AD Pipeline Watch: Rademikibart Maintains Efficacy Out to Week 52

IGA 0/1 and EASI-75 achieved at Week 16 with rademikibart treatment was maintained through Week 52 with every two weeks and every four weeks dosing regimens.

Connect Biopharma’s rademikibart continues to wow in patients with moderate-to-severe atopic dermatitis, according to topline results from the Stage 2 (maintenance period) of its China pivotal trial.

Rademikibart is an inhibitory human monoclonal antibody against the IL-4Rα a common subunit for IL-4Rα and IL-13 receptors. It binds to a distinct region in IL-4Rα to prevent the receptor from interacting with other receptor subunits that are required for activation of the signaling pathways that ultimately give rise to Th2-mediated diseases, including atopic dermatitis and asthma.

“The maintenance data of rademikibart out to Week 52 from the China pivotal trial are very compelling. They build upon the strong results shown in the first 16 weeks of treatment, showing additional gains in efficacy with continued treatment with rademikibart, as well as very high rates of maintained efficacy with Q4W dosing of rademikibart,” says Jonathan Silverberg, M.D., Ph.D., M.P.H., a Professor of Dermatology at The George Washington University School of Medicine and Health Sciences in Washington, DC, in a news release. “Multiple unmet needs remain with current treatment options. Having a therapy with more sustained efficacy and convenient dosing may improve clinical outcomes and is a welcome addition to our treatment armamentarium.”

In Stage 2, clinical response as measured by Investigator Global Assessment (IGA) 0/1 and Eczema Area and Severity Index (EASI-75) achieved at Week 16 with rademikibart treatment was maintained through Week 52 with both every two weeks (Q2W) and every four weeks (Q4W) dosing regimens. Approximately 90% of patients on Q4W dose maintained both IGA 0/1 and EASI-75 through Week 52.

These results follow the previously reported Stage 1 results of the trial, which met all primary and key secondary endpoints.

Over 36 weeks of treatment in Stage 2 of the study, the percentage of patients achieving IGA 0/1 and EASI-75 continued to increase. Moreover, rademikibart continued to be well tolerated over 52 weeks of treatment.

In Stage 2, patients who achieved EASI-50 (responders) regardless of initial treatment in the 16-week Stage 1 were randomized to either Q2W rademikibart (n=113) or Q4W rademikibart (n=112) arms. Patients who did not achieve EASI-50 (non-responders) were assigned to an open-label Q2W rademikibart arm (n=86).

An efficacy analysis in patients that achieved IGA 0/1 or EASI-75 at Week 16 showed that with both Q2W at Q4W dosing regimens, 76%-87% of them maintained their IGA 0/1 and 92% of patients maintained their EASI-75 at Week 52, respectively.

Evaluation of all patients that achieved EASI-50 at Week 16 with rademikibart (active drug responders) showed continued improvement from Week 16 to Week 52. Around 21% to 28% more patients achieved IGA 0/1, and 11%-16% more patients achieved EASI-75 at Week 52, the study showed.

Additionally, of the patients who achieved a clinically meaningful ≥4-point reduction in peak pruritus numerical rating scale (PP-NRS), 95.2% were able to maintain that level with Q4W dosing and 81.6% with Q2W dosing at the end of the study. Concerning quality of life, a ≥5-point reduction on the dermatology life quality index (DLQI) is considered clinically important and 93.4% (Q2W) and 90.0% (Q4W) were able to maintain this level at the end of the 52-week study.

Treatment with 300 mg Q2W and Q4W of rademikibart was generally well tolerated, and there were no new safety signals. There was only one patient discontinuation due to an adverse event (pregnancy) in the rademikibart Q2W open-label arm.

Connect Biopharma announced that it granted the development and commercial rights of rademikibart in Greater China to Simcere Pharmaceutical. Simcere will be responsible for rademikibart’s new drug application in China, which is still on track for submission by the end of Q1 2024. Additionally, Connect Biopharma remains on track for the topline readout next month from its global Phase 2 trial of rademikibart in patients with moderate-to-severe asthma.