Depemokimab Shows Significant Improvements in Rhinosinusitis with Nasal Polyps: New Research

Depemokimab demonstrated statistically significant improvements in nasal polyp size and nasal obstruction compared to placebo when administered alongside standard of care in patients with chronic rhinosinusitis with nasal polyps (CRSwNP), according to a release from GSK.¹

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In a March 1, 2025, press release, the company announced full results from its ANCHOR-1 and ANCHOR-2 phase 3 clinical trials. Depemokimab is an investigational, “ultra-long-acting” monoclonal antibody manufactured to target interleukin-5 (IL-5), the main cytokine triggering inflammation in 85% of patients with CRSwNP.¹

“Today’s data build on the body of evidence supporting depemokimab as an ultra-long-acting treatment and demonstrate significant reductions in nasal polyps with a twice-yearly dosing regimen,” Kaivan Khavandi, MD, MRes, PhD, and Global Head of Respiratory, Immunology/Inflammation R&D at GSK, said in the release.¹ “With nearly 40% of patients needing repeat surgeries and many requiring long-term systemic corticosteroids, there is a clear medical need for alternative treatment options to provide sustained symptom improvement and help alleviate the debilitating burden of this disease.”

The findings from each study were also presented at the 2025 AAAAI/WAO Joint Congress in San Diego and published in The Lancet.²

A total of 528 patients participated in the studies: 272 received depemokimab (ANCHOR-1: 143, ANCHOR-2: 129), and 256 received placebo (ANCHOR-1: 128, ANCHOR-2: 128). Depemokimab demonstrated significant improvements over placebo in both primary endpoints, which included total endoscopic nasal polyp score (NPS) and nasal obstruction.²

In pooled analysis, depemokimab demonstrated a treatment difference of -0.7 in NPS at 52 weeks (95% CI, -0.9 to -0.4, p<0.001) and a -0.24 treatment difference in nasal obstruction over weeks 49-52 (95% CI, -0.39 to -0.08, p=0.003). These outcomes suggest that depemokimab could offer a more effective, long-term option for managing CRSwNP compared to current treatment options, which include surgery and systemic corticosteroids.^1,2

The ANCHOR trials enrolled patients with inadequate control of CRSwNP symptoms, including nasal polyps, and reflected a broad range of symptom severity typical of real-world clinical practice. Notably, by week 52, 74% of patients receiving depemokimab had not required additional interventions, such as systemic corticosteroids, surgery, or disease-modifying medications, compared to 64% of patients in the placebo group.¹

In secondary endpoint analyses, depemokimab also showed nominally significant improvements in rhinorrhoea, loss of smell, and the Lund-Mackay CT score, a sinus imaging assessment. Additionally, the SNOT-22 score, which measures disease-related quality of life, improved in the depemokimab group.¹

Regarding safety, the incidence of adverse events (AEs) was similar between the depemokimab and placebo groups. In ANCHOR-1, 74% of patients receiving depemokimab experienced AEs, compared to 79% in the placebo group. In ANCHOR-2, 76% of the depemokimab group and 80% of the placebo group reported AEs. Serious adverse events were rare, with none considered related to study treatment by investigators. A small number of patients in both groups discontinued the trial due to AEs (<1% in the depemokimab group and 1% in the placebo group).¹

Depemokimab is currently being evaluated in other IL-5 mediated conditions, such as severe asthma and eosinophilic granulomatosis with polyangiitis. While the medication is not yet FDA-approved for any indications, GSK is using the findings from the ANCHOR and SWIFT phase 3 trials to support regulatory filings in various countries.¹

References:

1. Depemokimab delivers clinically meaningful and statistically significant improvements for patients with chronic rhinosinusitis with nasal polyps (CRSwNP). News release. GSK. March 1, 2025. Accessed March 5, 2025. https://www.gsk.com/en-gb/media/press-releases/depemokimab-delivers-clinically-meaningful-and-statistically-significant-improvements-for-patients-with-chronic-rhinosinusitis-with-nasal-polyps-crswnp/

2. Han J, Cornet M, Mullol J, et al. Efficacy and safety of twice per year depemokimab in chronic rhinosinusitis with nasal polyps (ANCHOR-1 and ANCHOR-2): phase 3, randomised, double-blind, parallel trials. Lancet. Published online February 28, 2025. doi: 10.1016/S0140-6736(25)00197-7