Efficacy, Safety, and Pharmacokinetics by Body Mass Index Category in Phase 3/3b Long-Acting Cabotegravir Plus Rilpivirine Trials.

BACKGROUND: Cabotegravir plus rilpivirine (CAB + RPV) is a guideline-recommended long-acting (LA) injectable regimen for the maintenance of human immunodeficiency virus-1 (HIV-1) virologic suppression. This post hoc analysis summarizes CAB + RPV LA results by baseline body mass index (BMI) category among phase 3/3b trial participants. METHODS: Data from CAB + RPV-naive participants receiving every 4 or 8 week dosing in FLAIR, ATLAS, and ATLAS-2M were pooled through week 48. Data beyond week 48 were summarized by study (FLAIR through week 96 and ATLAS-2M through week 152). HIV-1 RNA <50 and ≥50 copies/mL, confirmed virologic failure (CVF; 2 consecutive HIV-1 RNA ≥200 copies/mL), safety and tolerability, and plasma CAB and RPV trough concentrations were evaluated by baseline BMI (<30 kg/m2, lower; ≥30 kg/m2, higher). RESULTS: Among 1245 CAB + RPV LA participants, 213 (17%) had a baseline BMI ≥30 kg/m2. At week 48, 92% versus 93% of participants with lower versus higher BMI had HIV-1 RNA <50 copies/mL, respectively. Including data beyond week 48, 18 participants had CVF; those in the higher BMI group (n = 8) all had at least 1 other baseline factor associated with CVF (archived RPV resistance-associated mutations or HIV-1 subtype A6/A1). Safety and pharmacokinetic profiles were comparable between BMI categories. CONCLUSIONS: CAB + RPV LA was efficacious and well tolerated, regardless of baseline BMI category. CLINICAL TRIALS REGISTRATION: NCT02938520, NCT02951052, and NCT03299049.

Population pharmacokinetics of cabotegravir following intramuscular thigh injections in adults with and without HIV.

Cabotegravir intramuscular gluteal injection is approved for HIV treatment (with rilpivirine) and prevention. Thigh muscle is a potential alternative injection site. We aim to characterize cabotegravir pharmacokinetics and its association with demographics following intramuscular thigh injection in comparison with gluteal injection using population pharmacokinetic (PPK) analysis. Fourteen HIV-negative participants received 600 mg single thigh injection in phase 1 study 208832 and 118 participants with HIV received thigh injections 400 mg monthly 4× or 600 mg once-every-2-months 2× after ≥3 years of gluteal injections in phase 3b study ATLAS-2M provided 1,249 cabotegravir concentrations from 366 thigh injections and 1,998 concentrations from 1,618 gluteal injections. The established gluteal PPK model was modified by adding thigh injection compartment and fit to pharmacokinetic data following both gluteal and thigh injections, enabling within-person comparison in ATLAS-2M. Gluteal parameters were fixed. Similar to the gluteal absorption rate constant (KAgluteal), the thigh absorption rate constant (KAthigh) was slower in females than males and in participants with higher BMI. KAthigh was strongly correlated with KAgluteal (correlation coefficient 0.766), best described by the additive linear relationship KAthigh = KAgluteal + 0.0002527 h-1. Terminal half-life of thigh injection was 26% (male) and 39% (female) shorter than gluteal injection. Relative bioavailability of thigh to gluteal was estimated to be 89.9%. The impact of covariates on cabotegravir exposure following thigh injections was ≤35%. In conclusion, cabotegravir absorption following thigh injection was correlated with, faster than, and 10% less bioavailable than gluteal injection, and correlated with sex and BMI. The cabotegravir thigh PPK model can inform dosing strategies and future study design.

Pharmacokinetics and tolerability of cabotegravir and rilpivirine long-acting intramuscular injections to the vastus lateralis (lateral thigh) muscles of healthy adult participants.

