Kyowa Kirin Co., Ltd announced it will regain global control of the development and commercialization program for rocatinlimab, an investigational anti-OX40 monoclonal antibody targeting T-cell rebalancing in moderate-to-severe atopic dermatitis (AD), following termination of its collaboration with Amgen Inc. Under the revised arrangement, Kyowa Kirin will manage regulatory filings and future global commercialization efforts for the asset.

Amgen’s decision is described as a strategic portfolio reprioritization to focus on other pipeline priorities. Rocatinlimab, designed to inhibit pathogenic T-cell activity implicated in chronic inflammatory disease, has been evaluated extensively across Phase III studies, achieving all co-primary and secondary endpoints in the ROCKET-IGNITE and ROCKET-HORIZON studies in nearly 1,500 adults with AD. Kyowa Kirin said it plans to proceed with planned regulatory submissions and maintain continuity for ongoing trial participants as the transition unfolds.

The companies agreed to terminate the existing rocatinlimab collaboration, effectively transferring full program rights back to Kyowa Kirin. Amgen will continue manufacturing the asset, but Kyowa Kirin assumes responsibility for all regulatory and commercial activities worldwide. Financial details of any settlement or adjustments related to the unwinding were not disclosed. The original joint development pact, struck in 2021, included a USD 400 million upfront payment from Amgen and up to USD 850 million in potential milestones.

Mechanism and disease rationale

OX40 is a co-stimulatory receptor expressed on effector and memory T cells thought to drive chronic inflammation in AD. By inhibiting OX40 signalling, the antibody aims to reduce pathogenic T-cell activity and re-establish immune balance, addressing underlying pathophysiology rather than only suppressing symptoms. This approach differs from cytokine-targeting therapies by focusing on T-cell mediated immune regulation.