New Combination Treatment May Help Slow Advanced Melanoma

Immunotherapy has improved outcomes for many people with advanced melanoma, but it doesn’t work for everyone. Some patients do not respond to treatment, while others eventually see their cancer begin growing again. 

New results from a global phase 3 clinical trial suggest a potential way to improve today’s standard treatments. Physician-scientists found that adding HBI-8000 to the immunotherapy drug nivolumab helped patients go longer before their cancer worsened compared with nivolumab alone. 

The findings were presented at the European Society for Medical Oncology (ESMO) Congress 2026. 

Building on Today’s Melanoma Treatments 

Nikhil Khushalani, MD

Melanoma is the most serious form of skin cancer. While many cases can be successfully treated when caught early, advanced melanoma can spread to other parts of the body and become more difficult to treat. 

The introduction of immune checkpoint inhibitors, including drugs such as nivolumab and pembrolizumab, changed the outlook for many patients with advanced melanoma by helping the immune system recognize and attack cancer cells. These therapies are now a standard treatment for advanced disease and have helped many patients live longer. 

“Immunotherapy has significantly improved outcomes for many patients with advanced melanoma, but there is still a need for additional treatment options,” said Nikhil Khushalani, MD, principal investigator of the study and vice chair of the Cutaneous Oncology Department at Moffitt Cancer Center. 

A Different Way To Enhance Immunotherapy 

HBI-8000 is an oral medication designed to make melanoma more responsive to immunotherapy. 

The drug belongs to a class of medicines known as histone deacetylase, or HDAC, inhibitors. Unlike immunotherapy, it does not directly help the immune system find and attack cancer. Instead, it is designed to change conditions within and around a tumor in ways that may help immunotherapy work more effectively. 

“We wanted to understand whether adding HBI-8000 could improve the benefits patients receive from immunotherapy,” Khushalani said. 

Results From a Global Study 

The phase 3 study included 404 patients with advanced melanoma across 15 countries. Participants received either HBI-8000 plus nivolumab or nivolumab with a placebo. 

Patients who received the combination treatment lived a median of 11.7 months before their cancer worsened, compared with 7.4 months for those who received nivolumab alone. Patients were followed for a median of 37 months, giving investigators a longer-term view of how the treatment performed. 

Side effects seen with the combination were generally consistent with those previously reported for HDAC inhibitors and were considered manageable. Rates of hormone-related side effects were similar between patients who received the combination and those treated with nivolumab alone. 

Expanding Treatment Options 

Based on the results, investigators say the combination could become a new first-line treatment option for patients with advanced melanoma that cannot be removed with surgery. 

“We’ve seen significant progress in melanoma treatment over the last decade,” Khushalani said. “Studies like this help us understand how we can continue building on those advances and provide physicians with additional options for treating patients.”

Tune in from #ESMO2026 with @DrKhushalani 👇

— Moffitt Cancer Center (@MoffittNews) October 24, 2026

What’s Next 

The findings add to ongoing efforts to improve treatment for advanced melanoma and build on the success of immunotherapy. 

Additional regulatory review will be needed before the combination can become widely available. If approved, HBI-8000 and nivolumab could provide physicians with another option for treating patients with advanced melanoma that cannot be removed with surgery.