Realized gains and losses from sales of the Company’s investments are included in “Interest and other income” during the period when realized. Unrealized gains and losses are determined using the specific identification method and are recognized as a separate component of equity in other comprehensive income (loss) at the balance sheet date unless the loss is determined to be “other-than-temporary.”
In determining whether a decline in FV below original cost is other-than-temporary, the Company uses a systematic methodology that considers all available evidence, including the credit rating of the relevant trust, the parity score (a measure of the trust’s ability to meet its obligations as they come due), general market conditions, and industry and sector performance, among other factors. The Company considers the duration and extent to which the FV is less than cost, as well as the Company’s intent and ability to hold the investment until recovery or, if necessary, to the instrument’s maturity. When determining whether an impairment is other-than-temporary the Company also considers the following information: (i) if the market value of the investment is below its current carrying value for an extended period, which the Company generally defines as nine to twelve months; (ii) if the issuer has experienced significant financial declines; or (iii) if the issuer has experienced significant changes in its credit quality, among other factors
Equipment
Equipment consists primarily of computer hardware and software and furniture and fixtures and is recorded at cost. Depreciation is computed using an accelerated method over the estimated useful lives of the assets ranging from five to seven years. Accumulated depreciation at December 31, 2013 and 2012 totaled $0.7 million.
 Research and Development Costs, Including Clinical Trial Expenses
Research and development costs are charged to operations as incurred. The Company has included in research and development expenses the personnel costs associated with research and development activities and costs associated with pharmaceutical development, clinical trials, toxicology activities, and regulatory matters.
Income Taxes
Income taxes are computed using the asset and liability approach, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been recognized in the Company’s financial statements or tax returns. In estimating future tax consequences, the Company generally considers all expected future events other than enactment of changes in tax law or rates. If it is more likely than not that some or all of a deferred tax asset will not be realized, the Company records a valuation allowance.
Net (Loss) Income Per Share
Basic and diluted net loss or income per common share amounts have been computed using the weighted-average number of shares of common stock outstanding for the fiscal years ended December 31, 2013, 2012 and 2011. During the years ended December 31, 2013, 2012 and 2011, the Company had potential common stock equivalents related to its outstanding stock options. These potential common stock equivalents were not included in diluted loss per share, if the effect would have been antidilutive. The Company has excluded the impact of any shares which might be issued under the Rights Plan, detailed below, from the earnings per share calculation because the Rights are not exercisable since the specified contingent future event has not occurred.
 Reconciliation of denominators for basic and diluted earnings per share computations:
Fair Value of Financial Instruments
Financial instruments consist of cash and cash equivalents, short-term investments, accounts receivable and accounts payable. The carrying values of these amounts approximate the fair value due to the short-term nature of such instruments.
Patent Costs
The Company expenses patent costs, including legal expenses, in the period in which they are incurred. Patent expenses are included in general and administrative expenses in the Company’s Statements of Comprehensive Income (Loss).
Stock-Based Compensation
Stock-based compensation cost is estimated at the grant date based on the fair value of the award and is recognized as expense over the requisite service period of the award. The fair value of restricted stock awards is determined by reference to the fair market value of our common stock on the date of grant. We use the Black-Scholes model to value service condition and performance condition option awards. For awards with only service conditions and graded-vesting features, we recognize compensation cost on a straight-line basis over the requisite service period. For awards with performance conditions granted we recognize compensation cost over the expected period to achieve the performance conditions, provided achievement of the performance conditions are deemed probable.
 Contingencies
We and GSK received Paragraph IV Notice Letters from Par, Alphapharm, Teva and Dr. Reddy's informing us that each company (or in the case of Alphapharm, its designated agent in the United States, Mylan, had filed an Abbreviated New Drug Application, or ANDA, with the FDA seeking approval to market sumatriptan 85 mg/naproxen sodium 500 mg tablets. Par, Alphapharm, Teva, and Dr. Reddy’s each indicated in their respective Notice Letters that they intended to market a generic version of Treximet tablets before the expiration of U.S. Patent Nos. 6,060,499, or the ‘499 patent, 6,586,458, or the ‘458 patent and 7,332,183, or the '183 patent, listed with respect to Treximet in the FDA’s Approved Drug Products with Therapeutic Equivalents Evaluation publication (commonly referred to as the “Orange Book”). GSK advised us that it elected not to exercise its first right to bring infringement suits against Par, Alphapharm, Teva, and Dr. Reddy’s. Accordingly, we filed suit against Par on November 14, 2008, Alphapharm and Mylan on January 2, 2009, Teva, on April 14, 2009, and Dr. Reddy’s on August 21, 2009, all in the United States District Court for the Eastern District of Texas. On April 14, 2010, we announced that we had entered into a Settlement Agreement with Teva. Under the terms of the Settlement Agreement, Teva was dismissed without prejudice from the