Protocol-defined Virologic Failure Research Articles

Characterization of clinical envelopes with lack of sensitivity to the HIV-1 inhibitors temsavir and ibalizumab

Previous data suggest a lack of cross-resistance between the gp120-directed attachment inhibitor temsavir (active moiety of fostemsavir) and the CD4-directed post-attachment inhibitor ibalizumab. Recently, analysis of HIV-1 envelopes with reduced sensitivity to both inhibitors was undertaken to determine whether they shared genotypic correlates of resistance. Sequences from 2 envelopes with reduced susceptibility to both agents were mapped onto a temsavir-bound gp120 structure. Residues within 5.0 Å of the temsavir binding site were evaluated using reverse genetics. Broader applicability and contextual determinants of key substitutions were further assessed using envelopes from participants in the phase 3 BRIGHTE study. Temsavir sensitivity was measured by half-maximal inhibitory concentration (IC50) and ibalizumab sensitivity by IC50 and maximum percent inhibition (MPI). One envelope required substitutions of E113D and T434M for full restoration of temsavir susceptibility. Neither substitution nor their combination affected ibalizumab sensitivity. However, in the second envelope, an E202 substitution (HXB2, T202) was sufficient for observed loss of susceptibility to both inhibitors. One BRIGHTE participant with no ibalizumab exposure had an emergent K202E substitution at protocol-defined virologic failure, with reduced sensitivity to both inhibitors. Introducing T202E into previously susceptible clinical isolates reduced temsavir potency by ≥ 40-fold and ibalizumab MPI from >99% to ∼80%. Interestingly, introduction of the gp120 V5 region from a highly ibalizumab-susceptible envelope mitigated the E202 effect on ibalizumab but not temsavir. A rare HIV-1 gp120 E202 mutation reduced temsavir susceptibility, and depending on sequence context, could result in reduced susceptibility to ibalizumab.

Same-day initiation of bictegravir/emtricitabine/tenofovir alafenamide: Week 48 results of the FAST study-IMEA 055.

Initiating same-day ART for newly HIV-diagnosed individuals reduces secondary HIV transmissions and the risk of them being lost to follow-up between diagnosis and initiation of ART. The FAST study was a national, prospective, single-arm study assessing the efficacy, safety and feasibility of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) in a same-day initiation model. ART had to be started on the first medical appointment, before any laboratory results were available. Participants completed a self-administered questionnaire at each visit including a HIV anxiety 5-point Likert scale. The primary outcome was the proportion of participants in the ITT population with plasma HIV RNA (pVL) < 50 copies/mL at Week (W) 24 using the FDA Snapshot algorithm. Overall, 112 participants were included in the ITT population. During follow-up, seven participants discontinued the study drug but remained on the study, and seven others discontinued follow-up. According to FDA Snapshot analysis, at W24 and W48, 90/112, (80.4%; 95% CI: 71.8-87.3) and 95/112 (84.8%; 95% CI: 76.8-90.9) of participants achieved pVL < 50 copies/mL, respectively. The protocol-defined virological failure (PDVF, 2 consecutive pVL ≥ 50 copies/mL as of W24) was observed in 11/112 (9.8%) at W24 and 14/112 (12.5%) at W48. No emergent resistance-associated mutation was detected in those with PDVF at W24 and W48. BIC/FTC/TAF was well tolerated through to W48, with a low incidence of grade 3-4 adverse events (15/100 person-years). Patient opinion of same-day treatment initiation and continuing BIC/FTC/TAF was very favourable. These results suggest that BIC/FTC/TAF is safe, effective and well accepted for same-day initiation.

Doravirine and Islatravir Have Complementary Resistance Profiles and Create a Combination with a High Barrier to Resistance.

Doravirine (DOR), a non-nucleoside reverse transcriptase inhibitor (NNRTI), was approved for treatment of HIV-1 infection in 2018. In the pivotal phase 3 trials, DRIVE-FORWARD and DRIVE-AHEAD, 7 out of 747 (0.9%) treatment-naive participants treated with DOR plus two nucleos(t)ide reverse transcriptase inhibitors (NRTIs) met protocol-defined virologic failure criteria and showed phenotypic resistance to DOR at week 48. The most common DOR resistance-associated mutation (RAM) detected in 5 of the 7 resistant isolates was F227C. Six isolates bearing NRTI RAMs (M184V and/or K65R) were resistant to lamivudine (3TC) and emtricitabine (FTC) but not to other approved NRTIs. All DOR-resistant isolates were susceptible or hypersusceptible (fold change of <0.25) to islatravir (ISL), a nucleoside reverse transcriptase translocation inhibitor (NRTTI). Isolate hypersusceptibility to ISL required F227C, in contrast to zidovudine, an NRTI, which required M184V. Based on the frequent emergence of F227C, we hypothesized that DOR and ISL would create a combination (DOR/ISL) with a high barrier to resistance. In de novo resistance selection studies in MT4-GFP cells (MT4 cells engineered to express green fluorescent protein), DOR/ISL synergistically prevented viral breakthrough at a threshold of 2× the half-maximal inhibitory concentration (IC50). DOR/ISL exhibited a higher barrier to resistance than DOR/3TC and dolutegravir (DTG)/3TC. Resistance analysis showed no emergence of substitutions at F227, an observation consistent with its ability to confer hypersusceptibility to ISL. Overall, the data demonstrate that DOR/ISL creates a 2-drug combination with a higher barrier to resistance, consistent with the reported clinical activity.

