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

Background: In 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. Methods: LATTE 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. Results: Of 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%). Conclusions: Oral 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.

Satisfaction and acceptability of cabotegravir long-acting injectable suspension for prevention of HIV: Patient perspectives from the ECLAIR trial.

BACKGROUND: Cabotegravir (GSK1265744) is an integrase strand transfer inhibitor in development as a long-acting (LA) intramuscular injectable suspension for HIV-1 pre-exposure prophylaxis (PrEP). OBJECTIVE: We report participant outcomes from the phase IIa ECLAIR study related to tolerability, acceptability, and satisfaction of cabotegravir LA. METHODS: The ECLAIR study (ClinicalTrials.gov identifier, NCT02076178) was a randomized, placebo-controlled study in healthy men not at high risk of acquiring HIV-1. Participants were randomized (5:1) to once-daily oral cabotegravir 30 mg or placebo tablets for 4 weeks, followed by gluteal intramuscular injections of cabotegravir LA 800 mg or saline placebo every 12 weeks. The primary objective was to evaluate the safety of cabotegravir LA over three injection cycles (to Week 41). Secondary objectives assessed the tolerability, satisfaction, and acceptability of cabotegravir LA. RESULTS: Among 115 participants who received injections in the cabotegravir (n = 94) and placebo (n = 21) groups, 93% (n = 87) and 95% (n = 20) completed the injection phase, respectively. Injection intolerability led to withdrawal in 4 participants (4%) receiving cabotegravir LA. The most frequently reported Grade ≥2 adverse event was injection-site pain. Most participants (74% [n = 67]) receiving consecutive injections favored cabotegravir LA vs oral cabotegravir. Most participants were satisfied with cabotegravir LA (75% [n = 64]), were willing to continue (79% [n = 68]), and would recommend (87% [n = 75]) the therapy. CONCLUSIONS: While Grade ≥2 injection-site pain was common, most participants reported overall satisfaction with and preference for cabotegravir LA, with few discontinuations due to injection intolerance. These findings support investigation of cabotegravir LA as an alternative to daily oral PrEP regimens.

HIV prevention trial design in an era of effective pre-exposure prophylaxis.

Pre-exposure prophylaxis (PrEP) has demonstrated remarkable effectiveness protecting at-risk individuals from HIV-1 infection. Despite this record of effectiveness, concerns persist about the diminished protective effect observed in women compared with men and the influence of adherence and risk behaviors on effectiveness in targeted subpopulations. Furthermore, the high prophylactic efficacy of the first PrEP agent, tenofovir disoproxil fumarate/emtricitabine (TDF/FTC), presents challenges for demonstrating the efficacy of new candidates. Trials of new agents would typically require use of non-inferiority (NI) designs in which acceptable efficacy for an experimental agent is determined using pre-defined margins based on the efficacy of the proven active comparator (i.e. TDF/FTC) in placebo-controlled trials. Setting NI margins is a critical step in designing registrational studies. Under- or over-estimation of the margin can call into question the utility of the study in the registration package. The dependence on previous placebo-controlled trials introduces the same issues as external/historical controls. These issues will need to be addressed using trial design features such as re-estimated NI margins, enrichment strategies, run-in periods, crossover between study arms, and adaptive re-estimation of sample sizes. These measures and other innovations can help to ensure that new PrEP agents are made available to the public using stringent standards of evidence.

Safety and tolerability of long-acting cabotegravir injections in HIV-uninfected men (ECLAIR): a multicentre, double-blind, randomised, placebo-controlled, phase 2a trial.

