The first non-surgical treatment option for a rare cancer subtype

WASHINGTON — Mitomycin gel (Jelmyto), an alkylating drug, is now FDA-approved as the first non-surgical treatment for low-grade upper tract urothelial cancer (UTUC).

UTUC, a urothelial cancer subset that impacts the lining of the kidney or ureter, can develop as either low- or high-grade tumors. While low-grade tumors are not invasive and rarely spread outside of these areas, “they often recur and management involves treating visible tumors and trying to preserve the urinary tract, as these tumors are more likely to recur in the urinary system than they are to spread,” the FDA explained. And, while low-grade UTUC is rare, it impacts approximately 6,000-8,000 new patients every year in the U.S.

Now, with this new approval, patients have a viable treatment option for their low-grade UTUC. To help expedite the drug’s availability, the agency granted mitomycin gel Priority Review, as well as Breakthrough Therapy, Fast Track, and Orphan Drug designations.

“This is the first approval specifically for patients with low-grade UTUC and provides an option for some patients who may otherwise require a nephroureterectomy,” said Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Oncologic Diseases in the FDA’s Center for Drug Evaluation and Research, in a statement. “Due to substantial treatment challenges associated with the complex anatomy of the upper urinary tract, many patients need to be treated with radical surgery — usually complete removal of the affected kidney, ureter, and bladder cuff. [Mitomycin gel] gives patients, for the first time, an alternative treatment option for low-grade UTUC.”

This approval was based on the results of a clinical trial of 71 patients with low-grade UTUC. “These patients had never undergone treatment or had recurrent low-grade non-invasive UTUC with at least one measurable papillary tumor,” the FDA wrote. “Patients received [mitomycin gel] once a week for six weeks and, if assessed as a complete response (complete disappearance of the papillary tumor), monthly for up to 11 additional months. Efficacy of [mitomycin gel] was evaluated using urine cytology, ureteroscopy, and biopsy (if warranted) three months following the initiation of therapy.”

According to the agency, 41 of the 71 patients (58%) met the primary endpoint — complete response at three months following initiation of therapy — after 6 weekly treatments with mitomycin gel, and 19 of those 41 (46%) continued to have a complete response at 12-month follow-up.

The FDA noted several side effects for patients taking mitomycin gel, including ureteric obstruction, flank pain, urinary tract infection, hematuria, renal dysfunction, fatigue, nausea, abdominal pain, dysuria, vomiting, and possibly urosepsis.

“Patients with ureteric obstruction may require transient or long-term stents to relieve this obstruction,” the FDA warned. “The obstruction may be persistent and did not resolve or did not resolve completely in 51% of patients who experienced obstruction due to [mitomycin gel]. [Mitomycin gel] should be avoided in patients with a glomerular filtration rate of less than 30mL/min.

“Women who are pregnant should not take [mitomycin gel] because it may cause harm to a developing fetus or newborn baby,” the agency continued. “The FDA advises health care professionals to tell females of reproductive age to use effective contraception during treatment with [mitomycin gel], and for six months following the last dose. Male patients with female partners of reproductive potential should also use effective contraception during treatment with [mitomycin gel] and for three months following the last dose.”

Mitomycin gel is manufactured by UroGen Pharma, Inc.

John McKenna, Associate Editor, BreakingMED™

Cat ID: 120

Topic ID: 78,120,730,120,192,725