DELSTRIGO

DELSTRIGO is a fixed-dose combination, film-coated tablet, containing doravirine, lamivudine, and TDF for oral administration. Doravirine is an HIV-1 non-nucleoside reverse transcriptase inhibitor (NNRTI). Lamivudine is the (-)enantiomer of a dideoxy analogue of cytidine and is an HIV-1 nucleoside analogue reverse transcriptase inhibitor. TDF (a prodrug of tenofovir) is a fumaric acid salt of the bis-isopropoxycarbonyloxymethyl ester derivative of tenofovir. In vivo TDF is converted to tenofovir, an acyclic nucleoside phosphonate (nucleotide) analog of adenosine 5'-monophosphate. Tenofovir is an HIV-1 reverse transcriptase inhibitor. Each tablet contains 100 mg of doravirine, 300 mg of lamivudine, and 300 mg of TDF (equivalent to 245 mg of tenofovir disoproxil) as active ingredients. The tablets include the following inactive ingredients: colloidal silicon dioxide, croscarmellose sodium, hypromellose acetate succinate, magnesium stearate, microcrystalline cellulose, and sodium stearyl fumarate. The tablets are film coated with a coating material containing the following inactive ingredients: hypromellose, iron oxide yellow, lactose monohydrate, titanium dioxide, and triacetin. The coated tablets are polished with carnauba wax. Doravirine : 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 Lamivudine : The chemical name for lamivudine is (-)-1-[(2 R ,5 S )-2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-cytosine. It has a molecular formula of C 8 H 11 N 3 O 3 S and a molecular weight of 229.26. It has the following structural formula: Lamivudine is soluble in water. Chemical Structure TDF : The chemical name for TDF is 9-[(R)-2-[[bis[[(isopropoxycarbonyl)oxy]methoxy] phosphinyl]- methoxy]propyl]adenine fumarate (1:1). It has a molecular formula of C 19 H 30 N 5 O 10 P∙C 4 H 4 O 4 and a molecular weight of 635.52. It has the following structural formula: TDF is slightly soluble in water. Chemical Structure

DELSTRIGO ® is indicated as a complete regimen 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 the individual components of DELSTRIGO [see Clinical Studies (14) ] . DELSTRIGO is a three-drug combination of doravirine (a non-nucleoside reverse transcriptase inhibitor [NNRTI]), lamivudine, and tenofovir disoproxil fumarate (both nucleoside analogue reverse transcriptase inhibitors) and is indicated as a complete regimen for the treatment of HIV-1 infection in adults and pediatric patients weighing at least 35 kg: with no 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 the individual components of DELSTRIGO. ( 1 )

Testing: Prior to or when initiating DELSTRIGO, test for HBV infection. Prior to or when initiating DELSTRIGO, and during treatment with DELSTRIGO, on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose and urine protein in all patients. In patients with chronic kidney disease, also assess serum phosphorus . ( 2.1 ) Recommended dosage: One tablet taken orally once daily with or without food in adults and pediatric patients weighing at least 35 kg. ( 2.2 ) Renal impairment: Not recommended in patients with estimated creatinine clearance below 50 mL per minute. ( 2.3 ) Dosage adjustment with rifabutin: Take one tablet of DELSTRIGO once daily, followed by one tablet of doravirine 100 mg (PIFELTRO) approximately 12 hours after the dose of DELSTRIGO. ( 2.4 ) 2.1 Testing When Initiating and During Treatment with DELSTRIGO Prior to or when initiating DELSTRIGO, test patients for HBV infection [see Warnings and Precautions (5.2) ]. Prior to or when initiating DELSTRIGO, and during treatment with DELSTRIGO, on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all patients. In patients with chronic kidney disease, also assess serum phosphorus [see Warnings and Precautions (5.3) ]. 2.2 Recommended Dosage DELSTRIGO is a fixed-dose combination product containing 100 mg of doravirine (DOR), 300 mg of lamivudine (3TC), and 300 mg of TDF. The recommended dosage of DELSTRIGO in adults and pediatric patients weighing at least 35 kg is one tablet taken orally once daily with or without food [see Clinical Pharmacology (12.3) ] . 2.3 Renal Impairment Because DELSTRIGO is a fixed-dose combination tablet and the dosage of lamivudine and TDF cannot be adjusted, DELSTRIGO is not recommended in patients with estimated creatinine clearance less than 50 mL/min [see Warnings and Precautions (5.3) and Use in Specific Populations (8.6) ] . 2.4 Dosage Adjustment with Rifabutin If DELSTRIGO is co-administered with rifabutin, take one tablet of DELSTRIGO once daily, followed by one tablet of doravirine 100 mg (PIFELTRO) approximately 12 hours after the dose of DELSTRIGO for the duration of rifabutin co-administration [see Drug Interactions (7.2) and Clinical Pharmacology (12.3) ].

