Dr Nikhil Khushalani talks to ecancer at ESMO 2026 about the primary analysis of the phase III HBI-8000-303 trial, evaluating the addition of the histone deacetylase (HDAC) inhibitor HBI-8000 to nivolumab in patients with unresectable or metastatic melanoma.

The study randomised 404 patients to receive HBI-8000 plus nivolumab or placebo plus nivolumab.

After a median follow-up of 37 months, the combination significantly improved median progression-free survival (11.7 versus 7.4 months; HR 0.73; p=0.0141) and achieved a higher objective response rate (41.4% versus 32.3%).

However, grade 3 or higher treatment-related adverse events were more frequent with the combination (55% versus 18%).

The findings suggest that HBI-8000 plus nivolumab offers a promising treatment option for patients with advanced melanoma who have not previously received anti-PD-(L)1 therapy, although increased toxicity remains an important consideration.