Long-Term Efficacy, Safety, and Durability of Cabotegravir and Rilpivirine as 2-Drug Oral Maintenance Therapy After 6 Years of Study.

BackgroundIn the LATTE study, daily oral cabotegravir + rilpivirine demonstrated higher rates of efficacy than efavirenz + 2 nucleoside reverse-transcriptase inhibitors (NRTIs) through Week 96 in antiretroviral therapy (ART)-naive adults with human immunodeficiency virus (HIV)-1. We present the results from 6 years of continued treatment with oral cabotegravir + rilpivirine.MethodsLATTE was a phase IIb, randomized, multicenter, partially blinded, dose-ranging study in ART-naive adults with HIV-1. After a 24-week induction phase with cabotegravir + 2 NRTIs, participants with HIV-1 ribonucleic acid (RNA) <50 copies/mL were randomized to receive cabotegravir (10, 30, or 60 mg) + rilpivirine (25 mg) in the maintenance phase through Week 96 and switched to cabotegravir 30 mg + rilpivirine 25 mg in the open-label phase through Week 312.ResultsOf 160 participants who entered the maintenance phase, 111 completed the study at Week 312. At Week 312, 105 (66%) participants maintained HIV-1 RNA <50 copies/mL, 15 (9%) had HIV-1 RNA ≥50 copies/mL, and 40 (25%) had no virologic data. Eight participants met protocol-defined virologic failure criteria through Week 312, 2 of whom met protocol-defined virologic failure criteria after Week 144. Six participants developed treatment-emergent resistance to 1 or both agents during the study, 3 of whom developed integrase inhibitor resistance substitutions. Two participants (1%) reported drug-related serious adverse events. Few adverse events led to withdrawal during the open-label phase (n = 5, 3%).ConclusionsOral cabotegravir + rilpivirine demonstrated efficacy in the majority of participants and an acceptable safety profile through 6 years of treatment, demonstrating its durability as maintenance therapy for HIV-1.

626. The Efficacy and Safety of Maintenance with Doravirine Plus Two NRTIs after Initial Suppression in Adults with HIV-1 in the DRIVE-FORWARD Clinical Trial: Results from the Study Extension through 192 Weeks

BackgroundDRIVE-FORWARD is a phase 3 trial with a completed double-blind period comparing doravirine (DOR) 100 mg with ritonavir-boosted darunavir (DRV/r) 800/100 mg, both administered with two nucleos(t)ide reverse transcriptase inhibitors (NRTIs; tenofovir and emtricitabine, or abacavir and lamivudine), and an ongoing open-label extension. At Week (W) 48, DOR demonstrated non-inferior efficacy to DRV/r, with a superior lipid profile. Those results were sustained at W96. Here we present efficacy and safety results through W192.MethodsParticipants who completed the 96-week double-blind phase and met inclusion criteria were eligible to receive open-label DOR plus two NRTIs in a 96-week extension. Efficacy and safety at W192 were assessed in two groups: participants initially randomized to DOR and maintained on DOR (n=259) and those who switched from DRV/r to DOR at W96 (n=233).ResultsHIV-1 RNA < 50 copies/mL were maintained through W192 in 81.1% of participants who continued DOR and 80.7% of those who switched from DRV/r to DOR. The mean increase in CD4 T-cell counts from W96 to W192 was similar for participants maintained on DOR (47 cells/mm3) and those switched from DRV/r (53 cells/mm3). Protocol-defined virologic failure occurred in 3.1% and 5.6% of participants maintained on DOR and switched from DRV/r, respectively, and development of genotypic resistance was low in both groups (Table 1). Discontinuation due to adverse events was also low (Table 1). Fasting LDL-cholesterol, non-HDL-cholesterol, and triglycerides showed minimal increase in participants maintained on DOR and were reduced in those switched from DRV/r to DOR (Table 1). Participants maintained on DOR had minimal weight gain after W96 (median 1 kg), and a small increase overall (median 1.9 kg, Day 1 through W192); participants who switched to DOR had a small increase after W96 (median 1.5 kg), similar to the median weight gain in the base study (DOR 1.8 kg; DRV/r 0.7 kg).ConclusionAmong participants who continued DOR in the DRIVE-FORWARD open-label extension, virologic suppression and favorable safety were maintained for an additional 96 weeks. Participants who switched from DRV/r to DOR maintained virologic suppression and demonstrated favorable safety for 96 weeks. Disclosures Pedro Cahn, MD, PHD, Merck (Advisor or Review Panel member)ViiV Healthcare (Grant/Research Support, Advisor or Review Panel member) Kathleen Squires, MD, Merck (Employee) Sushma Kumar, PhD, Merck (Employee) Hong Wan, PhD, Merck (Employee) Valerie Teal, MS, Merck (Employee) Ernest Asante-Appiah, PhD, Merck (Employee) Peter Sklar, MD, Merck (Employee) Elizabeth A. Martin, DO, MPH, MBA, Merck (Employee) Rima Lahoulou, n/a, Merck (Employee)

Dolutegravir-Based Dual Therapies in HIV Pretreated Patients: A Real-Life Study in Madrid.

