Eisai takes over all Arena's rights for obesity drug

The US pharmaceutical subsidiary of Japanese drug major Eisai (TYO: 4523) has reached an agreement with Arena Pharmaceuticals (Nasdaq: ARNA) to revise the November 2013 marketing and supply agreement it concluded with Arena's wholly-owned subsidiary, Arena Pharmaceuticals GmbH, for the chronic weight management treatment lorcaserin hydrochloride CIV.

Under the new agreement, Eisai acquires all of Arena's rights to develop and market lorcaserin, which is sold under the trade names Belviq and Belviq XR. Arena’s shares rose 7.3% to $1.61 in after-hours trading on Wednesday, while Eisai was barely changed.

As a result, Eisai becomes solely responsible for all decision-making and implementation related to global development and submissions for regulatory approvals, as well as global marketing for lorcaserin. The previously negotiated financial terms such as purchase price based on net sales have also been reduced and modified.