consolidated litigation currently pending, but agreed to be bound by the outcome of such litigation or any resulting settlements with third parties. On August 8, 2011, we announced that on August 5, 2011, the District Court ruled the ʼ499 patent and the ʼ458 patent to be valid, enforceable and infringed by Par, Alphapharm and Dr. Reddy’s. A third patent, the ʼ183 patent, covering the Treximet formulation was held to be valid, enforceable and infringed by Par and Dr. Reddy’s. The ʼ183 patent was not asserted against Alphapharm. The District Court also ordered that defendants’ ANDAs not be approved by the FDA until, with respect to Par and Dr. Reddy’s, at least the expiration of the ʼ183 on October 2, 2025, and with respect to Alphapharm the expiration of the ʼ499 and ʼ458 patents on August 14, 2017. On September 6, 2011, we announced that Par, Alphapharm, and Dr. Reddy’s had each appealed the decision of the District Court to the United States Court of Appeals for the Federal Circuit. (Appeal Nos.  On April 15, 2011, the Company and GSK received a Paragraph IV Notice Letter from Sun informing us that Sun had filed an ANDA, with the FDA seeking approval to market a generic version of Treximet tablets before the expiration of ’499, ’458 and ’183 patents. Sun’s Paragraph IV Notice Letter asserts that its generic product will not infringe the listed patents or that the listed patents are invalid or unenforceable. On May 26, 2011, the Company filed suit against Sun for patent infringement in the United States District Court for the Eastern District of Texas. The Company amended its complaint on November 11, 2011 to include U.S. Patent No. 8,022,095, or the ‘095 patent, which was listed in the Orange Book subsequent to the filing of the suit. The parties agreed that the claim construction entered by the District Court in the prior Treximet litigation will control this litigation. On July 16, 2013, we entered into a Settlement Agreement with Sun. Under the terms of the Settlement Agreement, which are confidential, Sun was dismissed without prejudice from the currently pending litigation. In compliance with U.S. law, the Settlement Agreement was submitted to the U.S. Federal Trade Commission and the Department of Justice for review. On September 17, 2013, the District Court entered an order dismissing the case with prejudice.
On November 23, 2011, we entered into the Purchase Agreement with CII, pursuant to which we sold, and CII purchased, our right to receive future royalty payments arising from U.S. sales of MT 400, including Treximet. Under the Purchase Agreement, CII assumed financial responsibility for and would receive the proceeds, if any, from our patent litigation concerning Treximet against Par, Alphapharm, Dr. Reddy’s and Sun.
 The Company has no continuing involvement in the selling or marketing of Treximet, nor does it have any impact on the future royalty stream. The upfront payment of $75 million received is non-refundable, is fixed in amount and is not dependent on the future royalty stream of Treximet.
 On March 14, 2011, we and AstraZeneca received a Paragraph IV Notice Letter from Dr. Reddy’s informing us that it had filed an ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO before the expiration of the '907 patent in 2023. The patent is assigned to us and listed with respect to VIMOVO in the Orange Book. On September 19, 2011, Dr. Reddy’s amended its ANDA to include a Paragraph IV certification against the '504 patent, the '085 patent, the '872 patent, the '070 patent, and the '466 patent, which are assigned to AstraZeneca or its affiliates and listed in in the Orange Book, with respect to VIMOVO. The patents listed in the Orange Book which are owned by AstraZeneca or its affiliates expire at various times between 2014 and 2018. AstraZeneca has advised us that it has elected to exercise its first right to prosecute the infringement suit against Dr. Reddy’s. Accordingly, we and AstraZeneca filed suit against Dr. Reddy’s on April 21, 2011 in the United States District Court for the District of New Jersey, asserting only the ‘907 patent against Dr. Reddy’s. An amended complaint was filed on October 28, 2011 to include the AstraZeneca patents. The case has been consolidated with the case against Lupin and Anchen. The case is currently in the discovery phase. On December 19, 2012, the District Court conducted a pre-trial “Markman” hearing to determine claim construction. On April 15, 2013 a Stipulation of Partial Dismissal was filed which sought dismissal of all infringement claims relating to the '504 patent, the '085 patent, the '872 patent, the '070 patent, and the '466 patent (which are each assigned to AstraZeneca), as well as Dr. Reddy’s defenses and counterclaims relating to those patents. On April 18, 2013, the District Court issued a Stipulation and Order dismissing with prejudice those claims and defenses. On May 1, 2012, the Court issued a Markman Order construing the claim terms disputed by the parties.
 On June 13, 2011, we and AstraZeneca received a Paragraph IV Notice Letter from Lupin informing us that Lupin had filed an ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO before the expiration of the ‘907 patent, which is assigned to the Company and the 504 patent, patent, the '085 patent, the '872 patent, the '070 patent, the '466 patent and, each of which assigned to AstraZeneca or its affiliates. The patents are listed with respect to VIMOVO in the Orange Book and expire at various times between 2014 and 2023. Lupin’s Paragraph IV Notice Letter asserts that its generic product will not infringe the listed patents or that the listed patents are invalid or unenforceable. AstraZeneca has advised us that it has elected to exercise its first right to prosecute the infringement suit against Lupin and, accordingly, we and AstraZeneca filed suit against Lupin on July 25, 2011 in the United States District Court for the District of New Jersey. The case is currently in the discovery phase. On December 19, 2012, The District Court conducted a pre-trial “Markman” hearing to determine claim construction. On May 1, 2012, the Court issued a Markman Order construing the claim terms disputed by the parties.
