F**k Cancer! With Breakthrough Melanoma Drug

breakthrough melanoma drug

Malignant melanoma

After a recent successful phase 1 clinical trial the FDA have approved a breakthrough melanoma drug. This drug called Keytruda (pembrolizumab) proved so successful it is being fast tracked to market by the FDA.

Melanoma is a type of skin cancer that causes about 5% of all cancers in the US. It starts in the skin cells that produce the pigment melanin. Melanoma is the most dangerous form of skin cancer. This is due to its high rate of metastasis, spread to different parts of the body. The cause of the cancer is UV exposure, i.e. sunburn from the bright glowing orb known as the sun.

Breakthrough Melanoma Drug Rushed towards Approval

The breakthrough melanoma drug is the first anti-PD-1 receptor drug, it targets the programmed death receptor-1. In a trial by merck consisting of 89 patients with advanced melanoma there was a response rate, meaning tumor shrinkage, at the rate of 24%. One complete response and 20 partial responses in the trial. Of the patients that had a response, 86% continued to have ongoing responses for months after treatment. 40% of the patients is still responding to treatment as late as 6 months or more later.

In the main trial involving 600 patients with an advanced form of melanoma tumors shrunk in 72% of the patients given the Keytruda drug. 34% of patients showed what’s called an objective response  where tumors shrunk by more than 30% and didn’t regrow.

Keytruda is another of a long line of drugs that are monoclonal antibodies. The Keytruda antibody blocks the PD-1 receptor preventing binding and activation by the molecules that normally bind to it. This receptor exists on the surface of T-cells and is usually up-regulated in tumors. This up regulation causes suppression of the immune system’s T-cells that usually attack the cancer.  Activation of the PD-1 receptor causes the immune system to “hold” its attack on cancer cells. The Keytruda drug releases this “hold” on the immune cells enabling them to attack the cancer cells.

To use the immune system to treat cancers that have spread far from the original tumor site is an interesting approach. This fast track of a breakthrough melanoma drug could help increase survivability in these very advanced forms of cancers.

Content image credit: National Cancer Institute via wikimedia, public domain

Cover image credit: A healthy T-cell, NIAID via flickr.com in accordance with CC BY 2.0