Cabotegravir + rilpivirine administered via intramuscular gluteal injections is the first complete long-acting (LA) regimen approved for maintaining HIV-1 virologic suppression. The vastus lateralis (lateral) thigh muscle could be a potential alternative site of administration in circumstances such as injection site fatigue, intolerability, or contraindication for gluteal administration. Cabotegravir and rilpivirine pharmacokinetics and participant tolerability were evaluated following single intramuscular injections to the lateral thigh. Healthy adult participants received 4 weeks of daily oral cabotegravir (30 mg) and rilpivirine (25 mg), followed by a 10- to 14-day washout and single 3 mL intramuscular injections of cabotegravir LA 600 mg and rilpivirine LA 900 mg to the lateral thigh. Safety, tolerability, and pharmacokinetics were evaluated through 52 weeks post injection. Pharmacokinetic parameters were estimated using non-compartmental analysis. Fifteen participants (female at birth, n = 6) enrolled. Median age was 33 years. Median weight was 93.6 kg. Median body mass index was 31.4 kg/m2. One participant withdrew due to pregnancy after oral dosing before receiving an injection. Plasma concentrations at Weeks 4 and 8 were 15.4- and 5.3-fold above the protein-adjusted 90% inhibitory concentration for cabotegravir and 4.7- and 2.4-fold for rilpivirine, respectively. The most common injection site reactions were pain [28/28 (100%)], induration [15/28 (54%)], and swelling [12/28 (42%)]; 94% were Grade 1 or 2. Cabotegravir and rilpivirine plasma pharmacokinetic profiles observed in this study support further evaluation of thigh administration in target populations of people living with HIV-1. Tolerability of cabotegravir + rilpivirine LA intramuscular lateral thigh injections was similar to gluteal administration.

Asian participants' experience in phase 3/3b studies of long-acting cabotegravir and rilpivirine: Efficacy, safety, pharmacokinetic, and virological outcomes through week 96.

OBJECTIVES: Cabotegravir + rilpivirine (CAB + RPV) dosed monthly or every 2 months is the first complete long-acting (LA) regimen recommended by treatment guidelines for the maintenance of HIV-1 virological suppression. This post hoc analysis summarizes outcomes for Asian participants through week 96. METHODS: Data from Asian participants naive to CAB + RPV randomized to receive dosing every 4 weeks (Q4W) or every 8 weeks (Q8W) in the FLAIR (NCT02938520) and ATLAS-2M (NCT03299049) phase 3/3b studies were pooled. The proportion of participants with plasma HIV-1 RNA ≥50 and <50 copies/mL (per FDA Snapshot algorithm), incidence of confirmed virological failure (CVF; two consecutive HIV-1 RNA ≥200 copies/mL), pharmacokinetics, safety, and tolerability through week 96 were assessed. RESULTS: Overall, 41 Asian participants received CAB + RPV (Q8W, n = 17; Q4W, n = 24). At week 96, 83% (n = 34/41) of participants maintained HIV-1 RNA <50 copies/mL, none had HIV-1 RNA ≥50 copies/mL, and 17% (n = 7/41) had no virological data. No Asian participant met the CVF criterion. Drug-related adverse events occurred in 44% (n = 18/41) of participants; none were Grade ≥3. All injection site reactions were Grade 1 or 2; median duration was 2 days and most resolved within 7 days (90%, n = 390/435). CAB and RPV trough concentrations remained well above their respective protein-adjusted 90% inhibitory concentrations (CAB, 0.166 µg/mL; RPV, 12 ng/mL) through week 96. CONCLUSIONS: CAB + RPV LA demonstrated high efficacy, with no participants having CVF, and an acceptable safety profile in Asian participants through week 96. These data support CAB + RPV LA as a complete regimen for the maintenance of HIV-1 virological suppression in Asian individuals.

Improvements in Patient-Reported Outcomes After 12 Months of Maintenance Therapy With Cabotegravir + Rilpivirine Long-Acting Compared With Bictegravir/Emtricitabine/Tenofovir Alafenamide in the Phase 3b SOLAR Study.

