Everolimus, a kinase inhibitor already approved for treating kidney cancer, has been approved as a treatment for slowly growing, benign tumors in patients with tuberous sclerosis, the Food and Drug Administration announced on Nov. 1.
Everolimus, marketed as Afinitor for kidney cancer, was approved for treating subependymal giant cell astrocytoma (SEGA) associated with the rare genetic disorder, in cases in which these tumors cannot be treated surgically. (Everolimus is also approved for prophylaxis of organ rejection in adult patients at low-moderate immunologic risk receiving a kidney transplant and is marketed as Zortress for this indication.) It will be marketed as Afinitor for the SEGA indication and will be available in a tablet formulation.
"Patients with this disease currently have limited treatment options beyond surgical intervention," Dr. Richard Pazdur, director of the Office of Oncology Drug Products in the Center for Drug Evaluation and Research, said in an FDA statement announcing the approval. "It is important for research to continue in rare diseases where patients have few or no existing drug treatment options." About 6%-9% of patients with tuberous sclerosis have SEGAs, which are potentially fatal, slow-growing tumors.
The accelerated approval was based on a study of 28 patients with SEGAs, which found that after 6 months of treatment, 9 patients (32%) had more than a 50% reduction in the volume of their largest SEGA tumor, which included several patients whose tumors had recurred after surgery. The duration of response in these patients ranged from about 3 months to 2½ years (median 266 days). Of the nine patients, seven still had a 50% reduction in tumor volume at the last follow-up, according to the FDA.
In addition, none of the patients in the study developed any new tumors, although none of the tumors completely resolved.
The most common adverse events reported by patients in patients treated for SEGA included upper respiratory tract infections, sinus and ear infections, mouth sores, and fever. Laboratory test abnormalities associated with treatment included liver enzyme elevations, hyperlipidemia, high blood sugar, and decreases in white blood cells, red blood cells, and platelets.
Everolimus was approved in 2009 for the kidney cancer indication, in patients who failed treatment with sunitinib (Sutent) or sorafenib (Nexavar).