DELSTRIGO is contraindicated when co-administered with drugs that are strong cytochrome P450 (CYP)3A enzyme inducers as significant decreases in doravirine plasma concentrations may occur, which may decrease the effectiveness of DELSTRIGO [see Warnings and Precautions (5.4) , Drug Interactions (7.2) , and Clinical Pharmacology (12.3) ] . These drugs include, but are not limited to, the following: - the anticonvulsants carbamazepine, oxcarbazepine, phenobarbital, phenytoin - the androgen receptor inhibitor enzalutamide - the antimycobacterials rifampin, rifapentine - the cytotoxic agent mitotane - St. John's wort ( Hypericum perforatum) DELSTRIGO is contraindicated in patients with a previous hypersensitivity reaction to lamivudine. DELSTRIGO is contraindicated when co-administered with drugs that are strong cytochrome P450 (CYP)3A enzyme inducers as significant decreases in doravirine plasma concentrations may occur, which may decrease the effectiveness of DELSTRIGO. ( 4 ) DELSTRIGO is contraindicated in patients with a previous hypersensitivity reaction to lamivudine.

The following adverse reactions are discussed in other sections of the labeling: Severe Acute Exacerbation of Hepatitis B in people with concomitant HIV-1 and HBV [see Warnings and Precautions (5.2) ] New Onset or Worsening Renal Impairment [see Warnings and Precautions (5.3) ] Bone Loss and Mineralization Defects [see Warnings and Precautions (5.5) ] Immune Reconstitution Syndrome [see Warnings and Precautions (5.6) ] Most common adverse reactions (incidence greater than or equal to 5%, all grades) are dizziness, nausea, and abnormal dreams. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Merck Sharp & Dohme LLC at 1-877-888-4231 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Adverse Reactions in Adults with No Antiretroviral Treatment History The safety assessment of DELSTRIGO is based on Week 96 data from two Phase 3, randomized, international, multicenter, double-blind, active-controlled trials. A total of 747 participants received doravirine either as the single entity in combination with other antiretroviral drugs as background regimens (n=383) or as the fixed-dose DELSTRIGO (n=364), and a total of 747 participants were randomized to control arms. In DRIVE-AHEAD (Protocol 021), 728 adult participants received either DELSTRIGO (n=364) or EFV/FTC/TDF once daily (n=364). By Week 96, 3% in the DELSTRIGO group and 7% in the EFV/FTC/TDF group had adverse events leading to discontinuation of study medication. Adverse reactions reported in greater than or equal to 5% of participants in any treatment group in DRIVE-AHEAD are presented in Table 1. Table 1: Adverse Reactions Frequencies of adverse reactions are based on all adverse events attributed to trial drugs by the investigator. (All Grades) Reported in ≥5% No adverse reactions of Grade 2 or higher (moderate or severe) occurred in ≥2% of participants treated with DELSTRIGO. of Participants in Any Treatment Group in Adults with No Antiretroviral Treatment History in DRIVE-AHEAD (Week 96) DELSTRIGO Once Daily N=364 EFV/FTC/TDF Once Daily N=364 Dizziness 7% 32% Nausea 5% 7% Abnormal Dreams 5% 10% Headache 4% 5% Insomnia 4% 5% Diarrhea 4% 6% Somnolence 3% 7% Rash Rash: includes rash, rash erythematous, rash generalized, rash macular, rash maculo-papular, rash papular, rash pruritic. 