Few studies describe the use of dolutegravir (DTG)-based dual therapies under routine clinical practice. To report real-life data on the use of DTG-based dual therapies in treatment-experienced patients. This was an observational, retrospective study. It included all treatment-experienced HIV patients starting a DTG-based dual therapy from 2014 to 2018. The primary end point was to identify the incidence and reasons for the switch. The secondary end points were to assess the effectiveness, safety, adherence, and costs after 48 weeks of treatment (W48). The incidence of the switch to a DTG-based dual therapy increased from 1.6 patients per 1000 patient-years in 2014 to 38.6 in 2018. A total of 241 patients initiated this therapy: 113 (46.9%) patients started DTG plus rilpivirine (RPV), 72 (29.9%), DTG plus lamivudine (3TC), and 68 (28.2%), DTG plus boosted-darunavir (b-DRV). A total of 170 patients completed W48 of follow-up. By intention-to-treat analysis, 89.3% of virologically suppressed (VS) patients (94.3% with DTG plus b-DRV, 91.3% with DTG plus 3TC, and 87.2% with DTG plus RPV) and 56.7% of non-VS patients (71.4% with DTG plus RPV and 52.2% with DTG plus b-DRV) achieved a viral load <50 copies/mL at W48. The protocol-defined virological failure was 6.5%. Overall, 8.8% of patients had early discontinuation. The annual cost increased by €800 per patient ($916). The use of DTG-based dual therapies has increased in real life, showing a favorable effectiveness and safety profile. Treatment costs increased, except for the switch to DTG plus 3TC.

Participants on Dolutegravir Resuppress Human Immunodeficiency Virus RNA After Virologic Failure: Updated Data from the ADVANCE Trial.

Following evidence of HIV RNA re-suppression on DTG-based regimens, we assess the re-suppressive capacity of ADVANCE participants on TAF/FTC+DTG, TDF/FTC+DTG, and TDF/FTC/EFV. Viraemic participants were able to re-suppress within 3 follow-up visits of protocol-defined virological failure (PDVF) in 77/121 (64%), 85/126 (67%), and 44/138 (32%) cases respectively (DTG regimens vs. TDF/FTC/EFV; P < 0.001).

638. Safety, Efficacy, and Durability of Long-Acting CAB and RPV as Maintenance Therapy for HIV-1 Infection: LATTE-2 Week 256 Results

BackgroundLong-acting (LA) injectable suspensions of cabotegravir (CAB) & rilpivirine (RPV) are in phase III development. LATTE-2 W160 results demonstrated high rates of virologic response & overall tolerability. This W256 analysis evaluated long-term efficacy, safety, & tolerability of every 8-week (Q8W) & 4-week (Q4W) intramuscular (IM) dosing.MethodsLATTE-2 is a phase IIb, multicenter, parallel arm, open-label study in antiretroviral therapy–naive adults with HIV. After a 20-week Induction Period on oral CAB+abacavir/lamivudine, participants (pts) with plasma HIV-1 RNA< 50c/mL were randomized 2:2:1 to IM CAB LA+RPV LA Q8W, Q4W, or continue oral (PO) regimen in the Maintenance Period (MP). After W96, pts on IM regimens continued their current MP regimen. Pts randomized to PO in MP chose a Q8W or Q4W IM regimen in the Extension Period (EP). W256 analysis of MP & EP included virologic success with HIV-1 RNA< 50 c/mL (Food & Drug Administration Snapshot analysis), protocol-defined virologic failure (PDVF), & safety (intention-to-treat–Maintenance Exposed population).ResultsAt W256, 88% (101/115; Q8W) & 74% (85/115; Q4W) of randomized IM pts had HIV-1 RNA< 50 c/mL, as did 93% (41/44) of PO to IM pts. No pt developed PDVF after W48. In the randomized IM arm (MP & EP), excluding injection-site reactions (ISRs), nasopharyngitis (45%), diarrhea (28%), & headache (24%) were the most common adverse events (AEs), with 34% (39/115; Q8W) & 33% (38/115; Q4W) of pts reporting AEs ≥grade 3, of which 12% (14/115; Q8W) & 11% (13/115; Q4W) were drug related. 3% (3/115; Q8W) & 17% (20/115; Q4W) of pts had AEs leading to withdrawal. 22% (25/115; Q8W) & 23% (27/115; Q4W) reported serious AEs (3 were drug related). In the PO to IM arm (EP only), most common AEs excluding ISRs were nasopharyngitis (25%), influenza (23%), & back pain (18%). 23% (10/44) reported AEs ≥grade 3 & 5% (2/44) had AEs leading to withdrawal. Majority of ISRs were mild/moderate pain & discomfort. < 1% of ISRs were severe, with 5 pts discontinuing due to ISRs.Table 1 Table 2 ConclusionCAB+RPV LA injectable therapy, administered Q8W or Q4W, demonstrated high rates of virologic response & tolerability through 5 years. W256 results add to previous results & demonstrate long-term durability of CAB+RPV LA for people living with HIV.Disclosures Keith Henry, MD, Gilead (Research Grant or Support, Paid to institution)GSK/ViiV (Research Grant or Support, Paid to institution)Janssen (Research Grant or Support, Paid to institution)Merck (Research Grant or Support, Paid to institution) Daniel Podzamczer, MD, PhD, Gilead (Grant/Research Support, Advisor or Review Panel member)Janssen Pharmaceutica (Grant/Research Support, Advisor or Review Panel member)Merck Sharp & Dohme (Grant/Research Support, Advisor or Review Panel member)ViiV Healthcare (Grant/Research Support, Advisor or Review Panel member) Mar Masiá, MD, PhD, Janssen Pharmaceutica (Consultant, Other Financial or Material Support, Travel/accommodations/meeting expenses)Merck Sharp & Dohme (Consultant, Other Financial or Material Support, Travel/accommodations/meeting expenses)ViiV Healthcare (Consultant, Other Financial or Material Support, Travel/accommodations/meeting expenses) Hans Jaeger, MD, Abbvie (Consultant, Speaker’s Bureau)Gilead Sciences (Consultant, Speaker’s Bureau)Janssen (Consultant, Speaker’s Bureau)MSD Sharp & Dohme (Consultant, Speaker’s Bureau)ViiV Healthcare (Consultant, Research Grant or Support, Speaker’s Bureau) Marie-Aude Khuong-Josses, MD, Viiv HC (Advisor or Review Panel member) Kenneth Sutton, MA, GlaxoSmithKline (Shareholder)ViiV Healthcare (Employee) Cynthia C. McCoig, MD, ViiV Healthcare (Employee) Kati Vandermeulen, MSC, Janssen Pharmaceutica (Employee, Shareholder) Rodica Van Solingen-Ristea, MD, Janssen R&D (Employee) William Spreen, PharmD, ViiV Healthcare (Employee, Shareholder) David Margolis, MD, MPH, GlaxoSmithKline (Shareholder)ViiV Healthcare (Employee)

