Nivolumab/Relatlimab-rmbw: A Novel Dual Combination Therapy to Treat Adult and Pediatric Patients With Unresectable or Metastatic Melanoma

BACKGROUND: Immune checkpoint inhibitors control effector mechanisms and work to restore downregulated T-cells in patients with melanoma. Examples of such include programmed death-1 inhibitors and lymphocyte-activating gene 3 inhibitors. The combination of nivolumab, a programmed death-1 inhibitor, and relatlimab-rmbw, a lymphocyte-activating gene 3 inhibitor, has shown antitumor activity and improved progression-free survival in patients with unresectable or metastatic melanoma. MECHANISM OF ACTION PHARMACOKINETICS/PHARMACODYNAMICS: The fixed-dose combination of nivolumab and relatlimab immunotherapy is approved for adults and pediatrics 12 years of age or older with metastatic or unresectable melanoma. Volume of distribution is 6.6 L for relatlimab and nivolumab, and half-life is 27 and 26 days, respectively. Clearance at steady state is 7.6 mL/h for nivolumab and 5.5 mL/h for relatlimab. Sex, age, race, and mild hepatic/renal impairment had no clinical effect on clearance. The exposure-response relationship and pharmacodynamic response for the safety and effectiveness of nivolumab/relatlimab-rmbw have not been fully characterized. Safety concerns include severe and fatal immune-mediated adverse reactions, infusion-related reactions, and complications of allogeneic hematopoietic stem cell transplantation, and fetal toxicity. Dosing is determined by patient's age and weight. Solution is infused over a 30-minute timeframe. CLINICAL TRIALS: In the RELATIVITY-047 trial, patients received nivolumab or nivolumab/relatlimab-rmbw. Results showed superiority of dual therapy over monotherapy with a progression-free survival of 10.1 months (95% CI, 6.4-15.7) compared with 4.6 months (95% CI, 3.4-5.6) and hazard ratio of 0.75 (95% CI, 0.62-0.92); P = 0.006, respectively. No safety concerns were observed compared with monotherapy with treatment-related adverse events occurring in 18.9% of patients on combination therapy compared with 9.7% on nivolumab alone. THERAPEUTIC ADVANCE: The novel mechanism and improvement in progression-free survival compared with standard of care highlight the therapeutic advancement of nivolumab/relatlimab-rmbw in the treatment of unresectable and metastatic melanoma.