Jasper Therapeutics (JSPR) Study Result summary

Study background and design

• SPOTLIGHT is a Phase 1b/2a open-label trial evaluating subcutaneous briquilimab in adults with chronic inducible urticaria (CIndU) refractory to antihistamines, focusing on cold urticaria and symptomatic dermographism, with single ascending doses at 40mg, 120mg, and 180mg cohorts.

• The study enrolled 15 adults (≥18 years) with H1-antihistamine-refractory CIndU for at least 3 months across 7 EU sites, using provocation tests, urticaria control scores, and PK/PD measures for efficacy assessment.

• Efficacy was assessed using TempTest, prick test, UCT score, and serum tryptase over a 12-week period, with additional skin biopsies.

• The study population reflected typical CIndU demographics, with severe disease at baseline and low UCT scores indicating poor disease control.

Patient demographics and baseline characteristics

• 15 patients were dosed: 3 at 40mg and 12 at 120mg; mean ages were 35.3 and 46.4 years, respectively.

• Most patients were female (67% in 120mg group) and had a mix of cold urticaria and symptomatic dermographism.

• Baseline provocation thresholds and urticaria control scores were similar across cohorts.

Efficacy results

• 93% (14/15) of participants achieved a clinical response within 6 weeks post-dosing.

• In the 120mg cohort, 83% (10/12) achieved a complete response and 92% (11/12) achieved either complete or partial response at six weeks.

• In the 40mg cohort, all three participants achieved a clinical response, with one complete and two partial responses.

• Rapid onset of effect was observed, with most responses occurring by week two and sustained in many patients at week six.

• UCT scores improved significantly, with most patients reaching well-controlled or complete control by day 29.