relatlimab — Drug Monograph

Brand names: Opdualag (with nivolumab)

Drug class: Checkpoint Inhibitor

Mechanism of Action

LAG-3 (Lymphocyte-Activation Gene 3) blocking monoclonal antibody. LAG-3 is an inhibitory co-receptor expressed on exhausted CD4+ and CD8+ T cells, and its engagement by MHC class II molecules (and other ligands) suppresses T-cell proliferation and effector function. Relatlimab blocks LAG-3 signaling, restoring T-cell activity. When combined with nivolumab (PD-1 blockade), dual checkpoint inhibition achieves synergistic reinvigoration of tumor-infiltrating T cells. Relatlimab is only available as a fixed-dose combination with nivolumab (Opdualag: relatlimab 160 mg + nivolumab 480 mg per 20…

FDA Indications

• Unresectable or metastatic melanoma (adults and pediatric patients ≥12 years), as a fixed-dose combination with nivolumab (Opdualag) (FDA approval March 2022, RELATIVITY-047: PFS 10.1 vs 4.6 months, HR 0.75; OS HR 0.80 vs nivolumab monotherapy)

Common Side Effects

• Fatigue
• Musculoskeletal pain
• Rash
• Pruritus
• Diarrhea
• Hypothyroidism
• Nausea
• Decreased appetite

Clinical Pearl

Relatlimab represents the first approved LAG-3 inhibitor in oncology and the first approved dual checkpoint combination targeting two distinct co-inhibitory receptors (LAG-3 + PD-1). RELATIVITY-047 showed ~2-fold improvement in PFS vs nivolumab alone in first-line metastatic melanoma. Importantly, LAG-3 and PD-1 co-expression on tumor-infiltrating lymphocytes (TILs) is a biomarker of T-cell exhaustion; dual blockade is synergistic. The irAE profile resembles nivolumab but with higher rates due…

Related Therapies & Mechanisms

• Ipilimumab (Yervoy) — Checkpoint Inhibitor · Melanoma
• Nivolumab (Opdivo) — Checkpoint Inhibitor · Melanoma
• Pembrolizumab (Keytruda) — Checkpoint Inhibitor · Melanoma
• Atezolizumab (Tecentriq) — Checkpoint Inhibitor