Ocular disorders
Prior to initiating Balversa, a baseline ophthalmological exam including an Amsler grid test, fundoscopy, visual acuity and, if available, an optical coherence tomography (OCT) should be performed.
Balversa can cause ocular disorders, including central serous retinopathy (CSR) (a grouped term including retinal pigment epithelial detachment (RPED)) resulting in visual field defect (see sections 4.7 and 4.8). The overall incidence of central serous retinopathy was higher in patients ≥65 years of age (33.3%) compared with patients <65 years of age (28.8%). Events of RPED were reported more frequently in patients ≥65 years of age (6.3%) compared with patients <65 years of age (2.1%). Close clinical monitoring is recommended in patients aged 65 years and older as well as with patients that have clinically significant medical eye disorders, such as retinal disorders, including but not limited to, central serous retinopathy, macular/retinal degeneration, diabetic retinopathy, and previous retinal detachment (see section 4.8).
Dry eye symptoms occurred in 16.7% of patients during treatment with Balversa and were Grade 3 or 4 in 0.3% of patients (see section 4.8). All patients should receive dry eye prophylaxis or treatment with ocular demulcents (for example artificial tear substitutes, hydrating or lubricating eye gels or ointment) at least every 2 hours during waking hours. Severe treatment-related dry eye should be evaluated by an ophthalmologist.
Perform monthly ophthalmological examinations including an Amsler grid test during the first 4 months of treatment and every 3 months afterwards, and urgently at any time for visual symptoms (see section 4.2). If any abnormality is observed, follow the management guidelines in Table 3. Ophthalmological examination should include assessment of visual acuity, slit lamp examination, fundoscopy, and optical coherence tomography. Close monitoring including clinical ophthalmological examinations should be performed in patients who have restarted Balversa after an ocular adverse event.
When CSR occurs Balversa should be withheld and permanently discontinued if it does not resolve within 4 weeks or if Grade 4 in severity. For ocular adverse reactions, follow the dose modification guidelines (see section 4.2, Eye disorder management).
Hyperphosphataemia
Balversa can cause hyperphosphataemia. Prolonged hyperphosphataemia can lead to soft tissue mineralisation, cutaneous calcinosis, non-uraemic calciphylaxis, hypocalcaemia, anaemia, secondary hyperparathyroidism, muscle cramps, seizure activity, QT interval prolongation and arrhythmias. Hyperphosphataemia was reported early during Balversa treatment, with most events occurring within the first 3-4 months and Grade 3 events occurring within the first month.
Monitor for hyperphosphataemia throughout treatment. Dietary phosphate intake (600-800 mg daily) should be restricted and concomitant use of agents that may increase serum phosphate levels should be avoided for serum phosphate levels ≥5.5 mg/dL (see section 4.2). Supplementation with vitamin D in patients receiving erdafitinib is not recommended due to potential contribution to increased serum phosphate and calcium 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. Consider withholding, reducing the dose, or permanently discontinuing Balversa based on duration and severity of hyperphosphataemia, according to Table 2 (see section 4.2).
Use with products known to prolong QT interval
Caution is advised when administering Balversa with medicinal products known to prolong the QT interval or medicinal products with a potential to induce torsades de pointes, such as class IA (e.g., quinidine, disopyramide) or class III (e.g., amiodarone, sotalol, ibutilide) antiarrhythmic medicinal products, macrolide antibiotics, SSRIs (e.g., citalopram, escitalopram), methadone, moxifloxacin, and antipsychotics (e.g., haloperidol and thioridazine).
Hypophosphataemia
Hypophosphataemia can occur during treatment with Balversa. Serum phosphate level should be monitored during erdafitinib treatment and erdafitinib treatment breaks. If the serum phosphate level falls below normal, phosphate-lowering therapy and dietary phosphate restrictions (if applicable) should be discontinued. Severe hypophosphataemia may present with confusion, seizures, focal neurologic findings, heart failure, respiratory failure, muscle weakness, rhabdomyolysis, and haemolytic anaemia. For dose modifications see section 4.2. Hypophosphataemia reactions were Grade 3-4 in 1.0% of patients.
Nail disorders
Nail disorders including onycholysis, nail discolouration and paronychia can occur very commonly with Balversa treatment (see section 4.8).
Patients should be monitored for signs and symptoms of nail toxicities. Patients should be advised on preventative treatment such as good hygiene practices, over-the-counter nail strengthener as needed and monitor for signs of infection. Treatment with Balversa should be discontinued or modified based on erdafitinib-related toxicity as described in Table 4.
Skin disorders
Skin disorders including dry skin, palmar-plantar erythrodysaesthesia (PPES) syndrome, alopecia and pruritus can occur very commonly with Balversa treatment (see section 4.8). Patients should be monitored and provided supportive care such as avoiding unnecessary exposure to sunlight and excessive use of soap and bathing. Patients should use moisturisers regularly and avoid perfumed products. Treatment with Balversa should be discontinued or modified based on erdafitinib-related toxicity as described in Table 4.
Photosensitivity reactions
Care should be taken with sun exposure by wearing protective clothing and/or sunscreen due to the potential risk of phototoxicity reactions associated with Balversa treatment.
Mucosal disorders
Stomatitis and dry mouth can occur very commonly with Balversa treatment (see section 4.8). Patients should be counselled to seek medical attention should symptoms worsen. Patients should be monitored and provided supportive care as such as good oral hygiene, baking soda mouthwashes 3 or 4 times per day as needed and avoidance of spicy and/or acidic foods. Treatment with Balversa should be discontinued or modified based on erdafitinib-related toxicity as described in Table 4.
Laboratory tests
Creatinine elevations, hyponatraemia, transaminase elevations, and anaemia have been reported in patients receiving Balversa (see section 4.8). Complete blood counts and serum chemistries should be performed regularly during treatment with Balversa to monitor for these changes.
Reproductive and developmental toxicity
Based on the mechanism of action and findings in animal reproduction studies, erdafitinib is embryotoxic and teratogenic (see section 5.3). Pregnant women should be advised of the potential risk to the foetus. Female patients of reproductive potential should be advised to use highly effective contraception prior to and during treatment, and for 1 month after the last dose (see section 4.6). Male patients should be counselled to use effective contraception (e.g., condom) and not donate or store semen during treatment with and for 1 month after the last dose of Balversa (see section 4.6).
Pregnancy testing with a highly sensitive assay is recommended for females of reproductive potential prior to initiating Balversa.
Combination with strong or moderate CYP2C9 or CYP3A4 inhibitors
Concomitant use of Balversa with moderate CYP2C9 or strong CYP3A4 inhibitors requires dose adjustment (see section 4.5).
Combination with strong or moderate CYP3A4 inducers
Concomitant use of Balversa with strong CYP3A4 inducers is not recommended. Concomitant use of Balversa with moderate CYP3A4 inducers requires dose adjustment (see section 4.5).
Combination with hormonal contraceptives
Concomitant administration of Balversa may reduce the efficacy of hormonal contraceptives. Patients using hormonal contraceptives should be advised to use an alternative contraceptive not affected by enzyme inducers (e.g., non-hormonal intrauterine device) or an additional nonhormonal contraception (e.g., condom) during treatment with and until 1 month after the last dose of Balversa (see sections 4.5 and 4.6).
Excipients with known effect
Each film‑coated tablet contains less than 1 mmol sodium (23 mg), that is to say essentially 'sodium‑free'.