Dolutegravir with emtricitabine and tenofovir alafenamide or tenofovir disoproxil fumarate versus efavirenz, emtricitabine, and tenofovir disoproxil fumarate for initial treatment of HIV-1 infection (ADVANCE): week 96 results from a randomised, phase 3, non-inferiority trial

ADVANCE compared the efficacy and safety of two antiretroviral first-line combinations (dolutegravir combined with emtricitabine and either tenofovir disoproxil fumarate or tenofovir alafenamide), with a third regimen (efavirenz combined with emtricitabine and tenofovir disoproxil fumarate) previously recommended by WHO. Here, we report the 96-week data for the study. This randomised, open-label, non-inferiority phase 3 trial, was done at two research sites in Johannesburg, South Africa, after participant recruitment from 11 public health clinics also in Johannesburg. Eligible participants were aged 12 years or older with HIV-1 infection, who weighed at least 40 kg, had no antiretroviral exposure in the previous 6 months, with a creatinine clearance of more than 60 mL/min (>80 mL per min in individuals aged <19 years), and a plasma HIV-1 RNA concentration of 500 copies per mL or higher. Individuals who were pregnant or had tuberculosis were excluded. Participants were randomly assigned (1:1:1) by study staff using a computerised randomisation system. Randomisation was stratified by age (12 and <19 years and ≥19 years). Participants were randomly assigned to once-daily oral fixed-dose combination tenofovir alafenamide 25 mg and emtricitabine 200 mg, and once-daily oral dolutegravir 50 mg; once-daily oral fixed-dose combination tenofovir disoproxil fumarate 300 mg and emtricitabine 200 mg, and once-daily oral dolutegravir 50 mg; or once-daily oral fixed-dose combination of tenofovir disoproxil fumarate 300 mg, emtricitabine 200 mg, and efavirenz 600 mg. The primary efficacy endpoint was the proportion of participants who had a plasma HIV-1 RNA concentration of less than 50 copies per mL at week 48, which has been reported previously. Here, we report the key secondary efficacy endpoint of the proportion of participants who had a plasma HIV-1 RNA concentration of less than 50 copies per mL at the week 96 visit, assessed in all participants who received at least one dose of any study drug, with a prespecified non-inferiority margin of -10%. Safety data, including clinical, dual-energy X-ray absorptiometry and laboratory data, are also reported. This study was registered with ClinicalTrials.gov, NCT03122262. Between Jan 17, 2017, and May 14, 2018, we screened 1453 individuals, of whom 1053 were enrolled: 351 participants were randomly assigned to the tenofovir alafenamide, emtricitabine, and dolutegravir group, 351 to the tenofovir disoproxil fumarate, emtricitabine, and dolutegravir group, and 351 to the tenofovir disoproxil fumarate, emtricitabine, and efavirenz group. All participants received at least one dose of study medication and were included in the primary analysis. At week 96, 276 (79%) of 351 participants in the tenofovir alafenamide, emtricitabine, and dolutegravir group, 275 (78%) of 351 participants in the tenofovir disoproxil fumarate, emtricitabine, and dolutegravir group, and 258 (74%) of 351 participants in the tenofovir disoproxil fumarate, emtricitabine, and efavirenz group had achieved a plasma HIV-1 RNA concentration of less than 50 copies per mL. Non-inferiority was established in all three comparisons. The proportion of patients with protocol-defined virological failure at week 96 was low in all treatment groups. Participants in the tenofovir alafenamide, emtricitabine, and dolutegravir group had fewer changes in bone density than the two other treatment groups. Mean weight gain was substantial (7·1 kg [SD 7·4] in the tenofovir alafenamide, emtricitabine, and dolutegravir group; 4·3 kg [6·7] in the tenofovir disoproxil fumarate, emtricitabine, and dolutegravir group, and 2·3 kg [7·0] in the tenofovir disoproxil fumarate, emtricitabine, and efavirenz group), and was greater among women than men. Ten (3%) of 351 participants in the tenofovir disoproxil fumarate, emtricitabine, and efavirenz group discontinued due to treatment-related adverse events, of which liver dysfunction (n=4) and rash (n=4) were most common. Medium-term and long-term metabolic and clinical consequences of the considerable increase in bodyweight observed in participants given these antiretroviral regimens and the trajectory of this weight gain over time, especially among women, require further study. USAID, Unitaid, South African Medical Research Council, ViiV Healthcare.

