Cabotegravir (CAB) is a novel strand-transfer integrase inhibitor being developed for HIV treatment and prevention. CAB is formulated both as an immediate-release oral tablet for daily administration ...and as a long-acting injectable suspension (long-acting CAB CAB LA) for intramuscular (IM) administration, which delivers prolonged plasma exposure to the drug after IM injection. HIV Prevention Trials Network study 077 (HPTN 077) evaluated the safety, tolerability, and pharmacokinetics of CAB LA in HIV-uninfected males and females at 8 sites in Brazil, Malawi, South Africa, and the United States.
HPTN 077 was a double-blind, placebo-controlled phase 2a trial. Healthy individuals age 18-65 years at low HIV risk were randomized (3:1) to receive CAB or placebo (PBO). In the initial oral phase, participants received 1 daily oral tablet (CAB or PBO) for 4 weeks. Those without safety concerns in the oral phase continued and received injections in the injection phase (Cohort 1: 3 injections of CAB LA 800 mg or 0.9% saline as PBO IM every 12 weeks for 3 injection cycles; Cohort 2: CAB LA 600 mg or PBO IM for 5 injection cycles; the first 2 injections in Cohort 2 were separated by 4 weeks, the rest by 8 weeks). The primary analysis included weeks 5 to 41 of study participation, encompassing the injection phase. The cohorts were enrolled sequentially. Primary outcomes were safety and tolerability. Secondary outcomes included pharmacokinetics and events occurring during the oral and injection phases. Between February 9, 2015, and May 27, 2016, the study screened 443 individuals and enrolled 110 participants in Cohort 1 and 89 eligible participants in Cohort 2. Participant population characteristics were as follows: 66% female at birth; median age 31 years; 27% non-Hispanic white, 41% non-Hispanic black, 24% Hispanic/Latino, 3% Asian, and 6% mixed/other; and 6 transgender men and 1 transgender woman. Twenty-two (11%) participants discontinued the oral study product; 6 of these were for clinical or laboratory adverse events (AEs). Of those who received at least 1 CAB LA injection, 80% of Cohort 1 and 92% of Cohort 2 participants completed all injections; injection course completion rates were not different from those in the PBO arm. Injection site reactions (ISRs) were common (92% of Cohort 1 and 88% of Cohort 2 participants who received CAB LA reported any ISR). ISRs were mostly Grade 1 (mild) to Grade 2 (moderate), and 1 ISR event (Cohort 1) led to product discontinuation. Grade 2 or higher ISRs were the only AEs reported more commonly among CAB LA recipients than PBO recipients. Two Grade 3 (severe) ISRs occurred in CAB recipients, 1 in each cohort, but did not lead to product discontinuation in either case. Seven incident sexually transmitted infections were diagnosed in 6 participants. One HIV infection occurred in a participant 48 weeks after last injection of CAB LA: CAB was not detectable in plasma both at the time of first reactive HIV test and at the study visit 12 weeks prior to the first reactive test. Participants in Cohort 2 (unlike Cohort 1) consistently met prespecified pharmacokinetic targets of at least 95% of participants maintaining CAB trough concentrations above PA-IC90, and 80% maintaining trough concentrations above 4× PA-IC90. Study limitations include a modest sample size, a short course of injections, and a low-risk study population.
In this study, CAB LA was well tolerated at the doses and dosing intervals used. ISRs were common, but infrequently led to product discontinuation. CAB LA 600 mg every 8 weeks met pharmacokinetic targets for both male and female study participants. The safety and pharmacokinetic results observed support the further development of CAB LA, and efficacy studies of CAB LA for HIV treatment and prevention are in progress.
ClinicalTrials.gov Registry: ClinicalTrials.gov Trial number: NCT02178800.
Abstract
Background
Tenofovir disoproxil fumarate-containing pre-exposure prophylaxis (PrEP) has been associated with decreases in bone mineral density (BMD), but the bone effects of other ...non-tenofovir disoproxil fumarate candidate PrEP regimens are not well described.
