License and Collaboration Agreements	12 Months Ended
Dec. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Abstract]
License and Collaboration Agreements	Note 7. License and Collaboration Agreements REGENXBIO License Agreement (XLMTM/Pompe) In July 2013, the Company entered into an exclusive license agreement with REGENXBIO Inc. (formerly ReGenX Biosciences, LLC), or REGENXBIO. Under the agreement, REGENXBIO granted the Company an exclusive worldwide license under certain patent rights to make, have made, use, import, sell and offer for sale licensed products in the treatment of both XLMTM and Pompe disease using both AAV8 and AAV9. As consideration for the licensed rights, the Company paid REGENXBIO an initial fee of $0.3 million and 50,228 shares of the Company’s common stock. The Company will also owe REGENXBIO (i) an annual maintenance fee; (ii) up to $8.85 million in combined milestone fees per licensed product related to XLMTM and up to $8.85 million in combined milestone fees per licensed product related to Pompe disease, a small portion of which may be paid in the form of shares of the Company’s common stock; (iii) mid to high single digit royalty percentages on net sales of licensed products and (iv) mid- single digit to low twenties royalty percentages of any sublicense fees received by the Company from sublicensees for the licensed patent rights. The Company is obligated to achieve certain development milestones, including submission to the FDA and subsequent effectiveness of an IND for each indication within a specified time period, which it may extend for additional time for a specified number of extensions upon the payment of a fee. The agreement will expire upon the expiration, lapse, abandonment or invalidation of the last claim of the licensed patent rights to expire, lapse or become abandoned or unenforceable in all countries worldwide. The Company may terminate the agreement upon prior written notice. REGENXBIO may terminate the agreement immediately if the Company or its affiliates become insolvent, if the Company is late by a specified number of days in paying money due under the agreement or if the Company or its affiliates commence any action against REGENXBIO or its licensors to declare or render any claim of the licensed patent rights invalid or unenforceable. Either party may terminate the agreement for material breach that is not cured within a specified number of days. REGENXBIO License Agreement (Crigler-Najjar Syndrome) In November 2015, the Company entered into a second license agreement with REGENXBIO. Under the agreement, REGENXBIO granted the Company an exclusive worldwide license under certain patent rights to make, have made, use, import, sell and offer for sale licensed products for the treatment of Crigler-Najjar syndrome in humans using AAV8. As consideration for the licensed rights, the Company paid REGENXBIO an upfront fee of $0.2 million and an additional $0.4 million upon the Company’s entry into the license and collaboration agreement with the University of Pennsylvania. The Company will also owe REGENXBIO (i) an annual maintenance fee; (ii) up to $7.6 million in combined development and regulatory milestone fees per licensed product; (iii) mid-single digit to low teens royalty percentages on net sales of licensed products sold by the Company, its affiliates and sublicensees and (iv) a low twenties percentage of certain sublicense fees received by the Company from sublicensees for the licensed products and certain fees received from the sale or transfer of specified rights related to a licensed product. Under the agreement, the Company is obligated to diligently use commercially reasonable efforts to develop, commercialize, market, promote and sell licensed products. The Company is also obligated to achieve certain development milestones, including submission to the FDA and subsequent effectiveness of an IND application, or acceptance by the European Medicines Agency of an equivalent application, within a specified time period, which the Company may extend for a specified number of extensions upon the payment of certain fees. The agreement will continue on a country-by-country and licensed product-by-licensed product basis and expire upon the later of the expiration, lapse, abandonment or invalidation of the last claim of the licensed patent rights to expire, lapse or become abandoned or unenforceable in such country, or ten years after first commercial sale of such licensed product in such country. The Company may terminate the agreement upon prior written notice. REGENXBIO may terminate the agreement immediately in case of the Company’s bankruptcy, or other similar events, if the Company is late in paying money due under the agreement and does not pay in full within a specified number of days after receiving written notice, or if the Company or its affiliates commence any action against REGENXBIO or its licensors to declare or render any claim of the licensed patent rights invalid or unenforceable. Either party may terminate the agreement for material breach that is not cured within a specified number of days. REGENXBIO License Agreement (CPVT) Also in November 2015, the Company entered into a third license agreement with REGENXBIO. Under the agreement, REGENXBIO granted the Company an exclusive worldwide license under certain patent rights to make, have made, use, import, sell and offer for sale licensed products for the treatment of CPVT in humans using AAV9. Within a specified time and upon written notice, the Company may elect to substitute for, or add to, CPVT certain other inherited arrhythmias. As consideration for the licensed rights, the Company paid REGENXBIO an upfront fee of $1.0 million. For each additional indication, the Company may elect to pursue under the licensed rights, the Company agreed to pay REGENXBIO a fee of $0.5 million upon such election. The Company will also owe REGENXBIO (i) an annual maintenance fee for each covered indication; (ii) up to $8.8 million in combined