More than four months after its original PDUFA date of Feb. 2, 2021, Mallinckrodt plc’s Stratagraft gained FDA approval for use in deep partial-thickness thermal burns.

Rapt Therapeutics Inc. CEO Brian Wong said RPT-193 monotherapy in atopic dermatitis (AD) “looks really promising, but there’s still quite a bit to learn” about the small molecule, designed to inhibit the migration of Th2 cells into inflamed tissues by blocking CCR4. Investors saw enough to push the shares of South San Francisco-based Rapt up 115.5%, or $21.45, to close at $40.02, after trading as high as $41.99 during the day.

Kyowa Kirin Co. Ltd. has partnered with Amgen Inc. to jointly develop and commercialize KHK-4083, Kyowa Kirin’s phase III-ready anti-OX40 fully human monoclonal antibody for the potential treatment of atopic dermatitis. Kyowa Kirin will receive a $400 million up front, while milestone payments could add an additional $850 million. Significant royalty payments on future global sales could sweeten the blockbuster deal.