General Information

Balversa (erdafitinib) is a once-daily, oral fibroblast growth factor receptor (FGFR) kinase inhibitor.

Balversa is specifically indicated for the treatment of adult patients with locally advanced or metastatic urothelial carcinoma (mUC), that has:

• susceptible FGFR3 or FGFR2 genetic alterations, and
• progressed during or following at least one line of prior platinum-containing chemotherapy, including within 12 months of neoadjuvant or adjuvant platinum-containing chemotherapy. Select patients for therapy based on an FDA-approved companion diagnostic for Balversa.

Balversa is supplied as a tablet for oral administration. 

Select patients based on the presence of susceptible FGFR genetic alterations in tumor specimens as detected by an FDA-approved companion diagnostic.

The recommended starting dose of Balversa is 8 mg (two 4 mg tablets) orally once daily, with a dose increase to 9 mg (three 3 mg tablets) once daily based on serum phosphate (PO4) levels and tolerability at 14 to 21 days. Swallow tablets whole with or without food. If vomiting occurs any time after taking Balversa, the next dose should be taken the next day. Treatment should continue until disease progression or unacceptable toxicity occurs.

If a dose of Balversa is missed, it can be taken as soon as possible on the same day. Resume the regular daily dose schedule for Balversa the next day. Extra tablets should not be taken to make up for the missed dose.

Dose Increase based on Serum Phosphate Levels: Assess serum phosphate levels 14 to 21 days after initiating treatment. Increase the dose of Balversa to 9 mg once daily if serum phosphate level is < 5.5 mg/dL and there are no ocular disorders or Grade 2 or greater adverse reactions. Monitor phosphate levels monthly for hyperphosphatemia.

Please see drug label for dose modifications for adverse reactions.

Mechanism of Action

Balversa (erdafitinib) is a once-daily, oral fibroblast growth factor receptor (FGFR) kinase inhibitor that binds to and inhibits enzymatic activity of FGFR1, FGFR2, FGFR3 and FGFR4 based on in vitro data. Erdafitinib also binds to RET, CSF1R, PDGFRA, PDGFRB, FLT4, KIT, and VEGFR2. Erdafitinib inhibited FGFR phosphorylation and signaling and decreased cell viability in cell lines expressing FGFR genetic alterations, including point mutations, amplifications, and fusions. Erdafitinib demonstrated antitumor activity in FGFR-expressing cell lines and xenograft models derived from tumor types, including bladder cancer.

Side Effects

Adverse effects associated with the use of Balversa may include, but are not limited to, the following:

• phosphate increased
• stomatitis
• fatigue
• creatinine increased
• diarrhea
• dry mouth
• onycholysis
• alanine aminotransferase increased
• alkaline phosphatase increased
• sodium decreased
• decreased appetite
• albumin decreased
• dysgeusia
• hemoglobin decreased
• dry skin
• aspartate aminotransferase increased
• magnesium decreased
• dry eye
• alopecia
• palmar-plantar erythrodysesthesia syndrome
• constipation
• phosphate decreased
• abdominal pain
• calcium increased
• nausea
• musculoskeletal pain

Clinical Trial Results

This indication is approved under accelerated approval based on tumor response rate. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials

Accelerated approval was based on results from a Phase 2 multicenter, open-label, single-arm study in 87 patients with disease that had progressed on or after at least one prior chemotherapy and that had at least one of the following genetic alterations: FGFR3 gene mutations (R248C, S249C, G370C, Y373C) or FGFR gene fusions (FGFR3-TACC3, FGFR3-BAIAP2L1, FGFR2-BICC1, FGFR2-CASP7), as determined by a clinical trial assay performed at a central laboratory. The results demonstrated a 32.2% objective response rate (ORR) as assessed by Blinded Independent Review Committee (BIRC). Responders included patients who had previously not responded to anti PD-L1/PD-1 therapy. In the trial, ORR was defined as the percentage of patients with measurable lesions achieving a complete response (CR) [2.3%] or partial response (PR) [29.9%] to treatment using the RECIST v1.1 criteria, as assessed per investigator. Results also showed a median duration of response (DoR) of 5.4 months in patients treated with Balversa. There were no confirmed responses to Balversa in the FGFR2 fusion patient population (n=6).