Methods
The HPTN 069/ACTG A5305 study randomized 406 US cisgender men and transgender women, and 188 cisgender women at risk for HIV infection to one of four double-blinded regimens: (i) maraviroc; (ii) maraviroc + emtricitabine; (iii) maraviroc + tenofovir disoproxil fumarate; or (iv) tenofovir disoproxil fumarate + emtricitabine. BMD was measured in a subset of participants at the lumbar spine (LS) and hip by dual-energy X-ray absorptiometry (DXA) at baseline and 48 weeks. Percentage change in LS and hip BMD was compared between the tenofovir disoproxil fumarate- and non-tenofovir disoproxil fumarate-containing arms by Wilcoxon rank-sum tests and multiple linear regression adjusting for sex, race and baseline BMI.
Results
At baseline (n = 307), the median age was 33 years, 56% male and 43% black. At the hip, the median percentage change in BMD at 48 weeks was –1.05% in the tenofovir disoproxil fumarate arms and 0.0% in the non-tenofovir disoproxil fumarate arms (between group P = 0.001). No interaction by sex was observed. The median percentage change in LS BMD was not different between arms.
Conclusions
Tenofovir disoproxil fumarate-containing PrEP was associated with significantly greater bone loss compared with maraviroc ± emtricitabine PrEP at the hip, but not the LS. The BMD changes at the hip were similar in magnitude in men and women.
Introduction
HPTN 083 demonstrated the superiority of long‐acting cabotegravir (CAB‐LA) versus daily oral emtricitabine/tenofovir disoproxil fumarate (TDF/FTC) as pre‐exposure prophylaxis (PrEP) ...among cisgender men and transgender women who have sex with men (MSM/TGW). HPTN 083 provided the first opportunity to understand experiences with injectable PrEP in a clinical trial.
Methods
Participants from two US sites (Chicago, IL and Atlanta, GA) and one international site (Rio de Janeiro, Brazil) were purposively sampled for individual qualitative interviews (N = 40), between November 2019 and March 2020, to explore trial experiences, barriers to adherence and other factors that may have impacted study implementation or outcomes. The blinded phase ended early due to efficacy; this analysis includes interviews conducted prior to unblinding with three groups defined by adherence (i.e. injection visit attendance): adherent (n = 27), non‐adherent (n = 12) and early discontinuers (n = 1). Data were organized using NVivo software and analysed using content analysis.
Results
Participants (mean age: 27) were primarily cisgender MSM (90%) and Black/African American (60%). Reasons for trial enrolment and PrEP use included a preference for using HIV prevention medication versus treatment in the event of HIV acquisition; the ability to enhance health via study‐related education and services; access to a novel, convenient HIV prevention product at no cost; and contributing to MSM/TGW communities through research. Participants contrasted positive experiences with study staff with their routine clinical care, and emphasized increased scheduling flexibility, thorough communication, non‐judgemental counselling and open, affirming environments (e.g. compassion, less stigma) as adherence facilitators. Injection experiences were positive overall; some described early injection‐related anxiety, which abated with time and when given some measure of control (e.g. pre‐injection countdown), and minimal injection site discomfort. Some concerns and misperceptions about injectable PrEP were reported. Barriers to adherence, across all adherence categories, included structural factors (e.g. financial constraints, travel) and competing demands (e.g. work schedules).
Conclusions
Respondents viewed injectable PrEP trial participation as a positive experience and a means of enhancing wellbeing. Study site flexibility and affirming clinic environments, inclusive of non‐judgemental counselling, were key facilitators of adherence. To support injection persistence, interventions that address structural barriers and promote flexible means of injection delivery may be most effective.
Tenofovir (TDF)-containing PrEP is effective for HIV prevention, but its effect on health-related quality of life (QOL) is unknown. Using data from HPTN 069/ACTG A5305, a randomized study of ...potential PrEP regimens comparing maraviroc alone, or together with TDF or emtricitabine (FTC), to TDF + FTC (control), we evaluated the impact of these regimens on QOL in at-risk HIV-uninfected U.S. women and men.
