Upstream Bio's verekitug met the primary endpoint in Phase 2 trial

Upstream Bio reported that verekitug met the Phase 2 Vibrant trial primary endpoint at week 24, and additional worst-observation carried-forward (WOCF) analyses showed larger placebo-adjusted reductions in nasal polyp score and nasal congestion score than the primary analysis.

Upstream Bio presented additional data from the Phase 2 Vibrant trial of verekitug in people with chronic rhinosinusitis with nasal polyps. The new analyses used a worst-observation carried-forward (WOCF) method to account for concomitant rescue therapies, including nasal polyp surgery, systemic corticosteroids, or escalation of background treatments. Verekitug was dosed at 100 mg every 12 weeks and met the study's primary endpoint at week 24 in both the primary and WOCF analyses. The data were presented in a late-breaking poster session at the American Academy of Allergy Asthma & Immunology 2026 Annual Meeting in Philadelphia. Key details: - The Phase 2 Vibrant trial evaluated verekitug in participants with chronic rhinosinusitis with nasal polyps. - Additional analyses applied a worst-observation carried-forward (WOCF) approach to adjust for use of rescue therapies such as surgery, systemic corticosteroids, or escalation of background treatments. - Verekitug 100 mg every 12 weeks met the primary endpoint at week 24 in both analyses, with a placebo-adjusted nasal polyp score (NPS) reduction of −1.95 in the WOCF analysis versus −1.77 in the primary analysis. - The trial also showed a placebo-adjusted reduction in the patient-reported nasal congestion score (NCS) of −0.96 in the WOCF analysis versus −0.77 in the primary analysis. - The results were presented as a late-breaking poster at AAAAI 2026 and are reported to support previously announced top-line findings. Summary: The WOCF analyses reinforced the trial's primary and key secondary endpoint findings, showing somewhat larger placebo-adjusted reductions in NPS and NCS compared with the primary analysis. The results were presented at AAAAI 2026 and are reported to support earlier top-line results. Undetermined at this time.