Trial results for the Phase 3 open-label extension study of depemokimab (NCT05243680) in participants with severe asthma were posted on ClinicalTrials.gov on 2026-01-15. The study characterized the long-term safety, efficacy, and immunogenic profile of depemokimab, with annualized rates of clinically significant exacerbations reported as 0.58 and 0.55 per participant per year across treatment groups.
Background
The study investigated depemokimab in participants with severe asthma with an eosinophilic phenotype who had previously completed other clinical studies (206713 or 213744).
Trial design
The study, identified as NCT05243680, was a Phase 3 open-label extension study that enrolled 641 participants with asthma. Its purpose was to continue to characterize the long-term safety, efficacy, and immunogenic profile of GSK3511294 (depemokimab) at a 100 mg SC dose over 12 months. Participants included those who had previously received either placebo or GSK3511294 in prior clinical studies (206713 or 213744) and then all received depemokimab in this extension study.
Key results
The extension study provided data on long-term safety, immunogenicity, and efficacy outcomes:
- Adverse Events (AEs) and Serious Adverse Events (SAEs): Among participants who were on placebo in previous studies and then received depemokimab 100 mg SC in the extension, 147 Participants experienced any AEs and 21 Participants experienced SAEs. For those who were on depemokimab in previous studies and continued with depemokimab 100 mg SC, 301 Participants experienced any AEs and 38 Participants experienced SAEs.
- Anti-Drug Antibodies (ADA): The number of participants with worst case post-baseline positive anti-GSK3511294 antibodies was 15 Participants in the group previously on placebo and 40 Participants in the group previously on depemokimab.
- Neutralizing Antibodies: 0 Participants in the group previously on placebo developed worst case post-baseline positive neutralizing antibodies, compared to 5 Participants in the group previously on depemokimab.
- Annualized Rate of Clinically Significant Exacerbations: The mean annualized rate was 0.58 Exacerbation per participant per year for the group previously on placebo and 0.55 Exacerbation per participant per year for the group previously on depemokimab. Both groups had a dispersion type of 95% Confidence Interval.
- Change From Baseline in Asthma Control Questionnaire-5 (ACQ-5) Score: The least squares mean change was -0.28 Scores on a Scale (Standard Error: 0.056) for the group previously on placebo, and -0.16 Scores on a Scale (Standard Error: 0.039) for the group previously on depemokimab.
What this means
The results from this 12-month open-label extension study provide further characterization of depemokimab's long-term profile in severe asthma. The annualized rates of clinically significant exacerbations were similar across both groups in the extension study, suggesting sustained efficacy for those continuing treatment and benefit for those initiating treatment after prior placebo exposure. The observed rates of adverse events, serious adverse events, and anti-drug antibodies were higher in participants with longer overall exposure to depemokimab, which is consistent with the nature of an extension study and helps to characterize the long-term safety and immunogenic profile of the drug. The improvement in ACQ-5 scores indicates a positive impact on asthma control for participants in both groups during the extension period.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT05243680, titled "An Open-Label Extension Study of GSK3511294 (Depemokimab) in Participants Who Were Previously Enrolled in 206713 (NCT04719832) or 213744 (NCT04718103)," were posted on 2026-01-15 on clinicaltrials.gov.