QOL was measured at baseline (before starting medications) and every 8 weeks through week 48 using the EQ-5D-3L. Responses were converted to a scale from 0.0 (death) to 1.0 (perfect health), using published valuation weights. Mean scores were compared between groups at each time point using nonparametric testing. Multivariable linear regression was used to adjust for potential confounders.
We analyzed 186 women (median age 35 years, 65% black, 17% Hispanic) and 405 men (median age 30 years, 28% black, 22% Hispanic), including 9 transgender participants analyzed based on sex-at-birth. Mean baseline QOL was 0.91 for women and 0.95 for men. There were minimal changes in mean QOL over time for any regimen (women: p = 0.29; men: p = 0.14). There were no significant differences between participants who continued the regimen compared to participants who discontinued early (women: p = 0.61; men: p = 0.1). Mean QOL did not differ significantly by regimen at any time point, both unadjusted and after adjustment for age, race/ethnicity, adherence, and use of alcohol, marijuana, opiates, and other substances.
QOL in at-risk individuals starting candidate PrEP regimens in a clinical trial is similar to the general population and maintained over time. This finding did not vary among regimens or when adjusted for demographics, adherence, and substance use. Our findings are the first to show that starting a candidate PrEP regimen in at-risk HIV-uninfected U.S. women and men was not associated with significant changes in QOL.
Clinicaltrials.gov NCT01505114.
Higher HIV diversity has been associated with virologic outcomes in children on antiretroviral treatment (ART). We examined the association of HIV diversity with virologic outcomes in adults from the ...HPTN 052 trial who initiated ART at CD4 cell counts of 350-550 cells/mm3. A high resolution melting (HRM) assay was used to analyze baseline (pre-treatment) HIV diversity in six regions in the HIV genome (two in gag, one in pol, and three in env) from 95 participants who failed ART. We analyzed the association of HIV diversity in each genomic region with baseline (pre-treatment) factors and three clinical outcomes: time to virologic suppression after ART initiation, time to ART failure, and emergence of HIV drug resistance at ART failure. After correcting for multiple comparisons, we did not find any association of baseline HIV diversity with demographic, laboratory, or clinical characteristics. For the 18 analyses performed for clinical outcomes evaluated, there was only one significant association: higher baseline HIV diversity in one of the three HIV env regions was associated with longer time to ART failure (p = 0.008). The HRM diversity assay may be useful in future studies exploring the relationship between HIV diversity and clinical outcomes in individuals with HIV infection.
The HIV Prevention Trials Network 052 study (HPTN 052) was a clinical trial designed to determine whether early treatment for HIV infection prevented transmission of the virus in couples where one ...partner was infected with HIV and the other was not, referred to as HIV serodiscordant or serodifferent couples. The study enrolled 1,763 couples at 13 sites in 9 countries in Asia, Africa, and the Americas. HPTN 052 demonstrated a minimum of 96% reduction of HIV in heterosexual couples ascribed to antiretroviral treatment; early treatment of HIV significantly reduced other infections in the HIV-infected subjects. This study, in conjunction with similar research, led to significant changes in international HIV treatment guidelines and the concept of treatment as prevention (TasP). This article provides the scientific background and history of how HPTN 052 came into being, the challenges it faced, and the ultimate impact it had on the fields of HIV treatment and prevention.
PURPOSE OF REVIEWPreexposure prophylaxis for HIV prevention is highly effective when taken as prescribed. Adherence to required dosing regimens for protection may pose challenges. Long-acting agents ...for HIV prevention may have the potential to improve adherence via favorable pharmacokinetics supportive of infrequent dosing. This review focuses on the potential benefits and considerations for the study and use of 2 long-acting injectable agents, cabotegravir (GSK1265744LA, CAB LA) and rilpivirine (TMC278LA, RPV LA), for use as chemoprophylaxis for HIV prevention.
