Doravirine, lamivudine, and tenofovir disoproxil

Because DELSTRIGO 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. ( 4 , 5.4 , 7 )

7.1 Concomitant Use with Other Antiretroviral Medications Because DELSTRIGO 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. Information regarding potential drug-drug interactions with other antiretroviral medications is not provided.

7.2 Effect of Other Drugs on DELSTRIGO Co-administration of DELSTRIGO with a CYP3A inducer decreases doravirine plasma concentrations, which may reduce DELSTRIGO efficacy [see Contraindications (4) , Warnings and Precautions (5.4) , and Clinical Pharmacology (12.3) ] . Co-administration of DELSTRIGO and drugs that are inhibitors of CYP3A may result in increased plasma concentrations of doravirine. Table 6 shows the significant drug interactions with the components of DELSTRIGO. The drug interactions described are based on studies conducted with either DELSTRIGO or the components of DELSTRIGO as individual agents.

Table 6: Drug Interactions with DELSTRIGO This table is not all-inclusive Concomitant Drug Class: Drug Name Effect on Concentration Clinical Comment ↑ = increase, ↓ = decrease All other drug-drug interactions shown are anticipated based on the known metabolic and elimination pathways. Androgen Receptors enzalutamide ↓ doravirine Co-administration is contraindicated with enzalutamide. At least a 4-week cessation period is recommended prior to initiation of DELSTRIGO. Anticonvulsants carbamazepine oxcarbazepine phenobarbital phenytoin ↓ doravirine Co-administration is contraindicated with these anticonvulsants.

At least a 4-week cessation period is recommended prior to initiation of DELSTRIGO. Antimycobacterials rifampin The interaction between doravirine and the concomitant drug was evaluated in a clinical study. rifapentine ↓ doravirine Co-administration is contraindicated with rifampin or rifapentine. At least a 4-week cessation period is recommended prior to initiation of DELSTRIGO. rifabutin ↓ doravirine If DELSTRIGO is co-administered with rifabutin, one tablet of doravirine (PIFELTRO) should be taken approximately 12 hours after the dose of DELSTRIGO [see Dosage and Administration (2.4) ] . Cytotoxic Agents mitotane ↓ doravirine Co-administration is contraindicated with mitotane.

At least a 4-week cessation period is recommended prior to initiation of DELSTRIGO. Hepatitis C Antiviral Agents ledipasvir/sofosbuvir sofosbuvir/velpatasvir ↑ tenofovir Monitor for adverse reactions associated with TDF. Herbal Products St. John's wort ↓ doravirine Co-administration is contraindicated with St. John's wort. At least a 4-week cessation period is recommended prior to initiation of DELSTRIGO. Other Agents sorbitol ↓ lamivudine Co-administration of single doses of lamivudine and sorbitol resulted in a sorbitol dose-dependent reduction in lamivudine exposures. When possible, avoid use of sorbitol-containing medicines with lamivudine-containing medicines.

Co-administration of DELSTRIGO with drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of lamivudine, tenofovir, and/or other renally eliminated drugs. Some examples of drugs that are eliminated by active tubular secretion include, but are not limited to, acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple NSAIDs [see Warnings and Precautions (5.3) and Clinical Pharmacology (12.3) ] .

No clinically significant changes in concentration were observed for doravirine when co-administered with the following agents: TDF, lamivudine, elbasvir and grazoprevir, ledipasvir and sofosbuvir, ritonavir, ketoconazole, aluminum hydroxide/magnesium hydroxide/simethicone containing antacid, pantoprazole, or methadone [see Clinical Pharmacology (12.3) ] . No clinically significant changes in concentration were observed for tenofovir when co-administered with tacrolimus or entecavir [see Clinical Pharmacology (12.3) ] .

7.3 Effect of DELSTRIGO on Other Drugs No clinically significant changes in concentration were observed for the following agents when co-administered with doravirine: lamivudine, TDF, elbasvir and grazoprevir, ledipasvir and sofosbuvir, atorvastatin, an oral contraceptive containing ethinyl estradiol and levonorgestrel, metformin, methadone, or midazolam. No clinically significant drug interactions have been observed between TDF and the following medications: entecavir, methadone, oral contraceptives, sofosbuvir, or tacrolimus in studies conducted in healthy participants.

Lamivudine is not significantly metabolized by CYP enzymes nor does it inhibit or induce this enzyme system; therefore, it is unlikely that clinically significant drug interactions will occur through these pathways [see Clinical Pharmacology (12.3) ] .

8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in individuals exposed to DELSTRIGO during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary There is insufficient prospective pregnancy data from the APR to adequately assess the risk of birth defects and miscarriage. Doravirine use in individuals during pregnancy has not been evaluated; however, lamivudine and TDF use during pregnancy has been evaluated in a limited number of individuals reported to the APR.

Available data from the APR show no difference in the overall risk of major birth defects for lamivudine and TDF compared with the background rate for major birth defects of 2.7% in the U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP) ( see Data ) . 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. In animal reproduction studies, oral administration of lamivudine to pregnant rabbits during organogenesis resulted in embryolethality at systemic exposure (AUC) similar to the recommended clinical dose; however, no adverse development effects were observed with oral administration of lamivudine to pregnant rats during organogenesis at plasma concentrations (C max ) 35 times the recommended clinical dose.

No adverse developmental effects were observed when doravirine and TDF were administered separately at doses/exposures ≥8 (doravirine) and ≥14 (TDF) times those of the recommended human dose (RHD) of DELSTRIGO ( see Data ). Data Human Data Lamivudine : The APR has received a total of over 13,000 prospective reports with follow-up data of possible exposure to lamivudine-containing regimens; over 5,900 reports in the first trimester; over 5,600 reports in the second trimester; and over 1,800 reports in the third trimester.

Birth defects occurred in 170 of 5,472 (3.1%, 95% CI: 2.7% to 3.6%) live births for lamivudine-containing regimens (first trimester exposure); and 218 of 7,513 (2.9%, 95% CI: 2.5% to 3.3%) live births for lamivudine-containing regimens (second/third trimester…