2% 12% The majority (66%) of adverse reactions associated with DELSTRIGO occurred at severity Grade 1 (mild). Neuropsychiatric Adverse Events For DRIVE-AHEAD, the analysis of participants with neuropsychiatric adverse events by Week 48 is presented in Table 2. The proportion of participants who reported one or more neuropsychiatric adverse events was 24% and 57% in the DELSTRIGO and EFV/FTC/TDF groups, respectively. A statistically significantly lower proportion of DELSTRIGO-treated participants compared to EFV/FTC/TDF-treated participants reported neuropsychiatric adverse events by Week 48 in the three pre-specified categories of dizziness, sleep disorders and disturbances, and altered sensorium. Table 2: DRIVE-AHEAD - Analysis of Participants with Neuropsychiatric Adverse Events All causality and all grade events were included in the analysis. (Week 48) DELSTRIGO Once Daily N=364 EFV/FTC/TDF Once Daily N=364 Treatment Difference (DELSTRIGO - EFV/FTC/TDF) Estimate (95% CI) The 95% CIs were calculated using Miettinen and Nurminen's method. Categories pre-specified for statistical testing were dizziness (p <0.001), sleep disorders and disturbances (p <0.001), and altered sensorium (p=0.033). Sleep disorders and disturbances Predefined using MedDRA preferred terms including: abnormal dreams, hyposomnia, initial insomnia, insomnia, nightmare, sleep disorder, somnambulism. 12% 26% -13.5 (-19.1, -7.9) Dizziness 9% 37% -28.3 (-34.0, -22.5) Altered sensorium Predefined using MedDRA preferred terms including: altered state of consciousness, lethargy, somnolence, syncope. 4% 8% -3.8 (-7.6, -0.3) Neuropsychiatric adverse events in the pre-defined category of depression and suicide/self-injury were reported in 4% and 7% of participants, in the DELSTRIGO and EFV/FTC/TDF groups, respectively. In DRIVE-AHEAD through 48 weeks of treatment, the majority of participants who reported neuropsychiatric adverse events reported events that were mild to moderate in severity (97% [83/86] and 96% [198/207], in the DELSTRIGO and EFV/FTC/TDF groups, respectively) and the majority of participants reported these events in the first 4 weeks of treatment (72% [62/86] in the DELSTRIGO group and 86% [177/207] in the EFV/FTC/TDF group). Neuropsychiatric adverse events led to treatment discontinuation in 1% (2/364) and 1% (5/364) of participants in the DELSTRIGO and EFV/FTC/TDF groups, respectively. The proportion of participants who reported neuropsychiatric adverse events through Week 4 was 17% (62/364) in the DELSTRIGO group and 49% (177/364) in the EFV/FTC/TDF group. At Week 48, the prevalence of neuropsychiatric adverse events was 12% (44/364) in the DELSTRIGO group and 22% (81/364) in the EFV/FTC/TDF group. At Week 96, the prevalence of neuropsychiatric adverse events was 13% (47/364) in the DELSTRIGO group and 23% (82/364) in the EFV/FTC/TDF group. Laboratory Abnormalities The percentages of participants with selected laboratory abnormalities (that represent a worsening from baseline) who were treated with DELSTRIGO or EFV/FTC/TDF in DRIVE-AHEAD are presented in Table 3. Table 3: Selected Laboratory Abnormalities Reported in Adult Participants with No Antiretroviral Treatment History in DRIVE-AHEAD (Week 96) Laboratory Parameter Preferred Term (Unit)/Limit DELSTRIGO Once Daily N=364 EFV/FTC/TDF Once Daily N=364 Blood Chemistry Each participant is only counted once per parameter at the highest toxicity grade. Only participants with a baseline value and at least one on-treatment value for a given laboratory parameter are included. ULN = Upper limit of normal range. Total bilirubin (mg/dL) 1.1 - <1.6 × ULN 5% 0% 1.6 - <2.6 × ULN 2% 0% ≥2.6 × ULN 1% <1% Creatinine (mg/dL) >1.3 - 1.8 × ULN or Increase of >0.3 mg/dL above baseline 3% 2% >1.8 × ULN or Increase of ≥1.5 × above baseline 3% 2% Aspartate aminotransferase (IU/L) 2.5 - <5.0 × ULN 3% 3% ≥5.0 × ULN 1% 4% Alanine aminotransferase (IU/L) 2.5 - <5.0 × ULN 4% 4% ≥5.0 × ULN 1% 3% Alkaline phosphatase (IU/L) 2.5 - <5.0 × ULN <1% 1% ≥5.0 × ULN 0% <1% Lipase 1.5 - <3.0 × ULN 6% 4% ≥3.0 × ULN 2% 3% Creatine kinase (IU/L) 6.0 - <10.0 × ULN 3% 3% ≥10.0 × ULN 4% 6% Cholesterol, fasted (mg/dL) ≥300 mg/dL 