Pfizer, partner German Merck see FDA accept PD-L1 candidate for speedy review

Pfizer has put $850 million on the table for its PD-L1 development deal with German Merck.

Pfizer and Merck KGaA took a step closer to becoming the fourth to market in the new checkpoint inhibitor space as they announce that the FDA has accepted for review their BLA for avelumab as they eye a possible 2017 approval.

Specifically, the FDA said it has accepted for priority review the partners PD-L1 for avelumab in patients with metastatic Merkel cell carcinoma (MCC), based on tumor response results from the JAVELIN Merkel 200 trial. Last year, it was also handed a breakthrough tag in this setting.

It could be the first treatment indicated for metastatic MCC (a rare and aggressive form of skin cancer in older patients) in the U.S., if approved, and likely be the fourth co to bring a checkpoint inhibitor to market after Bristol-Myers, Merck and most recently Roche.

It would also be the second to bring a PD-L1 after Roche’s Tecentriq (atezolizumab) got the FDA nod earlier this year. It is looking to beat out AstraZeneca’s durvalumab to market, which has been hit by a series of setbacks in testing, although it was earlier this year given an FDA breakthrough tag in bladder cancer.

This also comes a month after the EMA said it was to also review avelumab for Merkel cell carcinoma.

“We are pleased the FDA has granted a priority review designation for avelumab,” said Luciano Rossetti, EVP and global head of R&D at the biopharma business of Merck.

“There are currently no approved treatment options for metastatic MCC, and we are committed to working with the FDA to potentially bring the first approved cancer immunotherapy to patients with this aggressive disease.”

Back in the summer, Merck’s Keytruda (pembrolizumab) saw some promising data coming out of a test in MCC, but avelumab, which inhibits PD-L1 interactions, showed in a midstage trial back in May of 61 patients that about 30% of those with Merkel skin cell carcinoma who had failed on a previous treatment saw their tumors shrink or disappear when treated with the experimental cancer immunotherapy.

Merkel skin cell carcinoma develops in the top layer of the skin and is a rare type of neuroendocrine tumor. These typically occur in the head and neck and are predominately found in older patients, or those with weakened immune systems.

Current treatments include surgery and chemotherapy agents, although Novartis is currently conducting a study of its marketed cancer drug Votrient to see if it too can help Merkel patients.

The drug was not tested against another medicine or placebo, but researchers concluded from an interim analysis that avelumab demonstrated a manageable safety profile with durable responses.

In all, six patients (10%) experienced complete responses with no signs of cancer, while 12 others saw significant tumor shrinkage. The data were also presented at ASCO in Chicago.

Pfizer, which has lagged behind its Big Pharma rivals in this therapy class, signed an $850 million deal with Germany’s Merck back in 2014 to gain access to its PD-L1 program. The two are also testing the drug in a host of other cancers in NSCLC, renal cell carcinoma and ovarian, gastric and bladder cancer, as well as joining them up with other meds from Pfizer’s pipeline and portfolio to see if a cocktail therapy can extend patients’ lives.