Pharmaceutical developer Merck & Co. has gained approval for their latest cancer medication, pembrolizumab, from the U.S. Food and Drug Administration (FDA). Originally approved last week for the treatment of urothelial cancer, which is a form of bladder cancer, the scope of pembrolizumab has been expanded by the FDA.
Now, Merck & Co. has the green light to begin manufacturing and distributing pembrolizumab to help cancer patients who share a specific genetic marker. Merck & Co.’s pembrolizumab, also known as Keytruda, is a promising option for treating a wide variety of cancers.
A Whirlwind Week for Pembrolizumab and Merck & Co.
In a groundbreaking approval, the FDA has paved the way for the country’s first cancer medication that isn’t targeted at only one part of the body. In the past, Merck & Co. may not have been able to get the FDA to move further than allowing this treatment to be used by people with bladder cancer.
Research indicates this could have greatly reduced the usefulness of a medication that appears to be well-poised to assist adults and children who have two things in common: a cancer diagnosis and the existence of the same biomarker. The potential of this new treatment was highlighted last week when the FDA quickly expanded their approval of pembrolizumab to include mesothelioma.
Fortunately, the typical long, drawn out process of getting additional approvals was skipped this time. Instead, the FDA acted very quickly to branch out from urothelial cancer to mesothelioma and, one week later, all cancers with the same biomarker. The unusualness of this type of approval process is perhaps only surpassed by Merck & Co.’s claim that pembrolizumab can help such a diverse list of cancer patients.
Whom has the FDA Approved for Pembrolizumab Usage?
Despite this game-changing approval, pembrolizumab still isn’t currently available to everyone who has the biomarker in question. The FDA did grant accelerated approval for patients who have a tumor with a MSI-H or dMMR genetic marker. However, in order to be eligible for a pembrolizumab prescription, cancer patients also must have metastatic solid tumors and be out of alternative treatment methods. In other words, although the FDA may grant further approvals to Merck & Co. in the future, pembrolizumab can only be used right now as a last resort treatment option for patients who have stage 4 cancer.
How Does Pembrolizumab Work?
As with most new medications, Merck & Co. cannot say with complete certainty exactly how and why pembrolizumab works. It’s strongly believed, though, that pembrolizumab blocks the PD-1/PD-L1 cellular pathway.
The targeted biomarkers, MSI-H and dMMR, are found most frequently with colorectal, gastrointestinal and endometrial cancers. These markers contain abnormalities that make it difficult for cells to help themselves via DNR repairs. Per the FDA, by blocking the cellular pathway, pembrolizumab “may help the body’s immune system fight the cancer cells.”
In layman’s terms, this means that the FDA and Merck & Co. have seen enough evidence from trials to support the theory that pembrolizumab helps prevent the deterioration of cells. By making it possible for the immune system to combat the negative effects of the cellular pathway, the body gains some much-needed support in the fight against cancer.
The Future of Cancer Treatments
When the FDA gave Merck & Co. the go-ahead to begin distributing pembrolizumab to any patient who meets the necessary criteria, the government organization also opened the door for a completely new type of cancer treatment. It now seems feasible that future efforts will mostly be targeted toward defeating specific biomarkers instead of aiming to assist just one type of cancer.
If pembrolizumab is successful, we can expect the U.S. Food and Drug Administration and companies such as Merck & Co. to approach cancer treatment research differently, which could provide new hope for millions of patients.
[Feature Image by Matt Rourke/AP Images]