Effectiveness, Safety, and Costs of Dolutegravir/Abacavir/Lamivudine Single-Tablet Regimen in a Real-Life Cohort of HIV-1 Adult Infected Patients.

Background: Real-life data on single-tablet regimen (STR) dolutegravir/abacavir/lamivudine (DTG/ABC/3TC) is scarce, and concerns about DTG neuropsychiatric adverse events (NP-AEs) have recently arisen. Objective: To explore the effectiveness and safety, in particular NP-AEs, of DTG/ABC/3TC in a cohort of HIV-1 adult infected patients. Pill burden, adherence to this STR, and the impact of switching on costs were also evaluated. Methods: This was an observational, retrospective study. The study population included antiretroviral therapy (ART)-naive and treatment-experienced (TE) patients who started DTG/ABC/3TC between February 1, 2016, and October 31, 2016. Effectiveness and safety were analyzed at week 48 (W48) by intention-to-treat analysis. The Cox regression model was used to investigate predictors of DTG/ABC/3TC discontinuation. Results: A total of 253 patients were included (44 ART naïve, 209 TE). At W48, the proportion of patients with virological suppression was 72.7% (95% CI = 58.4-87.0) in ART-naive patients, 85.6% (95% CI = 80.3-90.9) in previously suppressed TE patients, and 86.4% (95% CI = 65.1-97.1) in previously not suppressed TE patients. The rate of protocol-defined virological failure was 4.3%. The incidence of AEs was higher in the subgroup of ART-naive patients (56.1% vs 39.0%), with a rate of interruptions for this reason of 13.6% and 7.6%, respectively. The incidence of NP-AEs was 20.6%, with 3.9% of patients requiring discontinuation. Patients who had switched from a raltegravir-containing regimen discontinued DTG/ABC/3TC because of AEs more frequently (relative risk = 2.83; 95% CI = 1.04-7.72; P = 0.041) in the multivariate analysis. After switching to DTG/ABC/3TC, the median pill burden was reduced from 3 to 1 and the proportion of patients with an adherence <90%, from 20.1% to 12.0%. The annual per-patient ART costs increased by €48 (0.6% increase). Conclusion and Relevance: DTG/ABC/3TC is an effective strategy as first-line and switching ART. Our data suggest a worse tolerance in ART-naive patients, although the rate of discontinuation resulting from NP-AEs was relatively low. In the short-term, the adherence was slightly improved without significant changes in costs.

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

BackgroundRapid 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.MethodsDIAMOND (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.ResultsOverall, 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.ConclusionIn 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. Disclosures All Authors: No reported Disclosures.

2509. Pooled Resistance Analyses of Darunavir (DRV) Once Daily (QD) Regimens and Formulations Across 10 Clinical Studies of Treatment-Naïve (TN) and Treatment-Experienced (TE) Patients with Human Immunodeficiency Virus (HIV)-1 Infection

BackgroundDRV has demonstrated high efficacy and barrier to resistance development across diverse populations, from TN to heavily TE patients. We evaluated resistance data from 10 clinical studies of different DRV 800 mg QD–based antiretroviral regimens and formulations.MethodsThe analysis included patients from 10 phase 2/3 studies (48–192 weeks in duration) of ritonavir- and cobicistat-boosted DRV 800 mg QD–based regimens in TN and virologically failing or suppressed TE patients with HIV-1 (table). Three were phase 3 studies of the DRV/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg single-tablet regimen (STR). Post-baseline resistance was evaluated in patients experiencing protocol-defined virologic failure (PDVF); definitions and criteria for resistance testing varied slightly among studies. Resistance-associated mutations (RAMs) were based on respective International Antiviral Society–USA mutation lists over time.ResultsOf the 3,635 patients evaluated, 250 met PDVF criteria and 205 had post-baseline genotypes/phenotypes. Overall, 4 (0.1%) patients developed (or had identified [switch studies]) ≥1 DRV and/or primary protease inhibitor (PI) RAM (table), and only 1 (< 0.1%, ODIN) patient lost DRV phenotypic susceptibility; this TE patient had prior VF with lopinavir. Among those who used a nucleos(t)ide reverse transcriptase inhibitor (NRTI) backbone (mostly emtricitabine [FTC] + tenofovir [TFV]), 12 (0.4%) patients had ≥1 NRTI RAM, including 10 with M184I/V associated with FTC resistance. No TFV RAMs were observed. Among patients receiving D/C/F/TAF (n = 1,949), none had post-baseline DRV, primary PI, or TFV RAMs; only 2 (0.1%) patients developed an FTC RAM.ConclusionAcross a large, diverse population using DRV 800 mg QD–based regimens and formulations, resistance development remains rare; 0.1% of patients had ≥1 DRV and/or primary PI RAM post-baseline. Among 3 trials of the D/C/F/TAF STR, no patients developed a DRV or primary PI RAM. After > 10 years of investigating DRV 800 mg QD–based regimens in clinical trials, loss of phenotypic susceptibility to DRV has never been observed in TN or TE virologically suppressed patients and was only once observed in a TE patient with prior VF on multiple antiretrovirals, including a PI. Disclosures All authors: No reported disclosures.

