o the general recommendations. There are only very limited data available in patients with moderate to severe hepatic impairment. Patients with moderate to severe hepatic impairment may have increased exposure (see section 5.2). Thus close monitoring is warranted especially after the first few weeks of treatment as accumulation may occur over an extended period of time (several weeks). In addition ECG monitoring every month during the first three months is recommended.
Renal impairment
No adjustment to the starting dose is needed for patients with mild or moderate renal impairment. There are only limited data available in patients with severe renal impairment (see section 5.2). Vemurafenib should be used with caution in patients with severe renal impairment and patients should be closely monitored.
Photosensitivity
Mild to severe photosensitivity was reported in patients who received vemurafenib in clinical studies (see section 4.8). All patients should be advised to avoid sun exposure while taking vemurafenib. While taking the medicinal product, patients should be advised to wear protective clothing and use a broad spectrum Ultraviolet A (UVA)/Ultraviolet B (UVB) sunscreen and lip balm (Sun Protection Factor ≥ 30) when outdoors to help protect against sunburn.
For photosensitivity grade 2 (intolerable) or greater, dose modifications are recommended (see section 4.2).
Effects of vemurafenib on other medicinal products
Vemurafenib may increase the plasma exposure of medicinal products predominantly metabolised by CYP1A2 and decrease the plasma exposure of medicines predominantly metabolised by CYP3A4, including oral contraceptives. Dose adjustments for medicinal products predominantly metabolised via CYP1A2 or CYP3A4 should be considered based on their therapeutic windows before concomitantly treating with vemurafenib (see sections 4.5 and 4.6).
Exercise caution and consider additional INR (International Normalised Ratio) monitoring when vemurafenib is used concomitantly with warfarin.
Effect of other medicinal products on vemurafenib
Vemurafenib pharmacokinetics could be affected by medicines that inhibit or influence P-gp (e.g. verapamil, clarithromycin, cyclosporine, ritonavir, quinidine, dronedarone, amiodarone, itraconazole, ranolazine) (see section 4.5).
Concomitant administration of potent inducers of P-gp, glucuronidation, CYP3A4 (e.g. rifampicin, rifabutin, carbamazepine, phenytoin or St John's Wort [hypericin]) should be avoided when possible (see section 4.5). Alternative treatment with less inducing potential should be considered to maintain the efficacy of vemurafenib.
Concurrent administration with ipilimumab
In a Phase I trial, asymptomatic grade 3 increases in transaminases (ALT/AST >5 x ULN) and bilirubin (total bilirubin >3x ULN) were reported with concurrent administration of ipilimumab (3 mg/kg) and vemurafenib (960 mg BID or 720 mg BID). Based on these preliminary data, the concurrent administration of ipilimumab and vemurafenib is not recommended.
4.5 Interaction with other medicinal products and other forms of interaction
Effects of vemurafenib on CYP substrates
CYP1A2 inhibition was observed when a single dose of caffeine was co-administered after repeat dosing with vemurafenib for 15 days. This resulted in an average 2.5-fold increase (maximum up to 10-fold) in caffeine plasma exposure after vemu
