Japanese firm Eisai has entered into an agreement with Gilead Sciences, Inc. for the commercialisation and distribution of filgotinib (generic name, product name: Jyseleca), an oral, JAK1 preferential inhibitor for indications of rheumatoid arthritis (RA), ulcerative colitis, and Crohn's disease in Asia (South Korea, Taiwan, Hong Kong and Singapore).

In December 2019, Eisai signed a partnership agreement with Gilead Sciences K.K., a Japanese subsidiary of Gilead, for the distribution and co-promotion of filgotinib in Japan.

Under the terms of the new agreement, Eisai will obtain an exclusive marketing right for filgotinib in South Korea, Taiwan, Hong Kong and Singapore from Gilead. Gilead has received approval for the treatment of RA in Taiwan and has applied for approval of filgotinib for the treatment of RA in South Korea.

Following approvals, Eisai will take over the manufacturing and marketing licenses for filgotinib from Gilead in South Korea and Taiwan. In Hong Kong and Singapore, Eisai will apply for approval for filgotinib. With this agreement, Eisai will pay Gilead a contractual up-front payment, as well as regulatory milestones and sales milestones.