SOLAR (NCT04542070; registered 2020-09-09) is a Phase 3b study that demonstrated the noninferior virological efficacy of switching to cabotegravir + rilpivirine long-acting (CAB + RPV LA) dosed every 2 months vs. continuing daily oral bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) over 12 months. Participants were randomised (2:1) to switch to CAB + RPV LA or to continue BIC/FTC/TAF. Patient-reported endpoints included treatment preference, treatment satisfaction (12-item HIV Treatment Satisfaction Questionnaire status version), acceptability of injections (Perception of Injection questionnaire [acceptability domain]) and three single-item questions exploring psychological challenges related to HIV treatment (fear of disclosure, adherence-related anxiety and reminder of HIV status). Of 670 participants, 447 participants switched to CAB + RPV LA and 223 continued BIC/FTC/TAF. Overall, 18% were female, median age was 37 years and 31% were non-White. At Month 12, CAB + RPV LA significantly improved treatment satisfaction vs. BIC/FTC/TAF (mean [95% confidence interval (CI)] change: + 3.36 [2.59, 4.13] vs. -1.59 [-2.71, -0.47]; p < 0.001). At Month 12, a higher proportion of CAB + RPV LA arm participants reported improvements across the psychological challenges related to HIV treatment questions compared with BIC/FTC/TAF participants. Participants indicating ≥ 1 psychological challenge at baseline experienced a statistically significant and clinically meaningful improvement in treatment satisfaction after 12 months of CAB + RPV LA vs. continuing BIC/FTC/TAF (adjusted difference [95% CI]: 7.96 [5.65, 10.26]; p < 0.001). Most (90%, 382/425) questionnaire respondents preferred CAB + RPV LA vs. BIC/FTC/TAF (5%, 21/425). Switching to CAB + RPV LA was associated with significantly improved treatment satisfaction and relief from the fear of disclosure, anxiety surrounding adherence and reminder of HIV status.

RESUMEN: SOLAR (NCT04542070; registrado el 09-09-2020) es un estudio de fase IIIb que ha demostrado la eficacia virológica no inferior de cambiar a cabotegravir+rilpivirina de acción prolongada (CAB+RPV LA) administrado cada 2 meses frente a continuar con la administración oral diaria de bictegravir/emtricitabina/tenofovir alafenamida (BIC/FTC/TAF) durante 12 meses. Los participantes fueron asignados de forma aleatoria (2:1) al grupo de cambio a CAB+RPV LA o de continuación con BIC/FTC/TAF. Los parámetros declarados por los pacientes incluían la preferencia del tratamiento, la satisfacción del tratamiento (versión del estado del cuestionario de satisfacción del tratamiento de VIH de 12 preguntas), la aceptación de las inyecciones (cuestionario de percepción de las inyecciones [dominio de aceptación]) y tres preguntas individuales que analizaban los problemas psicológicos relacionados con el tratamiento del VIH (miedo a la revelación, ansiedad relacionada con el cumplimiento terapéutico y recordatorio del estado del VIH). De los 670 participantes, 447 participantes cambiaron a CAB+RPV LA y 223 continuaron con BIC/FTC/TAF. En general, el 18 % eran mujeres, el promedio de edad era de 37 años y el 31 % no eran blancos. En el mes 12, el tratamiento con CAB+RPV LA aumentó considerablemente la satisfacción del tratamiento frente al BIC/FTC/TAF (cambio [intervalo de confianza (IC) del 95 %] medio: +3.36 [2.59; 4.13] frente a ­1.59 [­2.71; ­0.47]; p<0.001). En el mes 12, una mayor proporción de participantes del grupo de CAB+RPV LA declararon mejoras en todos los problemas psicológicos relacionados con las preguntas sobre el tratamiento del VIH en comparación con los participantes del grupo de BIC/FTC/TAF. Los participantes que indicaron ≥ 1 problema psicológico en el inicio experimentaron una mejora importante estadísticamente y significativa clínicamente con respecto a la satisfacción del tratamiento al cabo de 12 meses del cambio a CAB+RPV LA frente a la continuación con BIC/FTC/TAF (diferencia ajustada [IC del 95 %]: 7.96 [5.65; 10.26]; p<0.001). La mayoría de encuestados (el 90 %, 382/425) preferían CAB+RPV LA frente a BIC/FTC/TAF (el 5 %, 21/425). El cambio a CAB+RPV LA se asoció a un aumento considerable de la satisfacción del tratamiento y al alivio del miedo a la revelación, la ansiedad en torno al cumplimiento terapéutico y el recordatorio del estado del VIH.

