1571. BIC/FTC/TAF in Virologically Suppressed PLWHIV: 48-96 weeks RETROBIC Multicenter Cohort study results.

BACKGROUND: Switching strategy with bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) has become a gold standard for people with HIV (PLWHIV) with high efficacy and safety rates in long-term data of pivotal clinical trials. However, data regarding immune status restoration in real-life cohorts of long-time treated patients are needed. METHODS: We performed a multicenter, retrospective study of suppressed PLWHIV switching to BIC/FTC/TAF. We evaluated the efficacy and immune status regarding CD4+ and CD8+ T-cell counts and CD4/CD8 ratio at 48 and 96 weeks after the switch. RESULTS: The study population comprised 1315 persons from 11 centers in Spain, of whom 78.5% were men, and the median age was 51 [42.0 – 57.0] years. The median time of HIV infection was 17 [10.0 – 27.0] years, and patients with AIDS diagnosis represented 23.6%. The main reasons for switching to BIC/FTC/TAF were simplification (57.5%), poor tolerability (11.5%), and drug-to-drug interactions (7.3%). Patients reached weeks 48 and 96 in 98.7% and 83.2% of cases, respectively, with only 16 (1.2%) virological failures but no resistance mutations. Other reasons for discontinuation comprised toxicity issues 3.3.% (44), loss to follow-up 2,8% (37), and simplification 5.0% (66). The baseline median CD4 was 718.0 [494.0 – 946.8]. In week 48, we found a decrease in CD8+ T-cell count of -37.5 cells/mm(3) (-244.3 – 135.3) and an increase in CD4+ T-cell count of 39.0 (-104.3 – 165.3) compared to baseline. In week 96, we found a decrease in CD8+ T-cell count of -25.0 cells/mm(3) (-245.3 – 178.5) and an increase in CD4+ T-cell count of 40.5 (-157.0 – 230.0) compared to baseline. The CD4/CD8 ratio increased by 0.05 (-0.09 – 0.29) and 0.08 (-0.12 – 0.31) in weeks 48 and 96, respectively. In the subgroup of AIDS-diagnosed patients, a significant increase in the CD4+ T-cell count of 39.0 cells/mm(3)(-77.0 – 149.0), p=0.025, was found at week 48, and a decrease in the CD8+ T-cell count of -5.0 (-202.0 – 181.5) cells/mm(3); p=0.050, at week 96. CONCLUSION: In patients with HIV-controlled infection, switching to triple therapy with BIC/FTC/TAF slightly improved the immune status during the first 48-96 weeks after switching, not only in terms of CD4+ T-cell count increase and CD8+ decrease but also in CD4/CD8 ratio with high rates of viral control and safety. DISCLOSURES: Luis Buzón, MD, PhD, Janssen: Advisor/Consultant|Janssen: Expert Testimony|MSD: Expert Testimony|Viiv: Advisor/Consultant|Viiv: Expert Testimony Carlos Galera, MD, Gilead: Expert Testimony|Jannsen: Expert Testimony|MSD: Expert Testimony|VIIV: Expert Testimony Jose Sanz, MD, PhD, Gilead: Expert Testimony|Janssen: Expert Testimony|MSD: Expert Testimony|ViiV: Expert Testimony Ignacio Santos, MD. PhD, Gilead: Expert Testimony Carlos Dueñas, MD, Gilead: Advisor/Consultant|Gilead: Expert Testimony|Jannsen: Advisor/Consultant|Jannsen: Expert Testimony Noemí Cabello, MD. PhD, Gilead: Expert Testimony|Janssen: Expert Testimony|ViiV: Expert Testimony Cristina Martín, MD, Gilead: Expert Testimony|Janssen: Expert Testimony|Pfizer: Expert Testimony María José Galindo, MD, PhD, Gilead: Expert Testimony|janssen: Expert Testimony Cristina Hernández, MD, Gilead: Expert Testimony|MSD: Expert Testimony|Viiv: Expert Testimony Jesús Troya, Staff, Gilead: Advisor/Consultant|Gilead: Expert Testimony|Janssen: Board Member|Janssen: Grant/Research Support|ViiV: Advisor/Consultant