Phase 3 HIV Treatment Switch Studies: Key Findings From Recent Clinical Trials

New Drug Combination - Doravirine and Islatravir

Key Themes:

• Novel Combination Therapy: A late-breaker study presented at the Conference on Retroviruses and Opportunistic Infections showed noninferiority of doravirine (nonnucleoside reverse transcriptase inhibitor [NNRTI]) plus islatravir (nucleoside reverse transcriptase translocation inhibitor [NRTTI]) compared with a standard bictegravir-based regimen.
• Patient Selection Criteria: The study enrolled patients suppressed for at least 3 months on bictegravir with T-cell counts greater than 50 and no prior virologic failure.
• Safety Monitoring: Special attention was given to effects on CD4 counts and lymphocytes, as earlier studies with islatravir showed potential toxicity.
• Hepatitis B Considerations: The new combination lacks anti–hepatitis B virus (HBV) activity, requiring HBV screening before switching.

Notable Insights From Dr Sharon Walmsley:

• The doravirine/islatravir combination maintained viral suppression in more than 90% of patients over 144 weeks.
• No cases of treatment resistance were observed in participants experiencing virologic failure.
• Unlike in earlier studies, no evidence of lymphopenia or CD4 cell count reduction was observed with the islatravir component.

Only 2% to 3% of patients discontinued due to adverse events, indicating good tolerability.