FDA Approves First Targeted Therapy for Bladder Cancer

The U.S. Food and Drug Administration (FDA) approved erdafitinib (BALVERSA™) for the treatment of adults with metastatic locally advanced or metastatic FGFR3– or FGFR2-positive bladder cancer that has progressed during or following prior platinum-containing chemotherapy.

The approval was based on results of a multicenter, open-label, single-arm, phase II clinical trial that included 87 patients with locally advanced or metastatic bladder cancer with FGFR3 or FGFR2 genetic alterations. The overall response rate was 32.2% (95% CI, 22.4-42.0), including a complete response rate of 2.3% and a partial response rate of 29.9%. Median duration of response was 5.4 months (95% CI, 4.2-6.9).

The most common adverse events (AEs) associated with erdafitinib were phosphate increased (76%), stomatitis (56%), fatigue (54%), creatinine increased (52%), diarrhea (47%), dry mouth (45%), onycholysis (41%), alanine aminotransferase increased (41%), alkaline phosphatase increased (41%), sodium decreased (40%), decreased appetite (38%), albumin decreased (37%), dysgeusia (37%), hemoglobin decreased (35%), dry skin (34%), aspartate aminotransferase increased (30%), magnesium decreased (30%), dry eye (28%), alopecia (26%), palmar-plantar erythrodysesthesia syndrome (26%), constipation (28%), phosphate decreased (24%), abdominal pain (23%), calcium increased (22%), nausea (21%), and musculoskeletal pain (20%). The most common grade ≥3 AEs were stomatitis (9%), nail dystrophy, palmar-plantar erythrodysesthesia syndrome (6%), paronychia (3%), nail disorder, keratitis, onycholysis (10%), and hyperphosphatemia.

Erdafitinib may cause serious eye problems, including inflamed eyes, inflamed cornea, and disorders of the retina. Patients should have eye examinations intermittently and should inform their physician immediately if they develop blurred vision, loss of vision, or other visual changes. Physicians should check patients’ blood phosphate level between 14 and 21 days after starting treatment and monthly.

The FDA said patients should be chosen for this treatment using an agency-approved companion diagnostic device: The QIAGEN therascreen® FGFR RGQ Reverse-transcription-polymerase chain reaction (PCR) Kit, which is the first PCR-based companion diagnostic approved to detect FGFR alterations.