Results from the Phase 3 open-label extension study of Depemokimab (NCT05243680) for severe asthma were posted on ClinicalTrials.gov on 2025-05-19. The study continued to characterize the long-term safety, efficacy, and immunogenic profile of Depemokimab, reporting annualized rates of clinically significant exacerbations of 0.58 and 0.55 per participant per year across two treatment groups.
Background
Depemokimab is an investigational drug for severe asthma with an eosinophilic phenotype. This Phase 3 extension study aimed to gather long-term data on its safety, efficacy, and immunogenicity.
Trial design
The Phase 3 open-label extension study (NCT05243680) enrolled 641 participants with severe asthma with an eosinophilic phenotype. The study aimed to characterize the long-term safety, efficacy, and immunogenic profile of GSK3511294 (Depemokimab). Participants were from prior studies and were grouped based on their previous treatment: one group received Depemokimab 100 mg SC in the extension after receiving placebo previously, and another group continued Depemokimab 100 mg SC after receiving it in previous studies. Primary outcome measures were not detailed in the provided data.
Key results
The study reported on various safety, immunogenicity, and efficacy outcomes. For 'Number of Participants With Any Adverse Events (AEs) and Serious AEs (SAEs)':
- In the group that received placebo previously and Depemokimab in the extension, 147 participants experienced any AEs and 21 participants experienced SAEs.
- In the group that continuously received Depemokimab, 301 participants experienced any AEs and 38 participants experienced SAEs.
Regarding immunogenicity, for 'Number of Participants With Worst Case Post-Baseline Positive Anti-GSK3511294 Antibodies (ADA)':
- 15 participants in the placebo/Depemokimab group developed positive ADA, while 40 participants in the continuous Depemokimab group developed positive ADA.
- For 'Number of Participants With Worst Case Post-Baseline Positive Neutralizing Antibodies', 0 participants in the placebo/Depemokimab group and 5 participants in the continuous Depemokimab group developed positive neutralizing antibodies.
For 'Annualized Rate of Clinically Significant Exacerbations':
- The group that received placebo in previous studies and Depemokimab in the extension study had a mean rate of 0.58 exacerbation per participant per year.
- The group that received Depemokimab in previous studies and continued with Depemokimab in the extension study had a mean rate of 0.55 exacerbation per participant per year.
For 'Change From Baseline in Asthma Control Questionnaire-5 (ACQ-5) Score':
- The least squares mean change for the placebo/Depemokimab group was -0.28 scores on a scale (Standard Error: 0.056).
- The least squares mean change for the continuous Depemokimab group was -0.16 scores on a scale (Standard Error: 0.039).
What this means
This Phase 3 open-label extension study provides further insights into the long-term safety, immunogenicity, and efficacy profile of Depemokimab in participants with severe asthma. Annualized rates of clinically significant exacerbations were similar across both treatment groups. Participants who initiated Depemokimab after previously receiving placebo showed a numerically greater mean improvement in ACQ-5 scores compared to those who continuously received Depemokimab. The study also characterized adverse events, serious adverse events, and the development of anti-drug antibodies and neutralizing antibodies.
Source
The information for this article 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 2025-05-19 on clinicaltrials.gov.