Feb. 18, 2025 — The FDA has approved vimseltinib, a new oral drug for a rare, noncancerous tumor of the joints known as tenosynovial giant cell tumor (TGCT). It is intended for adults with symptomatic TGCT when surgery could worsen their condition.
TGCTs are noncancerous tumors that develop in the joints or nearby tissues due to a faulty CSF1 gene, leading to excessive colony-stimulating factor 1 (CSF1) protein production and tumor growth. They cause pain, swelling, stiffness, and difficulty in movement. While surgery is the primary treatment, tumors often return, and repeated procedures can damage joints. This highlights the need for better, less invasive treatment options.
Marketed under the brand name Romvimza, the drug blocks enzymes that help the CSF1 protein drive tumor growth, reducing both tumor size and inflammation. The oral capsules are expected to be commercially available in the United States this week, according to a press release from Deciphera Pharmaceuticals, the drug’s maker. The FDA has advised a twice-weekly dose with at least 72 hours required between doses.
The FDA approved Romvimza based on results from a clinical trial involving TGCT patients who couldn’t have surgery. Patients received either a placebo or 30 milligrams of Romvimza twice a week for 24 weeks. Romvimza shrank tumors in 40% of patients (vs. 0% taking a placebo) and improved movement, function, and pain. Most patients (85%) experienced benefits for about six months; 58% had benefits for over nine months.
The most common side effects include high liver enzyme and cholesterol levels, tiredness, rash, itching, swelling in the legs, face, or around the eyes, and low white blood cell counts.
Romvimza can affect liver function, and patients should inform their doctors about any existing liver or kidney problems before starting treatment. Patients should also discuss their medical history, allergies, and all prescription and over-the-counter medicines they take to avoid possible drug reactions. The drug may harm an unborn baby, so birth control is recommended for both men and women during treatment and for one month after the last dose. Breastfeeding mothers are advised to not breastfeed during treatment and to consult their doctors.