RECENT FINDINGSOral RPV is United States Food and Drug Administration approved for HIV treatment (in combination with other antiretrovirals). Both CAB LA and RPV LA are currently in phase 2a safety/tolerability/pharmacokinetic studies in anticipation and support of future efficacy evaluation. Both agents have favorable pharmacokinetics, and use is complicated by injection site reactions.
SUMMARYLong-acting injectable formulations, if safe and well tolerated, may improve pharmacokinetic coverage of exposures to HIV infection. Complexities around safety, tolerability, and starting/stopping protocols require careful consideration.
HIV treatment as prevention and HPTN 052 Cohen, Myron S; McCauley, Marybeth; Gamble, Theresa R
Current opinion in HIV & AIDS,
2012-March, 2012-Mar, 2012-03-00, 20120301, Letnik:
7, Številka:
2
Journal Article
Odprti dostop
PURPOSE OF REVIEWThis review summarizes the development and implementation of a large clinical trial, HIV Prevention Trials Network (HPTN) 052, whose initial results were recently presented and ...published.
RECENT FINDINGSA randomized, clinical trial demonstrated that antiretroviral therapy reduces the sexual transmission of HIV in HIV-serodiscordant couples by more than 96%. The logistical challenges in preparing for and conducting such a trial were considerable.
SUMMARYHPTN 052 required many years of preparation, considerable collaboration between National Institute of Health and six pharmaceutical companies, and careful ongoing consideration of a large number of ethical issues. HPTN 052 revealed the magnitude of benefit when using antiretroviral therapy to prevent the transmission of HIV, and served as proof of a concept. The results have proven central to the development of new global HIV-prevention efforts.
Abstract
Background
The HIV Prevention Trials Network (HPTN) 083 trial demonstrated that long-acting cabotegravir (CAB-LA) was more effective than tenofovir disoproxil fumarate–emtricitabine ...(TDF/FTC) in preventing human immunodeficiency virus (HIV) in cisgender men and transgender women who have sex with men. We characterized HIV infections that occurred in the blinded phase of HPTN 083.
Methods
Retrospective testing included HIV testing, viral load testing, quantification of study drugs, and HIV drug resistance testing.
Results
Fifty-eight infections were evaluated, including 51 incident infections (12 in CAB arm and 39 in TDF/FTC arm). In many cases (5 in CAB arm and 37 in TDF/FTC arm), infection was associated with low or unquantifiable study drug concentrations. In 4 cases, infection occurred with on-time CAB-LA injections and expected plasma CAB concentrations. CAB exposure was associated with prolonged viral suppression and delayed antibody expression. In some cases, delayed HIV diagnosis resulted in CAB provision to participants with undetected infection, delayed antiretroviral therapy, and emergence of drug resistance; most of these infections would have been detected earlier with viral load testing.
Conclusions
Early detection of HIV infection and prompt antiretroviral therapy initiation could improve clinical outcomes in persons who become infected despite CAB-LA prophylaxis. Further studies are needed to elucidate the correlates of HIV protection in persons receiving CAB-LA.
Injectable cabotegravir is highly effective for preventing human immunodeficiency virus infection. Infections can occur despite on-time injections and expected drug concentrations. Integrase strand transfer inhibitor resistance is observed in some cases. Viral load testing may help detect incident infections.
In this large, international study of HIV-1–serodiscordant couples, the receipt of antiretroviral therapy by the infected partner decreased transmission to the uninfected partner as well as rates of ...clinical events in the HIV-1–infected partner.
Combination antiretroviral therapy decreases the replication of human immunodeficiency virus type 1 (HIV-1) and improves the survival of infected persons.
1
,
2
Such therapy has been shown to reduce the amount of HIV-1 in genital secretions.
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–
5
Because the sexual transmission of HIV-1 from infected persons to their partners is strongly correlated with concentrations of HIV-1 in blood
6
and in the genital tract,
7
it has been hypothesized that antiretroviral therapy could reduce sexual transmission of the virus. Several observational studies have reported decreased acquisition of HIV-1 by sexual partners of patients receiving antiretroviral therapy.
8
–
11
These results have been extrapolated to . . .
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