The U.S. Food and Drug Administration (FDA) has approved the orphan drug Jelmyto (mitomycin gel) treat low-grade upper tract urothelial cancer (UTUC).
Low-grade UTUC affects about 6,000 – 8,000 Americans each year. It is a subset of urothelial cancers that begin in the lining of the kidney or the ureter that can cause swelling, infections and impairment of kidney function.
In a news release, Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence stated, “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. ”
Dr. Pazdur added, “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. Jelmyto gives patients, for the first time, an alternative treatment option for low-grade UTUC.”
Mitomycin gel is an alkylating drug that the FDA approved based largely on a clinical trial involving 71 patients with low-grade UTUC. Patients received mitomycin gel once a week for 6 weeks and, if the patient had a complete response, they continued to receive the medication for up to an additional 11 months.
The primary endpoint was complete response (via urine cytology, ureteroscopy, and biopsy) at 3 months following initiation of therapy and that was observed in 41 of the 71 patients (58%). Nineteen patients of the 41 patients who achieved a complete response continued to have a complete response after 1 year.
Common side effects were ureteric stenosis (43.7%), urinary tract infection (32.4%), haematuria (31.0%), flank pain (29.6%) nausea (23.9%), dysuria (21.1%), renal impairment (19.7%) and vomiting (19.7%)
Patients who develop ureteric obstruction may require transient or long-term stents to relieve this obstruction. The FDA noted that 51% of patients taking mitomycin gel who experience ureteric obstruction did not get the problem resolved. Mitomycin gel should be avoided in patients with a glomerular filtration rate > 30mL/min.
Also, women who are pregnant should not take mitomycin gel because it may cause harm to a developing fetus or newborn baby. The FDA is advising health care professionals to tell females of reproductive age to use effective contraception during treatment with mitomycin gel, and for 6 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 3 months following the last dose.
The FDA granted this application Priority Review and Breakthrough Therapy designation, Fast Track designation, and Orphan Drug designation.
