Drug Interactions between asciminib and pemigatinib

Pemigatinib may be taken with or without food. Do not consume grapefruit, grapefruit juice, or any supplements that contain grapefruit extract during treatment with pemigatinib unless directed otherwise by your doctor. Grapefruit juice can increase the blood levels of pemigatinib. This may increase the frequency and severity of serious side effects such as elevated phosphate levels in the blood (which can eventually lead to low blood calcium levels; calcium deposits in the skin, muscles, and other tissues; anemia; muscle cramps; seizures; and irregular heart rhythm), eye and vision problems, joint pain, mouth sores and inflammation, hair loss, diarrhea, nausea, vomiting, and constipation. 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.

Food may reduce the absorption of asciminib, which may lead to lower blood levels of the medication and possibly reduced effectiveness. You should avoid eating for at least 2 hours before and 1 hour after taking asciminib. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. 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.

Cardiovascular toxicity has been reported with asciminib in patients with preexisting cardiovascular conditions or risk factors for cardiovascular disease. Reports of cardiovascular toxicity have included ischemia, arterial thrombotic and embolic conditions, and cardiac failure. Arrhythmia, including QTc prolongation, has been reported. Monitor patients with history of cardiovascular risk factors for cardiovascular signs and symptoms. Treat as clinically indicated. For cardiovascular toxicity, temporarily withhold, reduce dose, or permanently discontinue therapy, based on persistence of cardiovascular toxicity.

Asciminib can cause increases in serum lipase. Patients with a previous history of pancreatitis might be at increased risk and should be monitored carefully for lipase elevations and any abdominal symptoms. Serum lipase should be monitored monthly and as clinically indicated. If lipase and amylase elevations are accompanied by abdominal symptoms, hold therapy, and rule out pancreatitis.

The use of asciminib may cause hypertension. Blood pressure should be well-controlled prior to initiating asciminib and treated as needed with standard anti-hypertensive therapy. For persistent hypertension despite anti-hypertensive medications, temporarily withhold, reduce dose, or permanently discontinue therapy, based on the persistence of hypertension.

The recommended dosage of pemigatinib should be reduced in patients with severe hepatic dysfunction. No dose adjustment is recommended for patients with mild or moderate hepatic impairment.

The recommended dosage of pemigatinib should be reduced in patients with severe renal disease. No dose adjustment is recommended for patients with mild or moderate renal impairment, or those patients with end-stage renal disease receiving intermittent hemodialysis.

Pemigatinib can cause retinal pigment epithelial detachment (RPED), which may cause symptoms such as blurred vision, visual floaters, or photopsia. A comprehensive ophthalmological examination including an optical coherence tomography should be performed prior to treatment initiation. Patients with visual disturbances should be closely monitored.