Revisiting efavirenz in the era of dolutegravir: Low-dose efavirenz, a viable alternative capable of holding its own against dolutegravir-based regimens

Background: First-line dual NRTI + NNRTI-based ART has shown good virological effectiveness; however, toxicity is common and is often the most common reason for modification of first-line ART. Aims: The purpose of this study is to revisit low-dose efavirenz (EFV) in the era of dolutegravir (DTG) by investigating anti-retroviral therapy (ART) switch strategies for outcomes of virological effectiveness and safety in virologically suppressed Indian persons living with HIV (PLH) on first-line dual nucleoside reverse transcriptase inhibitors (NRTI) + non-NRTI (NNRTI)-based ART. Methods: A phase-IV comparative study of consecutive cases who switched their first-line NNRTI-based ART to either EFV-400 or DTG with a dual NRTI backbone between October 2020 to December 2021 and underwent at least 48 weeks of follow-up. The study is a non-randomised trial, wherein ART regimens were based on physician choice, patient preference and drug availability. Results: A total of 102 [DTG arm: 52; EFV-400 arm: 50; intention-to-treat (ITT) population] participants met the inclusion criteria. At 48-week follow-up, virological failure was not observed in either arm. Virological suppression to < 200 cp/mL was attained in 97.9% (n = 48/49; 95% confidence interval [CI]: 89.1–99.9) and 95.9% (n = 47/49; 95% CI: 86.02–99.5) of patients, respectively, in the DTG and-EFV-400 arm (ITT-populations). There was no significant difference in mean change from baseline in body weight and body mass index between DTG and-EFV-400 arms. The proportion of patients who gained ≥ 10% of their baseline body weight at 24 weeks of exposure to DTG was 16% (n = 8, 95% CI: 5.8 to 26.2) and that to EFV-400 was 10% (n = 5, 95% CI: 1.7 to 18.3) with a difference in proportions: 6.0% (95% CI: −7.1–19.1)]. There was a significant decrease at 24 weeks in mean fasting levels of lipid fractions in the DTG arm as compared to EFV-400 [total cholesterol: − 24.3 mg/dL, 95% CI: −35.2 to − 13.3 vs. −6.9 mg/dL, 95% CI: −17.9–4.1 (P = 0.029) and triglycerides:−35.9 mg/dL, 95% CI: −60.9 to − 10.9 vs. 8.6 mg/dL, 95% CI: −16.6 to 33.8 (P = 0.014)]. Adverse events (AEs) of any grade including laboratory derangements to DTG were experienced by 6% (n = 3, 95% CI: −0.6 to 12.6) and that to EFV-400 by 8% (n = 4, 95% CI: 0.5 to 15.5) with a difference in proportions: 2.0% (95% CI: −7.9 to 11.9). Grades 3–4-AE occurred in two patients, both in the EFV-400 arm. Central nervous system AEs were not observed in the DTG arm and occurred in two patients in the EFV-400 arm. Two patients in the EFV-400 arm discontinued the regimen due to AEs. Conclusion: Both DTG and EFV-400-based first-line ART show good virological effectiveness and safety profiles in patients who are virologically suppressed on dual NRTI + NNRTI-based first-line ART.