 On September 19, 2011, we and AstraZeneca AB received Paragraph IV Notice Letter from Anchen informing us that Anchen had filed an ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO before the expiration of the ‘907 patent, the '085 patent, the '070 patent, and the '466 patent. The patents are among those listed with respect to VIMOVO in the Orange Book and expire at various times between 2018 and 2023. Anchen’s Paragraph IV Notice Letter asserts that its generic product will not infringe those five listed patents or that those five listed patents are invalid or unenforceable. AstraZeneca has advised us that it has elected to exercise its first right to prosecute the infringement suit against Anchen and, accordingly, we and AstraZeneca filed suit against Anchen on October 28, 2011 in the United States District Court for the District of New Jersey. The case is currently in the initial phases of discovery. On December 19, 2012, the District Court conducted a pre-trial “Markman” hearing to determine claim construction. On May 1, 2012, the Court issued a Markman Order construing the claim terms disputed by the parties. On October 4, 2013, Anchen filed an amendment to its ANDA seeking to change its Paragraph IV certification to a Paragraph III. It is unclear when or if the FDA will enter Anchen’s amendment. On October 25, 2013, Anchen filed a Motion to Dismiss the case against it, based on its proposed re-certification. On November 18, 2013, we and AstraZeneca filed an Opposition to Anchen’s Motion to Dismiss. The Court has yet to rule on Anchen’s Motion.
 On November 20, 2012 the Company received a Paragraph IV Notice Letter from Dr. Reddy’s, indicating that Dr. Reddy’s had filed a second ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO. In that Paragraph IV Notice Letter, Dr. Reddy asserts, among other things, that the ‘907 patent is invalid and/or not infringed. AstraZeneca has advised us that it has elected to exercise its first right to prosecute the infringement suit against Dr. Reddy’s on its second ANDA filing and, accordingly, we and AstraZeneca filed suit against Dr. Reddy’s on January 4, 2013, in the United States District Court for the District of New Jersey. On April 15, 2013 a Stipulation of Partial Dismissal was filed which sought dismissal of all infringement claims relating to the '504 patent, the '085 patent, the '872 patent, the '070 patent, and the '466 patent (which are each assigned to AstraZeneca), as well as Dr. Reddy’s defenses and counterclaims relating to those patents. On April 15, 2013 a Stipulation of Partial Dismissal was filed which sought dismissal of all infringement claims relating to the '504 patent, the '085 patent, the '872 patent, the '070 patent, and the '466 patent (which are each assigned to AstraZeneca), as well as Dr. Reddy’s defenses and counterclaims relating to those patents. On April 18, 2013, the District Court issued a Stipulation and Order dismissing with prejudice those claims and defenses. On May 5, 2013, this case was consolidated with the originally filed Dr. Reddy’s case. On June 28, 2013 we and AstraZeneca filed a Motion for Summary Judgment relating to the second ANDA filing asserting that U.S. Patent No. 6,926,907 is not invalid. On August 12, 2013, DRL filed its opposition to the Motion for Summary Judgment. The District Court has yet to rule on the Motion. On October 11, 2013, DRL filed a Motion for Summary Judgment asserting that the product which is the subject matter of its second ANDA does not infringe the ‘907 patent. On November 4, 2013, Pozen and AstraZeneca filed a Motion for an Order Denying DRL's Motion for Summary Judgment Pursuant to Rule 56(d) and an Opposition to DRL’s Motion for Summary Judgment. The Court has yet to rule on DRL’s Motion.
 On March 29, 2013, we and AstraZeneca received a received a Paragraph IV Notice Letter from Watson informing the companies that it had filed an ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO before the expiration of the ‘907 patent, which is assigned to the Company and the ‘504 patent, the '085 patent, the ‘424 patent, the '872 patent, the '070 patent, and the '466 patent, each of which assigned to AstraZeneca or its affiliates. The patents are listed with respect to VIMOVO in the Orange Book and expire at various times between 2014 and 2023. Watson’s Paragraph IV Notice Letter asserts that its generic product will not infringe the listed patents or that the listed patents are invalid or unenforceable. On May 10, 2013, we and AstraZeneca filed a patent infringement lawsuit against Watson in the U.S. District Court of New Jersey. A schedule has yet to be set in the case.
 On May 16, 2013, POZEN and AstraZeneca AB received a Paragraph IV Notice Letter from Mylan informing the companies that it had filed an ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO before the expiration of the ‘907 patent, which is assigned to the Company and the ‘504 patent, the '085 patent, the ‘424 patent, the '872 patent, the '070 patent, and the '466 patent, each of which assigned to AstraZeneca or its affiliates. The patents are listed with respect to VIMOVO in the Orange Book and expire at various times between 2014 and 2023. Mylan’s Paragraph IV Notice Letter asserts that its generic product will not infringe the listed patents or that the listed patents are invalid or unenforceable. On June 28, 2013, we and AstraZeneca filed a patent infringement lawsuit against Mylan in the U.S. District Court of New Jersey. A schedule has yet to be set in the case.