development and regulatory milestone fees for each indication and each licensed product; (iii) up to $45.0 million in combined commercial milestone fees based on various annual aggregate net sales thresholds; (iv) mid-single digit to low teens royalty percentages on net sales of licensed products sold by the Company, its affiliates and sublicensees and (v) a low twenties percentage of any sublicense fees received by the Company from sublicensees for the licensed products and certain fees it received from the sale or transfer of specified rights related to a licensed product. Under the agreement, the Company is obligated to use commercially reasonable efforts to develop, commercialize, market, promote and sell licensed products for each indication. It is also obligated to achieve certain development milestones for each indication, including submission to the FDA and subsequent effectiveness of an IND application, or acceptance by the European Medicines Agency of an equivalent application, within a specified time period, which it may extend for additional time and for a specified number of extensions upon the payment of certain fees. The agreement will continue on a country-by-country and licensed product-by-licensed product basis and expire upon the later of the expiration, lapse, abandonment or invalidation of the last claim of the licensed patent rights to expire, lapse or become abandoned or unenforceable in such country, or ten years after first commercial sale of such licensed product in such country. The Company may terminate the agreement in its entirety or for each elected disease indication upon prior written notice. REGENXBIO may terminate the agreement immediately in case of the Company’s bankruptcy, or other similar events, if the Company is late in paying money due under the agreement and does not pay in full within a specified number of days after receiving written notice, or if the Company or its affiliates commence any action against REGENXBIO or its licensors to declare or render any claim of the licensed patent rights invalid or unenforceable. Either party may terminate the agreement for material breach that is not cured within a specified number of days. Genethon Collaborative Development Agreement In January 2014, the Company entered into a collaborative development agreement with Genethon, a French not-for-profit organization. Subject to certain limitations on patents that are co-owned or in-licensed by the Company, Genethon granted the Company a royalty-free, exclusive, worldwide license under certain background intellectual property rights controlled by Genethon to research, develop, make and commercialize certain products for the treatment of XLMTM. In addition, the collaboration agreement provides that new intellectual property arising from the performance of the development plan will be owned jointly by both parties and Genethon granted the Company a royalty-free, exclusive, worldwide license to Genethon’s interest in such new intellectual property to research, develop, make and commercialize certain products for the treatment of XLMTM. Genethon also granted the Company a right of first negotiation to negotiate rights to other internal research programs conducted by Genethon to research, develop, manufacture or commercialize other products for the treatment of XLMTM that are not already included within the scope of this agreement. In connection with the entry into the collaborative development agreement, the Company issued 262,396 shares of its common stock to Genethon, of which 87,465 shares vested immediately, 87,465 shares vested in January 2015 and 87,466 shares vested in January 2016. The agreement provides Genethon with the exclusive right to manufacture licensed product for preclinical and clinical purposes, subject to Genethon’s ability to supply required quantities in accordance with applicable timelines. Manufacturing costs will be paid by the Company. Under the agreement, the Company is obligated to fund Genethon’s research and development activities related to AT132. Unless earlier terminated, the agreement will stay in effect until completion of the research program and the Company’s license grants will survive any expiration of the agreement. Either party may terminate the agreement for the other party’s uncured material breach of the agreement or for the other party’s bankruptcy. The Company may terminate the agreement for convenience upon prior written notice. Genethon may terminate the agreement upon raising an objection to continued development on grounds of a safety or efficacy issue and upon prior written notice of such objection. University of Florida License Agreement Effective July 2015, the Company entered into a license agreement with the University of Florida Research Foundation, or UFRF, which was amended in June 2016. Under the agreement, UFRF granted the Company an exclusive, worldwide license under certain patent rights and a non-exclusive license to certain related know-how for the treatment of Pompe. The Company agreed to pay an upfront license fee, an annual maintenance fee until first commercial sale of a licensed product, up to $1.2 million in combined development and regulatory milestone payments, and a low single digit royalty on net sales of licensed products sold by the Company and its sublicensees, subject to minimum annual royalty payments following the first commercial sale of a licensed product. The Company is obligated to pay royalties on a country-by-country basis until the later of expiration of the last valid claim within the licensed patent rights in such country and ten years after first commercial sale of a licensed product in such country. The Company also agreed to pay to UFRF certain percentages of sublicense fees it receives from sublicensees of the licensed patent rights based on the stage of development at the time the sublicense is executed. Under the agreement, the Company is obligated to diligently perform a specified development plan and to use commercially