Week 96 Genotypic and Phenotypic Results of the Fostemsavir Phase 3 BRIGHTE Study in Heavily Treatment-Experienced Adults Living with Multidrug-Resistant HIV-1.

In the phase 3 BRIGHTE study in heavily treatment-experienced adults with multidrug-resistant HIV-1, fostemsavir plus optimized background therapy (OBT) resulted in sustained rates of virologic suppression through 96 weeks. HIV-1 RNA <40 copies/mL was achieved in 163/272 (60%) Randomized Cohort (RC) participants (with 1 or 2 remaining approved fully active antiretrovirals) and 37/99 (37%) Non-randomized Cohort (NRC) participants (with 0 fully active antiretrovirals). Here we report genotypic and phenotypic analyses of HIV-1 samples from 63/272 (23%) RC participants and 49/99 (49%) NRC participants who met protocol-defined virologic failure (PDVF) criteria through Week 96. The incidence of PDVF was as expected in this difficult-to-treat patient population and, among RC participants, was comparable regardless of the presence of predefined gp120 amino acid substitutions that potentially influence phenotypic susceptibility to temsavir (S375H/I/M/N/T, M426L, M434I, M475I) or baseline temsavir 50% inhibitory concentration fold change (IC50 FC). The incidence of PDVF was lower among participants with higher overall susceptibility score to newly used antiretrovirals (OSS-new), indicating that OSS-new may be a preferred predictor of virologic outcome in heavily treatment-experienced individuals. Predefined gp120 substitutions, most commonly M426L or S375N, were emergent on treatment in 24/50 (48%) RC and 33/44 (75%) NRC participants with PDVF, with related increases in temsavir IC50 FC. In BRIGHTE, PDVF was not consistently associated with treatment-emergent genotypic or phenotypic changes in susceptibility to temsavir or to antiretrovirals in the initial OBT. Further research will be needed to identify which factors are most likely to contribute to virologic failure in this heavily treatment-experienced population (ClinicalTrials.gov, NCT02362503).

Long-term safety and impact of immune recovery in heavily treatment-experienced adults receiving fostemsavir for up to 5 years in the phase 3 BRIGHTE study.

Introduction: Fostemsavir is a gp120-directed attachment inhibitor approved for heavily treatment-experienced (HTE) adults with multidrug-resistant HIV-1. We provide detailed week 240 safety results from the BRIGHTE study and evaluate the impact of immune recovery on safety outcomes. Methods: The phase 3 BRIGHTE trial is ongoing; data for this analysis were collected from the first participant's first visit (February 23, 2015) through the last participant's last visit for week 240 (March 22, 2021). Safety endpoints were assessed in participants who received fostemsavir + optimized background therapy. In participants with baseline CD4+ T-cell count <200 cells/mm3, exposure-adjusted adverse event (AE) rates were assessed among subgroups with or without CD4+ T-cell count ≥200 cells/mm3 at any time during 48-week analysis periods through week 192. Results: Through a median of 258 weeks (range, 0.14-319) of treatment, discontinuations due to AEs occurred in 30/371 (8%) participants. Serious AEs were reported in 177/371 (48%) participants, including 16 drug-related events in 13 (4%) participants. Thirty-five (9%) deaths occurred, primarily related to AIDS or acute infections. COVID-19-related events occurred in 25 (7%) participants; all resolved without sequelae. Among participants with baseline CD4+ T-cell count <200 cells/mm3, 122/162 (75%) achieved CD4+ T-cell count ≥200 cells/mm3 at week 192. Exposure-adjusted AE rates were markedly lower among participants achieving CD4+ T-cell count ≥200 cells/mm3 at any time vs those sustaining <200 cells/mm3. No new AIDS-defining events were reported after week 48 in participants with CD4+ T-cell count ≥200 cells/mm3. Conclusions: Cumulative safety findings through the BRIGHTE 240-week interim analysis are consistent with other trials in HTE participants with advanced HIV-1 and comorbid disease. Reduced rates of AIDS-defining events and AEs were observed in participants with immunologic recovery on fostemsavir-based treatment. Clinical trial number: NCT02362503, https://clinicaltrials.gov/study/NCT02362503.

Week 240 Efficacy and Safety of Fostemsavir Plus Optimized Background Therapy in Heavily Treatment-Experienced Adults with HIV-1.

