Keytruda is also approved for the use in the treatment of melanoma when the disease has spread and can not be removed by surgery, or the tumor is resistant to BRAF inhibitors, or the drug ipilimumab is not impacting the tumor.
The FDA's accelerated approval of Keytruda (pembrolizumab) in this setting marks the first time the agency has cleared a cancer treatment based on a common biomarker rather than the location in the body where the tumour originated.
It was the first time the US agency has approved a cancer therapy based on a common biomarker rather than the location in the body where the tumor originated, FDA said in a press release.
Keytruda, which is already approved to treat various cancers, belongs to a new class of drugs, called PD-1 or PD-L1 inhibitors, that block a mechanism tumors use to evade detection by the immune system.
The new pembrolizumab approval covers adult and pediatric patients with any type of tumor that exhibits microsatellite instability-high (MSI-H) or mismatch fix deficiency (dMMR).
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However, there is a chance that the storm shifts north slightly, which would result in an increase in rain during the day. Showers and thunderstorms expected to stay in the area into late Sunday evening and possibly into early Monday morning.
The safety and efficacy of Keytruda for this indication were studied in patients with MSI-H or dMMR solid tumors enrolled in one of five uncontrolled, single-arm clinical trials. The ORR was 36% in patients with CRC and 46% in patients with other tumor types. Ninety patients had colorectal cancer (CRC) and the remaining 59 patients had one of 14 other tumor types. Of those patients, 78% had a response that lasted for 6 months or longer.
Merck shares rose 0.8 percent to $64.55.
"This is an important first for the cancer community", said Dr. Richard Pazdur, acting director of the agency's Office of Hematology and Oncology Products.
In the initial studies nearly 40% of patients saw a partial or complete response with Keytruda at a fixed dose of 200mg every three weeks, and in 78% of them the effect lasted for at least six months.
Keytruda has additional approved indications in melanoma, lung cancer, head and neck cancer, Hodgkin lymphoma and urothelial carcinoma. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials. The unusualness of this type of approval process is perhaps only surpassed by Merck & Co.'s claim that pembrolizumab is able to help such a diverse list of cancer patients. Immune-mediated side effects are also associated with pembrolizumab; these include colitis, endocrinopathies, hepatitis, nephritis, and pneumonitis. "We look forward to working with the FDA to bring Keytruda to people with gastric cancer who have progressed after receiving chemotherapy and are in urgent need of another option".