reasonable efforts to market and commercialize at least one licensed product which has obtained regulatory approval. The Company is also obligated to achieve a number of diligence milestones, including the achievement of first commercial sale within a specific time period. If the Company fails to meet any of these diligence milestones and the deadlines are not extended in accordance with the terms of the agreement, then UFRF may terminate the agreement. The Company may terminate the agreement for convenience upon prior written notice. UFRF may terminate the agreement upon prior written notice for breach of the agreement by the Company, including specific listed breaches, any violation of laws or regulations in the development or commercialization of licensed products or the Company’s bankruptcy or liquidation. In addition, UFRF may terminate the agreement immediately if the Company or its affiliates challenge the validity, patentability or enforceability of the licensed patents rights. If the challenge is brought by a sublicensee, UFRF may request that the Company terminate the sublicense. FSM License Agreement As a result of the acquisition of Cardiogen (see note 6), the Company acquired a license agreement previously entered into by Cardiogen with the Fondazione Salvatore Maugeri, or FSM an Italian non-profit organization. Under the license agreement, the Company obtained an exclusive worldwide license to certain intellectual property to develop, use and commercialize products related to recessive CPVT, as well as to several additional inherited arrhythmias. Under the agreement, the Company is obligated to use commercially reasonable efforts to develop and, after receiving regulatory approval for products in a given country, commercialize such products in such country. As consideration for the license, Cardiogen issued 425,000 shares of Cardiogen common stock to FSM. In connection with the Company’s acquisition of Cardiogen, the Cardiogen shares held by FSM were cancelled and converted into 51,968 shares of the Company’s common stock. The Company also agreed to pay FSM low single digital royalties on net sales of licensed products for as long as such product is covered by a valid claim of the licensed patents in the applicable country. The Company may terminate the agreement for convenience upon prior written notice. Either party may terminate the agreement upon prior written notice for the uncured material breach of the agreement by the other party or the other party’s bankruptcy or liquidation. University of Pennsylvania License and Collaboration Agreement In May 2016, the Company entered into a license and collaboration agreement with The Trustees of the University of Pennsylvania, or the University of Pennsylvania. Under the agreement, the University of Pennsylvania granted the Company an exclusive worldwide license under certain patent rights to research, develop, use, sell, offer for sale, have sold, make, have made and import licensed products for the treatment of Crigler-Najjar. As consideration for the licensed rights, the Company paid the University of Pennsylvania an upfront fee of $0.5 million, as well as $4.5 million for certain preclinical development activities. The Company is obligated to pay the University of Pennsylvania (i) up to an aggregate of $6.0 million for preclinical development activities agreed upon by both parties, of which $5.7 million had been paid as of December 31, 2016, subject to adjustment based on the work plan; (ii) up to an aggregate of $13.7 million in development, regulatory and net sales milestone payments for the first licensed product; (iii) low to mid-single-digit royalty percentages on tiered annual net sales of the licensed products sold by the Company, its affiliates or sublicensees and (iv) mid-single-digit to low double-digit percentages of any sublicense fees received by it from third parties for the grant of sublicenses to any licensed patent rights. Under the agreement, the Company is obligated to use commercially reasonable efforts to develop, pursue regulatory approval for, market and commercialize at least one licensed product. The University of Pennsylvania will be responsible for conducting preclinical development activities according to a work plan, including all IND-enabling non-clinical studies and research grade manufacturing. The Company will be responsible for regulatory strategy and operations, clinical development, GMP manufacture and commercialization of the licensed products. The agreement will continue on a country-by-country basis and expire upon the later of the expiration of the last valid claim of the licensed patent rights that covers the exploitation of such licensed patent rights in such country, or ten years after first commercial sale of such licensed product in such country. The Company may terminate the agreement upon 60 days’ prior written notice. Either party may terminate the agreement for material breach that is not cured within a specified number of days. During the year ended December 31, 2016, the Company entered into two other intellectual property license agreements to develop and commercialize products in multiple therapeutic areas. Pursuant to these agreements, it paid an aggregate of $0.1 million upfront that was recorded as research and development expense during the year ended December 31, 2016. The agreements also provide for the Company to pay up to an aggregate of $1.9 million in contingent future development and commercialization milestones, a royalty on related product sales of 1% or less, and a portion of any sub-license fees the Company receives. As of December 31, 2016, the Company had not developed a commercial product using the licensed technologies and no milestones had been achieved under these agreements, except for $0.7 million to the University of Pennsylvania as a result the Company’s filing an IND for AT342 and $0.4 million to REGENXBIO based upon the entry into the license and collaboration agreement with the University of Pennsylvania.

