Drug Interaction Report

Consumer information for this interaction is not currently available.

MONITOR: Coadministration with other hepatotoxic agents may increase the risk of liver injury and decrease the therapeutic efficacy of valoctocogene roxaparvovec, a liver-directed adeno-associated virus (AAV) vector designed to help replace missing coagulation factor VIII. Most of the patients treated with valoctocogene roxaparvovec in clinical studies experienced ALT elevations, presumably due to immune-mediated injury of transduced hepatocytes, which may decrease the therapeutic efficacy of valoctocogene roxaparvovec. In a clinical trial of adults with severe hemophilia (n=134) receiving a single dose of valoctocogene roxaparvovec (6 x 10[13] vector genomes [vg]/kg), 107 patients (96%) experienced increased ALT levels greater than or equal to 1.5 times baseline or greater than the upper limit of normal (ULN), while 12 patients (9%) experienced increased ALT levels greater than 5 to 20 times ULN. Some of the ALT elevations were associated with decreased factor VIII activity. Most patients treated with valoctocogene roxaparvovec required immunosuppressive medications, including corticosteroids, to control elevations in transaminases and prevent loss of transgene expression.

MANAGEMENT: The risk of additive hepatotoxicity and decreased therapeutic efficacy of valoctocogene roxaparvovec should be considered after coadministration with other hepatotoxic agents. Alternative treatment may be required if an interaction is suspected. Monitoring of ALT and factor VIII activity levels (e.g., weekly to every 2 weeks for the first month) is recommended when a new medication is started following valoctocogene roxaparvovec administration.

Consumer information for this interaction is not currently available.

GENERALLY AVOID: Coadministration with grapefruit juice may increase the plasma concentrations of taletrectinib. The proposed mechanism for the interaction 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 other CYP450 3A4 inhibitors. In a clinical study, taletrectinib peak plasma concentration (Cmax) increased by 1.8-fold and systemic exposure (AUC) increased by 3.3-fold following concomitant administration of itraconazole, a potent CYP450 3A inhibitor. According to the product labeling, administration of taletrectinib with a moderate CYP450 3A inhibitor is predicted to increase taletrectinib Cmax and AUC by up to 1.5- and 2.6-fold, respectively. Increased exposure to taletrectinib may increase the risk and/or severity of adverse effects such as hepatotoxicity with liver enzyme elevations, lung toxicities, QT prolongation, hyperuricemia, myalgia with creatine phosphokinase elevation, and skeletal fractures.

ADJUST DOSING INTERVAL: Coadministration with high-fat food (1000 calories, 50% fat) increased taletrectinib Cmax and AUC by 1.5-fold, and the predicted increase in the QTc interval is 20.5 msec.

MANAGEMENT: The manufacturer recommends avoiding food or drink containing grapefruit during treatment with taletrectinib. In addition, taletrectinib should be administered on an empty stomach at about the same time each day, at least 2 hours before or 2 hours after food intake.

After receiving valoctocogene roxaparvovec, alcohol consumption should be avoided for at least 1 year and limited thereafter. Valoctocogene roxaparvovec can cause liver problems, which may make the medication less effective in treating your condition. Consuming other substances that can also affect the liver such as alcohol after receiving valoctocogene roxaparvovec may increase that risk. Symptoms of liver problems include fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, abdominal pain, dark urine, pale stools, and/or yellowing of the skin or eyes. Blood tests to monitor liver function should be performed before and after treatment with valoctocogene roxaparvovec. Talk to your doctor if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.