Merck and Pfizer’s new immunotherapy, avelumab, has been approved by the European Commission to treat metastatic Merkel cell carcinoma, an aggressive form of skin cancer.
The approval is based on data from a Phase II study, JAVELIN Merkel 200, where subjects responded well to treatment for a sustained period of time. Earlier this year, Avelumab was approved in the US and Switzerland, and its EC approval means it could be released in the UK and Germany as early as next month. Release in the remaining EU countries, as well as Norway, Liechtenstein, and Iceland will follow.
Avelumab is a monoclonal antibody that acts as an immune checkpoint inhibitor. Checkpoint inhibitors prevent cancer cells from pressing ‘brakes’ on immune cells that dampen their response. By specifically binding one of these ‘brakes’, programmed death ligand-1 (PD-L1), avelumab prevents cancer cells from escaping immune cells.PD-L1 on cancer cells turns off T cells by binding their PD-1 receptor. PD-L1 and PD-1 inhibitors have since been developed as potential cancer therapies.
Metastatic Merkel cell carcinoma (mMCC) is a particularly rare and aggressive form of skin cancer. Risk factors include sun exposure and infection with the Merkel cell polyomavirus. Caucasian males over the age of 50 are also at a heightened risk. Stages I and II of disease progression are localized to the skin, usually in areas that are regularly exposed to the sun, for example, the head, neck, and arms. As it progresses to stages III and IV, tumors spread to the lymph nodes and beyond.
Current treatment options for the dangerous skin cancer are limited to surgery, chemotherapy, and radiotherapy, so avelumab offers an alternative approach. A lot of hype surrounds the targeting of PD-L1, and Roche won the race to release the first PD-L1 checkpoint inhibitor onto the market for the treatment of bladder cancer. In the field of skin cancer, competition comes in the shape of Actelion’s compound, chlormethine, which is described as a ‘modern-day chemotherapy’.
Although immune checkpoint inhibitors offer a new way of treating cancer, there are problems. They appear to have some nasty side effects if they misfire. The FDA commenced the Breakthrough Therapy Designation in 2012, and this has seen many immunotherapies, including checkpoint inhibitors, fast-tracked. Although it’s clear that a new approach to mMCC would make a big difference, it is worth taking the time to make sure that patients are not put at risk.
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