Note 7. License and Collaboration Agreements

REGENXBIO License Agreement (XLMTM/Pompe)

In July 2013, the Company entered into an exclusive license agreement with REGENXBIO Inc. (formerly ReGenX Biosciences, LLC), or REGENXBIO. Under the agreement, REGENXBIO granted the Company an exclusive worldwide license under certain patent rights to make, have made, use, import, sell and offer for sale licensed products in the treatment of both XLMTM and Pompe disease using both AAV8 and AAV9.

As consideration for the licensed rights, the Company paid REGENXBIO an initial fee of $0.3 million and 50,228 shares of the Company’s common stock. The Company will also owe REGENXBIO (i) an annual maintenance fee; (ii) up to $8.85 million in combined milestone fees per licensed product related to XLMTM and up to $8.85 million in combined milestone fees per licensed product related to Pompe disease, a small portion of which may be paid in the form of shares of the Company’s common stock; (iii) mid to high single digit royalty percentages on net sales of licensed products and (iv) mid- single digit to low twenties royalty percentages of any sublicense fees received by the Company from sublicensees for the licensed patent rights.

The Company is obligated to achieve certain development milestones, including submission to the FDA and subsequent effectiveness of an IND for each indication within a specified time period, which it may extend for additional time for a specified number of extensions upon the payment of a fee.

The agreement will expire upon the expiration, lapse, abandonment or invalidation of the last claim of the licensed patent rights to expire, lapse or become abandoned or unenforceable in all countries worldwide. The Company may terminate the agreement upon prior written notice. REGENXBIO may terminate the agreement immediately if the Company or its affiliates become insolvent, if the Company is late by a specified number of days in paying money due under the agreement or if the Company or its affiliates commence any action against REGENXBIO or its licensors to declare or render any claim of the licensed patent rights invalid or unenforceable. Either party may terminate the agreement for material breach that is not cured within a specified number of days.