INTRODUCTION: Efficacy and safety of the attachment inhibitor fostemsavir + optimized background therapy (OBT) were evaluated through 48 and 96 weeks in the phase 3 BRIGHTE trial in heavily treatment-experienced (HTE) adults failing their current antiretroviral regimen. Here, we report 240-week efficacy and safety of fostemsavir + OBT in adults with multidrug-resistant human immunodeficiency virus (HIV)-1 in BRIGHTE. METHODS: Heavily treatment-experienced adults failing their current regimen entered the randomized cohort (RC; 1-2 fully active antiretrovirals available) or non-randomized cohort (NRC; no fully active antiretrovirals available) and received open-label fostemsavir + OBT (starting Day 8 in RC and Day 1 in NRC). Endpoints included proportion with virologic response (HIV-1 RNA < 40 copies/mL, Snapshot), immunologic efficacy, and safety. RESULTS: At Week 240, 45% and 22% of the RC and NRC, respectively, had virologic response (Snapshot); 7% of the RC and 5% of the NRC had missing data due to coronavirus disease 2019 (COVID-19)-impacted visits. In the observed analysis, 82% of the RC and 66% of the NRC had virologic response. At Week 240, mean change from baseline in CD4+ T-cell count was 296 cells/mm3 (RC) and 240 cells/mm3 (NRC); mean CD4+/CD8+ ratio increased between Weeks 96 and 240 (RC 0.44 to 0.60; NRC 0.23 to 0.32). Between Weeks 96 and 240, four participants discontinued for adverse events, one additional participant experienced a drug-related serious adverse event, and six deaths occurred (median last available CD4+ T-cell count, 3 cells/mm3). COVID-19-related events occurred in 25 out of 371 participants; all resolved without incident. CONCLUSION: Through ~5 years, fostemsavir + OBT demonstrated durable virologic and immunologic responses with no new safety concerns between Weeks 96 and 240, supporting this regimen as a key therapeutic option for HTE people with multidrug-resistant HIV-1. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02362503.

Patient-Reported Outcomes in the Phase III BRIGHTE Trial of the HIV-1 Attachment Inhibitor Prodrug Fostemsavir in Heavily Treatment-Experienced Individuals.

INTRODUCTION: Heavily treatment-experienced (HTE) people living with HIV-1 (PLWH) have limited viable antiretroviral regimens available because of multidrug resistance and safety concerns. The first-in-class HIV-1 attachment inhibitor fostemsavir demonstrated efficacy and safety in HTE participants in the ongoing phase III BRIGHTE trial. OBJECTIVES: We describe patient-reported outcomes (PROs) through week 48. METHODS: Eligible participants for whom their current regimen was failing were assigned to the randomized cohort (RC; one to two fully active agents remaining) or the nonrandomized cohort (NRC; no fully active agents remaining). PRO assessments included the EQ-5D-3L, EQ-VAS, and Functional Assessment of HIV Infection (FAHI) instruments. RESULTS: Both cohorts achieved increases in EQ-5D-3L US- and UK-referenced utility score from baseline at week 24. Mean visual analog scale (VAS) scores in the RC and NRC increased from baseline by 8.7 (95% CI 6.2-11.2) and 5.6 points (95% CI 1.5-9.7) at week 24 and increased from baseline by 9.8 (95% CI 7.0-12.6) and 4.9 points (95% CI 0.6-9.2) at week 48, respectively. Mean increases in FAHI total score from baseline to weeks 24 and 48 in the RC were 6.9 (95% CI 4.2-9.7) and 5.8 (95% CI 2.7-9.0), respectively, whereas mean increases in physical and emotional well-being subscale scores were 2.7 (95% CI 1.9-3.6) and 2.4 (95% CI 1.3-3.4) and 3.2 (95% CI 2.2-4.2) and 2.6 (95% CI 1.6-3.7), respectively, with little to no change in other subscales. CONCLUSIONS: Improvements in major domains of the EQ-VAS and FAHI through week 48, combined with efficacy and safety results, support the use of fostemsavir for HTE PLWH. TRIAL REGISTRATION NUMBER AND DATE: NCT02362503; February 13, 2015.

Long-term efficacy and safety of fostemsavir among subgroups of heavily treatment-experienced adults with HIV-1.

OBJECTIVES: The aim of this study was to understand how demographic and treatment-related factors impact responses to fostemsavir-based regimens. DESIGN: BRIGHTE is an ongoing phase 3 study evaluating twice-daily fostemsavir 600 mg and optimized background therapy (OBT) in heavily treatment-experienced individuals failing antiretroviral therapy with limited treatment options (Randomized Cohort 1-2 and Nonrandomized Cohort 0 fully active antiretroviral classes). METHODS: Virologic response rates (HIV-1 RNA <40 copies/ml, Snapshot analysis) and CD4+ T-cell count increases in the Randomized Cohort were analysed by prespecified baseline characteristics (age, race, sex, region, HIV-1 RNA, CD4+ T-cell count) and viral susceptibility to OBT. Safety results were analysed by baseline characteristics for combined cohorts (post hoc). RESULTS: In the Randomized Cohort, virologic response rates increased between Weeks 24 and 96 across most subgroups. Virologic response rates over time were most clearly associated with overall susceptibility scores for new OBT agents (OSS-new). CD4+ T-cell count increases were comparable across subgroups. Participants with baseline CD4+ T-cell counts less than 20 cells/µl had a mean increase of 240 cells/µl. In the safety population, more participants with baseline CD4+ T-cell counts less than 20 vs. at least 200 cells/µl had grade 3/4 adverse events [53/107 (50%) vs. 24/96 (25%)], serious adverse events [58/107 (54%) vs. 25/96 (26%)] and deaths [16/107 (15%) vs. 2/96 (2%)]. There were no safety differences by other subgroups. CONCLUSION: Week 96 results for BRIGHTE demonstrate comparable rates of virologic and immunologic response (Randomized Cohort) and safety (combined cohorts) across subgroups. OSS-new is an important consideration when constructing optimized antiretroviral regimens for heavily treatment-experienced individuals with limited remaining treatment options.