Long-Acting Cabotegravir and Rilpivirine Dosed Every 2 Months in Adults With Human Immunodeficiency Virus 1 Type 1 Infection: 152-Week Results From ATLAS-2M, a Randomized, Open-Label, Phase 3b, Noninferiority Study.

BACKGROUND: Cabotegravir (CAB) + rilpivirine (RPV) dosed intramuscularly monthly or every 2 months is a complete, long-acting (LA) regimen for the maintenance of HIV-1 virologic suppression. Here, we report the antiretroviral therapy as long acting suppression (ATLAS)-2M study week 152 results. METHODS: ATLAS-2M is a phase 3b, randomized, multicenter study assessing the efficacy and safety of CAB+RPV LA every 8 weeks (Q8W) versus every 4 weeks (Q4W). Virologically suppressed (HIV-1 RNA <50 copies/mL) individuals were randomized to receive CAB+RPV LA Q8W or Q4W. Endpoints included the proportion of participants with plasma HIV-1 RNA ≥50 copies/mL and <50 copies/mL, incidence of confirmed virologic failure (CVF; 2 consecutive measurements ≥200 copies/mL), safety, and tolerability. RESULTS: A total of 1045 participants received CAB+RPV LA (Q8W, n = 522; Q4W, n = 523). CAB+RPV LA Q8W demonstrated noninferior efficacy versus Q4W dosing, with 2.7% (n = 14) and 1.0% (n = 5) of participants having HIV-1 RNA ≥50 copies/mL, respectively, with adjusted treatment difference being 1.7% (95% CI: 0.1-3.3%), meeting the 4% noninferiority threshold. At week 152, 87% of participants maintained HIV-1 RNA <50 copies/mL (Q8W, 87% [n = 456]; Q4W, 86% [n = 449]). Overall, 12 (2.3%) participants in the Q8W arm and 2 (0.4%) in the Q4W arm had CVF. Eight and 10 participants with CVF had treatment-emergent, resistance-associated mutations to RPV and integrase inhibitors, respectively. Safety profiles were comparable, with no new safety signals observed since week 48. CONCLUSIONS: These data demonstrate virologic suppression durability with CAB+RPV LA Q8W or Q4W for ∼3 years and confirm long-term efficacy, safety, and tolerability of CAB+RPV LA as a complete regimen to maintain HIV-1 virologic suppression.

Expanded Multivariable Models to Assist Patient Selection for Long-Acting Cabotegravir + Rilpivirine Treatment: Clinical Utility of a Combination of Patient, Drug Concentration, and Viral Factors Associated With Virologic Failure.

BACKGROUND: Previously reported post hoc multivariable analyses exploring predictors of confirmed virologic failure (CVF) with cabotegravir + rilpivirine long-acting (CAB + RPV LA) were expanded to include data beyond week 48, additional covariates, and additional participants. METHODS: Pooled data from 1651 participants were used to explore dosing regimen (every 4 or every 8 weeks), demographic, viral, and pharmacokinetic covariates as potential predictors of CVF. Prior dosing regimen experience was accounted for using 2 populations. Two models were conducted in each population-baseline factor analyses exploring factors known at baseline and multivariable analyses exploring baseline factors plus postbaseline model-predicted CAB/RPV trough concentrations (4 and 44 weeks postinjection). Retained factors were evaluated to understand their contribution to CVF (alone or in combination). RESULTS: Overall, 1.4% (n = 23/1651) of participants had CVF through 152 weeks. The presence of RPV resistance-associated mutations, human immunodeficiency virus-1 subtype A6/A1, and body mass index ≥30 kg/m2 were associated with an increased risk of CVF (P < .05 adjusted incidence rate ratio), with participants with ≥2 of these baseline factors having a higher risk of CVF. Lower model-predicted CAB/RPV troughs were additional factors retained for multivariable analyses. CONCLUSIONS: The presence of ≥2 baseline factors (RPV resistance-associated mutations, A6/A1 subtype, and/or body mass index ≥30 kg/m2) was associated with increased CVF risk, consistent with prior analyses. Inclusion of initial model-predicted CAB/RPV trough concentrations (≤first quartile) did not improve the prediction of CVF beyond the presence of a combination of ≥2 baseline factors, reinforcing the clinical utility of the baseline factors in the appropriate use of CAB + RPV LA.