REGENXBIO License Agreement (Crigler-Najjar Syndrome)

In November 2015, the Company entered into a second license agreement with REGENXBIO. Under the agreement, REGENXBIO granted the Company an exclusive worldwide license under certain patent rights to make, have made, use, import, sell and offer for sale licensed products for the treatment of Crigler-Najjar syndrome in humans using AAV8.

As consideration for the licensed rights, the Company paid REGENXBIO an upfront fee of $0.2 million and an additional $0.4 million upon the Company’s entry into the license and collaboration agreement with the University of Pennsylvania. The Company will also owe REGENXBIO (i) an annual maintenance fee; (ii) up to $7.6 million in combined development and regulatory milestone fees per licensed product; (iii) mid-single digit to low teens royalty percentages on net sales of licensed products sold by the Company, its affiliates and sublicensees and (iv) a low twenties percentage of certain sublicense fees received by the Company from sublicensees for the licensed products and certain fees received from the sale or transfer of specified rights related to a licensed product.

Under the agreement, the Company is obligated to diligently use commercially reasonable efforts to develop, commercialize, market, promote and sell licensed products. The Company is also obligated to achieve certain development milestones, including submission to the FDA and subsequent effectiveness of an IND application, or acceptance by the European Medicines Agency of an equivalent application, within a specified time period, which the Company may extend for a specified number of extensions upon the payment of certain fees.

The agreement will continue on a country-by-country and licensed product-by-licensed product basis and expire upon the later of the expiration, lapse, abandonment or invalidation of the last claim of the licensed patent rights to expire, lapse or become abandoned or unenforceable in such country, or ten years after first commercial sale of such licensed product in such country. The Company may terminate the agreement upon prior written notice. REGENXBIO may terminate the agreement immediately in case of the Company’s bankruptcy, or other similar events, if the Company is late in paying money due under the agreement and does not pay in full within a specified number of days after receiving written notice, or if the Company or its affiliates commence any action against REGENXBIO or its licensors to declare or render any claim of the licensed patent rights invalid or unenforceable. Either party may terminate the agreement for material breach that is not cured within a specified number of days.

REGENXBIO License Agreement (CPVT)

Also in November 2015, the Company entered into a third license agreement with REGENXBIO. Under the agreement, REGENXBIO granted the Company an exclusive worldwide license under certain patent rights to make, have made, use, import, sell and offer for sale licensed products for the treatment of CPVT in humans using AAV9. Within a specified time and upon written notice, the Company may elect to substitute for, or add to, CPVT certain other inherited arrhythmias.

As consideration for the licensed rights, the Company paid REGENXBIO an upfront fee of $1.0 million. For each additional indication, the Company may elect to pursue under the licensed rights, the Company agreed to pay REGENXBIO a fee of $0.5 million upon such election. The Company will also owe REGENXBIO (i) an annual maintenance fee for each covered indication; (ii) up to $8.8 million in combined development and regulatory milestone fees for each indication and each licensed product; (iii) up to $45.0 million in combined commercial milestone fees based on various annual aggregate net sales thresholds; (iv) mid-single digit to low teens royalty percentages on net sales of licensed products sold by the Company, its affiliates and sublicensees and (v) a low twenties percentage of any sublicense fees received by the Company from sublicensees for the licensed products and certain fees it received from the sale or transfer of specified rights related to a licensed product.

Under the agreement, the Company is obligated to use commercially reasonable efforts to develop, commercialize, market, promote and sell licensed products for each indication. It is also obligated to achieve certain development milestones for each indication, including submission to the FDA and subsequent effectiveness of an IND application, or acceptance by the European Medicines Agency of an equivalent application, within a specified time period, which it may extend for additional time and for a specified number of extensions upon the payment of certain fees.

