US FDA approves Merck KGaA and Pfizer drug for rare skin cancer

US health regulators on Thursday approved a drug developed by Merck KGaA and Pfizer Inc that helped the immune system to fight a rare form of skin cancer once it had spread to other parts of the body.

The Food and Drug Administration (FDA) said the drug Bavencio, known chemically as avelumab, had been approved to treat metastatic Merkel cell carcinoma (MCC) in patients 12 years and older.

Bavencio belongs to a new class of oncology drugs called PD-L1 inhibitors that block a mechanism used by tumours to evade detection from the immune system.

The approval marked the first immunotherapy approval for the collaboration of Pfizer and Germany-based Merck, which had been looking to catch-up with rivals, such as Bristol-Myers Squibb Co, Merck & Co and Roche Holding AG.

"While skin cancer is one of the most common cancers, patients with a rare form called Merkel cell cancer have not had an approved treatment option until now," Dr Richard Pazdur, director of the FDA's Oncology Center of Excellence, said in a statement.

Bavencio received accelerated approval, which enabled the use of drugs for serious conditions to fill an unmet medical need on the basis of data the agency believed was likely to predict a clinical benefit.

The companies were conducting required trials to confirm actual benefit to patients.

 ''The scientific community continues to make advances targeting the body's immune system mechanisms for the treatment of various types of cancer. These advancements are leading to new therapies - even in rare forms of cancer where treatment options are limited or non-existent,'' Pazdur said.

According to the National Cancer Institute, approximately 1,600 people in the US were diagnosed with MCC every year and even as the majority of patients presented with localised tumours that could be treated with surgical resection, approximately half of all patients experienced recurrence, and over 30 per cent developed metastatic disease.