Clinical Impact of Virological Failure and Resistance Analysis Definitions used in Pivotal Clinical Trials of Initial Antiretroviral Treatment: A Systematic Review

There are no standardized criteria to characterize confirmed protocol-defined virological failure (PDVF) nor the inclusion criteria for the resistance analysis population (RAP) in Phase III randomized clinical trials (RCTs) of initial antiretroviral therapy (ART). We assessed the clinical impact of mismatching between virological non-response (HIV-1 RNA ≥50 copies/mL), confirmed PDVF (48 weeks), and RAP definition in studies with the newest first-line ART. A systematic review of all Phase III RCTs was performed, including preferred once-daily ART (EACS European AIDS guidelines) or recently approved by the US Food and Drug Administration. We identified 16 treatment arms (14 RCTs) with 6175 participants treated with dolutegravir, bictegravir, elvitegravir/cobicistat, raltegravir, darunavir/cobicistat, rilpivirine, or doravirine. Plasma HIV-1 RNA thresholds for PDVF or RAP ranged from 40 to 50, 200, 400, and 500 copies/mL. This led to discrepancies between trials regarding the participants defined as virological non-responders, PDVF, or included in RAP. Overall, 85/296 (29%) patients with PDVF were not genotyped. There was a linear correlation between the threshold of HIV RNA chosen to perform genotyping and rates of participants with PDVF but not genotyped. Only eight treatment arms genotyped all participants with PDVF. Most of the remaining eight arms genotyped roughly < 50% of those with PDVF. In summary, the absence of standardized definitions of VF and criteria for resistance testing in pivotal Phase III RCTs of the first-line ART leads to the possibility of underreporting of resistance mutations when genotypes are only performed at higher viral load cutoffs. Stringent homogeneous criteria should be defined to ensure that all participants with PDVF (e.g., confirmed HIV RNA ≥ 50 copies/mL and the second > 200 copies/mL) undergo genotyping.

IN2 - Long-Term Health Benefit of Ibalizumab In The Treatment of Adults with Multidrug-Resistant HIV-1 Infection

Individuals with multidrug-resistant (MDR) HIV-1 infection represent a difficult-to-treat population with limited remaining antiretroviral options and substantial associated morbidity and mortality. Ibalizumab is a first-in-class, long-acting, post-attachment HIV-1 inhibitor administered by infusion every 2 weeks for adults with MDR HIV-1 infection. This analysis examines the long-term health benefit of ibalizumab treatment for this population. A Markov model was developed to follow a cohort of adults with MDR HIV-1 infection over their remaining lifetimes as they progressed through two final lines of antiretroviral therapy, receiving either ibalizumab + optimized background therapy (OBT) or OBT alone prior to salvage therapy. Over time, individuals could respond (HIV RNA < 50 copies/mL at week 25), transition between health states based on CD4 cell count, and experience treatment failure or death from HIV-related or non–HIV-related causes. Upon treatment failure (defined for responders as protocol-defined virologic failure and for partial/non-responders as two consecutive visits with HIV RNA ≥ 200 copies/mL), individuals discontinued ibalizumab and switched to salvage therapy. Treatment efficacy was based on preliminary phase 3 (ibalizumab+OBT) and adjusted phase 2a (OBT alone) clinical trial data, and published literature estimates were used to parameterize other model inputs. Average per-person outcomes were discounted at 3% per year. Compared with individuals receiving OBT alone, the model showed that individuals treated with ibalizumab+OBT experienced 0.77 more life years (9% improvement) and had a 7% reduction in HIV-related deaths. Individuals receiving ibalizumab also spent 0.28 more years on initial therapy (65% improvement) and 0.95 more years with CD4 cell counts above 200 cells/µL (28% improvement). Results were robust in sensitivity analysis. Ibalizumab treatment is predicted to provide substantial health and life-expectancy benefits for adults with MDR HIV-1 infection. For this population with limited remaining antiretroviral options, ibalizumab could represent an important step toward improved outcomes.

Long-acting intramuscular cabotegravir and rilpivirine in adults with HIV-1 infection (LATTE-2): 96-week results of a randomised, open-label, phase 2b, non-inferiority trial