The agreement will continue on a country-by-country and licensed product-by-licensed product basis and expire upon the later of the expiration, lapse, abandonment or invalidation of the last claim of the licensed patent rights to expire, lapse or become abandoned or unenforceable in such country, or ten years after first commercial sale of such licensed product in such country. The Company may terminate the agreement in its entirety or for each elected disease indication upon prior written notice. REGENXBIO may terminate the agreement immediately in case of the Company’s bankruptcy, or other similar events, if the Company is late in paying money due under the agreement and does not pay in full within a specified number of days after receiving written notice, or if the Company or its affiliates commence any action against REGENXBIO or its licensors to declare or render any claim of the licensed patent rights invalid or unenforceable. Either party may terminate the agreement for material breach that is not cured within a specified number of days.

Genethon Collaborative Development Agreement

In January 2014, the Company entered into a collaborative development agreement with Genethon, a French not-for-profit organization. Subject to certain limitations on patents that are co-owned or in-licensed by the Company, Genethon granted the Company a royalty-free, exclusive, worldwide license under certain background intellectual property rights controlled by Genethon to research, develop, make and commercialize certain products for the treatment of XLMTM. In addition, the collaboration agreement provides that new intellectual property arising from the performance of the development plan will be owned jointly by both parties and Genethon granted the Company a royalty-free, exclusive, worldwide license to Genethon’s interest in such new intellectual property to research, develop, make and commercialize certain products for the treatment of XLMTM. Genethon also granted the Company a right of first negotiation to negotiate rights to other internal research programs conducted by Genethon to research, develop, manufacture or commercialize other products for the treatment of XLMTM that are not already included within the scope of this agreement.

In connection with the entry into the collaborative development agreement, the Company issued 262,396 shares of its common stock to Genethon, of which 87,465 shares vested immediately, 87,465 shares vested in January 2015 and 87,466 shares vested in January 2016.

The agreement provides Genethon with the exclusive right to manufacture licensed product for preclinical and clinical purposes, subject to Genethon’s ability to supply required quantities in accordance with applicable timelines. Manufacturing costs will be paid by the Company. Under the agreement, the Company is obligated to fund Genethon’s research and development activities related to AT132.

Unless earlier terminated, the agreement will stay in effect until completion of the research program and the Company’s license grants will survive any expiration of the agreement. Either party may terminate the agreement for the other party’s uncured material breach of the agreement or for the other party’s bankruptcy. The Company may terminate the agreement for convenience upon prior written notice. Genethon may terminate the agreement upon raising an objection to continued development on grounds of a safety or efficacy issue and upon prior written notice of such objection.

University of Florida License Agreement

Effective July 2015, the Company entered into a license agreement with the University of Florida Research Foundation, or UFRF, which was amended in June 2016. Under the agreement, UFRF granted the Company an exclusive, worldwide license under certain patent rights and a non-exclusive license to certain related know-how for the treatment of Pompe. The Company agreed to pay an upfront license fee, an annual maintenance fee until first commercial sale of a licensed product, up to $1.2 million in combined development and regulatory milestone payments, and a low single digit royalty on net sales of licensed products sold by the Company and its sublicensees, subject to minimum annual royalty payments following the first commercial sale of a licensed product. The Company is obligated to pay royalties on a country-by-country basis until the later of expiration of the last valid claim within the licensed patent rights in such country and ten years after first commercial sale of a licensed product in such country. The Company also agreed to pay to UFRF certain percentages of sublicense fees it receives from sublicensees of the licensed patent rights based on the stage of development at the time the sublicense is executed.

Under the agreement, the Company is obligated to diligently perform a specified development plan and to use commercially reasonable efforts to market and commercialize at least one licensed product which has obtained regulatory approval. The Company is also obligated to achieve a number of diligence milestones, including the achievement of first commercial sale within a specific time period. If the Company fails to meet any of these diligence milestones and the deadlines are not extended in accordance with the terms of the agreement, then UFRF may terminate the agreement.

The Company may terminate the agreement for convenience upon prior written notice. UFRF may terminate the agreement upon prior written notice for breach of the agreement by the Company, including specific listed breaches, any violation of laws or regulations in the development or commercialization of licensed products or the Company’s bankruptcy or liquidation. In addition, UFRF may terminate the agreement immediately if the Company or its affiliates challenge the validity, patentability or enforceability of the licensed patents rights. If the challenge is brought by a sublicensee, UFRF may request that the Company terminate the sublicense.