Long-Acting Cabotegravir and Rilpivirine after Oral Induction for HIV-1 Infection.

BACKGROUND: Long-acting injectable regimens may simplify therapy for patients with human immunodeficiency virus type 1 (HIV-1) infection. METHODS: We conducted a phase 3, randomized, open-label trial in which adults with HIV-1 infection who had not previously received antiretroviral therapy were given 20 weeks of daily oral induction therapy with dolutegravir-abacavir-lamivudine. Participants who had an HIV-1 RNA level of less than 50 copies per milliliter after 16 weeks were randomly assigned (1:1) to continue the current oral therapy or switch to oral cabotegravir plus rilpivirine for 1 month followed by monthly injections of long-acting cabotegravir plus rilpivirine. The primary end point was the percentage of participants who had an HIV-1 RNA level of 50 copies per milliliter or higher at week 48 (Food and Drug Administration snapshot algorithm). RESULTS: At week 48, an HIV-1 RNA level of 50 copies per milliliter or higher was found in 6 of 283 participants (2.1%) who received long-acting therapy and in 7 of 283 (2.5%) who received oral therapy (adjusted difference, -0.4 percentage points; 95% confidence interval [CI], -2.8 to 2.1), a result that met the criterion for noninferiority for the primary end point (margin, 6 percentage points). An HIV-1 RNA level of less than 50 copies per milliliter at week 48 was found in 93.6% who received long-acting therapy and in 93.3% who received oral therapy (adjusted difference, 0.4 percentage points; 95% CI, -3.7 to 4.5), a result that met the criterion for noninferiority for this end point (margin, -10 percentage points). Of the participants who received long-acting therapy, 86% reported injection-site reactions (median duration, 3 days; mild or moderate severity, 99% of cases); 4 participants withdrew from the trial for injection-related reasons. Grade 3 or higher adverse events and events that met liver-related stopping criteria occurred in 11% and 2%, respectively, who received long-acting therapy and in 4% and 1% who received oral therapy. Treatment satisfaction increased after participants switched to long-acting therapy; 91% preferred long-acting therapy at week 48. CONCLUSIONS: Therapy with long-acting cabotegravir plus rilpivirine was noninferior to oral therapy with dolutegravir-abacavir-lamivudine with regard to maintaining HIV-1 suppression. Injection-site reactions were common. (Funded by ViiV Healthcare and Janssen; FLAIR ClinicalTrials.gov number, NCT02938520.).

Compassionate use of long-acting cabotegravir plus rilpivirine for people living with HIV-1 in need of parenteral antiretroviral therapy.

OBJECTIVES: Physicians could request compassionate use of oral and long-acting (LA) cabotegravir + rilpivirine for people living with HIV-1 under a single-patient request programme supported by ViiV Healthcare and Janssen. Outcomes are reported. METHODS: Eligibility criteria included need for parenteral therapy, no primary resistance mutations to cabotegravir or rilpivirine, and established retention in care. Demographic, efficacy, and safety data were obtained from standardized programme applications and quarterly clinical updates. Individuals received a loading dose of LA cabotegravir 600 mg + rilpivirine 900 mg, followed by LA maintenance doses of 400 mg/600 mg every 4 weeks; some received lead-in oral cabotegravir and rilpivirine. RESULTS: Through July 2020, 35 people living with HIV-1 had data available. The most frequent reason for compassionate use request was chronic non-adherence due to psychological conditions (n = 15). Of 35 people living with HIV-1, 28 had detectable viremia (median viral load 60 300 copies/mL) and seven were virologically suppressed at programme entry; 16/28 and 6/7 achieved or maintained virological suppression at data cutoff, respectively. Seven people living with HIV-1 discontinued for incomplete virological response, six with detectable viremia at initiation; six and four had new reverse transcriptase and integrase mutations at discontinuation, respectively. Six non-fatal serious adverse events were reported, two considered possibly treatment related. Four deaths were reported; none were treatment related. One individual reported two pregnancies and continued LA dosing. CONCLUSIONS: Most people living with HIV-1 had advanced disease and achieved (16/28) or maintained (6/7) virological suppression with LA therapy. Cabotegravir LA + rilpivirine LA as compassionate use provided a valuable treatment option for individuals with adherence issues with oral therapy and advanced disease.

