The US Food and Drug Administration (FDA) approved Jelmyto (mitomycin gel) for a type of urothelial cancer, which is a cancer of the lining of the urinary system. This is the first drug approved to treat cancer that grows in the upper part of the urinary system known as upper tract urothelial cancer.

Most urothelial cancers start in the bladder, but upper tract cancers start in the lining of the kidney or the tube that connects the kidney to the bladder (ureter). In some people, upper tract cancers can block the ureter or kidney and cause problems including swelling, infection, and kidneys not working well. These problems might lead to surgery to remove the kidney and the ureter.  

Mitomycin is a chemotherapy drug that is already used to treat people with some types of bladder cancer. Jelmyto is a newer gel form that is injected through a catheter directly into the ureter or through a tube that goes right into the kidney from the back. The FDA based its approval on a clinical trial of 71 people with low grade upper tract cancer and at least one papillary tumor big enough to measure. A papillary tumor is shaped like a mushroom with its stem attached to the inner lining of the urinary system.

Patients had Jelmyto inserted once a week for 6 weeks. If the tumor disappeared (a complete response), they were given Jelmyto once a month for up to 11 more months. Forty-one of the 71 patients (58%) had a complete response after the once-a-week treatments. Of those, 19 patients (46%) still had a complete response after the additional once-a-month treatments.

One common side effect of people on Jelmyto was a narrowing or blockage of the ureter that can cause urine to back up in the kidney. Other side effects included pain in the lower back, pain in the abdomen, pain when urinating, urinary tract infection, blood in the urine, kidney problems, fatigue, nausea, and vomiting. A serious side effect that can occur is blockage of the ureter that requires treatment with stents.

People taking Jelmyto should be tested to see how well their kidneys are working. Pregnant women should not take Jelmyto because it may harm the fetus or newborn baby. Both men and women of reproductive age should use birth control while taking Jelmyto and continue for 6 months (women) or 3 months (men) after the last dose.

The FDA approved Jelmyto using several approaches designed to make drugs for serious diseases available to patients faster: breakthrough therapy, priority review, and fast track. It also used orphan drug designation, which provides financial incentives to encourage the development of drugs for rare diseases such as upper tract urothelial cancers.

Jelmyto is marketed by UroGen Pharma, Inc.