FSM License Agreement

As a result of the acquisition of Cardiogen (see note 6), the Company acquired a license agreement previously entered into by Cardiogen with the Fondazione Salvatore Maugeri, or FSM an Italian non-profit organization. Under the license agreement, the Company obtained an exclusive worldwide license to certain intellectual property to develop, use and commercialize products related to recessive CPVT, as well as to several additional inherited arrhythmias. Under the agreement, the Company is obligated to use commercially reasonable efforts to develop and, after receiving regulatory approval for products in a given country, commercialize such products in such country.

As consideration for the license, Cardiogen issued 425,000 shares of Cardiogen common stock to FSM. In connection with the Company’s acquisition of Cardiogen, the Cardiogen shares held by FSM were cancelled and converted into 51,968 shares of the Company’s common stock. The Company also agreed to pay FSM low single digital royalties on net sales of licensed products for as long as such product is covered by a valid claim of the licensed patents in the applicable country.

The Company may terminate the agreement for convenience upon prior written notice. Either party may terminate the agreement upon prior written notice for the uncured material breach of the agreement by the other party or the other party’s bankruptcy or liquidation.

University of Pennsylvania License and Collaboration Agreement

In May 2016, the Company entered into a license and collaboration agreement with The Trustees of the University of Pennsylvania, or the University of Pennsylvania. Under the agreement, the University of Pennsylvania granted the Company an exclusive worldwide license under certain patent rights to research, develop, use, sell, offer for sale, have sold, make, have made and import licensed products for the treatment of Crigler-Najjar.

As consideration for the licensed rights, the Company paid the University of Pennsylvania an upfront fee of $0.5 million, as well as $4.5 million for certain preclinical development activities. The Company is obligated to pay the University of Pennsylvania (i) up to an aggregate of $6.0 million for preclinical development activities agreed upon by both parties, of which $5.7 million had been paid as of December 31, 2016, subject to adjustment based on the work plan; (ii) up to an aggregate of $13.7 million in development, regulatory and net sales milestone payments for the first licensed product; (iii) low to mid-single-digit royalty percentages on tiered annual net sales of the licensed products sold by the Company, its affiliates or sublicensees and (iv) mid-single-digit to low double-digit percentages of any sublicense fees received by it from third parties for the grant of sublicenses to any licensed patent rights.

Under the agreement, the Company is obligated to use commercially reasonable efforts to develop, pursue regulatory approval for, market and commercialize at least one licensed product. The University of Pennsylvania will be responsible for conducting preclinical development activities according to a work plan, including all IND-enabling non-clinical studies and research grade manufacturing. The Company will be responsible for regulatory strategy and operations, clinical development, GMP manufacture and commercialization of the licensed products.

The agreement will continue on a country-by-country basis and expire upon the later of the expiration of the last valid claim of the licensed patent rights that covers the exploitation of such licensed patent rights in such country, or ten years after first commercial sale of such licensed product in such country. The Company may terminate the agreement upon 60 days’ prior written notice. Either party may terminate the agreement for material breach that is not cured within a specified number of days.

During the year ended December 31, 2016, the Company entered into two other intellectual property license agreements to develop and commercialize products in multiple therapeutic areas. Pursuant to these agreements, it paid an aggregate of $0.1 million upfront that was recorded as research and development expense during the year ended December 31, 2016. The agreements also provide for the Company to pay up to an aggregate of $1.9 million in contingent future development and commercialization milestones, a royalty on related product sales of 1% or less, and a portion of any sub-license fees the Company receives.

As of December 31, 2016, the Company had not developed a commercial product using the licensed technologies and no milestones had been achieved under these agreements, except for $0.7 million to the University of Pennsylvania as a result the Company’s filing an IND for AT342 and $0.4 million to REGENXBIO based upon the entry into the license and collaboration agreement with the University of Pennsylvania.