Recently, Blueprint Medicines Corporation (“Blueprint”) shared that the European Commission (EC) approved marketing authorization of AYVAKYT (avapritinib). The therapy is designed to treat adult patients with PDGFRA D842V mutated gastrointestinal stromal tumors (GIST). As these patients either have metastatic cancer, or are unable to surgically remove the tumors, AYVAKYT offers a new and potential efficacious treatment option. Additionally, this is the first therapy designed to treat patients with this specific gene mutation.

AYVAKYT

Already approved for the treatment of GIST in the United States as AYVAKIT, AYVAKYT is a kinase inhibitor. It is designed specifically for patients with PDGFRA gene mutations. Prior to this marketing approval, AYVAKYT was granted Orphan Medicinal Product designation. As described by the European Medicines Agency (EMA):

‘Orphan’ medicinal products are for diagnosing, preventing or treating life-threatening or very serious conditions that are rare and affect not more than 5 in 10,000 persons in the European Union (EU).

In this case, the EC approved AYVAKYT based on data from the Phase 1 NAVIGATOR clinical trial and Phase 3 VOYAGER clinical trials. Through these trials, AYVAKYT reduced symptoms and improved progression-free survival rates. The therapy also showed a durable response, with a median response duration of 22.1 months. In the NAVIGATOR clinical trial, 38 patients with PDGFRA D842V mutated GIST enrolled. These patients received 300-400mg AYVAKYT daily.

Ultimately, the therapy was effective, as well as fairly safe and well-tolerated. Side effects included anemia, fatigue, nausea and vomiting, diarrhea, swelling of the eyes and face, watery eyes, and a lowered appetite.

Gastrointestinal Stromal Tumor (GIST)

In many cases, gastrointestinal stromal tumors (GISTs) result from spontaneous gene mutations. PDGFRA D842V gene mutations cause up to 6% of GISTs. Cells begin growing at an excessive rate and eventually form into a tumor. GISTs are soft-tissue sarcomas that commonly occur in the digestive tract, particularly in the stomach or small intestine. However, these tumors also form in the esophagus, colon, and rectum. Soft-tissue sarcomas are rare and occur in connective tissue. GISTs are often found in patients between ages 40-70. While some are benign, others are not and might spread to the bones, liver, or lungs.

Many patients will not experience symptoms. Those who do may see:

• Bloody stool
• Vomiting blood
• Loss of appetite
• Abdominal pain and swelling
• Anemia
• Fatigue
• Unintended weight loss

Learn more about GIST here.