Nivolumab – a new treatment option in melanoma

The authors aimed to determine whether nivolumab (Opdivo) can improve survival in advanced melanoma patients without the BRAF mutation. 

Nivolumab is a man-made immune cell (protects the body from disease). It works by blocking a protein called programmed cell death 1 (PD-1) that is found on active immune cells. Cancer cells produce a substance which attaches to PD-1. Together, these stop the immune cells from destroying cancer cells so that the cancer grows uninhibited.

Nivolumab stops PD-1 from attaching this substance. This allows the immune cells to work properly in killing the cancer cells and can increase survival rates in advanced melanoma (cancer has spread to another part of the body).

BRAF is a gene that produces a protein responsible for cell growth. It is thought to be mutated (altered so that it does not function properly) in 40 – 60% of melanomas. However, many current treatments target this mutation, and options are limited for patients without the mutation. It is hoped that nivolumab may be beneficial in these patients. 

The aim of this study was to determine whether nivolumab could increase survival in advanced melanoma patients without the BRAF mutation.

This study involved 418 patients. They were randomly split into two groups. 210 patients received nivolumab and 208 patients received dacarbazine (previously dacarbazine was the first option treatment used in advanced melanoma without a BRAF mutation).

The overall survival rate at 1 year for the nivolumab group was 72.9% compared to 42.1% in the dacarbazine group. The average progression-free survival (time during and after treatment where patient lives and cancer does not progress) was 5.1 months in the nivolumab group compared to 2.2 months in the dacarbazine group. The objective response rate (a measurable response, such as tumor shrinkage) of the nivolumab group was 40% compared to 13.9% in the dacarbazine group.

The overall response to nivolumab was as follows: 7.6% of patients had a complete response (complete disappearance of signs and symptoms of cancer) to treatment, 32.4% had a partial response (at least 50% of the signs and symptoms had disappeared) to treatment, 16.7% were classified as having a stable disease (disease status remains the same) and 32.9% of patients had a progressive disease (new tumor growth or the cancer has spread).

Nivolumab had a low risk of toxic side effects.

The authors concluded that nivolumab increased survival in advanced melanoma patients.

Dacarbazine is no longer the first line treatment in melanoma with BRAF mutations so the results cannot be compared to the existing preferred treatment.