Drug Interactions between panobinostat and Tavneos

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of panobinostat. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Increased exposure to panobinostat may increase the risk of adverse effects such as nausea, vomiting, diarrhea, anorexia, peripheral edema, cardiotoxicity, ECG abnormalities, electrolyte disturbances, bleeding complications, hepatotoxicity, and myelosuppression.

Food may delay the rate of absorption of panobinostat, but does not significantly affect the overall extent of absorption. When a single oral dose of panobinostat was administered to 36 patients with advanced cancer 30 minutes after a high-fat meal, panobinostat peak plasma concentration (Cmax) and systemic exposure (AUC) were approximately 44% and 16% lower, respectively, compared to administration under fasting conditions. The median time to maximum concentration (Tmax) was prolonged by 2.5 hours.

MANAGEMENT: Patients should avoid consumption of grapefruit or grapefruit juice during treatment with panobinostat. The manufacturer also recommends avoiding star fruit, Seville oranges, pomegranate, and pomegranate juice. Panobinostat may be administered with or without food.

ADJUST DOSING INTERVAL: Food significantly enhances the oral bioavailability of avacopan. When a 30 mg capsule of avacopan was administered with a high-fat, high-calorie meal, avacopan peak plasma concentration (Cmax) and systemic exposure (AUC) increased by approximately 8% and 72%, respectively, while the time to reach peak concentration (Tmax) was delayed by approximately 4 hours (from 2.0 hours to 6.0 hours).

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of avacopan. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Inhibition of hepatic CYP450 3A4 may also contribute. The interaction has not been studied with grapefruit juice, but has been reported for itraconazole, a potent CYP450 3A4 inhibitor. When avacopan was administered with itraconazole (200 mg once daily for 4 days), avacopan peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 1.9-fold and 2.2-fold, respectively. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Pharmacokinetic interactions involving grapefruit juice are also subject to a high degree of interpatient variability, thus the extent to which a given patient may be affected is difficult to predict. Increased exposure to avacopan may increase the risk and/or severity of serious adverse reactions such as hepatotoxicity and infections.

MANAGEMENT: To ensure maximal oral absorption, avacopan should be administered with food. Patients should preferably avoid or limit consumption of grapefruit, grapefruit juice, or any supplement containing grapefruit extract during avacopan therapy.