887. High Rates of Virologic Suppression Achieved in HIV-1–Infected Adults Rapidly Starting Antiretroviral Therapy (ART) with the Single-Tablet Regimen (STR) of Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide (D/C/F/TAF) 800/150/200/10 mg Regardless of Baseline Disease Characteristics: Week 48 Subgroup Analyses From the Phase 3 DIAMOND Trial

BACKGROUND: Rapid initiation of ART requires that clinicians start therapy prior to having baseline laboratory Results. High rates of virologic suppression and retention were reported in the DIAMOND trial. Efficacy and safety are presented, according to baseline disease characteristics. METHODS: DIAMOND (ClinicalTrials.gov: NCT03227861), a phase 3, single-arm, open-label, prospective, multicenter study, assessed efficacy/safety of D/C/F/TAF in rapid initiation. Adults enrolled within 14 days of diagnosis and started D/C/F/TAF without baseline laboratory results; investigators reviewed results as they became available. Primary endpoint was virologic suppression (HIV-1 RNA < 50 copies[c]/mL; intent-to-treat (ITT); Food and Drug Administration [FDA] snapshot) at Week 48. Virologic suppression <50 c/mL and <200 c/mL were also assessed via an observed analysis, excluding patients with missing data. RESULTS: Overall, 109 patients were enrolled; 25% had HIV-1 RNA ≥100,000 c/mL and 21% had CD4+ < 200 cells/μL (Table 1). 21% of patients started therapy within 24 hours of diagnosis. At Week 48, 84%, and 88% of patients had HIV-1 RNA <50 c/mL and <200 c/mL (FDA snapshot), respectively. In the observed analysis, 96% and 100% of patients had HIV-1 RNA <50 c/mL and <200 c/mL, respectively, at Week 48. Earlier ART initiation, HIV-1 RNA <100,000 c/mL, and CD4+ >200 cells/μLwere associated with numerically higher virologic suppression rates (ITT-FDA snapshot; Table 2). No patient discontinued due to lack of efficacy or met protocol-defined virologic failure (PDVF) criteria. In the observed analysis, virologic suppression rates were consistent across all subgroups; all patients were suppressed <200 c/mL at Week 48. One patient discontinued due to an adverse event (AE); incidences of grade 3/4 (10%) and serious (9%) AEs were low, with no serious AEs related to study drug and no deaths. CONCLUSION: In the first phase 3 study of an STR in a rapid initiation model, no patients rapidly starting D/C/F/TAF discontinued therapy due to lack of efficacy or had PDVF through 48 weeks. High rates of virologic suppression were achieved and maintained with a variety of baseline characteristics, and treatment was safe and well tolerated, indicating D/C/F/TAF as a preferred ART option for patients rapidly starting treatment. [Image: see text] [Image: see text] DISCLOSURES: All Authors: No reported Disclosures.