Jan 09, 2020: The U.S. Food and Drug Administration approved Blueprint Medicines, Ayvakit (avapritinib) for the treatment of adults with unresectable (unable to be removed with surgery) or metastatic (when cancer cells spread to other parts of the body) gastrointestinal stromal tumor (GIST) – a type of tumor that occurs in the gastrointestinal tract, most commonly in the stomach or small intestine – harboring a platelet-derived from growth factor receptor alpha (PDGFRA) exon 18 mutation.
This approval includes GIST that harbors a PDGFRA D842V mutation (most common exon 18 mutation). Ayvakit is a kinase inhibitor that blocks a type of enzyme called a kinase and helps keeps the cancer cells from growing.
GISTs occurs from specialized nerve cells found in the walls of the gastrointestinal tract. One or more sudden changes in the DNA of one of these cells may lead to the development of GIST. These cells aid in the movement of food all the way through the intestines and control various digestive processes.
More than half of the GISTs start in the stomach. Most of the others begins in the small intestine, but GISTs can start anywhere along the gastrointestinal tract.
The activating mutations in PDGFRA have been linked to the development of GISTs, and up to around 10% of GIST cases involve mutations of this gene.
Based on the results of a clinical trial, FDA approved Ayvakit involving 43 patients with GIST harboring a PDGFRA exon 18 mutation, including 38 patients with PDGFRA D842V mutation.
Patients received Ayvakit 300 mg or 400 mg orally once daily until disease progression or they experienced undesirable toxicity.
For patients harboring a PDGFRA exon 18 mutation, the overall response rate was 84%, 7% have a complete response and that have 77% partial response Ayvakit may cause harm to a developing fetus or newborn baby, should advise pregnant women.
Additionally, the FDA advises health care professionals to advice females of reproductive potential, and males with female partners of reproductive potential, to use effective contraception during treatment with Ayvakit and for six weeks after the final dose. https://fda.einnews.com/pr_news/506787911/fda-approves-the-first-targeted-therapy-to-treat-a-rare-mutation-in-patients-with-gastrointestinal-stromal-tumors
