PIFELTRO is a film-coated tablet containing doravirine for oral administration. Doravirine is an HIV-1 non-nucleoside reverse transcriptase inhibitor (NNRTI). Each tablet contains 100 mg of doravirine as the active ingredient. The tablets include the following inactive ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose acetate succinate, lactose monohydrate, magnesium stearate, and microcrystalline cellulose. The tablets are film coated with a coating material containing the following inactive ingredients: hypromellose, lactose monohydrate, titanium dioxide, and triacetin. The coated tablets are polished with carnauba wax. The chemical name for doravirine is 3-chloro-5-[[1-[(4,5-dihydro-4-methyl-5-oxo-1 H -1,2,4-triazol-3-yl)methyl]-1,2-dihydro-2-oxo-4-(trifluoromethyl)-3-pyridinyl]oxy]benzonitrile. It has a molecular formula of C 17 H 11 ClF 3 N 5 O 3 and a molecular weight of 425.75. It has the following structural formula: Doravirine is practically insoluble in water. Chemical Structure

PIFELTRO ® is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection in adults and pediatric patients weighing at least 35 kg: with no prior antiretroviral treatment history; OR to replace the current antiretroviral regimen in those who are virologically-suppressed (HIV-1 RNA less than 50 copies per mL) on a stable antiretroviral regimen with no history of treatment failure and no known substitutions associated with resistance to doravirine . PIFELTRO, a non-nucleoside reverse transcriptase inhibitor (NNRTI), is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection in adults and pediatric patients weighing at least 35 kg: with no prior antiretroviral treatment history, OR to replace the current antiretroviral regimen in those who are virologically-suppressed (HIV-1 RNA less than 50 copies per mL) on a stable antiretroviral regimen with no history of treatment failure and no known substitutions associated with resistance to doravirine.

PIFELTRO film-coated tablets are white, oval-shaped tablets, debossed with the corporate logo and 700 on one side and plain on the other side. Each tablet contains 100 mg doravirine. Tablets: 100 mg doravirine.

Recommended dosage: One tablet taken orally once daily with or without food in adults and pediatric patients weighing at least 35 kg. Dosage adjustment with rifabutin: One tablet taken twice daily (approximately 12 hours apart)

Recommended Dosage The recommended dosage regimen of PIFELTRO in adults and pediatric patients weighing at least 35 kg is one 100 mg tablet taken orally once daily with or without food

Dosage Adjustment with Rifabutin If PIFELTRO is co-administered with rifabutin, increase PIFELTRO dosage to one tablet twice daily (approximately 12 hours apart) for the duration of rifabutin co-administration .

Severe skin reactions, including Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), have been reported during the postmarketing experience with doravirine-containing regimens. Discontinue PIFELTRO, and other medications known to be associated with severe skin reactions, immediately if a painful rash with mucosal involvement or a progressive severe rash develops, and closely monitor clinical status. Monitor for Immune Reconstitution Syndrome. 5.1 Severe Skin Reactions Severe skin reactions, including Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), have been reported during the postmarketing experience with doravirine-containing regimens . Discontinue PIFELTRO, and other medications known to be associated with severe skin reactions, immediately if a painful rash with mucosal involvement or a progressive severe rash develops. Clinical status should be closely monitored, and appropriate therapy should be initiated

Risk of Adverse Reactions or Loss of Virologic Response Due to Drug Interactions The concomitant use of PIFELTRO and certain other drugs may result in known or potentially significant drug interactions, some of which may lead to loss of therapeutic effect of PIFELTRO and possible development of resistance . See Table 6 for steps to prevent or manage these possible and known significant drug interactions, including dosing recommendations. Consider the potential for drug interactions prior to and during PIFELTRO therapy, review concomitant medications during PIFELTRO therapy, and monitor for adverse reactions

Immune Reconstitution Syndrome Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy. During the initial phase of combination antiretroviral treatment, patients whose immune system responds may develop an inflammatory response to indolent or residual opportunistic infections (such as Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia (PCP), or tuberculosis), which may necessitate further evaluation and treatment. Autoimmune disorders (such as Graves' disease, polymyositis, Guillain-Barré syndrome, and autoimmune hepatitis) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable and can occur many months after initiation of treatment.

Consult the full prescribing information prior to and during treatment for important potential drug-drug interactions. ( 4 , 5.2 , 7 ) 7.1 Effect of Other Drugs on PIFELTRO Co-administration of PIFELTRO with a CYP3A inducer decreases doravirine plasma concentrations, which may reduce PIFELTRO efficacy . Co-administration of PIFELTRO and drugs that are inhibitors of CYP3A may result in increased plasma concentrations of doravirine. Table 6 shows significant drug interactions with PIFELTRO. Table 6: Drug Interactions with PIFELTRO 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 PIFELTRO. 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 PIFELTRO. Antimycobacterials rifampin The interaction between PIFELTRO 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 PIFELTRO. rifabutin ↓ doravirine Increase PIFELTRO dosage to one tablet twice daily when co-administered with rifabutin . Cytotoxic Agents mitotane ↓ doravirine Co-administration is contraindicated with mitotane. At least a 4-week cessation period is recommended prior to initiation of PIFELTRO. HIV Antiviral Agents efavirenz etravirine nevirapine ↓ doravirine Use with efavirenz, etravirine, or nevirapine is not recommended. 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 PIFELTRO. No clinically significant changes in concentration were observed for doravirine when co-administered with the following agents: dolutegravir, TDF, lamivudine, elbasvir and grazoprevir, ledipasvir and sofosbuvir, ritonavir, ketoconazole, aluminum hydroxide/magnesium hydroxide/simethicone containing antacid, pantoprazole, and methadone

Effect of PIFELTRO on Other Drugs No clinically significant changes in concentration were observed for the following agents when co-administered with doravirine: dolutegravir, lamivudine, TDF, elbasvir and grazoprevir, ledipasvir and sofosbuvir, atorvastatin, an oral contraceptive containing ethinyl estradiol and levonorgestrel, metformin, methadone, and midazolam .