Connect Biopharma Holdings Limited announced positive topline results from the Stage 2 (maintenance period) of its China pivotal trial evaluating rademikibart?s (formerly known as CBP-201) efficacy and safety in patients with moderate-to-severe atopic dermatitis (AD). These results follow the previously reported Stage 1 results of the trial, which met all primary and key secondary endpoints. In Stage 2, patients that 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 that 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. 21%-28% more patients achieved IGA 0/1, and 11%-16% more patients achieved EASI-75 at Week 52.

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. With respect to 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. The Company separately announced that it granted the development and commercial rights of rademikibart in Greater China to Simcere Pharmaceutical, a large pharmaceutical company in China with an extensive partnership track record and proven capabilities in regulatory affairs, manufacturing, clinical operations and commercialization. Simcere will be responsible for rademikibart?s new drug application in China, which is still on track for submission by the end of First Quarter 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. The China pivotal trial comprised of two stages. The 16-week Stage 1 included patients randomized to Q2W rademikibart (n=219) and placebo arms (n=111).

A primary analysis of 255 patients from Stage 1 (induction stage) showed that all primary and key secondary endpoints were met, showing statistically significant improvements in IGA 0/1 and EASI-75. Following communications with China?s Center for Drug Evaluation, the trial was expanded to include an additional 75 patients towards the end of Stage 1. Consistent with the initial analysis, all primary and key secondary endpoints were met in the expanded trial population. In Stage 2 (maintenance stage), patients that achieved EASI-50 (responders) regardless of initial treatment in 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).

Patients were treated with 300 mg Q2W or Q4W for an additional 36-week period (through Week 52).