Overview

Erdafitinib is approved for adults with locally advanced or metastatic urothelial carcinoma harbouring susceptible FGFR3 genetic alterations, making biomarker-defined patient selection the central theme of its use. BALVERSA supplies erdafitinib 4 mg tablets in 56-tablet boxes, supporting the titration schedule from 4 mg to 5 mg once daily. This article focuses on how B2B clinical buyers and prescribers identify the eligible population through tumour genomic testing. Choosing the right cohort is what separates effective use from futile exposure to a targeted agent.

How It Works

Erdafitinib is a selective fibroblast growth factor receptor (FGFR) 1 to 4 tyrosine kinase inhibitor. In urothelial cancers driven by FGFR3 mutations, fusions, or amplifications, constitutive FGFR signalling promotes tumour survival and proliferation. By occupying the kinase domain, erdafitinib shuts down this dependency. The clinical corollary is that benefit is concentrated in tumours with a documented FGFR alteration, which is why genomic profiling precedes therapy. Patients without the biomarker derive little, underscoring the population-first approach.

Indications

Erdafitinib is indicated for previously treated, unresectable or metastatic urothelial carcinoma with susceptible FGFR3 alterations, confirmed by an approved companion test. Eligibility requires tumour tissue or plasma-based NGS showing the relevant alteration. Prescribers also assess baseline phosphate, since on-target effects can raise serum phosphate. The 56-tablet pack is dimensioned for the titration and maintenance phases of the once-daily oral regimen.

Dosage & Administration

Treatment begins at 4 mg orally once daily, with dose escalation to 5 mg once daily from day 15 onward if tolerated and per labelling. Tablets are swallowed whole with water, with or without food. A 56-tablet box covers the initial titration window. Dose modifications for adverse events such as hyperphosphatemia follow the prescribing information, often involving phosphate-lowering agents or temporary holds.

Storage & Sourcing

Store at room temperature below 30°C, in the original blister, away from moisture. As a prescription targeted therapy, erdafitinib procurement requires supplier licensing and market authorisation. Because use depends on a companion diagnostic, buyers should coordinate test kits and drug supply so eligible patients start without delay. Verify batch expiry and certificate of analysis on receipt, and plan inventory around confirmed genomic-test-positive cohorts.

FAQ

Q: Which patients should be tested for erdafitinib eligibility? A: Adults with previously treated metastatic urothelial carcinoma should undergo FGFR3 mutation or fusion testing; only those with a documented susceptible alteration are candidates.

Q: Can erdafitinib be used without genomic testing? A: No. Approval is restricted to tumours with confirmed FGFR alterations, so a companion diagnostic result is required before initiation.

Q: Why does the starting dose escalate after two weeks? A: The regimen begins at 4 mg and steps up to 5 mg on day 15, a schedule designed to improve tolerability while reaching the effective exposure.