Celldex Therapeutics (CLDX) Study Result summary

Study overview and design

• Phase II randomized, double-blind, placebo-controlled study evaluated Barzolvolimab in chronic inducible urticaria (CIndU), including cold urticaria and symptomatic dermatographism, in patients unresponsive to antihistamines.

• 196 patients enrolled across 78 sites in 11 countries, randomized to two dosing regimens or placebo for 20 weeks, with a 24-week follow-up and optional open-label extension.

• Primary endpoint was the percentage of patients with a negative provocation test at week 12, using standardized tests for each urticaria subtype.

• Secondary endpoints included safety and other clinical activity assessments such as critical temperature threshold, critical friction threshold, and worst itch numeric rating scale.

• Study population had well-balanced demographics and baseline disease characteristics across treatment groups.

Efficacy results

• Barzolvolimab met the primary endpoint in both CIndU subtypes and both dosing regimens, with highly statistically significant and clinically meaningful results.

• In cold urticaria, 46.9% (150mg) and 53.1% (300mg) achieved complete response vs. 12.5% placebo at 12 weeks.

• In symptomatic dermatographism, 57.6% (150mg) and 42.4% (300mg) achieved complete response vs. 3.2% placebo at 12 weeks.

• Barzolvolimab demonstrated rapid, durable, and clinically meaningful responses in patients with CIndU refractory to antihistamines.

• Results are considered unprecedented and represent the first large, randomized, placebo-controlled study to demonstrate success in CIndU.

Safety and tolerability

• Barzolvolimab was well-tolerated with a favorable safety profile consistent with prior studies; most adverse events were mild to moderate.

• Most common adverse events were hair color changes (13%) and neutropenia (11%), consistent with prior studies.

• Infection rates were similar between Barzolvolimab and placebo, with no link between neutropenia and infections.

• Four serious adverse events occurred: two in placebo, two in Barzolvolimab (one unrelated, one adjudicated as not anaphylaxis).

• Only one confirmed anaphylaxis case in the entire Barzolvolimab program to date, unrelated to this study.