Patients with Merkel cell carcinoma (MCC) are a step closer to having access to the first drug indicated for the disease after regulators in Europe validated a marketing application for Merck KGaA and Pfizer's avelumab.

MCC is a rare and aggressive skin cancer affecting around 2,500 Europeans a year. Patients face a very bleak prognosis, with less than 20 percent surviving beyond five years.

Validation of the application, which kickstarts the review process, could eventually result in the first approved treatment indicated for metastatic MCC in the EU.

The submission is supported by data from JAVELIN Merkel 200, a multicenter, single-arm, open-label, Phase II study of 88 patients with metastatic MCC whose disease had progressed after at least one chemotherapy treatment.

The data, recently published in the Lancet Oncology, showed durable responses to drug; the proportion of patients who achieved an objective response was 28 (31·8 percent) of 88 patients, including eight complete responses and 20 partial responses.

"While early-stage Merkel cell carcinoma can be generally managed with surgery, there are significant unmet needs in metastatic disease, where treatment options are severely limited," said Luciano Rossetti, global head of research and development at Merck's biopharma business.

"We are pleased that the EMA is initiating its review of avelumab, as this means we are one step closer to bringing a much-needed new treatment option to European patients."

Avelumab, a fully human anti-PD-L1 IgG1 monoclonal antibody, has not yet been approved anywhere in the world. The clinical development programme for the drug, known as JAVELIN, is evaluating its potential across more than 15 different tumour types, including breast, gastric/gastro-esophageal junction, head and neck, Hodgkin's lymphoma and urothelial (primarily bladder).