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Cabotegravir (CAB) is an integrase strand-transfer inhibitor of HIV that has proven effective for HIV treatment and prevention in a long-acting injectable formulation, typically preceded by an oral formulation lead-in phase. Previous in vitro studies have demonstrated that CAB is primarily metabolized via glucuronidation by uridine diphosphate glucuronosyltransferase (UGT) 1A1 and 1A9. In this study, we performed next-generation sequencing of genomic DNA isolated from the HPTN 077 participants to explore the variants within UGT1A1 and UGT1A9. Additionally, to enable correlation of UGT1A1 and UGT1A9 genotypes with plasma CAB-glucuronide levels, we quantified glucuronidated CAB following both oral administration of CAB and intramuscular injection of long-acting CAB. From these studies, 48 previously unreported variants of UGT1A1 and UGT1A9 were detected. Notably, 5/68 individuals carried a UGT1A1 454C>A variant that resulted in amino acid substitution P152T, and the use of in silico tools predicted a deleterious effect of the P152T substitution. Thus, the impact of this mutant on a range of UGT1A1 substrates was tested using a COS-7 cell-based assay. The glucuronide conjugates of CAB, dolutegravir, and raltegravir, were not formed in the COS-7 cells expressing the UGT1A1 P152T mutant. Further, formation of glucuronides of raloxifene and 7-ethyl-10-hydroxycamptothecin were reduced in the cells expressing the UGT1A1 P152T mutant. Using the same approach, we tested the activities of two UGT1A9 mutants, UGT1A9 H217Y and UGT1A9 R464G, and found that these mutations were tolerated and decreased function, respectively. These data provide insight into previously unreported genetic variants of UGT1A1 and UGT1A9.

Summary Background Long-acting injectable cabotegravir is a novel integrase inhibitor currently in advanced clinical development for HIV prevention and treatment. We aimed to assess the terminal phase pharmacokinetics and safety of long-acting injectable cabotegravir in participants included in the HPTN 077 trial. Methods HPTN 077 was a multicentre, double-blind, randomised, placebo-controlled phase 2a trial done at eight sites in Brazil, Malawi, South Africa, and the USA. Participants (aged 18–65 years), who were HIV-uninfected and at low-risk for HIV, were randomly assigned (3:1) to long-acting injectable cabotegravir (800 mg given three times at 12 week intervals or 600 mg given five times, administered at one 4 week interval, and every 8 weeks thereafter) or placebo. Participants were followed up to 76 weeks after final injection. In a prespecified analysis of secondary and exploratory outcomes, we assessed the safety, measured by the proportion of participants with grade 2 or worse adverse events, and pharmacokinetics, measured by apparent terminal phase half-life (t1/2app) and estimated time to lower limit of quantification (LLOQ) of long-acting injectable cabotegravir during the injection phase (defined as the time between first injection and 12 weeks or 8 weeks after the last injection in cohort 1 or cohort 2 respectively) and tail phase (defined as the time between final injection and 52–76 weeks post-final injection). Safety was analysed in all participants who received at least one injection. Pharmacokinetic analyses included all participants who had received at least one injection and had at least three cabotegravir measurements higher than the LLOQ after the final injection. Pharmacokinetic outcomes were estimated using non-compartmental methods. The trial is completed, and was registered with ClinicalTrials.gov , NCT02178800 . Findings Between Feb 9, 2015, and May 27, 2016, 177 participants (134 participants in the cabotegravir group [74 participants in cohort 1; 60 participants in cohort 2] and 43 participants in the placebo group [25 participants in cohort 1; 18 participants in cohort 2) were enrolled and received at least one injection and thus were included in the safety analysis. The incidence of grade 2 or worse adverse events was significantly lower during the tail phase than the injection phase (p Interpretation The clinical significance of the long pharmacokinetic tail of cabotegravir observed in female participants compared with male participants, and those with higher BMI compared with a lower BMI, need to be addressed in future trials. Funding National Institute of Allergy and Infectious Diseases.

