FDA Approves First Gene Therapy for Bladder Cancer

The FDA has approved Adstiladrin (nadofaragene firadenovec-vncg) to treat adult patients with high-risk non-muscle-invasive bladder cancer (NMIBC) with carcinoma in situ with or without papillary tumors. It is indicated for patients who are resistant to Bacillus Calmette-Guérin (BCG), an immunotherapy that is used to treat patients with early-stage bladder cancer.

Bladder cancer is the sixth most common cancer in the United States with non-muscle-invasive bladder cancer representing about 75% of all new bladder cancer cases. Non-muscle-invasive bladder cancer is a cancer that has grown through the lining of the bladder but hasn't yet invaded the muscle layer. This type of cancer is associated with high rates of recurrence and risk of metastatic cancer.

Developed by Ferring Pharmaceuticals, Adstiladrin is an adenoviral vector‑based gene therapy containing the gene interferon alfa-2b, administered by catheter into the bladder once every three months. The cells pick up the gene and translate its DNA sequence, resulting in the cells secreting high quantities of interferon alfa-2b protein, a naturally occurring protein the body uses to fight cancer.

Ferring expects that Adstiladrin will be commercially available in the United States in the second half of 2023, following manufacturing capacity expansion. A company spokesperson indicated it is too early to discuss pricing, but said their goal is to make Adstiladrin widely accessible.

Stephen A. Boorjian, M.D.

“Patients with BCG-unresponsive NMIBC have historically had limited treatment options other than bladder removal surgery,” Stephen A. Boorjian, M.D., Carl Rosen Professor and chair of the Department of Urology at Mayo Clinic, and lead investigator on the recent clinical trial of Adstiladrin, said in a press release. “The approval of Adstiladrin is, therefore, a significant advance in the current treatment landscape and provides a novel treatment option for patients.”

Approval of Adstiladrin is based on results of a phase 3 clinical trial, which met its primary endpoint with 51% of the 157 enrolled patients with carcinoma in situ achieving a complete response by three months. Of the patients who achieved an initial complete response, 46% continued to remain free of high-grade recurrence at 12 months. The median duration of response was 9.7 months. Forty-six percent of responding patients remained in complete response for at least one year.