1% <1% LDL cholesterol, fasted (mg/dL) ≥190 mg/dL <1% 2% Triglycerides, fasted (mg/dL) >500 mg/dL 1% 3% Change in Lipids from Baseline For DRIVE-AHEAD, changes from baseline at Week 48 in LDL-cholesterol, non-HDL-cholesterol, total cholesterol, triglycerides, and HDL-cholesterol are shown in Table 4. Changes from baseline at Week 96 were similar to findings at Week 48. The LDL and non-HDL comparisons were pre-specified and are summarized in Table 4. The differences were statistically significant, showing superiority of DELSTRIGO for both parameters. The clinical benefit of these findings has not been demonstrated. Table 4: Mean Change from Baseline in Fasting Lipids in Adult Participants with No Antiretroviral Treatment History in DRIVE-AHEAD (Week 48) Laboratory Parameter Preferred Term DELSTRIGO Once Daily N=320 EFV/FTC/TDF Once Daily N=307 Difference Estimates (DELSTRIGO - EFV/FTC/TDF) Baseline Change Baseline Change Difference (95% CI) Participants on lipid-lowering agents at baseline were excluded from these analyses (DELSTRIGO n=15 and EFV/FTC/TDF n=10). Participants initiating a lipid-lowering agent post-baseline had their last fasted on-treatment value (prior to starting the agent) carried forward (DELSTRIGO n=3 and EFV/FTC/TDF n=8). LDL-Cholesterol (mg/dL) p-value for the pre-specified hypothesis testing for treatment difference was <0.0001. 91.7 -2.1 91.3 8.3 -10.2 (-13.8, -6.7) Non-HDL Cholesterol (mg/dL) 114.7 -4.1 115.3 12.7 -16.9 (-20.8, -13.0) Total Cholesterol (mg/dL) Not pre-specified for hypothesis testing. 156.8 -2.2 156.8 21.1 - Triglycerides (mg/dL) 118.7 -12.0 122.6 21.6 - HDL-Cholesterol (mg/dL) 42.1 1.8 41.6 8.4 - Adverse Reactions in Virologically-Suppressed Adults The safety of DELSTRIGO in virologically-suppressed adults was based on Week 48 data from 670 participants in the DRIVE-SHIFT trial (Protocol 024), a randomized, international, multicenter, open-label trial in which virologically-suppressed participants were switched from a baseline regimen consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) in combination with a protease inhibitor (PI) plus either ritonavir or cobicistat, or elvitegravir plus cobicistat, or an NNRTI to DELSTRIGO. Overall, the safety profile in virologically-suppressed adult participants was similar to that in participants with no antiretroviral treatment history. Laboratory Abnormalities Serum ALT and AST Elevations: In the DRIVE-SHIFT trial, 22% and 16% of participants in the immediate switch group experienced ALT and AST elevations of greater than 1.25 × ULN, respectively, through 48 weeks on DELSTRIGO. For these ALT and AST elevations, no apparent time patterns with regard to time to onset relative to switch were observed. One percent of participants had ALT or AST elevations greater than 5 × ULN through 48 weeks on DELSTRIGO. The ALT and AST elevations were generally asymptomatic, and not associated with bilirubin elevations. In comparison, 4% and 4% of participants in the delayed switch group experienced ALT and AST elevations of greater than 1.25 × ULN through 24 weeks on their baseline regimen. Change in Lipids from Baseline Changes from baseline at Week 24 in LDL-cholesterol, non-HDL-cholesterol, total cholesterol, triglycerides, and HDL-cholesterol in participants on a PI plus ritonavir-based regimen at baseline are shown in Table 5. The LDL and non-HDL comparisons were pre-specified, and the differences were statistically significant, showing superiority for an immediate switch to DELSTRIGO for both parameters. The clinical benefit of these findings has not been demonstrated. Table 5: Mean Change from Baseline in Fasting Lipids in Adult Virologically-Suppressed Participants on a PI plus Ritonavir-based Regimen at Baseline in DRIVE-SHIFT (Week 