The Food and Drug Administration has approved a new method for cancer treatment that's different from any of its predecessors.
Merck & Co's immunotherapy method, Keytruda, is on the rise with one approval after the other, and May 23 was its biggest one yet, Scientific American reported.
The FDA just released its approval for a cancer treatment that uses a genetic biomarker -- rather than basing its use on where the cancer started -- a first for the agency. This biomarker is called microsatellite instability-high (MSI-H), or mismatch repair deficient (dMMR). PharmaTimes explains that MSI results in a cell's inability to repair errors in its DNA sequence that occur during cell division, and MSI-H is a well known biomarker for certain types of cancer.
Keytruda falls under a new class of drugs called PD-1 or PD-L1 inhibitors. These inhibitors work to help the immune system fight cancer by preventing tumors from evading detection. In Keytruda's case, this immunotherapy tackles the biomarker that allows tumors to hide from treatment methods.
By focusing on the genetic marker, rather than the origin spot of the cancer, Keytruda is addressing a massive audience.
By taking a genetic screening test which is widely available for between $300 and $600, you can see if you carry the MSI-H biomarker that accompanies many forms of cancer, like those Keytruda covers.
According to Dr. Drew Pardoll, director of the Johns Hopkins Bloomberg-Kimmel Institute where the trial was held, it is "a marriage of cancer genetics and cancer immunology."
Dr. Pardoll also said that 4 percent of advanced cancers, or 15,000 to 20,000 cases each year in the United States, are addressed with this new approval, Reuters writes.
Keytruda was picking up one approval after another from the FDA before this news broke out. It was approved to treat advanced melanoma, advanced NSCLC, head and neck cancers, classical Hodgkin lymphoma and bladder cancer. It is currently awaiting an FDA decision for gastric cancer treatment which, if approved, will add to its list of communities it will be helping.
The trial, in reference to the genetic biomarker, was a much larger success than anticipated.
Out of the 149 patients who received Keytruda in trials, 39.6 percent had a complete or partial response, and for 78 percent of those patients that received a response, it lasted for six months or more
"This was one of those eureka trials where it didn't take a lot of patients to see this was going to be something major," Dr. Pardoll said in an interview.
Merck now must follow up and conduct studies that confirm the anticipated benefits of the treatment.