Drug Update · Infectious Disease

FDA Approves IDVYNSO for Suppressed HIV-1: 1% ≥50 copies/mL

July 12, 2026

Approval date

2026-04-20

Indication

Complete two-drug regimen to replace current regimen in virologically-suppressed adults (HIV-1 RNA <50 copies/mL) [11]

Trial 051 Week 48 virologic failure

1% (IDVYNSO) versus 5% (baseline ART); treatment difference -3.6% (95% CI -7.8%, -0.8%) [11]

Trial 052 Week 48 virologic failure

1% (IDVYNSO) versus 1% (BIC/FTC/TAF); treatment difference 0.9% (95% CI -1.9%, 2.9%) [11]

Recommended dose

One tablet orally once daily; one tablet contains 100 mg doravirine and 0.25 mg islatravir [11]

Clinical Perspective

This approval affects clinicians who manage adults living with HIV-1 who are virologically suppressed on a stable antiretroviral regimen and have no history of virologic failure or known doravirine resistance substitutions ^[1]. The FDA decision supports using IDVYNSO as a complete two-drug, once-daily replacement regimen to maintain suppression at 48 weeks in the studied population, including switch from BIC/FTC/TAF or other stable regimens ^[1]. What patient subgroups (for example, those with historical resistance, active HBV coinfection, or prior treatment failure) may safely switch to IDVYNSO and how suppression durability compares beyond 48 weeks remain open questions?

Dr. Simran Kohli · Infectious Diseases

The FDA approved IDVYNSO (doravirine/islatravir) on 2026-04-20 as a complete two-drug regimen to replace a current antiretroviral regimen in adults with HIV-1 who are virologically suppressed (HIV-1 RNA less than 50 copies/mL) on a stable regimen with no history of virologic failure, based on randomized trials showing low rates of HIV-1 RNA ≥50 copies/mL at Week 48 ^[1]. The approval and prescribing information specify a single once-daily tablet containing 100 mg doravirine and 0.25 mg islatravir ^[1]. Clinicians should consult current prescribing information for full dosing guidance.

Clinical Context

IDVYNSO is a fixed-dose combination of doravirine, a non-nucleoside reverse transcriptase inhibitor (NNRTI), and islatravir, a nucleoside analog reverse transcriptase inhibitor (NRTI) marketed as a single-tablet regimen for adults with HIV-1 who are already virologically suppressed on a stable regimen ^[1]. The FDA labeling indicates the product is intended to replace the current antiretroviral regimen in virologically-suppressed adults with no history of virologic failure and no known doravirine-associated resistance substitutions ^[1]. The regimen provides an oral, once-daily two-drug alternative to three- or more‑drug regimens in the selected population studied in two randomized, active-controlled non-inferiority trials ^[1].

Key Findings

The primary endpoint in both trials was the proportion of participants with HIV-1 RNA ≥50 copies/mL at Week 48 ^[1].
Trial 051 (open-label, randomized 2:1) compared switching to once-daily IDVYNSO (N=366) versus remaining on baseline ART (N=185); at Week 48, 1% of participants on IDVYNSO had HIV-1 RNA ≥50 copies/mL versus 5% in the baseline ART group; the treatment difference was -3.6% (95% CI -7.8%, -0.8%) ^[1].
Trial 052 (double-blind, randomized 2:1) compared switching to once-daily IDVYNSO (N=342) versus remaining on bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) (N=171); at Week 48, 1% of participants in each arm had HIV-1 RNA ≥50 copies/mL; the treatment difference was 0.9% (95% CI -1.9%, 2.9%) ^[1].
Proportions with HIV-1 RNA <50 copies/mL at Week 48 were reported as follows: Trial 051 — 96% on IDVYNSO versus 92% on baseline ART; Trial 052 — 92% on IDVYNSO versus 94% on BIC/FTC/TAF ^[1].

Safety & Tolerability

Safety information was not available in the provided source excerpts.

Study Design

IDVYNSO approval was supported by two randomized, active-controlled, non-inferiority trials in virologically-suppressed adults: Trial 051 (open-label, randomized 2:1 switch vs baseline ART; N=551 randomized with N=366 to IDVYNSO and N=185 to baseline ART) and Trial 052 (double-blind, randomized 2:1 switch from BIC/FTC/TAF; N=513 randomized with N=342 to IDVYNSO and N=171 to BIC/FTC/TAF) ^[1]. The primary endpoint in both trials was the proportion with HIV-1 RNA ≥50 copies/mL at Week 48, and non-inferiority margins were applied in statistical comparisons reported in the label ^[1].

FAQ

Q1 What is IDVYNSO (doravirine/islatravir) approved for?

IDVYNSO is approved as a complete two-drug regimen to treat human immunodeficiency virus type 1 (HIV-1) infection in adults 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 virologic treatment failure and no known substitutions associated with resistance to doravirine. The approval was based on two randomized, active-controlled trials reporting Week 48 outcomes showing low rates of HIV-1 RNA ≥50 copies/mL in the studied switch populations.

Q2 How does IDVYNSO work?

IDVYNSO is a fixed-dose combination of doravirine and islatravir. Doravirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) and islatravir is a nucleoside analog reverse transcriptase inhibitor (NRTI); together they inhibit HIV-1 reverse transcriptase through complementary mechanisms, and the product is indicated as a two-drug complete regimen to replace a current suppressed regimen in selected adults.

Q3 What is the recommended dose of IDVYNSO?

The recommended dosage of IDVYNSO is one tablet taken orally once daily with or without food. One tablet contains 100 mg doravirine and 0.25 mg islatravir, per the prescribing information. If co‑administered with rifabutin, the label provides a specific doravirine dosing adjustment sequence described in the prescribing information. Clinicians should consult current prescribing information for complete dosing guidance.

Q4 What are the most common side effects of IDVYNSO?

[Information] was not available in the provided source excerpts.

Clinicians should consult current prescribing information for complete dosing guidance.

References

FDA (Prescribing Information) — FDA prescribing information — IDVYNSO

FDA Approves IDVYNSO for Suppressed HIV-1: 1% ≥50 copies/mL

FDA Approves IDVYNSO for Suppressed HIV-1: 1% ≥50 copies/mL

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

Study Design

FAQ

References

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