Retevmo recommended dosing and administration
Patient selection for treatment with Retevmo should be based on the presence of a RET gene fusion (non-small cell lung cancer (NSCLC) or thyroid cancer) or specific RET gene mutation (medullary thyroid cancer (MTC)) in tumor specimens or plasma. An FDA-approved test for the detection of RET gene fusions and RET mutations is not currently available.1
Retevmo is dosed based on body weight and should be administered orally (PO) twice daily (BID) until disease progression or unacceptable toxicity. Patients less than 50 kg in weight should receive 120 mg. Patients 50 kg or greater in weight should receive 160 mg.1
Permanently discontinue Retevmo in patients unable to tolerate 3 dose reductions.
Reduce the recommended dosage of Retevmo for patients with severe hepatic impairment to 80 mg orally twice daily.
Select Important Safety Information
Hepatotoxicity: Serious hepatic adverse reactions occurred in 2.6% of patients treated with Retevmo. Increased AST occurred in 51% of patients, including Grade 3 or 4 events in 8% and increased ALT occurred in 45% of patients, including Grade 3 or 4 events in 9%. The median time to first onset for increased AST was 4.1 weeks (range: 5 days to 2 years) and increased ALT was 4.1 weeks (range: 6 days to 1.5 years). Monitor ALT and AST prior to initiating Retevmo, every 2 weeks during the first 3 months, then monthly thereafter and as clinically indicated. Withhold, reduce dose or permanently discontinue Retevmo based on the severity.
Hypertension occurred in 35% of patients, including Grade 3 hypertension in 17% and Grade 4 in one (0.1%) patient. Overall, 4.6% had their dose interrupted and 1.3% had their dose reduced for hypertension. Treatment-emergent hypertension was most commonly managed with anti-hypertension medications. Do not initiate Retevmo in patients with uncontrolled hypertension. Optimize blood pressure prior to initiating Retevmo. Monitor blood pressure after 1 week, at least monthly thereafter, and as clinically indicated. Initiate or adjust anti-hypertensive therapy as appropriate. Withhold, reduce dose, or permanently discontinue Retevmo based on the severity.