Pregnancy outcomes and pharmacokinetics in pregnant women living with HIV exposed to long-acting cabotegravir and rilpivirine in clinical trials.

BACKGROUND: Limited data exist on pregnant women living with HIV exposed to cabotegravir + rilpivirine (CAB + RPV). Outcomes in pregnant participants exposed to CAB + RPV, and pharmacokinetic washout data in those exposed to CAB + RPV long-acting (LA) with live births, are presented. METHODS: Women exposed to one or more doses of CAB + RPV (oral/LA) from ViiV Healthcare-sponsored phase 2b/3/3b clinical trials and the compassionate use programme who became pregnant were included. Upon pregnancy in the trial programme, CAB + RPV was discontinued, an alternative antiretroviral regimen was initiated, and quarterly pharmacokinetic sampling for 52 weeks post-last injection was obtained. CAB + RPV continuation or alternative antiretroviral regimen initiation was decided by pregnant compassionate use programme participants and their treating physicians. RESULTS: As of 31 March 2021, 25 pregnancies following CAB + RPV exposure at conception were reported (five oral, 20 LA), including four who conceived during pharmacokinetic washout following treatment discontinuation. There were eight elective abortions, six miscarriages (five in first trimester), one ectopic pregnancy, and 10 live births (one oral, nine LA), including one infant born with congenital ptosis. Among participants exposed to CAB + RPV LA at conception with live births, plasma CAB and RPV washout concentrations during pregnancy were within the range of those observed in non-pregnant women. CONCLUSION: In this first analysis of pregnancy outcomes following CAB + RPV exposure at conception, 10 live births, including one with congenital anomaly, were reported. Plasma CAB and RPV washout concentrations during pregnancy were within the range of those in non-pregnant women. Pregnancy surveillance within ViiV Healthcare-sponsored clinical trials is ongoing, with dedicated pregnancy studies planned.

Impact of Integrase Sequences from HIV-1 Subtypes A6/A1 on the In Vitro Potency of Cabotegravir or Rilpivirine.

The FLAIR study demonstrated noninferiority of monthly long-acting cabotegravir + rilpivirine versus daily oral dolutegravir/abacavir/lamivudine for maintaining virologic suppression. Three participants who received long-acting therapy had confirmed virologic failure (CVF) at Week 48, and all had HIV-1 that was originally classified as subtype A1 and contained the baseline integrase polymorphism L74I; updated classification algorithms reclassified all 3 as HIV-1 subtype A6. Retrospectively, the impact of L74I on in vitro sensitivity and durability of response to cabotegravir in HIV-1 subtype B and A6 backgrounds was studied. Site-directed L74I and mutations observed in participants with CVF were generated in HIV-1 subtype B and a consensus integrase derived from 3 subtype A6 CVF baseline sequences. Rilpivirine susceptibility was assessed in HIV-1 subtype B and A1 containing reverse transcriptase mutations observed in participants with CVF. HIV-1 subtype B L74I and L74I/G140R mutants and HIV-1 subtype A6 I74L and I74/G140R mutants remained susceptible to cabotegravir; L74I/Q148R double mutants exhibited reduced susceptibility in HIV-1 subtypes B and A6 (half maximal effective capacity fold change, 4.4 and 4.1, respectively). Reduced rilpivirine susceptibility was observed across HIV-1 subtypes B and A1 with resistance-associated mutations K101E or E138K (half maximal effective capacity fold change, 2.21 to 3.09). In cabotegravir breakthrough experiments, time to breakthrough was similar between L74 and I74 viruses across HIV-1 subtypes B and A6; Q148R was selected at low cabotegravir concentrations. Therefore, the L74I integrase polymorphism did not differentially impact in vitro sensitivity to cabotegravir across HIV-1 subtype B and A6 integrase genes (ClinicalTrials.gov identifier: NCT02938520).