24) Laboratory Parameter Preferred Term DELSTRIGO (Week 0-24) Once Daily N=244 PI+ritonavir (Week 0-24) Once Daily N=124 Difference Estimates Baseline Change Baseline Change Difference (95% CI) Participants on lipid-lowering agents at baseline were excluded from these analyses (DELSTRIGO n=26 and PI+ritonavir n=13). Participants initiating a lipid-lowering agent post-baseline had their last fasted on-treatment value (prior to starting the agent) carried forward (DELSTRIGO n=4 and PI+ritonavir n=2). LDL-Cholesterol (mg/dL) p-value for the pre-specified hypothesis testing for treatment difference was <0.0001. 108.7 -16.3 110.5 -2.6 -14.5 (-18.9, -10.1) Non-HDL Cholesterol (mg/dL) 138.6 -24.8 138.8 -2.1 -22.8 (-27.9, -17.7) Total Cholesterol (mg/dL) Not pre-specified for hypothesis testing. 188.5 -26.1 187.4 -0.2 - Triglycerides (mg/dL) 153.1 -44.4 151.4 -0.4 - HDL-Cholesterol (mg/dL) 50.0 -1.3 48.5 1.9 - Adverse Reactions in Pediatric Participants The safety of DELSTRIGO was evaluated in 45 virologically-suppressed or treatment-naïve pediatric participants 12 to less than 18 years of age living with HIV, through Week 24 in an open-label trial (IMPAACT 2014 (Protocol 027)) [see Clinical Studies (14.3) ] . The safety profile in pediatric participants was similar to that in adults. There were no serious or Grade 3 or 4 adverse reactions. No participants discontinued due to an adverse event. 6.2 Postmarketing Experience The following adverse reactions have been identified during postmarketing experience in patients receiving doravirine-, lamivudine- or TDF-containing regimens. Because postmarketing reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Doravirine : Skin and Subcutaneous Tissue Disorders: Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) Hepatobiliary Disorders : hepatitis Investigations : hepatic enzyme increased Lamivudine: Body as a Whole: redistribution/accumulation of body fat Endocrine and Metabolic: hyperglycemia General: Weakness Hemic and Lymphatic: anemia (including pure red cell aplasia and severe anemias progressing on therapy) Hepatic and Pancreatic : lactic acidosis and hepatic steatosis, posttreatment exacerbations of hepatitis B Hypersensitivity: anaphylaxis, urticaria Musculoskeletal: muscle weakness, CPK elevation, rhabdomyolysis Skin: alopecia, pruritus TDF: Immune System Disorders: allergic reaction, including angioedema Metabolism and Nutrition Disorders: lactic acidosis, hypokalemia, hypophosphatemia Respiratory, Thoracic , and Mediastinal Disorders: dyspnea Gastrointestinal Disorders: pancreatitis, increased amylase, abdominal pain Hepatobiliary Disorders: hepatic steatosis, hepatitis, increased liver enzymes (most commonly AST, ALT gamma GT) Skin and Subcutaneous Tissue Disorders: rash Musculoskeletal and Connective Tissue Disorders: rhabdomyolysis, osteomalacia (manifested as bone pain and which may contribute to fractures), muscular weakness, myopathy Renal and Urinary Disorders: acute renal failure, renal failure, acute tubular necrosis, Fanconi syndrome, proximal renal tubulopathy, interstitial nephritis (including acute cases), nephrogenic diabetes insipidus, renal insufficiency, increased creatinine, proteinuria, polyuria General Disorders and Administration Site Conditions: asthenia The following adverse reactions, listed under the body system headings above, may occur as a consequence of proximal renal tubulopathy: rhabdomyolysis, osteomalacia, hypokalemia, muscular weakness, myopathy, hypophosphatemia.

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) ] .

Store DELSTRIGO in the original bottle. Keep the bottle tightly closed to protect from moisture. Do not remove the desiccants. Store DELSTRIGO at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature].