduction may be material.

        The Company has recorded Alios' cash and cash equivalents as restricted cash and cash equivalents (Alios) because (i) the Company does not have any interest in or control over Alios' cash and cash equivalents and (ii) the Alios Agreement does not provide for these assets to be used for the development of the assets that the Company licensed from Alios pursuant to the collaboration. Assets recorded as a result of consolidating Alios' financial condition into the Company's condensed consolidated balance sheets do not represent additional assets that could be used to satisfy claims against the Company's general assets.

Research and Development Funding

        The Company's collaborators funded portions of the Company's research and development programs related to specific drugs, drug candidates and research targets, including telaprevir, VX-661 and research directed toward identifying additional corrector compounds for the treatment of cystic fibrosis. The Company's collaborative revenues, including amortization of up-front license fees and milestone revenues, were $11.6 million and $29.9 million in the three months ended June 30, 2012 and

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Vertex Pharmaceuticals Incorporated

Notes to Condensed Consolidated Financial Statements (Continued)

(unaudited)

C. Collaborative Arrangements (Continued)

2011, respectively, and $35.9 million and $97.5 million in the six months ended June 30, 2012 and 2011, respectively. The Company's research and development expenses allocated to programs in which a collaborator funded at least a portion of the research and development expenses were approximately $30 million and $40 million in the three months ended June 30, 2012 and 2011, respectively, and approximately $66 million and $64 million in the six months ended June 30, 2012 and 2011, respectively.

D. Acquisition of ViroChem Pharma Inc.

        On March 12, 2009, the Company acquired 100% of the outstanding equity of ViroChem Pharma Inc. ("ViroChem"), a privately-held biotechnology company based in Canada. As of June 30, 2012 and December 31, 2011, the Company reflected on its condensed consolidated balance sheets $412.9 million of intangible assets related to VX-222, a non-nucleoside HCV polymerase inhibitor that it added to its HCV drug development portfolio when the Company acquired ViroChem. The Company's condensed consolidated balance sheets as of June 30, 2012 and December 31, 2011 also reflected goodwill of $26.1 million related to the ViroChem acquisition. Goodwill and VX-222 are tested for impairment on an annual basis as of October 1, and more frequently if indicators are present or changes in circumstance suggest that impairment may exist. No impairment has been found with respect to goodwill or VX-222 since the acquisition date.

        A deferred tax liability related to ViroChem of $127.6 million recorded as of June 30, 2012 and December 31, 2011 primarily relates to the tax effect of future amortization or impairments associated with VX-222, which are not deductible for tax purposes.

E. Earnings Per Share

        Basic and diluted net income per share attributable to Vertex common shareholders are presented in conformity with the two-class method required for participating securities. Under the two-class method, earnings are allocated to (i) Vertex common shares, excluding shares of restricted stock that have been issued but have not yet vested, and (ii) participating securities, based on their respective weighted-average shares outstanding for the period. Shares of unvested restricted stock have the non-forfeitable right to receive dividends on an equal basis with other outstanding common stock. As a result, these unvested shares of restricted stock are considered participating securities that must be included in the calculation of basic and diluted net income per share attributable to Vertex common shareholders using the two-class method. Potentially dilutive shares result from the assumed exercise of outstanding stock options (the proceeds of which are then assumed to have been used to repurchase outstanding stock using the treasury stock method) and the assumed conversion of convertible notes.

        Basic net loss per share attributable to Vertex common shareholders is based upon the weighted-average number of common shares outstanding during the period, excluding restricted stock that has been issued but is not yet vested. Diluted net loss per share attributable to Vertex common shareholders is based upon the weighted-average number of common shares outstanding during the period plus additional weighted-average common equivalent shares outstanding during the period when the effect is dilutive.

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