Kyowa Kirin Reports Phase 3 Rocatinlimab Results for Adult Atopic Dermatitis

Kyowa Kirin Co., Ltd. has announced promising results from its Phase 3 ROCKET HORIZON trial of the investigational therapy rocatinlimab, which targets the OX40 receptor. Rocatinlimab is being developed as a treatment for moderate to severe atopic dermatitis, commonly known as eczema. The trial met its co-primary endpoints, demonstrating significant efficacy over placebo.

The HORIZON trial achieved a validated Investigator Global Assessment for Atopic Dermatitis (vIGA-ADTM) score of 0 (clear) or 1 (almost clear) with a ≥ 2-point reduction from baseline, with 19.3% of rocatinlimab patients reaching this benchmark compared to 6.6% in the placebo group—a statistically significant difference of 12.8% (p<0.001). The trial also saw 32.8% of rocatinlimab patients achieving a 75% reduction from baseline in their Eczema Area and Severity Index score (EASI-75) compared to 13.7% in the placebo group, a difference of 19.1% (p<0.001). Additionally, the trial met the more stringent revised Investigator Global Assessment (rIGA 0/1), with 16.4% of rocatinlimab patients achieving this versus 4.9% in the placebo group, a difference of 11.5% (p<0.001).

The HORIZON trial is a Phase 3, 24-week, randomized, placebo-controlled, double-blind study designed to evaluate the efficacy, safety, and tolerability of rocatinlimab monotherapy in adults with moderate to severe atopic dermatitis. The trial included 726 adult participants who received either rocatinlimab or a placebo via subcutaneous injection every four weeks, with additional dosing at week two. Key endpoints were evaluated at weeks 16 and 24.

In addition to the co-primary endpoints, the study also found statistically significant differences from placebo for all key secondary endpoints. These secondary endpoints included measurements of skin clearance (vIGA 0/1 and EASI-75 at week 16 and EASI-90 at week 24), the Pruritus Numeric Rating Scale, Atopic Dermatitis Skin Pain Scale, Dermatology Quality of Life Index, and severity scores for both hand and facial atopic dermatitis.

Overall safety findings in the HORIZON trial were consistent with those observed in the Phase 2b study. The comprehensive ROCKET Phase 3 clinical trial program includes eight studies aimed at establishing the safety and efficacy profile of rocatinlimab in both adult and adolescent populations with moderate to severe atopic dermatitis, as well as exploring multiple dosing regimens.

Atopic dermatitis is a chronic inflammatory skin condition marked by dry, itchy, and painful skin. The disease affects 15-20% of children and up to 10% of adults, with moderate to severe forms causing significant discomfort and disruption to daily life. T-cell imbalance is a crucial factor in the pathophysiology of the disease, leading to its recurring and unpredictable symptoms.

Rocatinlimab is an anti-OX40 human monoclonal antibody that targets the OX40 receptor, a key player in driving systemic and local inflammatory responses in atopic dermatitis and other conditions. By inhibiting and reducing pathogenic T cells, rocatinlimab has the potential to be the first and only T-cell rebalancing therapy for moderate to severe atopic dermatitis. It is also being investigated for other inflammatory conditions such as moderate to severe uncontrolled asthma and prurigo nodularis.

Kyowa Kirin and Amgen are collaborating on the development and commercialization of rocatinlimab. Under their agreement, Amgen will lead the efforts globally, excluding Japan where Kyowa Kirin will retain all rights. The companies intend to co-promote the therapy in the United States and have options for co-promotion in Europe and Asia.

Detailed results from the HORIZON trial will be shared at forthcoming medical conferences. Both companies will continue to analyze data from the remaining studies in the ROCKET program as part of ongoing discussions with global regulatory authorities.