Cabotegravir and rilpivirine are antiretroviral drugs in development as long-acting injectable formulations. The LATTE-2 study evaluated long-acting cabotegravir plus rilpivirine for maintenance of HIV-1 viral suppression through 96 weeks. In this randomised, phase 2b, open-label study, treatment-naive adults infected with HIV-1 initially received oral cabotegravir 30 mg plus abacavir-lamivudine 600-300 mg once daily. The objective of this study was to select an intramuscular dosing regimen based on a comparison of the antiviral activity, tolerability, and safety of the two intramuscular dosing regimens relative to oral cabotegravir plus abacavir-lamivudine. After a 20-week induction period on oral cabotegravir plus abacavir-lamivudine, patients with viral suppression (plasma HIV-1 RNA <50 copies per mL) were randomly assigned (2:2:1) to intramuscular long-acting cabotegravir plus rilpivirine at 4-week intervals (long-acting cabotegravir 400 mg plus rilpivirine 600 mg; two 2 mL injections) or 8-week intervals (long-acting cabotegravir 600 mg plus rilpivirine 900 mg; two 3 mL injections) or continued oral cabotegravir plus abacavir-lamivudine. Randomisation was computer-generated with stratification by HIV-1 RNA (<50 copies per mL, yes or no) during the first 12 weeks of the induction period. The primary endpoints were the proportion of patients with viral suppression at week 32 (as defined by the US Food and Drug Administration snapshot algorithm), protocol-defined virological failures, and safety events through 96 weeks. All randomly assigned patients who received at least one dose of study drug during the maintenance period were included in the primary efficacy and safety analyses. The primary analysis used a Bayesian approach to evaluate the hypothesis that the proportion with viral suppression for each long-acting regimen is not worse than the oral regimen proportion by more than 10% (denoted comparable) according to a prespecified decision rule (ie, posterior probability for comparability >90%). Difference in proportions and associated 95% CIs were supportive to the primary analysis. The trial is registered at ClinicalTrials.gov, number NCT02120352. Among 309 enrolled patients, 286 were randomly assigned to the maintenance period (115 to each of the 4-week and 8-week groups and 56 to the oral treatment group). This study is currently ongoing. At 32 weeks following randomisation, both long-acting regimens met primary criteria for comparability in viral suppression relative to the oral comparator group. Viral suppression was maintained at 32 weeks in 51 (91%) of 56 patients in the oral treatment group, 108 (94%) of 115 patients in the 4-week group (difference 2·8% [95% CI -5·8 to 11·5] vs oral treatment), and 109 (95%) of 115 patients in the 8-week group (difference 3·7% [-4·8 to 12·2] vs oral treatment). At week 96, viral suppression was maintained in 47 (84%) of 56 patients receiving oral treatment, 100 (87%) of 115 patients in the 4-week group, and 108 (94%) of 115 patients in the 8-week group. Three patients (1%) experienced protocol-defined virological failure (two in the 8-week group; one in the oral treatment group). Injection-site reactions were mild (3648 [84%] of 4360 injections) or moderate (673 [15%] of 4360 injections) in intensity and rarely resulted in discontinuation (two [<1%] of 230 patients); injection-site pain was reported most frequently. Serious adverse events during maintenance were reported in 22 (10%) of 230 patients in the intramuscular groups (4-week and 8-week groups) and seven (13%) of 56 patients in the oral treatment group; none were drug related. The two-drug combination of all-injectable, long-acting cabotegravir plus rilpivirine every 4 weeks or every 8 weeks was as effective as daily three-drug oral therapy at maintaining HIV-1 viral suppression through 96 weeks and was well accepted and tolerated. ViiV Healthcare and Janssen R&D.

Genotypic tropism testing of proviral DNA to guide maraviroc initiation in aviraemic subjects: 48‐week analysis of results from the PROTEST study

Maraviroc (MVC) is a suitable drug for aviraemic subjects on antiretroviral treatment (ART) developing toxicity. Its prescription requires prior tropism testing. It is unknown if proviral DNA genotypic tropism testing is reliable for guiding MVC initiation in aviraemic subjects, so this study was carried out to address this issue. PROTEST was a phase 4, prospective, single-arm clinical trial carried out in 24 HIV care centres in Spain. MVC-naïve HIV-1-infected patients with HIV-1 RNA < 50 copies/mL on stable ART during the previous 6 months who required an ART change because of toxicity and who had R5 HIV, as determined by proviral DNA genotypic tropism testing, initiated MVC with two nucleoside reverse transcriptase inhibitors (NRTIs) and were followed for 48 weeks. Virological failure was defined as two consecutive viral load measurements > 50 copies/mL. Tropism results were available for 141 of 175 (80.6%) subjects screened: 60% had R5 and 85% of these (n = 74) were finally included in the study. Previous ART included protease inhibitors (PIs) in 62% of subjects, nonnucleoside reverse transcriptase inhibitors (NNRTIs) in 36%, and integrase inhibitors (INIs) in 2%. Main reasons for treatment change were dyslipidaemia (42%), gastrointestinal symptoms (22%) and liver toxicity (15%). MVC was given alongside tenofovir (TDF)/emtricitabine (FTC) (54%) and abacavir (ABC)/lamivudine (3TC) (40%) in most patients. Eighty-four per cent of patients maintained a viral load < 50 copies/mL to week 48, whereas 16% discontinued treatment: two withdrew informed consent, one had an R5 to X4 shift between screening and baseline, one was lost to follow-up, one developed an adverse event (rash), two died from non-study-related causes, and five developed protocol-defined virological failure. Initiation of MVC plus two NRTIs in aviraemic subjects based on genotypic tropism testing of proviral HIV-1 DNA is associated with low rates of virological failure for up to 1 year.

Abacavir/dolutegravir/lamivudine single-tablet regimen: a review of its use in HIV-1 infection.

A fixed-dose, single-tablet regimen comprising the integrase strand transfer inhibitor (INSTI) dolutegravir and the nucleos(t)ide reverse transcriptase inhibitors (NRTIs) abacavir and lamivudine (abacavir/dolutegravir/lamivudine; Triumeq®) is now available for the treatment of HIV-1 infection. In a randomized, double-blind, phase III trial in antiretroviral therapy (ART)-naive adults (SINGLE), once-daily dolutegravir plus abacavir/lamivudine had noninferior efficacy to once-daily efavirenz/tenofovir disoproxil fumarate (tenofovir DF)/emtricitabine with regard to establishing and sustaining virological suppression over 144 weeks, and subsequent superiority testing significantly favoured dolutegravir plus abacavir/lamivudine. This outcome was predominantly driven by more favourable rates of discontinuation due to adverse events versus the efavirenz/tenofovir DF/emtricitabine group. These data were generally supported by findings from other phase III trials in ART-naive adults receiving dolutegravir plus either abacavir/lamivudine or tenofovir DF/emtricitabine (SPRING-2 and FLAMINGO). Dolutegravir plus abacavir/lamivudine is generally well tolerated, with a tolerability profile that appears to be more favourable than efavirenz/tenofovir DF/emtricitabine. In the SINGLE trial, there were no major treatment-emergent INSTI or NRTI resistance-associated mutations in dolutegravir plus abacavir/lamivudine recipients with protocol-defined virological failure, indicating a high genetic barrier to resistance. Thus, triple combination therapy with abacavir, dolutegravir and lamivudine is an effective, generally well tolerated option for the management of HIV-1 infection, with the convenient once-daily fixed-dose tablet providing the first single-tablet regimen option without tenofovir DF.

