FDA Approves PD-L1 Immunotherapy Developed by Pfizer and Merck KGaA

Pfizer and Merck KGaA’s PD-L1 inhibitor, Bavencio (avelumab), has become the first immunotherapy to be approved by the US Food and Drug Administration (FDA) to treat a rare form of skin cancer, known as metastatic Merkel cell carcinoma (MCC). The drug is the fourth checkpoint inhibitor to be approved in the US.

As patients with MCC currently have no other approved treatment options, Bavencio was approved under the FDA’s accelerated approval process. The approval is conditional on the drugmakers conducting additional clinical trials to back-up their efficacy claims for the immunotherapy.

“At the heart of this FDA approval is our drive to make a meaningful difference for patients with hard-to-treat cancers like metastatic Merkel cell carcinoma,” said Belén Garijo, CEO Healthcare and Member of the Executive Board of Merck KGaA. “Bavencio’s journey has included years of hard work – from the scientists who discovered this molecule in our labs, to our alliance with Pfizer and to the study participants and investigators worldwide. We are grateful to all who have made it possible for us to bring this important new treatment option to patients.”

The checkpoint inhibitor drugs bolster a patient’s immune system to help them destroy cancer cells. While the immunotherapy could be beneficial to a range of patients, some trials have found that patients who naturally express higher levels of PD-L1 may show an increased benefit from the therapy.

In an effort to broaden the patient population who might respond to PD-L1 inhibitors, drugmakers have been pairing their immunotherapy treatments with other cancer therapies. For example, Merck Inc.’s Keytruda is being combined with chemotherapy to improve its efficacy.

“Merkel cell carcinoma is rarer than some of the more well-known skin cancers, however, it’s very aggressive and the proportion of people who die from MCC is much higher than that of people with melanoma,” said Dr. Deborah S. Sarnoff, President of the Skin Cancer Foundation. “With this approval, I believe there is new hope for people and their families touched by this rare form of skin cancer.”

The approval was based on results from a small clinical trial involving 88 patients with MCC who had previously been treated using chemotherapy. Just over 30 percent of patients experienced tumor shrinkage in response to treatment with Bavencio. Eighty-six percent of those that responded to treatment saw improvements that lasted more than 6 months, while 45 percent of responders saw improvements lasting over one year.

Development of Bavencio was shared by both Pfizer and German Merck, and commercialization of the therapy will also be collaborated upon. Pfizer first began development of Bravencio with Merck in late 2014, when Pfizer paid the pharmaceutical company $850 million, with an additional $2 billion conditional on meeting milestones.