Drug Interaction Report

MONITOR: The concomitant or sequential administration of multiple antineoplastic agents may result in additive toxicities, particularly in the bone marrow, gastrointestinal tract and heart.

MANAGEMENT: Close clinical and laboratory monitoring for hematologic and nonhematologic toxicities are recommended when antineoplastic agents are administered concurrently or during close intervals. Dosing adjustments may be necessary. The manufacturers' recommendations and institutional protocols for dosage, treatment regimens, monitoring, and management of toxicities should be consulted.

MONITOR: Coadministration with lenacapavir may increase the plasma concentrations of drugs that are substrates of the efflux transporters P-glycoprotein (P-gp) and/or breast cancer resistance protein (BCRP). Lenacapavir is an inhibitor of P-gp and BCRP. In pharmacokinetic studies in subjects without HIV, coadministration of oral lenacapavir (600 mg twice daily for 2 days, then single 600 mg dose) with the P-gp substrate tenofovir alafenamide increased the peak plasma concentration (Cmax) and systemic exposure (AUC) of tenofovir alafenamide by 24% and 32%, respectively. In addition, under similar conditions, coadministration of lenacapavir with the BCRP substrate rosuvastatin (single 5 mg dose) led to an increase in rosuvastatin Cmax and AUC by 57% and 31%, respectively. However, these changes for tenofovir alafenamide and rosuvastatin are not reported to be clinically significant.

MANAGEMENT: Caution and monitoring are advised if lenacapavir is used concomitantly with drugs that are substrates of the transporters P-gp and/or BCRP, particularly sensitive substrates, or those with a narrow therapeutic range. Dose adjustments or alternative therapy may be necessary if an interaction is suspected.