Author(s): Blair, Cherie S; Li, Sue; Chau, Gordon; Cottle, Leslie; Richardson, Paul; Marzinke, Mark A; Eshleman, Susan H; Adeyeye, Adeola; Rinehart, Alex R; Margolis, David; McCauley, Marybeth; Hendrix, Craig W; Landovitz, Raphael J; HPTN 077 Study Team | Abstract: ObjectivesTo evaluate whether hormonal contraceptive use among cisgender women is associated with differences in pharmacokinetic (PK) parameters of a long-acting injectable formulation of the integrase strand transfer inhibitor, cabotegravir (CAB-LA).SettingThis is a secondary analysis of 85 cisgender women enrolled in HPTN 077, a phase 2a multicenter study that enrolled HIV-uninfected, low-risk individuals in Malawi, Brazil, South Africa, and the United States.MethodsParticipants received 4-week daily oral cabotegravir lead-in, followed by CAB-LA 800 mg injection every 12 weeks (cohort 1) or 600 mg every 8 weeks (after 4-week initial interval between injections, cohort 2), over 41 weeks. Participants were followed 52-76 weeks subsequent to final injection. Generalized estimating equations and linear regression were used to evaluate differences in CAB-LA PK parameters (peak concentration, trough concentration, area under the curve, apparent terminal half-life, and time to lower limit of quantification) and self-reported hormonal contraceptive stratified by type (oral, injectable, implants, and other), controlling for body mass index and cohort.ResultsCompared to women reporting no hormonal contraception (n = 6), oral contraceptive use (n = 18) was associated with lower CAB-LA peak concentration but was not associated with differences in other PK parameters. No other hormonal contraceptive type (injectable, implants, and other) was associated with significant differences in CAB-LA PK parameters.ConclusionAlthough oral contraceptive use was associated with differences in CAB-LA peak concentration, no differences were observed in other PK parameters, suggesting that this association is not likely to be clinically significant. However, these data highlight the need for further research exploring potential drug-drug interactions between CAB-LA and hormonal contraceptives.

Long-acting injectable PrEP could offer an alternative to daily oral PrEP, improve adherence and protection, if found acceptable, safe and effective. HPTN 077 evaluated injectable cabotegravir safety, tolerability and pharmacokinetics among HIV-uninfected males and females in sequentially-enrolled cohorts of two dosing strategies. We compared acceptability of product attributes, prevention preferences and future interest in injectable PrEP (FIIP) by region, sex-at-birth, arm and cohort and used multivariable analysis to identify FIIP determinants. Baseline injectable PrEP preferences were higher in non-U.S. sites and increased in both regions over time. In multivariable models, FIIP was most strongly associated with acceptability of product attributes, was higher in non-U.S. sites and more altruistic participants. Treatment arm and report of pain were not associated with FIIP. Injectable acceptability was highest in non-U.S. sites. Preferences for injectable versus other PrEP methods were higher among U.S. males than females, but higher among males and females in non-U.S. settings. Electronic supplementary material The online version of this article (10.1007/s10461-020-02808-2) contains supplementary material, which is available to authorized users.

Studies in human immunodeficiency virus (HIV)–infected individuals suggest excess weight gain with integrase inhibitor–based antiretroviral therapy. The HIV Prevention Trials Network Study 077 evaluated changes in weight and fasting metabolic parameters in HIV-uninfected individuals randomized to cabotegravir or a placebo. No differences between arms were found for change in weight or fasting metabolic parameters overall or for subgroups.

