Oct. 24, 2024 – The FDA has approved a new drug called zolbetuximab designed to attack a novel target that’s in a type of stomach cancer.
Marketed under the brand name Vyloy, the drug is to be used with fluoropyrimidine- and platinum-based chemotherapy in adults with advanced cancer of the stomach or gastroesophageal junction (GEJ) that’s positive for claudin 18.2 (CLDN18.2), a protein that promotes tumor growth and spread. Vyloy is the first drug in the United States that targets this protein.
“While there have been advances in the first-line treatment of locally advanced unresectable and metastatic gastric and GEJ cancers in the last several years, there is still a tremendous unmet need among our patients,” Samuel J. Klempner, MD, a cancer specialist at Massachusetts General Hospital, Boston, and an associate professor at Harvard Medical School, said in a statement. The approval “brings forward a novel biomarker and new therapy for patients whose tumors are CLDN18.2 positive, and for those on the frontlines of treatment decision-making.”
The treatment is intended for patients with HER2-negative gastric or GEJ adenocarcinoma that has either spread or cannot be removed by surgery. In clinical trials, about 38% of these patients were found to be CLDN18.2-positive. The FDA also approved the VENTANA CLDN18 (43-14A) RxDx Assay, a test to detect CLDN18.2-positive tumors and confirm eligibility for the new treatment.
The approval was based on results of two international phase III clinical trials including 567 and 507 patients. The trials added Vyloy to two different chemotherapy regimens.
In one trial, patients who took Vyloy with chemotherapy went 10.6 months without the cancer worsening, compared with 8.7 months for those who took a placebo. The addition of Vyloy also improved overall survival by about three months. Patients in the other trial on chemotherapy saw similar results – those on Vyloy went 8.2 months without cancer worsening, compared to 6.8 months with chemotherapy alone. The overall survival benefit was about two months.
The FDA reported similar side effects in both trials, with common ones being nausea and vomiting, reduced appetite, diarrhea, pneumonia, and fever. The drug’s maker, Astellas, warned about serious allergic reactions and infusion-related reactions and has added an advisory for women to avoid breastfeeding while on Vyloy and for eight months after the final dose.
