資料來源：https://www.fiercepharma.com/marketing/pfizer-merck-kgaa-enter-starting-gate-cancer-immunotherapy-bavencio

Pfizer and Merck KGaA are officially fourth to market with their checkpoint inhibitor avelumab—but first with approval to target a rare, aggressive form of skin cancer, Merkel cell carcinoma.

Now branded as Bavencio, the drug follows immuno-oncology market leaders from Bristol-Myers Squibb, Merck & Co. and Roche, but squeaked in ahead of AstraZeneca’s durvalumab, which is under priority review at the agency. The two companies are testing Bavencio in more than two dozen studies in a variety of other cancers where it would compete head to head with those previously approved meds.

Bavencio won his first FDA nod under the agency’s accelerated approval program, based on a single-arm, 88-patient study in which one-third of participants saw their tumors shrink partially or completely, and 86% of patients who responded were still seeing results with therapy six months later.

About 1,600 people are diagnosed with Merkel cell carcinoma (MCC) every year in the U.S., the FDA said in a statement about the approval. In more than 30% of those patients, the disease has metastasized, or spread beyond the skin to other parts of the body. Bavencio is approved to treat patients with metastatic disease, and it’s the only drug specifically blessed to do so.

This approval adds another new cancer drug to Pfizer’s stable, where CDK4/6 inhibitor Ibrance now ranks as a fast-growing favorite child. And it’s a payoff for Merck, which hasn’t seen a new drug approval in more than 10 years. As part of its avelumab deal with Pfizer, the Darmstadt, Germany-based company stands to earn up to $2 billion in regulatory and commercial milestone payments.

With the MCC nod, Bavencio has its foot in the PD-1/PD-L1 door, where Pfizer and its partner are hoping eventually to compete with Bristol-Myers’ Opdivo, Merck & Co.’s Keytruda and the more recently approved contender from Roche, Tecentriq. Each of these meds has a set of indications in various cancers, with Opdivo and Keytruda, as the first two out of the gate, boasting the longest lists, including nods in melanoma, lung cancer and head and neck cancer.

Pfizer and Merck are studying Bavencio in non-small cell lung cancer (NSCLC), kidney cancer, ovarian cancer, bladder cancer and others, and it’s testing the med alongside some of Pfizer’s other meds in combination approaches.

The lung cancer field is the most hotly contested of these, and the two partners are looking to file their med in second-line NSCLC later this year. But, apparently mindful of some recent data posted by Opdivo and Keytruda, they’ve reworked the design of their trial of avelumab as a monotherapy in first-line lung cancer.

Among the tweaks: The primary endpoint was changed to comprise both progression-free survival and overall survival, and it will examine only patients with high expression of the PD-L1 biomarker, as opposed to those with any level of PD-L1. Plus, the size of the trial will more than double to 1,095 from 420.

Pfizer teamed up with the German Merck on cancer immunotherapies—Merck’s avelumab and a PD-1 in Pfizer’s pipeline—back in 2014, in a deal worth up to $2.8 billion, including $850 million up front. The partners are sharing development and commercialization costs and will share revenue 50-50 as well.

The partnership also includes co-promotion of Pfizer’s targeted lung cancer drug Xalkori in the U.S. and selected other markets.