Why Is Skin Disease-Focused Connect Biopharma Stock Lower Today?

Connect Biopharma Holdings Limited CNTB released topline results from 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 trial results, which met all primary and key secondary endpoints.

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. 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.

Treatment with 300 mg Q2W and Q4W of rademikibart was generally well tolerated, and there were no new safety signals. 

The company separately 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. 

Connect Biopharma will receive a ¥150 million ($21 million) upfront payment, up to ¥875 million ($120 million) in milestone payments, and royalties up to low double-digit percentages.

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.

Price Action: CNTB shares are down 31.8% at $1.41 on the last check Tuesday.