BACKGROUND: Cabotegravir (GSK1265744) is an HIV-1 integrase strand transfer inhibitor with potent antiviral activity and a long half-life when administered by injection that prevented simian-HIV infection upon repeat intrarectal challenge in male macaques. We aimed to assess the safety, tolerability, and pharmacokinetics of long-acting cabotegravir injections in healthy men not at high risk of HIV-1 infection. METHODS: We did this multicentre, double-blind, randomised, placebo-controlled, phase 2a trial at ten sites in the USA. Healthy men (aged 18-65 years) deemed not at high risk of acquiring HIV-1 at screening were randomly assigned (5:1), via computer-generated central randomisation schedules, to receive cabotegravir or placebo. Participants received oral cabotegravir 30 mg tablets or matching placebo once daily during a 4 week oral lead-in phase, followed by a 1 week washout period and, after safety assessment, three intramuscular injections of long-acting cabotegravir 800 mg or saline placebo at 12 week intervals. Study site staff and participants were masked to treatment assignment from enrolment through week 41 (time of the last injection). The primary endpoint was safety and tolerability from the first injection (week 5) to 12 weeks after the last injection. We did analysis in the safety population, defined as all individuals enrolled in the study who received at least one dose of the study drug. This study is registered with ClinicalTrials.gov identifier, NCT02076178. FINDINGS: Between March 27, 2014, and Feb 23, 2016, we randomly assigned 127 participants to receive cabotegravir (n=106) or placebo (n=21); 126 (99%) participants comprised the safety population. Most participants were men who have sex with men (MSM; n=106 [83%]) and white (n=71 [56%]). 87 (82%) participants in the cabotegravir group and 20 (95%) participants in the placebo group completed the injection phase. Adverse events (n=7 [7%]) and injection intolerability (n=4 [4%]) were the main reasons for withdrawal in the cabotegravir group. The frequency of grade 2 or higher adverse events was higher in participants in the long-acting cabotegravir group (n=75 [80%]) than in those in the placebo group (n=10 [48%]; p=0·0049), mostly due to injection-site pain (n=55 [59%]). No significant differences were noted in concomitant medications, laboratory abnormalities, electrocardiogram, and vital sign assessments. Geometric mean trough plasma concentrations were 0·302 µg/mL (95% CI 0·237-0·385), 0·331 µg/mL (0·253-0·435), and 0·387 µg/mL (0·296-0·505) for injections one, two, and three, respectively, indicating lower than predicted exposure. The geometric mean apparent terminal phase half-life estimated after the third injection was 40 days. Two (2%) MSM acquired HIV-1 infection, one in the placebo group during the injection phase and one in the cabotegravir group 24 weeks after the final injection when cabotegravir exposure was well below the protein-binding-adjusted 90% inhibitory concentration. INTERPRETATION: Despite high incidence of transient, mild-to-moderate injection-site reactions, long-acting cabotegravir was well tolerated with an acceptable safety profile. Pharmacokinetic data suggest that 800 mg administered every 12 weeks is a suboptimal regimen; alternative dosing strategies are being investigated. Our findings support further investigation of long-acting injectable cabotegravir as an alternative to orally administered pre-exposure prophylaxis regimens. FUNDING: ViiV Healthcare.

Cabotegravir plus rilpivirine, once a day, after induction with cabotegravir plus nucleoside reverse transcriptase inhibitors in antiretroviral-naive adults with HIV-1 infection (LATTE): a randomised, phase 2b, dose-ranging trial.

BACKGROUND: In phase 1 trials, the HIV-1 integrase strand transfer inhibitor cabotegravir (GSK1265744) was well tolerated, both alone, and in combination with the non-nucleoside reverse transcriptase inhibitor rilpivirine. We assessed cabotegravir plus rilpivirine, as a two-drug oral antiretroviral regimen, for the maintenance of viral suppression in antiretroviral-naive HIV-1-infected individuals. METHODS: In the phase 2b Long-Acting antireTroviral Treatment Enabling (LATTE) trial, a multicentre study done in Canada and the USA, antiretroviral-naive HIV-1-infected adults (aged ≥18 years) were randomly allocated in a 1:1:1:1 ratio to oral cabotegravir 10 mg once a day, 30 mg once a day, 60 mg once a day, or oral efavirenz 600 mg once a day with dual nucleoside reverse transcriptase inhibitors (NRTIs) for 24 weeks of induction. Patients who were virologically suppressed by week 24 received a two-drug maintenance regimen consisting of their randomly allocated cabotegravir dose plus oral rilpivirine 25 mg or continued efavirenz plus NRTIs for an additional 72 weeks. Patients and investigators were masked to doses of cabotegravir received for 96 weeks, but not to the assignment of cabotegravir or efavirenz. The primary endpoint was the proportion of patients with fewer than 50 copies per mL of HIV-1 RNA (US Food and Drug Administration snapshot algorithm) at week 48. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, NCT01641809. FINDINGS: Of 243 patients randomly allocated and treated, 156 (86%) of 181 patients in the cabotegravir groups (52 [87%] of 60, 51 [85%] of 60, and 53 [87%] of 61 patients in the 10 mg, 30 mg, and 60 mg groups, respectively) and 46 (74%) of 62 in the efavirenz group had fewer than 50 copies per mL of HIV-1 RNA after induction therapy. After patients in the cabotegravir groups were changed over from dual NRTIs to rilpivirine at week 24, 149 (82%; 95% CI 77-88) patients in the cabotegravir groups (48 [80%; 70-90], 48 [80%; 70-90], and 53 [87%; 78-95] patients in the 10 mg, 30 mg, and 60 mg groups, respectively) versus 44 (71%; 60-82) in the efavirenz group were virologically suppressed at week 48, and 137 (76%; 69-82) receiving cabotegravir (41 [68%; 57-80], 45 [75%; 64-86], and 51 [84%; 74-93] patients in the 10 mg, 30 mg, and 60 mg groups, respectively) versus 39 (63%; 51-75) in the efavirenz group were virologically suppressed at week 96. Treatment-related adverse events were reported by 93 (51%) cabotegravir-treated patients (28 [47%], 32 [53%], and 33 [54%] patients in the 10 mg, 30 mg, and 60 mg groups, respectively) and 42 (68%) efavirenz-treated patients. Six (3%) patients in the cabotegravir groups (one [2%], one [2%], and four [7%] patients in the 10 mg, 30 mg, and 60 mg groups, respectively) withdrew because of treatment-emergent adverse events compared with nine (15%) in the efavirenz group. INTERPRETATION: Cabotegravir plus dual NRTI therapy had potent antiviral activity during the induction phase. As a two-drug maintenance therapy, cabotegravir plus rilpivirine provided antiviral activity similar to efavirenz plus dual NRTIs until the end of week 96. Combined efficacy and safety results lend support to our selection of oral cabotegravir 30 mg once a day for further assessment. LATTE precedes studies of the assessment of longacting injectable formulations of both drugs as a two-drug regimen for the treatment of HIV-1 infection. FUNDING: ViiV Healthcare and Janssen Research and Development.