On October 15, 2013, the United States Patent Office issued ’285 patent. The ‘285 patent, entitled “Pharmaceutical compositions for the coordinated delivery of NSAIDs” and assigned to POZEN, is related to the ‘907 patent. AstraZeneca has advised us that it has elected to exercise its first right to prosecute the infringement of the ‘285 patent and, accordingly, on October 23, 2013, we, and AstraZeneca filed patent infringement lawsuits against DRL, Lupin, Watson and Mylan in the U.S. District Court of New Jersey alleging that their ANDA products infringe the ‘285 patent. On November 8, 2013, we, and AstraZeneca filed a Motion to Amend the Complaint in the actions against DRL, Lupin, Watson and Mylan or, in the alternative, to consolidate the actions involving the ‘285 patent with the existing consolidated action. The Court has yet to rule on those Motions.
 As part of Horizon’s purchase of all of AstraZeneca’s rights, title and interest to develop, commercialize and sell VIMOVO in the United States, Horizon has assumed AstraZeneca’s right to lead the above-described Paragraph IV litigation relating to VIMIVO currently pending in the United States District Court for the District of New Jersey and will assume all patent-related defense costs relating to such litigation, including reimbursement up to specified amounts of the cost of any counsel retained by us. On December 12, 2013, Horizon filed Motions to Join under Fed.R.Civ.Proc. 25(c) as a co-plaintiff in each of the above referenced actions and the consolidated action. On January 31, 2014 and February 2, 2014, the Court granted Horizon’s motions.
As with any litigation proceeding, we cannot predict with certainty the patent infringement suit against Dr. Reddy’s Lupin, Anchen, Mylan and Watson relating to a generic version of VIMOVO. We have incurred an aggregate of $17.2 million, in legal fees through the fiscal year ended December 31, 2013. Furthermore, we will have to incur additional expenses in connection with the lawsuits relating to VIMOVO, which may be substantial. In the event of an adverse outcome or outcomes, our business could be materially harmed. Moreover, responding to and defending pending litigation will result in a significant diversion of management’s attention and resources and an increase in professional fees.
 New Accounting Pronouncements
Fair Value Measurements
In May 2011, the FASB issued new accounting rules related to fair value measurements. The new accounting rules clarify some existing concepts, eliminate wording differences between GAAP and International Financial Reporting Standards (“IFRS”), and in some limited cases, change some principles to achieve convergence between GAAP and IFRS. The new accounting rules result in a consistent definition of fair value and common requirements for measurement of and disclosure about fair value between GAAP and IFRS. The new accounting rules also expand the disclosures for fair value measurements that are estimated using significant unobservable (Level 3) inputs. The new accounting rules were effective for the Company in the first quarter of 2012. The adoption of the new accounting rules in the first quarter of 2012 did not have a material effect on the Company’s financial condition, results of operations or cash flows.
Presentation of Comprehensive Income
In June 2011, the FASB issued new accounting rules that require an entity to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income, or in two separate but consecutive statements. The new accounting rules eliminate the option to present components of other comprehensive income as part of the statement of equity. The adoption of the new accounting rules in the first quarter of 2012 did not have a material effect on the Company’s financial condition, results of operations or cash flows.
 In December 2011, the FASB issued new accounting rules which deferred certain provisions of the rules issued in June 2011 that required entities to present reclassification adjustments out of accumulated other comprehensive income by component in both the statement in which net income is presented and the statement in which other comprehensive income is presented.
In February 2013, the FASB issued a final rule related to the reporting of amounts reclassified out of accumulated other comprehensive income that requires entities to report, either on their income statement or in a footnote to their financial statements, the effects on earnings from items that are reclassified out of other comprehensive income. The new accounting rules were effective for the Company in the first quarter of 2013. The Company does not expect the adoption of the new accounting rules to have a material effect on the Company’s financial condition, results of operations or cash flows.
Disclosures About Offsetting Assets and Liabilities
In December 2011, the FASB issued new accounting rules related to new disclosure requirements regarding the nature of an entity’s rights of setoff and related arrangements associated with its financial instruments and derivative instruments. The new rules were effective for the Company in the first quarter of 2013 with retrospective application required. The adoption of the new accounting rules had no material effect on Company’s financial condition, results of operations or cash flows.
2.
License Agreements
We have entered into and may continue to enter into collaborations with established pharmaceutical or pharmaceutical services companies to develop, commercialize and/or manufacture our product candidates. Our existing collaborations are described below.
