DELSTRIGO-PIFELTRO

DELSTRIGO® IMPORTANT SAFETY INFORMATION

Indications and clinical use:
DELSTRIGO® (doravirine/lamivudine/tenofovir disoproxil fumarate) is indicated as a complete regimen for the treatment of human immunodeficiency virus-1 (HIV-1) infection in adults and pediatric patients 12 years of age and older and weighing at least 35 kg without past or present evidence of viral resistance to doravirine, lamivudine, or tenofovir. The safety and efficacy of DELSTRIGO® have not been established in patients younger than 12 years of age and weighing less than 35 kg. Limited data on use in patients ≥ 65 years.

Contraindications:

• Use with drugs that are strong CYP3A enzyme inducers, including but not limited to the anticonvulsants carbamazepine, oxcarbazepine, phenobarbital, and phenytoin; the androgen receptor inhibitor enzalutamide; the antimycobacterials rifampin and rifapentine; the cytotoxic agent mitotane; and St. John’s wort (Hypericum perforatum)

Most serious warnings and precautions:

• Chronic HBV infection: Not approved for treatment of chronic HBV infection, and safety and efficacy not established in coinfected patients. Severe acute exacerbations of HBV have been reported in coinfected HBV/HIV-1 patients who discontinued lamivudine or tenofovir DF, two of the components of DELSTRIGO®. Monitor closely with clinical and laboratory follow-up for at least several months after stopping treatment. If appropriate, initiate anti-hepatitis B therapy, especially in patients with advanced liver disease or cirrhosis, since post-treatment exacerbation of hepatitis may lead to hepatic decompensation and liver failure
• Nephrotoxicity: Renal impairment including cases of acute renal failure and Fanconi syndrome has been reported with the use of tenofovir disoproxil fumarate (TDF)
• Breastfeeding: Mothers should not breastfeed if they are receiving DELSTRIGO®

Other relevant warnings and precautions:

• Do not administer with other antiretroviral drugs, with adefovir dipivoxil, or with single-agent doravirine unless doravirine dose adjustment required
• Has not been evaluated in patients with previous virologic failure to any other antiretroviral therapy
• Should not be used in antiretroviral-experienced patients with resistance mutations to doravirine, lamivudine, or tenofovir or with suspected such mutations if no genotype is available
• Bone loss and mineralization defects associated with TDF
• Avoid driving and operating machinery if fatigue, dizziness, and somnolence occur
• Avoid concomitant use with moderate CYP3A inducers, or if coadministration cannot be avoided, 1 tablet of doravirine 100 mg (PIFELTRO®) should be taken approximately 12 hours after the dose of DELSTRIGO®
• Increased TDF exposure when used with certain HCV regimens
• Consider measurement of serum lipids and blood glucose
• Very rare occurrences of pure red cell aplasia reported with lamivudine use
• Lactic acidosis/severe hepatomegaly with steatosis, including fatal cases, have been reported
• Immune reconstitution inflammatory syndrome
• Angioedema has been reported in patients taking TDF
• New onset or worsening renal impairment with TDF
• Physicians are encouraged to report pregnancy cases to the Antiretroviral Pregnancy Registry: http://www.apregistry.com/
• Severe skin reactions, including toxic epidermal necrolysis
• Special care advised in patients ≥ 65 years of age due to age-associated changes (e.g., decreases in renal function)
• Not recommended in patients with estimated creatinine clearance <50 mL/min
• Not studied in patients with severe hepatic impairment, therefore caution is advised
• Emergence of lamivudine-resistant HBV
• Patients coinfected with HIV-1 and HBV or HCV are at increased risk for severe hepatic adverse events

For more information:
Please consult the Product Monograph for important information relating to contraindications, warnings and precautions, adverse reactions, drug interactions, and dosing information, which have not  been discussed in this piece. The Product Monograph is also available by calling 1-800-567-2594.

Reference: DELSTRIGO® Product Monograph. Merck Canada Inc. September 23, 2025.