Unexpected finding of delayed-onset seizures in HIV-positive, treatment-experienced subjects in the Phase IIb evaluation of fosdevirine (GSK2248761).

BACKGROUND: Fosdevirine (GSK2248761) is a non-nucleoside reverse transcriptase inhibitor with HIV-1 activity against common efavirenz-resistant strains. Two partially blind, randomized, Phase IIb studies were initiated (1 in treatment-naive and 1 in treatment-experienced subjects with HIV) to select a once-daily dose of fosdevirine for Phase III trials. METHODS: In the SIGNET study, treatment-naive subjects were randomized 1:1:1 to receive once-daily fosdevirine 100 or 200 mg or efavirenz 600 mg, each along with tenofovir disoproxil fumarate/emtricitabine 300 mg/200 mg or abacavir/lamivudine 600 mg/300 mg. In the SONNET study, treatment-experienced subjects with non-nucleoside reverse transcriptase inhibitor-resistant HIV-1 were randomized 1:1:1 to treatment with fosdevirine 100 or 200 mg once daily or etravirine 200 mg twice daily, each along with twice-daily darunavir/ritonavir 600/100 mg and raltegravir 400 mg. The primary efficacy end point was the proportion of subjects with HIV-1 RNA<50 copies/ml. Safety and pharmacokinetics were also addressed. RESULTS: A total of 35 subjects were exposed to fosdevirine 100 or 200 mg. Trials were halted when 5 treatment-experienced subjects (1 receiving fosdevirine 100 mg, 4 receiving fosdevirine 200 mg) developed new-onset seizures after ≥4 weeks of exposure to fosdevirine. There was no clear association between seizures and fosdevirine plasma drug levels. Time to seizure onset ranged from 28 to 81 days, and all 5 subjects experienced ≥1 seizure after drug discontinuation. CONCLUSIONS: The delayed onset of seizures after fosdevirine exposure and persistence after discontinuation is without precedent in antiretroviral drug development, leading to additional investigation and underscoring the need for careful subject monitoring.

Evaluation of cardiovascular biomarkers in a randomized trial of fosamprenavir/ritonavir vs. efavirenz with abacavir/lamivudine in underrepresented, antiretroviral-naïve, HIV-infected patients (SUPPORT): 96-week results.