 GlaxoSmithKline (GSK)
In June 2003, we signed an agreement with GSK for the development and commercialization of proprietary combinations of a triptan (5-HT1B/1D agonist) and a long-acting NSAID. The combinations covered by the agreement are among the combinations of MT 400. Under the terms of the agreement, GSK has exclusive rights in the U.S. to commercialize all combinations which combine GSK’s triptans, including Imitrex® (sumatriptan succinate) or Amerge® (naratriptan hydrochloride), with a long-acting NSAID. We were responsible for development of the first combination product, while GSK provided formulation development and manufacturing. Pursuant to the terms of the agreement, we received $25.0 million in initial payments from GSK following termination of the waiting period under the Hart-Scott-Rodino notification program and the issuance of a specified patent. In May 2004, we received a $15.0 million milestone payment as a result of our commencement of Phase 3 clinical trial activities. In October 2005, we received a $20.0 million milestone payment upon the FDA’s acceptance for review of the NDA for Treximet, the trade name for the product. On April 26, 2008, we received, from GSK, $20.0 million in milestone payments which were associated with the approval of, and GSK’s intent to commercialize, Treximet. In addition, GSK will pay us two sales performance milestones totaling $80.0 million if certain sales thresholds are achieved. Up to an additional $10.0 million per product is payable upon achievement of milestones relating to other products. GSK will pay us royalties on all net sales of marketed products until at least the expiration of the last to expire issued applicable patent (October 2, 2025) based upon the scheduled expiration of currently issued patents. GSK may reduce, but not eliminate, the royalty payable to us if generic competitors attain a pre-determined share of the market for the combination product, or if GSK owes a royalty to one or more third parties for rights it licenses from such third parties to commercialize the product. The agreement terminates on the date of expiration of all royalty obligations unless earlier terminated by either party for a material breach or by GSK at any time upon ninety (90) days’ written notice to us for any reason or no reason. Among the contract breaches that would entitle us to terminate the agreement is GSK’s determination not to further develop or to launch the combination product under certain circumstances.  We and GSK received Paragraph IV Notice Letters from Par, Alphapharm, Teva and Dr. Reddy's informing us that each company (or in the case of Alphapharm, its designated agent in the United States, Mylan, had filed an Abbreviated New Drug Application, or ANDA, with the FDA seeking approval to market sumatriptan 85 mg/naproxen sodium 500 mg tablets. Par, Alphapharm, Teva, and Dr. Reddy’s each indicated in their respective Notice Letters that they intended to market a generic version of Treximet tablets before the expiration of U.S. Patent Nos. 6,060,499, or the ‘499 patent, 6,586,458, or the ‘458 patent and 7,332,183, or the '183 patent, listed with respect to Treximet in the FDA’s Approved Drug Products with Therapeutic Equivalents Evaluation publication (commonly referred to as the “Orange Book”). GSK advised us that it elected not to exercise its first right to bring infringement suits against Par, Alphapharm, Teva, and Dr. Reddy’s. Accordingly, we filed suit against Par on November 14, 2008, Alphapharm and Mylan on January 2, 2009, Teva, on April 14, 2009, and Dr. Reddy’s on August 21, 2009, all in the United States District Court for the Eastern District of Texas. On April 14, 2010, we announced that we had entered into a Settlement Agreement with Teva. Under the terms of the Settlement Agreement, Teva was dismissed without prejudice from the consolidated litigation currently pending, but agreed to be bound by the outcome of such litigation or any resulting settlements with third parties. On August 8, 2011, we announced that on August 5, 2011, the District Court ruled the ʼ499 patent and the ʼ458 patent to be valid, enforceable and infringed by Par, Alphapharm and Dr. Reddy’s. A third patent, the ʼ183 patent, covering the Treximet formulation was held to be valid, enforceable and infringed by Par and Dr. Reddy’s. The ʼ183 patent was not asserted against Alphapharm. The District Court also ordered that defendants’ ANDAs not be approved by the FDA until, with respect to Par and Dr. Reddy’s, at least the expiration of the ʼ183 on October 2, 2025, and with respect to Alphapharm the expiration of the ʼ499 and ʼ458 patents on August 14, 2017. On September 6, 2011, we announced that Par, Alphapharm, and Dr. Reddy’s had each appealed the decision of the District Court to the United States Court of Appeals for the Federal Circuit. (Appeal Nos.  On April 15, 2011, the Company and GSK received a Paragraph IV Notice Letter from Sun informing us that Sun had filed an ANDA, with the FDA seeking approval to market a generic version of Treximet tablets before the expiration of ’499, ’458 and ’183 patents. Sun’s Paragraph IV Notice Letter asserts that its generic product will not infringe the listed patents or that the listed patents are invalid or unenforceable. On May 26, 2011, the Company filed suit against Sun for patent infringement in the United States District Court for the Eastern District of Texas. The Company amended its complaint on November 11, 2011 to include U.S. Patent No. 8,022,095, or the ‘095 patent, which was listed in the Orange Book subsequent to the filing of the suit. The parties agreed that the claim construction entered by the District Court in the prior Treximet litigation will control this litigation. On July 16, 2013, we entered into a Settlement Agreement with Sun. Under the terms of the Settlement Agreement, which are confidential, Sun was dismissed without prejudice from the currently pending litigation. In compliance with U.S. law, the Settlement Agreement was submitted to the U.S. Federal Trade Commission and the Department of Justice for review. On September 17, 2013, the District Court entered an order dismissing the case with prejudice.
