Drug Interactions between asciminib and M-Phen

MONITOR: Central nervous system- and/or respiratory-depressant effects may be additively or synergistically increased in patients taking multiple drugs that cause these effects, especially in elderly or debilitated patients. Sedation and impairment of attention, judgment, thinking, and psychomotor skills may increase.

MANAGEMENT: During concomitant use of these drugs, patients should be monitored for potentially excessive or prolonged CNS and respiratory depression. Cautious dosage titration may be required, particularly at treatment initiation. Ambulatory patients should be counseled to avoid hazardous activities requiring mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.

MONITOR: It is uncertain whether asciminib causes clinically significant prolongation of the QT interval of the electrocardiogram. In clinical studies, prolongation of the Fridericia-corrected QT interval (QTcF) was reported in 3 of 356 (0.8%) of patients, with one report of QTcF greater than 500 msec together with more than 60 msec QTcF increase from baseline. Asciminib is not reported to prolong the corrected QT (QTc) interval by greater than 20 msec at the maximum recommended clinical dosage (200 mg twice daily); however, a prolongation of up to 10 msec cannot be excluded. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia, hypocalcemia). Moreover, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s).

MANAGEMENT: Some authorities recommend caution and clinical monitoring when asciminib is used with drugs that are known to cause QT interval prolongation. An ECG should be obtained at baseline and during treatment as clinically indicated, particularly in patients with a history of cardiac arrhythmias, uncontrolled or significant cardiac disease (including bradycardia), or congenital or family history of long QT syndrome. Serum electrolytes, including potassium and magnesium should also be corrected prior to starting asciminib therapy and monitored during treatment as clinically indicated. Patients should be advised to seek prompt medical attention if they experience symptoms that indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.