Drug Interactions between encorafenib and nintedanib

GENERALLY AVOID: Coadministration with potent or moderate inhibitors of CYP450 3A4 may significantly increase the plasma concentrations of encorafenib, which is primarily metabolized by the isoenzyme. When a single 50 mg dose of encorafenib (equivalent to 0.1 times the recommended dose) was administered with posaconazole, a potent CYP450 3A4 inhibitor, encorafenib peak plasma concentration (Cmax) increased by 68% and systemic exposure (AUC) increased by 3-fold. When the same dose of encorafenib was administered with diltiazem, a moderate CYP450 3A4 inhibitor, encorafenib Cmax increased by 45% and AUC increased by 2-fold. Increased exposure to encorafenib may increase the risk of serious and life-threatening adverse effects such as hemorrhage, uveitis, QT prolongation, hepatotoxicity, dermatologic reactions, and new malignancies.

MANAGEMENT: Concomitant use of encorafenib with grapefruit or grapefruit juice should generally be avoided. If coadministration is required, the manufacturer recommends reducing the encorafenib dose to one-third of the dose used prior to addition of a potent CYP450 3A4 inhibitor or one-half of the dose used prior to addition of a moderate CYP450 3A4 inhibitor. After the inhibitor has been discontinued for 3 to 5 elimination half-lives, the encorafenib dose that was taken prior to initiating the inhibitor may be resumed.

ADJUST DOSING INTERVAL: Food enhances the oral bioavailability of nintedanib. After food intake, nintedanib exposure increased by approximately 20% compared to administration under fasted conditions. Absorption was also delayed, as indicated by an increase in the median time to reach maximum plasma concentration (Tmax) from 2 hours in the fasted state to approximately 4 hours under fed conditions, irrespective of the type of food ingested. In an in vitro study, mixing nintedanib capsules with a small amount of apple sauce or chocolate pudding for up to 15 minutes did not have any impact on their pharmaceutical quality, but swelling and deformation of the capsules were observed with longer exposure time due to water uptake of the gelatin capsule shell. Therefore, administration with soft food would not be expected to alter the clinical effect of nintedanib when taken immediately.

GENERALLY AVOID: Grapefruit and grapefruit juice may increase the plasma concentrations of nintedanib, which has been shown to be a substrate of the P-glycoprotein (P-gp) efflux transporter and a minor substrate of the CYP450 3A4 isoenzyme. The proposed mechanism is inhibition of both P-gp-mediated efflux in the gut wall as well as CYP450 3A4-mediated first-pass metabolism in the intestinal tract by certain compounds present in grapefruit.

MANAGEMENT: Nintedanib should be administered with food to reduce the incidence of gastrointestinal effects. Nintedanib capsules may be taken with water or a small amount (teaspoonful) of cold or room temperature soft food, such as apple sauce or chocolate pudding, and must be swallowed whole (unchewed) immediately, to ensure the capsule stays intact. Food containing grapefruit, grapefruit juice, Seville orange (a citrus relative of the grapefruit), or Seville orange juice should be avoided during treatment with nintedanib.

The recommended maximum number of medicines in the 'multikinase inhibitors' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'multikinase inhibitors' category:

• encorafenib
• nintedanib

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.