ClinicalTrials.gov posted results on 26 August 2026 from a Phase 3 study of subcutaneous nivolumab plus relatlimab fixed-dose combination treatment in previously untreated metastatic or unresectable melanoma. Adjusted mean serum concentrations over the first 28 days were 4.141 ug/mL for nivolumab with subcutaneous treatment versus 3.901 ug/mL with intravenous treatment.

Background

The study evaluated a subcutaneous fixed-dose combination of nivolumab and relatlimab against the same combination given intravenously. Participants had previously untreated metastatic or unresectable melanoma. The registered interventions were nivolumab plus relatlimab and rhuph20.

Trial design

This was a Phase 3 trial enrolling 579 participants with melanoma. Its purpose was to determine whether exposure to the subcutaneous formulation was not worse than exposure to intravenous administration. The study status was active, not recruiting. The supplied record did not list primary outcome entries.

Key results

For adjusted time-averaged serum concentration over the first 28 days, nivolumab was 4.141 ug/mL with subcutaneous treatment, with a standard error of 0.0167, compared with 3.901 ug/mL and a standard error of 0.0164 with intravenous treatment. Relatlimab concentrations were 3.120 ug/mL and 2.721 ug/mL, respectively, with standard errors of 0.0186 and 0.0183.

At steady state, adjusted trough nivolumab concentration was 4.759 ug/mL for subcutaneous treatment versus 4.169 ug/mL for intravenous treatment. The corresponding relatlimab values were 3.629 ug/mL and 2.631 ug/mL. The registry also listed four adjusted mean differences with 90% confidence intervals: 0.239 (0.202–0.277), 0.398 (0.356–0.440), 0.591 (0.516–0.666), and 0.998 (0.880–1.116). The supplied record did not identify which measurement each analysis represented.

  • Objective response rate by BICR: 43.0% with subcutaneous treatment and 50.7% with intravenous treatment.
  • Disease control rate by BICR: 62.2% with subcutaneous treatment and 72.3% with intravenous treatment.

What this means

The posted pharmacokinetic results showed higher listed adjusted concentrations for both nivolumab and relatlimab with the subcutaneous formulation than with intravenous administration in this study. The response measurements were numerically higher in the intravenous group. The supplied data do not include p-values, complete confidence-interval values for the response rates, or an adverse-event summary, so they do not establish a comparative safety conclusion or a new approval.

Source

Source: ClinicalTrials.gov, trial-results record for NCT05625399, posted 26 August 2026. The registry record is available at clinicaltrials.gov/study/NCT05625399.