Background: Long-acting injectable cabotegravir (CAB LA) is a novel integrase inhibitor in advanced clinical development for HIV treatment and HIV prevention. We investigated the terminal pharmacokinetics and safety of CAB LA after final injection as part of a Phase 2 study. Methods: We performed a randomized, double-blind placebo-controlled trial at 8 sites in the United States (US), sub-Saharan Africa, and Brazil. Participants, age 18-65, HIV-uninfected and at low-risk for HIV, were randomized 3:1 to CAB LA or placebo. Participants received CAB LA at one of two doses/intervals, which were aggregated for this analysis. The current analysis includes participants who received at least one injection and examines the tail phase (time from final injection to 52-76 weeks post-final injection). The outcomes were safety and pharmacokinetics. Safety was reported as incidence rates of grade 2 or higher adverse events. The apparent terminal phase half-life (t1/2app) and time to decay of CAB drug concentration to below the lower limit of quantification (LLOQ) were estimated using non-compartmental methods. Findings: Overall, 177 participants received at least one injection. Median age was 31 years, 66.1% were female, 69.5% were non-white, 52.5% were from the US. Rates of grade 2 or higher adverse events on CAB were higher in the injection phase compared to the tail phase. At one time point from 52-60 weeks and at 76 weeks after final injection, 22% and 13% of males, respectively, had detectable CAB concentrations; 63% and 48% of females had detectable CAB concentrations at those time points. The estimated median time from last injection to CAB concentration below the LLOQ was 43.7 (range 20-4-152.5) weeks for males and 67.3 (range 17.7-225.5) weeks for females. Terminal phase half-life was 33% longer for female sex at birth participants compared to male participants, and 31% longer for participants with body mass index (BMI) above vs. below the study median of 26. Interpretation: No new adverse events were observed with long-term follow-up. The long pharmacokinetic tail will need to be addressed in pivotal trials of treatment and prevention. Trial Registration: The trial was registered with ClinicalTrials.gov, number NCT02178800. This trial is completed. Funding Statement: National Institute of Allergy and Infectious Diseases (UM1AI068619, UM1AI068613, and, UM1AI068617) Declaration of Interests: RJL has received study medication, consulting fees and travel support from Gilead Sciences, and consulting fees and travel support from Merck, Inc. JJE is a consultant to Merck, Gilead Sciences, Janssen, and ViiV Healthcare; and he is an investigator on research contracts from ViiV Healthcare, Janssen, and Gilead Sciences. HD has received honoraria from Pfizer-South Africa, Novartis-South Africa, MSD-South Africa and Adcock Ingram for speaking engagements and has received travel support from Mylan-South Africa, Novartis-South Africa and Aspen-South Africa. AYL received research grants from NIH and has led studies in which study drug was donated by Gilead Sciences. MAM received grant support through the NIH and received grant support through ViiV/GSK on work external to this study. ARR and DM are paid employees of ViiV Healthcare. CWH has research contracts with NIH, ViiV/GlaxoSmithKline, Gilead Sciences, and Merck through Johns Hopkins. Ethics Approval Statement: Local institutional review boards or ethics committees at each participating site granted ethics and regulatory approvals of the protocol and all participants provided written informed consent.

Background 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. Methods and findings 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. Conclusions 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. Trial registration ClinicalTrials.gov Registry: ClinicalTrials.gov Trial number: NCT02178800., In a phase 2a trial, Raphael Landovitz and colleagues investigate the safety of injectable cabotegravir in HIV-uninfected people, Author summary Why was this study done? Daily oral pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate/emtricitabine is highly effective in preventing HIV infection when taken as prescribed, but adherence challenges have compromised full effectiveness in some populations. Cabotegravir (CAB) is a novel strand-transfer integrase inhibitor in development as a long-acting injectable preparation for HIV treatment and HIV prevention. HIV Prevention Trials Network study 077 (HPTN 077) aimed to establish the safety, tolerability, and pharmacokinetics of 2 dose/interval regimens of long-acting CAB in HIV-uninfected, low-risk individuals globally. What did the researchers do and find? Participants were randomized to active CAB or placebo. All participants received a 4-week daily oral lead-in of CAB or placebo, followed by a series of injections of CAB or placebo. Participants received either 800 mg as a split 2-ml injection every 12 weeks, or 600 mg as a single 3-ml injection every 8 weeks, after receiving 2 injections 4 weeks apart. We observed frequent injection site reactions (mostly injection site pain), and they were more common with CAB than placebo, but only led to discontinuation of injections in rare cases. No other safety concerns were noted. Pharmacokinetics, using target values from nonhuman primate simian/human immunodeficiency virus challenge prevention studies, support the 600 mg every 8 weeks dose, meeting prespecified targets. What do these findings mean? We found that CAB was generally well tolerated in HIV-uninfected males and females in diverse geographic locations. Injection site reactions, although frequent, did not deter continued dosing, albeit with short courses. Studies are ongoing to evaluate efficacy in at-risk populations and to further evaluate the safety of the 600 mg every 8 weeks dose.

As a step towards developing a light-controlled reversible binding switch based on photochromic bisbenzospiropyran for investigating intracellular calcium signaling, substituted bisbenzospiropyran and phenolic chelators were synthesized and examined for metal binding strength. The complexation of these compounds with alkaline earth and zinc ions in methanol and buffer was characterized using NMR and luminescence spectroscopy. An increased length of convergent ligands on the rigid scaffold maintained binding affinity for Ca(2+) but decreased selectivity for Ca(2+) over Mg(2+). Results indicate that at least three carboxylate ligands are required for significant binding, and increased length of the ligands will result in a fully water-soluble photoswitch that exhibits two states with approximately 300-fold difference in binding affinity for Ca(2+).