On November 23, 2011, we entered into the Purchase Agreement with CII, pursuant to which we sold, and CII purchased, our right to receive future royalty payments arising from U.S. sales of MT 400, including Treximet. Under the Purchase Agreement, CII assumed financial responsibility for and would receive the proceeds, if any, from our patent litigation concerning Treximet against Par, Alphapharm, Dr. Reddy’s and Sun.
 AstraZeneca AB (AstraZeneca)
In August 2006, we entered into a collaboration and license agreement dated as of August 1, 2006 and effective September 7, 2006 with AstraZeneca, a Swedish corporation, regarding the development and commercialization of proprietary fixed dose combinations of the PPI esomeprazole magnesium with the NSAID naproxen, in a single tablet for the management of pain and inflammation associated with conditions such as osteoarthritis and rheumatoid arthritis in patients who are at risk for developing NSAID associated gastric ulcers. Under the terms of the agreement, we granted to AstraZeneca an exclusive, fee-bearing license, in all countries of the world except Japan, under our patents and know-how relating to combinations of gastroprotective agents and NSAIDs (other than aspirin and its derivatives). Pursuant to the terms of the agreement, we received an upfront license fee of $40.0 million from AstraZeneca following termination of the waiting period under the Hart-Scott-Rodino notification program.
 In September 2007, we agreed with AstraZeneca to amend our collaboration and license agreement effective as of September 6, 2007. Under the terms of the amendment, AstraZeneca has agreed to pay us up to $345.0 million, in the aggregate, in milestone payments upon the achievement of certain development, regulatory and sales events. In September 2007 we received a $10.0 million payment upon execution of the amendment and a $20.0 million payment in recognition of the achievement of the primary endpoints for the PN400-104 study, a study which compared acid suppression of different doses of VIMOVO (formerly PN 400), and achievement of the interim results of the PN200-301 study, a six month comparative trial of PN 200 as compared to EC naproxen in patients requiring chronic NSAID therapy, meeting mutually agreed success criteria. In May 2010, we received a $20.0 million payment for the NDA approval of VIMOVO. We also received an additional $25.0 million milestone in December 2010 when VIMOVO received approval (including pricing and reimbursement approval) in a major ex-U.S. market and up to $260.0 million will be paid as sales performance milestones if certain aggregate sales thresholds are achieved.
 The amendment revised the royalty rates we were to have received under the original agreement. Under the original agreement, we were to receive a royalty based on annual net sales by AstraZeneca, its affiliates or sublicensees during the royalty term. The royalty rate varied based on the level of annual net sales of products made by AstraZeneca, its affiliates and sublicensees, ranging from the mid-single digits to the mid-teens. Under the amendment, we will now receive a flat, low double digit royalty rate during the royalty term on annual net sales of products made by AstraZeneca, its affiliates and sublicensees, in the U.S. and royalties ranging from the mid-single digits to the high-teens on annual net sales of products made by AstraZeneca, its affiliates and sublicensees outside of the U.S. The amendment also revises the rate of reduction to the royalty rate based upon loss of market share due to generic competition inside and outside of the U.S. to account for the new royalty structure.
Our right to receive royalties from AstraZeneca for the sale of such products under the collaboration and license agreement, as amended, expires on a country-by-country basis upon the later of (a) expiration of the last-to-expire of certain patent rights relating to such products in that country, and (b) ten years after the first commercial sale of such products in such country.
We further amended the collaboration and license agreement effective October 1, 2008 to shorten the timing of AstraZeneca’s reimbursement obligation for certain development expenses incurred by us under the agreement and to update the description of the target product profile studies (as defined in the agreement) for VIMOVO.
 We retained responsibility for the development and filing of the NDA for the product in the U.S. AstraZeneca is responsible for all development activities outside the U.S., as well as for all manufacturing, marketing, sales and distribution activities worldwide. We agreed to bear all expenses related to certain specified U.S. development activities. All other development expenses, including all manufacturing-related expenses, will be paid by AstraZeneca. The agreement established joint committees with representation of both us and AstraZeneca to manage the development and commercialization of the product. The committees operate by consensus, but if consensus cannot be reached, we generally will have the deciding vote with respect to development activities required for marketing approval of the product in the U.S. and AstraZeneca generally will have the deciding vote with respect to any other matters.
