Melanoma Therapy Added to the PBS

From 1 February 2024, Opdualag® will be available on the Pharmaceutical Benefits Scheme (PBS) for the treatment of advanced melanoma. Opdualag® is a combination of two immune checkpoint inhibitors, nivolumab and relatlimab.

Nivolumab inhibits the programmed death 1 (PD‑1) receptor from binding to its ligands (PD‑L1 and PD‑L2). This reduces PD-1 pathway-mediated immune inhibition and can restore anti-tumour immune responses. Relatlimab blocks lymphocyte-activation gene 3 (LAG-3). Inhibition of this cell-surface molecule promotes T-cell proliferation and cytokine secretion. Studies suggest that inhibiting these two pathways offers synergistic anti-tumour activity.

A recent trial comparing nivolumab with nivolumab plus relatlimab in a fixed-dose combination found that median progression-free survival was 10.1 months (95% CI: 6.4-15.7) in the combination group compared with 4.6 months (95% CI: 3.4-5.6) in the nivolumab group. Patients receiving the combination therapy experienced more adverse events of any grade (97.2% vs 94.4%) and more adverse events of grade 3 or higher (40.3% vs 33.4%). Serious adverse events in the nivolumab plus relatlimab group include hepatitis, adrenal insufficiency, diarrhoea or colitis, fatigue, and renal dysfunction.

The usual recommended dose is 480 mg nivolumab and 160 mg relatlimab (i.e. two vials). This is administered as a 30-minute intravenous infusion once every four weeks until disease progression or unacceptable toxicity.