Immune recovery following switch from EFV-based regimens to bictegravir/emtricitabine/tenofovir alafenamide in virologically suppressed immunological non-responders: a 144-week real-world cohort study in China.

OBJECTIVE

To investigate the prevalence of immunological non-responders (INRs) among people living with HIV (PLWH) administered long-term antiretroviral therapy (ART) in Chongqing, China, and to evaluate whether switching from an efavirenz (EFV)-based regimen to bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) was associated with immune recovery in INR patients.

METHODS

This retrospective real-world cohort study was conducted at Chongqing Public Health Medical Center. PLWH administered continuous two-nucleoside reverse transcriptase inhibitors (NRTIs) plus EFV therapy for ≥4 years, who achieved sustained viral suppression (HIV RNA <50 copies/mL) but maintained CD4 cell counts <350 cells/μL were defined as INRs according to Chinese guidelines. PLWH were grouped according to whether they continued EFV-based therapy (EFV group) or switched to BIC/FTC/TAF between January and December 2022. Changes in CD4 cell counts, CD4/CD8 ratios, immune reconstitution rates, and virological suppression were assessed at weeks 48, 96, and 144.

RESULTS

Among 4,613 PLWH with long-term treatment, 1,379 were identified as INRs, yielding a prevalence of 29.9%. A total of 446 INRs consistently on a two-NRTI plus EFV regimen (no prior ART switches) were included (median age 50.0 years; median ART duration 69.5 months), of whom 131 switched to BIC/FTC/TAF and 315 continued EFV-based therapy. Compared with the EFV group, the BIC/FTC/TAF group showed greater CD4 cell increases from switching baseline at weeks 48 (66.0 vs. 29.0 cells/μL, P<0.001), 96 (82.5 vs. 46.0 cells/μL, P=0.001), and 144 (82.5 vs. 43.5 cells/μL, P<0.001). Immune reconstitution rates were higher in the BIC/FTC/TAF group at week 48 (34.4% vs. 24.1%, P=0.027) and week 144 (43.8% vs. 32.8%, P=0.005). The immunological benefit was primarily observed in patients aged ≤50 years. Virological suppression rates remained high in both groups.

CONCLUSION

INRs remain prevalent among PLWH with long-term treatment in southwestern China. In this observational cohort, switching from long-term EFV-based regimens to BIC/FTC/TAF was associated with greater CD4 cell recovery in virologically suppressed INRs, particularly among patients aged ≤50 years. These findings should be interpreted as exploratory and require confirmation in prospective studies.