Balversa Special Precautions

Ocular Disorders: BALVERSA can cause ocular disorders, including central serous retinopathy/retinal pigment epithelial detachment (CSR/RPED) resulting in visual field defect.
In the pooled safety population [see Adverse Reactions] CSR/RPED occurred in 22% of patients treated with BALVERSA, with a median time to first onset of 46 days. In 104 patients with CSR, 40% required dose interruptions and 56% required dose reductions; 2.9% of BALVERSA-treated patients required permanent discontinuation for CSR. Of the 24 patients who restarted BALVERSA after dose interruption with or without dose reduction, 67% had recurrence and/or worsening of CSR after restarting. CSR was ongoing in 41% of the 104 patients at the time of last evaluation.
Dry eye symptoms occurred in 26% of BALVERSA-treated patients. All patients should receive dry eye prophylaxis with ocular demulcents as needed.
Perform monthly ophthalmological examinations during the first 4 months of treatment and every 3 months afterwards, and urgently at any time for visual symptoms. Ophthalmological examination should include assessment of visual acuity, slit lamp examination, fundoscopy, and optical coherence tomography.
Withhold or permanently discontinue BALVERSA based on severity and/or ophthalmology exam findings [see Dose Modifications for Adverse Reactions under Dosage & Administration].
Hyperphosphatemia and Soft Tissue Mineralization: BALVERSA can cause hyperphosphatemia leading to soft tissue mineralization, cutaneous calcinosis, non-uremic calciphylaxis and vascular calcification. Increases in phosphate levels are a pharmacodynamic effect of BALVERSA [see Pharmacology: Pharmacodynamics under Actions].
In the pooled safety population [see Adverse Reactions], increased phosphate occurred in 73% of BALVERSA-treated patients. The median onset time of increased phosphate was 16 days (range: 8-421) after initiating BALVERSA. Twenty-four percent of patients received phosphate binders during treatment with BALVERSA. Vascular calcification was observed in 0.2% of patients treated with BALVERSA.
Monitor for hyperphosphatemia throughout treatment. Restrict dietary phosphate intake (600-800 mg daily) and avoid concomitant use of agents that may increase serum phosphate levels.
If serum phosphate is above 7.0 mg/dL, consider adding an oral phosphate binder until serum phosphate level returns to <7.0 mg/dL. Withhold, dose reduce, or permanently discontinue BALVERSA based on duration and severity of hyperphosphatemia according to Table 4 [see Dose Modifications for Adverse Reactions under Dosage & Administration].
Effects on ability to drive and use machine: No studies to establish the effects of erdafitinib on the ability to drive and use machines have been conducted. However, eye disorders such as central serous retinopathy or keratitis have been noted with FGFR inhibitors and with Balversa treatment. If patients experience treatment related symptoms affecting their vision, it is recommended that they do not drive or use machines until the effect subsides (see as previously mentioned).
Use in Pregnancy: Embryo-Fetal Toxicity: Based on the mechanism of action and findings in animal reproduction studies, BALVERSA can cause fetal harm when administered to a pregnant woman. In an embryo-fetal toxicity study, oral administration of erdafitinib to pregnant rats during the period of organogenesis caused malformations and embryo-fetal death at maternal exposures that were less than the human exposures at the maximum human recommended dose based on area under the curve (AUC). Advise pregnant women of the potential risk to the fetus. Advise female patients of reproductive potential to use effective contraception during treatment with BALVERSA and for one month after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with BALVERSA and for one month after the last dose [see Use in Pregnancy & Lactation, Use in Specific populations under Dosage & Administration and Pharmacology under Actions].