Once-daily dolutegravir is superior to once-daily darunavir/ritonavir in treatment-naïve HIV-1-positive individuals: 96 week results from FLAMINGO.

IntroductionDolutegravir (DTG) 50 mg once daily was superior to darunavir/ritonavir (DRV/r) 800 mg/100 mg once daily through Week 48, with 90% vs. 83% of participants achieving HIV RNA 50 c/mL (p=0.025) [1]. We present data through Week 96.Material and MethodsFLAMINGO is a multicentre, randomized, open-label, Phase IIIb non-inferiority study, in which HIV-1-positive ART-naïve adults with HIV-1 RNA≥1000 c/mL and no evidence of viral resistance were randomized 1:1 to receive DTG or DRV/r, with investigator-selected backbone NRTIs (TDF/FTC or ABC/3TC). Participants were stratified by screening HIV-1 RNA (≤100K c/mL) and NRTI backbone.ResultsA total of 484 adults were randomized and treated; 25% had baseline HIV RNA 100K c/mL. At Week 96, the proportion of participants with HIV RNA 50 c/mL was 80% in the DTG arm vs. 68% in the DRV/r arm (adjusted difference 12.4%; 95% CI 4.7, 20.2%; p=0.002). Secondary analyses supported primary results: per-protocol [(DTG 83% vs. DRV/r 70%), 95% CI 12.9 (5.3, 20.6)] and treatment-related discontinuation = failure [(98% vs. 95%), 95% CI 3.2 (−0.3, 6.7)]. Overall virologic non-response (DTG 8%; DRV/r 12%) and non-response due to other reasons (DTG 12%; DRV/r 21%) occurred less frequently on DTG. As at Week 48, the difference between arms was most pronounced in participants with high baseline viral load (82% vs. 52% response through Week 96) and in the TDF/FTC stratum (79% vs. 64%); consistent responses were seen in the ABC/3TC stratum (82% vs. 75%). Six participants (DTG 2, none post-Week 48; DRV/r 4, two post-Week 48) experienced protocol-defined virologic failure (PDVF; confirmed viral load 200 c/mL on or after Week 24); none had treatment-emergent resistance to study drugs. Most frequent drug-related adverse events (AEs) were diarrhoea, nausea and headache, with diarrhoea significantly more common on DRV/r (24%) than DTG (10%). Significantly more participants had Grade 2 fasting LDL toxicities on DRV/r (22%) vs. DTG (7%), p<0.001; mean changes in creatinine for DTG (~0.18 mg/dL) observed at Week 2 were stable through Week 96.ConclusionsOnce-daily DTG was superior to once-daily DRV/r in treatment-naïve HIV-1-positive individuals, with no evidence of emergent resistance to DTG in virologic failure and relatively similar safety profiles for DTG and DRV/r through 96 Weeks.

Predictors of suboptimal CD4 response among women achieving virologic suppression in a randomized antiretroviral treatment trial, Africa.

BackgroundA subset of HIV-1 infected patients starting highly active antiretroviral treatment (HAART) experience suboptimal CD4 response (SCR) despite virologic suppression. We studied the rate of and risk factors for SCR among women starting HAART in the ACTG A5208 study conducted in 7 African countries. 741 HAART-naive women with screening CD4 count <200 cells/μL were randomized to start HAART with Tenofovir/Emtricitabine plus either Nevirapine or Lopinavir/Ritonavir.MethodsThis analysis includes the 625 women who remained on-study through 48 weeks without experiencing protocol-defined virologic failure. We defined SCR as < 100 CD4 cells/μL increase from baseline and absolute CD4 cell count < 350 cells/μL, both at 48 weeks after HAART initiation.ResultsThe baseline characteristics for the 625 women prior to HAART initiation were: median age 33 years, screening CD4 count 134 cells/μL, and HIV-1 RNA 5.1 log10 copies/mL; 184 (29%) were WHO Stage 3 or 4.Seventy one (11%) of these 625 women experienced SCR. Baseline factors independently associated with increased odds of SCR included older age, lower HIV-1 RNA, positive Hepatitis B surface antigen, and site location. At 96 weeks, only 6% of the SCR group had CD4 ≥ 350 cells/μL compared with 67% in the non SCR group.ConclusionAfter starting HAART, 11% of women with virologic suppression through 48 weeks experienced SCR. These patients were also less likely to achieve CD4 ≥ 350 cells/μL by 96 weeks. The underlying causes and long term clinical implications of SCR deserve further investigation.Trial registrationClinicaltrials.gov Identifier: NCT00089505

5.0 What to start

5.0 What to start