 On December 31, 2013 we accrued $1.7 million of VIMOVO royalty revenue, which was subsequently received. The agreement, unless earlier terminated, will expire upon the payment of all applicable royalties for the products commercialized under the agreement. Either party has the right to terminate the agreement by notice in writing to the other party upon or after any material breach of the agreement by the other party, if the other party has not cured the breach within 90 days after written notice to cure has been given, with certain exceptions. The parties also can terminate the agreement for cause under certain defined conditions. In addition, AstraZeneca can terminate the agreement, at any time, at will, for any reason or no reason, in its entirety or with respect to countries outside the U.S., upon 90 days’ notice. If terminated at will, AstraZeneca will owe us a specified termination payment or, if termination occurs after the product is launched, AstraZeneca may, at its option, under and subject to the satisfaction of conditions specified in the agreement, elect to transfer the product and all rights to us.
 On May 3, 2013, AstraZeneca informed us that, after a strategic business review, it had decided to cease promotion and sampling of VIMOVO by the end of the third quarter of 2013 in certain countries, including the U.S. and all countries in Europe, other than Spain and Portugal, which have pre-existing contractual relationships with third parties. We understand that AstraZeneca will instead now focus on those countries where the product has shown growth and which AstraZeneca believes have the greatest potential for future growth. The decision to launch the product in additional countries will be made by AstraZeneca on a case by case basis. We continue to assess the financial impact this decision will have on our royalty revenue.
On September 16, 2013, we and AstraZeneca entered into another amendment to the Original Agreement which made clarifications to certain intellectual property provisions of the Original Agreement to clarify that AstraZeneca’s rights under those provisions do not extend to products which contain acetyl salicylic acid. On September 16, 2013, we and AstraZeneca also executed a letter agreement whereby we agreed that in the event that AstraZeneca divested its rights and obligations to market VIMOVO in the United States to a third party, AstraZeneca would be relieved of its obligations under the Original Agreement with respect to the United States as of the effective date of such divestiture, including its obligation under the Original Agreement to guarantee the performance of such assignee and/or sublicensee.
 On November 18, 2013, AstraZeneca and Horizon entered into certain agreements in connection with AstraZeneca’s divestiture of all of its rights, title and interest to develop, commercialize and sell VIMOVO in the United States to Horizon. In connection with this divestiture, on November 18, 2013 we and AstraZeneca entered into an Amended and Restated Collaboration and License Agreement for the United States (the U.S. Agreement”) and an Amended and Restated License and Collaboration Agreement for Outside the United States (the “ROW Agreement”), which agreements collectively amend and restate Original Agreement. AstraZeneca has assigned the U.S. Agreement to Horizon in connection with the Divestiture with our consent.
We and Horizon also entered into Amendment No. 1 to the U.S. Agreement which, among other things, amends the royalty provisions of the U.S. Agreement to provide for a guaranteed annual minimum royalty amount of $5 million in calendar year 2014, and a guaranteed annual minimum royalty amount of $7.5 million each calendar year thereafter, provided that the patents owned by us which cover VIMOVO are in effect and no generic forms of VIMOVO are in the marketplace. Amendment No. 1 also provides that Horizon has assumed AstraZeneca’s right to lead the on-going Paragraph IV litigation relating to VIMIVO currently pending in the United States District Court for the District of New Jersey and will assume all patent-related defense costs relating to such litigation, including reimbursement up to specified amounts of the cost of any counsel retained by us, amends certain time periods for Horizon’s delivery of quarterly sales reports to POZEN, and provides for quarterly update calls between the parties to discuss VIMOVO’s performance and Horizon’s commercialization efforts.
 Further, the Company, AstraZeneca and Horizon executed a letter agreement whereby POZEN expressly consented to the assignment by AstraZeneca and the assumption by Horizon of the U.S. Agreement. In addition, the letter agreement establishes a process for AstraZeneca and Horizon to determine if sales milestones set forth in the Original Agreement are achieved on a global basis and other clarifications and modifications required as a result of incorporating the provisions of the Original Agreement into the U.S. Agreement and the ROW Agreement or as otherwise agreed by the parties.
 On March 14, 2011, we and AstraZeneca received a Paragraph IV Notice Letter from Dr. Reddy’s informing us that it had filed an ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO before the expiration of the '907 patent in 2023. The patent is assigned to us and listed with respect to VIMOVO in the Orange Book. On September 19, 2011, Dr. Reddy’s amended its ANDA to include a Paragraph IV certification against the '504 patent, the '085 patent, the '872 patent, the '070 patent, and the '466 patent, which are assigned to AstraZeneca or its affiliates and listed in in the Orange Book, with respect to VIMOVO. The patents listed in the Orange Book which are owned by AstraZeneca or its affiliates expire at various times between 2014 and 2018. AstraZeneca has advised us that it has elected to exercise its first right to prosecute the infringement suit against Dr. Reddy’s. Accordingly, we and AstraZeneca filed suit against Dr. Reddy’s on April 21, 2011 in the United States District Court for the District of New Jersey, asserting only the ‘907 patent against Dr. Reddy’s. An amended complaint was filed on October 28, 2011 to include the AstraZeneca patents. The case has been consolidated with the case against Lupin and Anchen. The case is currently in the discovery phase. On December 19, 2012, the District Court conducted a pre-trial “Markman” hearing to determine claim construction. On April 15, 2013 a Stipulation of Partial Dismissal was filed which sought dismissal of all infringement claims relating to the '504 patent, the '085 patent, the '872 patent, the '070 patent, and the '466 patent (which are each assigned to AstraZeneca), as well as Dr. Reddy’s defenses and counterclaims relating to those patents. On April 18, 2013, the District Court issued a Stipulation and Order dismissing with prejudice those claims and defenses. On May 1, 2012, the Court issued a Markman Order construing the claim terms disputed by the parties.