BACKGROUND: Rates of cardiovascular disease are higher among HIV-infected patients as a result of the complex interplay between traditional risk factors, HIV-related inflammatory and immunologic changes, and effects of antiretroviral therapy (ART). This study prospectively evaluated changes in cardiovascular biomarkers in an underrepresented, racially diverse, HIV-1-infected population receiving abacavir/lamivudine as backbone therapy. METHODS: This 96-week, open-label, randomized, multicenter study compared once-daily fosamprenavir/ritonavir 1400/100 mg and efavirenz 600 mg, both with ABC/3TC 600 mg/300 mg, in antiretroviral-naïve, HLA-B*5701-negative adults without major resistance mutations to study drugs. We evaluated changes from baseline to weeks 4, 12, 24, 48, and 96 in interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), soluble vascular adhesion molecule-1 (sVCAM-1), d-dimer, plasminogen, and fibrinogen. Biomarker data were log-transformed before analysis, and changes from baseline were described using geometric mean ratios. RESULTS: This study enrolled 101 patients (51 receiving fosamprenavir/ritonavir; 50 receiving efavirenz): 32% female, 60% African American, and 38% Hispanic/Latino; 66% (67/101) completed 96 weeks on study. At week 96, levels of IL-6, sVCAM-1, d-dimer, fibrinogen, and plasminogen were lower than baseline in both treatment groups, and the decrease was statistically significant for sVCAM-1 (fosamprenavir/ritonavir and efavirenz), d-dimer (fosamprenavir/ritonavir and efavirenz), fibrinogen (efavirenz), and plasminogen (efavirenz). Values of hs-CRP varied over time in both groups, with a significant increase over baseline at Weeks 4 and 24 in the efavirenz group. At week 96, there was no difference between the groups in the percentage of patients with HIV-1 RNA <50 copies/mL (fosamprenavir/ritonavir 63%; efavirenz 66%) by ITT missing-equals-failure analysis. Treatment-related grade 2-4 adverse events were more common with efavirenz (32%) compared with fosamprenavir/ritonavir (20%), and median lipid concentrations increased in both groups over 96 weeks of treatment. CONCLUSIONS: In this study of underrepresented patients, treatment with abacavir/lamivudine combined with either fosamprenavir/ritonavir or efavirenz over 96 weeks, produced stable or declining biomarker levels except for hs-CRP, including significant and favorable decreases in thrombotic activity (reflected by d-dimer) and endothelial activation (reflected by sVCAM-1). Our study adds to the emerging data that some cardiovascular biomarkers are decreased with initiation of ART and control of HIV viremia. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT00727597.

Farglitazar lacks antifibrotic activity in patients with chronic hepatitis C infection.

BACKGROUND & AIMS: Farglitazar (GI262570), an insulin-sensitizing agent, selectively binds and activates peroxisome proliferator-activated receptor gamma (PPARgamma) and inhibits stellate cell activation. We evaluated its antifibrotic effect in patients with chronic hepatitis C that did not respond to standard-of-care therapy. METHODS: Patients with fibrosis of Ishak stages 2-4 (n = 265), based on analysis of liver biopsy samples, were randomly assigned to groups given once-daily doses of 0.5 mg farglitazar, 1.0 mg farglitazar, or placebo for 52 weeks; repeat liver biopsy samples were then obtained. The primary end points were changes in levels of alpha-smooth muscle actin (SMA) expression and collagen, based on morphometry and ranked histologic assessments. RESULTS: Two hundred nine patients had paired biopsy specimens adequate for analysis (81.5% with pretreatment Ishak scores of stage 2 or 3). There was no overall difference in SMA (P = .58) or collagen (P = .99) levels at week 52. SMA levels increased by a median of 49% in samples from patients given placebo, 58% in patients given 0.5 mg farglitizar and 52% in patients given 1.0 mg farglitizar, respectively. Collagen increased by 27% in placebo samples and 31% in samples from patients given either dose of farglitizar. There were no significant differences between treatment groups in the ranked assessment of paired biopsy specimens or in the proportion of patients with a change in fibrosis score > or = Ishak stage. CONCLUSIONS: In patients with chronic hepatitis C and moderate fibrosis, 52 weeks of treatment with farglitazar does not affect stellate cell activation or fibrosis (measured by morphometry or comparison of paired biopsy specimens).

High sensitivity of human leukocyte antigen-b*5701 as a marker for immunologically confirmed abacavir hypersensitivity in white and black patients.

BACKGROUND: Although the human leukocyte antigen (HLA)-B*5701 is highly associated with a hypersensitivity reaction (HSR) to abacavir (ABC), variable sensitivities have been reported when clinical data alone have been used to define an ABC HSR. This study evaluated the sensitivity of detection of the HLA-B*5701 allele as a marker of ABC HSRs in both white and black patients, using skin patch testing to supplement clinical diagnosis. METHODS: White and black patients, identified through chart review, were classified as having received a diagnosis of an ABC HSR based on clinical findings only (a clinically suspected ABC HSR) or based on clinical findings and a positive skin patch test result (an immunologically confirmed [IC] ABC HSR). Control subjects were racially matched subjects who tolerated ABC for >/=12 weeks without experiencing an ABC HSR. Patients and control subjects were tested for the presence of HLA-B*5701. Sensitivity, specificity, and odds ratios for the detection of HLA-B*5701 as a marker for an ABC HSR were calculated for white and black participants. RESULTS: Forty-two (32.3%) of 130 white patients and 5 (7.2%) of 69 black patients who met the criteria for clinically suspected HSRs had IC HSRs. All 42 white patients with IC HSRs were HLA-B*5701 positive (sensitivity, 100%; odds ratio, 1945; 95% confidence interval, 110-34,352). Among all white patients with clinically suspected HSRs, sensitivity was 44% (57 of 130 patients tested positive for HLA-B*5701); specificity among white control subjects was 96%. Five of 5 black patients with IC HSRs were HLA-B*5701 positive (sensitivity, 100%; odds ratio, 900; 95% confidence interval, 38-21,045). Among black patients with clinically suspected HSRs, the sensitivity was 14% (10 of 69 tested positive for HLA-B*5701); specificity among black control subjects was 99%. CONCLUSIONS: Although IC ABC HSRs are uncommon in black persons, the 100% sensitivity of HLA-B*5701 as a marker for IC ABC HSRs in both US white and black patients suggests similar implications of the association between HLA-B*5701 positivity and risk of ABC HSRs in both races.

