Kezar Initiates Strategic Review After FDA Setback; Taysha Regains Full Rights to Rett Syndrome Program as Astellas Agreement Ends

Kezar Life Sciences has begun exploring strategic alternatives—including potential mergers, partnerships, or sale—after failing to align with the FDA regarding the next clinical steps for its lead drug zetomipzomib in autoimmune hepatitis, prompted by the cancellation of a key regulatory meeting and additional FDA trial demands1 3 7 5.

The FDA setback is expected to delay Kezar’s progress by up to two years and complicate future patient recruitment, leading to broader cost-cutting measures including upcoming layoffs1 3 5.

Kezar has retained TD Cowen to assist in its strategic review; its board has also extended a shareholder rights plan to maintain the integrity of the process1 7.

Despite earlier positive safety and efficacy data from the PORTOLA study, the FDA now requires a dedicated pharmacokinetic study in severely impaired patients and longer in-clinic monitoring, increasing trial complexity1 7 11.

Taysha Gene Therapies has regained full global rights to its key Rett syndrome program (TSHA-102) after the expiration of its 2022 option agreement with Astellas, which had given Astellas an exclusive negotiation right and a 15% Taysha stake2 6 4 10 8.

Taysha’s TSHA-102 remains a promising one-time gene therapy, boasting FDA Breakthrough Therapy designation and strong early data; the company will move forward with a pivotal trial independently2 6 4.

Astellas’ decision not to license TSHA-102 marks the second time it declined to advance a Taysha CNS therapy; all rights and development flexibility now fully return to Taysha4 8.