 On June 13, 2011, we and AstraZeneca received a Paragraph IV Notice Letter from Lupin informing us that Lupin had filed an ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO before the expiration of the ‘907 patent, which is assigned to the Company and the 504 patent, patent, the '085 patent, the '872 patent, the '070 patent, the '466 patent and, each of which assigned to AstraZeneca or its affiliates. The patents are listed with respect to VIMOVO in the Orange Book and expire at various times between 2014 and 2023. Lupin’s Paragraph IV Notice Letter asserts that its generic product will not infringe the listed patents or that the listed patents are invalid or unenforceable. AstraZeneca has advised us that it has elected to exercise its first right to prosecute the infringement suit against Lupin and, accordingly, we and AstraZeneca filed suit against Lupin on July 25, 2011 in the United States District Court for the District of New Jersey. The case is currently in the discovery phase. On December 19, 2012, The District Court conducted a pre-trial “Markman” hearing to determine claim construction. On May 1, 2012, the Court issued a Markman Order construing the claim terms disputed by the parties.
 On September 19, 2011, we and AstraZeneca AB received Paragraph IV Notice Letter from Anchen informing us that Anchen had filed an ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO before the expiration of the ‘907 patent, the '085 patent, the '070 patent, and the '466 patent. The patents are among those listed with respect to VIMOVO in the Orange Book and expire at various times between 2018 and 2023. Anchen’s Paragraph IV Notice Letter asserts that its generic product will not infringe those five listed patents or that those five listed patents are invalid or unenforceable. AstraZeneca has advised us that it has elected to exercise its first right to prosecute the infringement suit against Anchen and, accordingly, we and AstraZeneca filed suit against Anchen on October 28, 2011 in the United States District Court for the District of New Jersey. The case is currently in the initial phases of discovery. On December 19, 2012, the District Court conducted a pre-trial “Markman” hearing to determine claim construction. On May 1, 2012, the Court issued a Markman Order construing the claim terms disputed by the parties. On October 4, 2013, Anchen filed an amendment to its ANDA seeking to change its Paragraph IV certification to a Paragraph III. It is unclear when or if the FDA will enter Anchen’s amendment. On October 25, 2013, Anchen filed a Motion to Dismiss the case against it, based on its proposed re-certification. On November 18, 2013, we and AstraZeneca filed an Opposition to Anchen’s Motion to Dismiss. The Court has yet to rule on Anchen’s Motion.
 On November 20, 2012 the Company received a Paragraph IV Notice Letter from Dr. Reddy’s, indicating that Dr. Reddy’s had filed a second ANDA with the FDA seeking regulatory approval to market a generic version of VIMOVO. In that Paragraph IV Notice Letter, Dr. Reddy asserts, among other things, that the ‘907 patent is invalid and/or not infringed. AstraZeneca has advised us that it has elected to exercise its first right to prosecute the infringement suit against Dr. Reddy’s on its second ANDA filing and, accordingly, we and AstraZeneca filed suit against Dr. Reddy’s on January 4, 2013, in the United States District Court for the District of New Jersey. On April 15, 2013 a Stipulation of Partial Dismissal was filed which sought dismissal of all infringement claims relating to the '504 patent, the '085 patent, the '872 patent, the '070 patent, and the '466 patent (which are each assigned to AstraZeneca), as well as Dr. Reddy’s defenses and counterclaims relating to those patents. On April 15, 2013 a Stipulation of Partial Dismissal was filed which sought dismissal of all infringement claims relating to the '504 patent, the '085 patent, the '872 patent, the '070 patent, and the '466 patent (which are each assigned to AstraZeneca), as well as Dr. Reddy’s defenses and counterclaims relating to those patents. On April 18, 2013, the District Court issued a Stipulation and Order dismissing with prejudice those claims and defenses. On May 5, 2013, this case was consolidated with the originally filed Dr. Reddy’s case. On June 28, 2013 we and AstraZeneca filed a Motion for Summary Judgment relating to the second ANDA filing asserting that U.S. Patent No. 6,926,907 is not invalid. On August 12, 2013, DRL filed its opposition to the Motion for Summary Judgment. The District Court has yet to rule on the Motion. On October 11, 2013, DRL filed a Motion for Summary Judgment asserting that the product which is the subject matter of its second ANDA does not infringe the ‘907 patent. On November 4, 2013, Pozen and AstraZeneca filed a Motion for an Order Denying DRL's Motion for Summary Judgment Pursuant to Rule 56(d) and an Opposition to DRL’s Motion for Summary Judgment. The Court has yet to rule on DRL’s Motion.