Safety and efficacy of the HIV-1 attachment inhibitor prodrug fostemsavir in heavily treatment-experienced individuals: week 96 results of the phase 3 BRIGHTE study.

BACKGROUND: Fostemsavir, a prodrug of the first-in-class attachment inhibitor, temsavir, is indicated for heavily treatment-experienced individuals with multidrug-resistant HIV-1. We previously reported superior efficacy of fostemsavir versus placebo in the randomised cohort of the BRIGHTE study after 8-day functional monotherapy (primary endpoint); here we report planned interim analyses through week 96. METHODS: BRIGHTE (NCT02362503) is an ongoing multicentre, two-cohort, phase 3 trial, done at 108 centres in 22 countries. We enrolled heavily treatment-experienced adults (≥18 years) failing antiretroviral therapy (HIV-1 RNA ≥400 copies per mL) into two cohorts: the randomised cohort, in which patients with one or two fully active antiretrovirals remaining received oral fostemsavir (600 mg twice a day) or placebo in combination with their failing regimen for 8 days, followed by fostemsavir plus optimised background therapy; or the non-randomised cohort, in which patients with no remaining antiretroviral options received oral fostemsavir (600 mg twice a day) plus optimised background therapy from day 1. Endpoints for the week 96 interim analyses included the proportions of participants with plasma HIV-1 RNA of less than 40 copies per mL, changes from baseline in CD4 cell counts, and the frequency of adverse events, adverse events leading to discontinuation, and deaths. The intention-to-treat exposed population and the safety population both included all participants who received at least one dose of study treatment. The response rates (proportion of participants with HIV-1 RNA <40 copies per mL) in the intention-to-treat exposed population were calculated via snapshot analysis at weeks 24, 48, and 96. FINDINGS: Between Feb 23, 2015, and Aug 11, 2016, 371 participants were enrolled and treated, of which 272 participants were in the randomised cohort and 99 in the non-randomised cohort. 320 (86%) of 371 reported a history of AIDS. In the randomised cohort, rates of virological suppression (HIV-1 RNA <40 copies per mL) increased from 53% (144 of 272) at week 24 to 60% (163 of 272) at week 96. Response rates in the non-randomised cohort were 37% (37 of 99) at week 24 and week 96. Mean increases in CD4 counts from baseline at week 96 were 205 cells per µL (SD 191) in the randomised cohort and 119 cells per µL (202) in the non-randomised cohort. Mean CD4/CD8 ratio increased from 0·20 at baseline to 0·44 at week 96 in the randomised cohort. Few adverse events led to discontinuation (26 [7%] of 371). 12 (4%) of 272 people in the randomised cohort and 17 (17%) of 99 in the non-randomised cohort died; the median baseline CD4 count for participants who died was 11 cells per µL. INTERPRETATION: In heavily treatment-experienced individuals with advanced HIV-1 disease and limited treatment options, fostemsavir-based antiretroviral regimens were generally well tolerated and showed a distinctive trend of increasing virological and immunological response rates through 96 weeks; these findings support fostemsavir as a treatment option for this vulnerable population. FUNDING: ViiV Healthcare.

Design of diverse and focused combinatorial libraries using an alternating algorithm.

There is considerable research in chemistry to develop reaction conditions so that any of a very large number of reactants will successfully form new compounds, e.g. for two components, A(i) + B(j) --> A-B(ij). The numbers of A's and B's usually make it impossible to make all the possible products; with multicomponent reactions, there could easily be millions to billions of possible products. There is a need to identify subsets of reagents so that the resulting products have desirable predicted properties. Our idea is to select reactants sequentially and iteratively to optimize the evolving candidate library. The new Alternating Algorithm, AA, can be used for diversity, a space-filling design, or for a focused design, using either a near neighborhood or structure-activity relationship, SAR. A diversity design seeks to select compounds different from one another; a focused design seeks to find compounds similar to an active compound or compounds that follow a structure activity relationship. The benefit of the method is rapid computation of diversity or focused combinatorial chemical libraries.