FDA approves Balversa, first targeted therapy for metastatic bladder cancer

Richard Pazdur

The FDA today granted accelerated approval to erdafitinib for the treatment of adults with locally advanced or metastatic bladder cancer that progressed during or following platinum-containing chemotherapy.

This indication for erdafitinib (Balversa, Janssen) applies to patients who harbor FGFR3 or FGFR2 mutations according to the FDA-approved companion diagnostic device, therascreen FGFR RGQ RT-PCR Kit (QIAGEN Manchester).

Bladder cancers often harbor genetic mutations in the bladder or entire urothelium. One in five patients with recurrent or refractory bladder cancer has fibroblast growth factor (FGFR) alterations.

“We’re in an era of more personalized or precision medicine, and the ability to target cancer treatment to a patient’s specific genetic mutation or biomarker is becoming the standard, with advances being made in new disease types. Today’s approval represents the first personalized treatment targeting susceptible FGFR genetic alternations for patients with metastatic bladder cancer,” Richard Pazdur, MD, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said in a press release. “FGFRs regulate important biological processes, including cell growth and division during development and tissue repair. This drug works by targeting genetic alterations in FGFRs.”

The FDA based this decision, in part, on data from a clinical trial of 87 patients with locally advanced or metastatic bladder cancer and FGFR3 or FGFR2 genetic alterations. All patients had progressed after treatment with chemotherapy.

Results showed an overall response rate of 32.2%, which included a 2.3% complete response rate and a nearly 30% partial response rate. Mean duration of response was about 5.5 months.

Approximately a quarter of patients had been treated with anti-PD-L1/PD-1 therapy; researchers observed responses to erdafitinib even among patients who had not responded to this prior therapy.

Adverse events associated with erdafitinib included increased phosphate level, mouth sores, fatigue, change in kidney function, diarrhea, dry mouth, nails separating from the bed or poor formation of the nails, change in liver function, low sodium levels, decreased appetite, change in sense of taste, anemia, dry skin, dry eyes and hair loss. Other side effects include redness, swelling, hand-foot syndrome, constipation, stomach pain, nausea and muscle pain.

Because erdafitinib can cause serious eye problems — including inflammation of the eye or cornea and retina disorders — patients should have eye examinations during treatment.

Also, patients should undergo blood phosphate level assessments 14 days to 21 days after stating treatment, with erdafitinib dose increases for those who have a serum phosphate below the target level.

Additional clinical trials are required to confirm erdafitinib’s benefit. As HemOnc Today previously reported, this application also received breakthrough therapy designation.