BMS paid Nektar $1.85 billion for the rights discussed above and 8.3 million shares of Nektar common stock representing a 4.8% ownership interest. BMS's equity ownership is subject to certain lock-up, standstill and voting provisions for a five-year period. The amount of the up-front payment allocated to the equity investment was $800 million after considering Nektar's stock price on the date of closing and current limitations on trading the securities. The remaining $1.05 billion of the up-front payment was allocated to the rights discussed above and included in Research and development expense in the second quarter of 2018. BMS will also pay up to $1.8 billion upon the achievement of contingent development, regulatory and sales-based milestones over the life of the alliance period. Research and development expense payable under this agreement with Nektar was $59 million for the year ended December 31, 2018. In 2018, BMS and Nektar commenced a worldwide license and collaboration for the development and commercialization of NKTR-214, Nektar's investigational immuno-stimulatory therapy designed to selectively expand specific cancer-fighting T cells and natural killer cells directly in the tumor micro-environment. The  Opdivo  and NKTR-214 combination therapy is currently in Phase II clinical studies for multiple cancer indications and in Phase III clinical studies for melanoma and RCC. A joint development plan agreed by the parties contemplates development in various indications and tumor types with each party responsible for the supply of their own product. BMS's share of the development costs associated with therapies comprising a BMS medicine used in combination with NKTR-214 is 67.5%, subject to certain cost caps for Nektar. The parties will also jointly commercialize the therapies, subject to regulatory approval. BMS's share of global NKTR-214 profits and losses will be 35% subject to certain annual loss caps for Nektar. Summarized financial information related to this alliance was as follows: Prior to 2018, BMS and Gilead operated a joint venture in the U.S. and Canada for  Atripla* , which was terminated following the launch of a generic version of  Sustiva  by a third-party in the U.S. As a result, deferred income and alliance receivables attributed to  Sustiva  product held by the joint venture at December 31, 2017 was reduced by $438 million to reflect the post-termination selling price. BMS is entitled to a fee equal to 55% of Atripla*  U.S. net sales multiplied by the ratio of the difference in the average net selling prices of  Atripla*  and  Truvada*  to the  Atripla*  average net selling price in 2018. The fee is reduced to 35% in 2019 and 15% in 2020, of  Atripla*  U.S. net sales multiplied by the ratio described above. BMS supplies  Sustiva  at cost plus a markup to Gilead during this three-year period but may terminate the supply agreement after a notice period. BMS and Gilead operate a joint venture in Europe to develop and commercialize a combination product named  Atripla*,  which combines BMS's Sustiva  with Gilead's  Truvada*.  The joint venture is consolidated by Gilead, who is the principal in end customer product sales. BMS receives a percentage of end customer sales which is recorded in Alliance revenues. The joint venture will continue until either party terminates the arrangement or the last patent expires that allows market exclusivity to  Atripla* . Gilead Nektar Year Ended December 31, Dollars in Millions 2018 2017 2016 Revenues from Gilead alliances: Alliance revenues $ 253 $ 623 $ 934 Equity in net loss of affiliates $ 2 $ 13 $ 12 70