Extended duration of efficacy of vardenafil when taken 8 hours before intercourse: a randomized, double-blind, placebo-controlled study.

OBJECTIVES: This study explored the efficacy of vardenafil in men with erectile dysfunction (ED) when taken 8 hours before sexual intercourse. METHODS: A 10-week, randomized, double-blind, placebo-controlled, parallel-group, flexible-dose study of vardenafil (5, 10 or 20mg) was conducted in men with ED for >6 months who failed >or=50% of intercourse attempts during a 4-week treatment-free run-in period. Sexual Encounter Profile Question 3 (SEP3) was the primary efficacy measure; secondary measures included SEP2, International Index of Erectile Function-Erectile Function (IIEF-EF) domain score, Global Assessment Question (GAQ), Global Confidence Question (GCQ) and Erection Quality Scale (EQS). Adverse-event and safety monitoring were conducted throughout. RESULTS: 383 patients were randomized to vardenafil (n=194) or placebo (n=189). Patients treated with vardenafil 8 hours before sexual activity achieved clinically meaningful (>or=18%) and statistically significantly greater least-squares mean per-patient SEP3 and SEP2 success rates over weeks 2-10, compared with patients receiving placebo (SEP3 69% vs 34%; SEP2 81% vs 51%; both p<0.001). SEP3 and SEP2 measures demonstrated the significant superiority of vardenafil over placebo from week 2 onwards (p<0.001). Measurements of IIEF-EF domain score, GAQ, GCQ and EQS showed that vardenafil led to significantly greater improvements in erectile function, compared with placebo (all p<0.001). Vardenafil was generally well tolerated. CONCLUSIONS: The extended duration of efficacy of vardenafil up to 8 hours postdose may provide couples with more flexibility in their sexual life than anticipated.

Sustained efficacy and safety of vardenafil for treatment of erectile dysfunction: a randomized, double-blind, placebo-controlled study.

OBJECTIVE: To evaluate the reliability, efficacy, and safety of vardenafil, 10 mg, for patients with erectile dysfunction. PATIENTS AND METHODS: Vardenafil-naive patients completed a 4-week treatment-free run-in phase and a 1-week single-dose vardenafil (10 mg) open-label challenge phase. Responders to vardenafil in the challenge phase were randomized to 12 weeks of double-blind, fixed-dose treatment with vardenafil at 10 mg or placebo. Diary responses to Sexual Encounter Profile (SEP) questions about erections and attempts at sexual activity were collected after 4, 8, and 12 weeks of randomized treatment. Adverse events were monitored throughout the study. RESULTS: During the open-label challenge phase, the proportions of patients with a first-time success for penetration (SEP2) and maintenance of erection (SEP3) were 87% and 74%, respectively. Of 600 patients challenged with a single dose of vardenafil at 10 mg, 260 were randomized to vardenafil and 263 to placebo. During the double-blind phase, the reliability of penetration and maintenance rates for patients successful during the challenge phase were significantly greater with vardenafil compared with placebo (83.4% vs 55.8% [SEP2] and 76.6% vs 42.1% [SEP3], respectively). At week 12, patients in the vardenafil group had a consistently higher least squares mean (SE) on the erectile function domain score of the International Index of Erectile Function than patients in the placebo group (23.5 [0.4] vs 15.8 [0.4], respectively [last observation carried forward]) and a greater proportion of positive responses to the Global Assessment Question (80.8% vs 32.3%, respectively [last observation carried forward]) at each assessment (Pc.001). Vardenafil was generally well tolerated; most adverse events were mild to moderate, with headache and flushing reported most frequently. CONCLUSION: During this 12-week study, vardenafil produced consistently higher reliability of penetration and maintenance of erection rates compared to placebo and was generally well tolerated in patients with erectile dysfunction.