Pfizer's BRAF Inhibitor Encorafenib Granted Clinical Trial Approval in China for Colorectal Cancer

According to information from the website of the Center for Drug Evaluation (CDE) under China’s National Medical Products Administration, Pfizer’s BRAF inhibitor encorafenib hard capsules have received implicit approval for a clinical trial, with plans to develop the drug for the treatment of colorectal cancer. Publicly available data indicate that encorafenib was acquired by Pfizer through its $11.4 billion purchase of Array Biopharma. The drug has already been approved by the U.S. FDA for the treatment of adult patients with metastatic colorectal cancer harboring the BRAF V600E mutation.

Colorectal cancer is one of the most common types of cancer worldwide. BRAF gene mutations occur in approximately 15% of metastatic colorectal cancer cases, and these patients have a particularly poor prognosis. The V600 mutation is the most common BRAF gene mutation, and patients carrying the BRAF V600E mutation have twice the risk of death compared to those with wild-type BRAF genes.

Encorafenib is an oral BRAF inhibitor developed by Array Biopharma. In June 2019, Pfizer acquired Array for $11.4 billion, gaining a portfolio of cancer targeted therapies including encorafenib. In the United States, the FDA approved encorafenib in combination with the EGFR inhibitor cetuximab in April 2020 for the treatment of adult patients with previously treated metastatic colorectal cancer harboring the BRAF V600E mutation. Publicly available information indicates that this was the first FDA-approved targeted therapy regimen for this patient population.

In the Phase 3 BEACON CRC clinical trial, researchers evaluated the efficacy of encorafenib in combination with cetuximab for the treatment of previously treated metastatic colorectal cancer patients harboring the BRAF V600E mutation. The data showed that the median overall survival (OS) was 8.4 months in patients receiving the combination therapy, compared to 5.4 months in the control group. Furthermore, the objective response rate (ORR) was 20% in the combination therapy group, versus only 2% in the control group.

Notably, Pfizer is also exploring the efficacy of encorafenib in combination with other agents for the treatment of colorectal cancer. At its 2020 virtual Investor Day, Pfizer presented results from a Phase 2 clinical trial evaluating the triplet regimen of encorafenib, the MEK inhibitor binimetinib, and cetuximab as first-line therapy for patients with metastatic colorectal cancer. The trial demonstrated an objective response rate of 50% and a disease control rate of 85% in previously untreated patients with metastatic colorectal cancer harboring BRAF V600E mutations.

According to data released by the International Agency for Research on Cancer (IARC) of the World Health Organization, there were 1.93 million new cases of colorectal cancer and approximately 1.07 million deaths worldwide in 2020. Among these, 560,000 (29%) new cases and 290,000 (27%) deaths occurred in China. Patients with colorectal cancer harboring the BRAF V600E mutation are in urgent need of new treatment options.

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