Doravirine and islatravir

Because IDVYNSO is a complete regimen, co-administration with other antiretroviral medications for treatment of HIV-1 infection is not recommended. ( 7.1 ) Consult the full prescribing information prior to and during treatment for important potential drug-drug interactions. ( 2.2 , 4 , 5.2 , 7 , 12.3 )

7.1 Concomitant Use with Other Antiretroviral Medications Because IDVYNSO is a complete regimen for the treatment of HIV-1 infection, co-administration with other antiretroviral medications for treatment of HIV-1 infection is not recommended.

7.2 Effects of Other Drugs on IDVYNSO Doravirine Co-administration of IDVYNSO with a CYP3A inducer decreases doravirine plasma concentrations, which may reduce the efficacy of IDVYNSO [see Contraindications (4) , Warnings and Precautions (5.2) , and Clinical Pharmacology (12.3) ] . Co-administration of IDVYNSO and drugs that are inhibitors of CYP3A may result in increased plasma concentrations of doravirine. Islatravir Islatravir requires phosphorylation by cellular kinases to form the pharmacologically active ISL-TP.

Co-administration of IDVYNSO and drugs that are substrates of dCK (e.g., certain nucleoside antiviral agents and nucleoside antimetabolites) may result in a decrease in ISL-TP concentrations and may reduce the therapeutic effect of islatravir [see Contraindications (4) , Warnings and Precautions (5.2) , and Clinical Pharmacology (12.3) ] . Islatravir is subject to ADA-mediated metabolism (approximately 53%). Co-administration of IDVYNSO and drugs that are ADA inhibitors (e.g., pentostatin) may result in increased plasma concentrations of islatravir and may increase the risk of adverse reactions [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3) ] .

The drug interactions described in Table 3 are based on studies conducted with IDVYNSO, its components, or are predicted drug interactions that may occur with IDVYNSO. Table 3: Drug Interactions with IDVYNSO This table is not all inclusive. Concomitant Drug Class: Drug Name Effect on Concentration Clinical Comment ↑ = increase, ↓ = decrease Strong CYP3A Inducers ↓ doravirine Co-administration with strong CYP3A inducers is contraindicated At least a 4-week cessation period is recommended prior to initiation of IDVYNSO. Moderate CYP3A Inducers ↓ doravirine If IDVYNSO is co-administered with rifabutin Interactions were evaluated in clinical studies.

All other drug-drug interactions are predicted. , one tablet of doravirine (PIFELTRO) should be taken approximately 12 hours after the dose of IDVYNSO [see Dosage and Administration (2.2) ] . Co-administration with other moderate CYP3A inducers is not recommended. dCK Substrates May include other nucleoside drugs Anti-virals lamivudine emtricitabine ↓ ISL-TP Co-administration is contraindicated with lamivudine or emtricitabine. Nucleoside Antimetabolites cladribine clofarabine cytarabine fludarabine gemcitabine ↓ ISL-TP Co-administration with these nucleoside antimetabolites is not recommended as dCK substrates may cause a decrease in the intracellular concentration of ISL-TP.

ADA Inhibitors pentostatin ↑ islatravir Co-administration with pentostatin is not recommended as it may cause an increase in plasma concentrations of islatravir.

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in individuals exposed to IDVYNSO during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary There are insufficient human data on the use of IDVYNSO during pregnancy to inform a drug-associated risk of birth defects and miscarriage.

In animal reproduction studies, no developmental effects were observed when the components of IDVYNSO were administered separately at exposures (AUC) at least 8 (doravirine) and 500 (islatravir) times the exposure at the recommended human dose (RHD) of these components in IDVYNSO (see Data .) The background rate of major birth defects is 2.7% in a U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP). The rate of miscarriage is not reported in the APR. The estimated background rate of miscarriage in the clinically recognized pregnancies in the U.S. general population is 15-20%.

Methodological limitations of the APR include the use of MACDP as the external comparator group. The MACDP population is not disease-specific, evaluates individuals and infants from the limited geographic area, and does not include outcomes for births that occurred at less than 20 weeks gestation. Data Animal Data Doravirine Doravirine was administered orally to pregnant rabbits (up to 300 mg/kg/day on Gestation Days (GD) 7 to 20) and rats (up to 450 mg/kg/day on GD 6 to 20 and separately from GD 6 to Lactation/Postpartum Day 20).

No significant toxicological effects on embryo-fetal (rats and rabbits) or pre/post-natal (rats) development were observed at exposures (AUC) approximately 9 times (rats) and 8 times (rabbits) the exposure in humans at the RHD. Doravirine was transferred to the fetus through the placenta in embryo-fetal studies, with fetal plasma concentrations of up to 40% (rabbits) and 52% (rats) that of maternal concentrations observed on GD 20. Islatravir Islatravir was administered orally to pregnant rabbits (up to 10 mg/kg/day on GD 7 to 20) and rats (up to 50 mg/kg/day on GD 6 to 20 and separately up to 10 mg/kg from GD 6 to Lactation/Postpartum Day 20).

No significant toxicological effects on embryo-fetal (rats and rabbits) or pre/post-natal (rats) development were observed at exposures (AUC) approximately 500 times (rats) and 1300 times (rabbits) the exposure in humans at the RHD. In rats, islatravir was transferred to the fetus through the placenta in rats, with fetal plasma…