According to a story from Markets Insider, the biopharmaceutical company CStone Pharmaceuticals has announced that China’s National Medical Products Administration (NMPA) has approved avapritinib (marketed as Ayvakit) as a treatment for adults living with gastrointestinal stromal tumors (GISTs). It is specifically approved for tumors that are metastatic (spreading from the original site) or unresectable (cannot be treated effectively with surgery) and carry a mutation on PDGFRA exon 18, including mutations of PDGFRA D842V. CStone is focused on the development of precision medicines and immuno-oncology therapies.
About Gastrointestinal Stromal Tumors (GISTs)
Gastrointestinal stromal tumors (GISTs) is a form of tumor that can appear in the digestive tract. These tumors appear in the interstitial cells of Cajal, which control smooth muscle activity. These tumors are connected to mutations that affect the KIT gene or the PDGFRA gene in the vast majority of cases. In most cases, these mutations appear sporadically, and are only rarely inherited. Typically they occur as part of another genetic disorder when they are inherited. They can occur in a number of locations along the digestive tract, most often the stomach, small intestine, or esophagus. Symptoms may include abdominal pain, difficulty swallowing, liver metastases, and gastrointestinal bleeding. Treatment usually involves surgery or medications when surgery is not possible. These tumors generally do not respond to radiation or chemotherapy. To learn more about gastrointestinal stromal tumors, click here.
A New Approval in China
This approval marks the first therapy in China for gastrointestinal stromal tumors that carry this mutation. The announcement is based on results from a phase 1/2 bridging study which investigated the safety of Ayvakit in Chinese patients that were living with this disease. A total of eight patients in the study were deemed evaluable; these patients were treated daily with a 300 mg dose. An overall response rate of 62.5 percent was achieved in this study.
Ayvakit is classified as an inhibitor of kinase. The drug had previously been approved by both the US Food and Drug Administration (FDA) and the European Commission for the treatment of gastrointestinal stromal tumors. The therapy, which was developed by Blueprint Medicines, is also being tested as a potential treatment for systemic mastocytosis.