Nivolumab in rare melanoma: is it effective in patients that progressed on ipilimumab?

This study investigated if nivolumab (Opdivo) is safe and effective in patients with rare melanoma subtypes (RMS) who progressed after ipilimumab (Yervoy). They found that this treatment was safe and improved survival in certain RMS.  

Melanoma the most common cancers. There are many subtypes of melanoma. The most common is non-acral cutaneous melanoma (NACM). Acral refers to cancer on the extremities such as palms, soles, nail beds or fingers. Other melanoma subtypes include mucosal (MM), ocular (OM; eye) and acral cutaneous melanoma (ACM). These account for approximately 15% of melanoma cases. 

Immune checkpoint inhibitors (ICIs) are a new type of drug to treat cancers including melanoma. Nivolumab (NVL) is an ICI that targets the PD-1 receptor. Ipilimumab (IPL) is an ICI that targets the CTLA-4 receptor. Both drugs are used to treat all types of melanoma. Some studies suggest that ICIs are more effective if cancer tumors have several mutations. This is called the tumor mutational burden (TMB). NACM has a high TMB. Other melanomas have a low TMB. It is unclear if ICIs are as effective in rare melanoma subtypes (RMS). 

This study included 1008 patients with melanoma. 71.7% had NACM. 10.2% had OM. 6.3% had MM, 5.5% had ACM and the rest had other rare subtypes. All patients were previously treated with IPL. These patients all had disease progression during or after IPL. Patients were prescribed NVL treatment. This was administered every 2 weeks for up to 2 years. The average follow-up period was 14.3 months.

Almost all patients stopped treatment before the end of the study. Severe side effects were reported in 14.6% of patients with OM, 20.6% with MM and 25.5% with ACM. This was compared to 18.8% of patients with NACM.

Overall survival (OS) rates at 18 months were similar in NACM and ACM patients (57.5% vs. 59%). Lower OS rates were observed in OM (34.8%) and MM (31.5%) patients. 

The authors concluded that NVL after IPL failure was safe and improved survival in certain RMS.

This study was funded by Bristol-Myers Squibb, the manufacturer of nivolumab.