Population pharmacokinetics of cabotegravir following administration of oral tablet and long-acting intramuscular injection in adult HIV-1-infected and uninfected subjects.

AIM: To characterize cabotegravir population pharmacokinetics using data from phase 1, 2 and 3 studies and evaluate the association of intrinsic and extrinsic factors with pharmacokinetic variability. METHODS: Analyses were implemented in NONMEM and R. Concentrations below the quantitation limit were modelled with likelihood-based approaches. Covariate relationships were evaluated using forward addition (P < .01) and backward elimination (P < .001) approaches. The impact of each covariate on trough and peak concentrations was evaluated through simulations. External validation was performed using prediction-corrected visual predictive checks. RESULTS: The model-building dataset included 23 926 plasma concentrations from 1647 adult HIV-1-infected (72%) and uninfected (28%) subjects in 16 studies at seven dose levels (oral 10-60 mg, long-acting [LA] intramuscular injection 200-800 mg). A two-compartment model with first-order oral and LA absorption and elimination adequately described the data. Clearances and volumes were scaled to body weight. Estimated relative bioavailability of oral to LA was 75.6%. Race and age were not significant covariates. LA absorption rate constant (KALA ) was 50.9% lower in females and 47.8% higher if the LA dose was given as two split injections. KALA decreased with increasing BMI and decreasing needle length. Clearance was 17.4% higher in current smokers. The impact of any covariate was ≤32% on trough and peak concentrations following LA administration. The final model adequately predicted 5097 plasma concentrations from 647 subjects who were not included in the model-building dataset. CONCLUSIONS: A cabotegravir population pharmacokinetic model was developed that can be used to inform dosing strategies and future study design. No dose adjustment based on subject covariates is recommended.

Multiparametric magnetic resonance imaging to characterize cabotegravir long-acting formulation depot kinetics in healthy adult volunteers.

AIM: Cabotegravir long-acting (LA) intramuscular (IM) injection is being investigated for HIV preexposure prophylaxis due to its potent antiretroviral activity and infrequent dosing requirement. A subset of healthy adult volunteers participating in a Phase I study assessing cabotegravir tissue pharmacokinetics underwent serial magnetic resonance imaging (MRI) to assess drug depot localization and kinetics following a single cabotegravir LA IM targeted injection. METHODS: Eight participants (four men, four women) were administered cabotegravir LA 600 mg under ultrasonographic-guided injection targeting the gluteal muscles. MRI was performed to determine injection-site location in gluteal muscle (IM), subcutaneous (SC) adipose tissue and combined IM/SC compartments, and to quantify drug depot characteristics, including volume and surface area, on Days 1 (≤2 hours postinjection), 3 and 8. Linear regression analysis examined correlations between MRI-derived parameters and plasma cabotegravir exposure metrics, including maximum observed concentration (Cmax ) and partial area under the concentration-time curve (AUC) through Weeks 4 and 8. RESULTS: Cabotegravir LA depot locations varied by participant and were identified in the IM compartment (n = 2), combined IM/SC compartments (n = 4), SC compartment (n = 1) and retroperitoneal cavity (n = 1). Although several MRI parameter and exposure metric correlations were determined, total depot surface area on Day 1 strongly correlated with plasma cabotegravir concentration at Days 3 and 8, Cmax and partial AUC through Weeks 4 and 8. CONCLUSION: MRI clearly delineated cabotegravir LA injection-site location and depot kinetics in healthy adults. Although injection-site variability was observed, drug depot surface area correlated with both plasma Cmax and partial AUC independently of anatomical distribution.

Multicompartmental pharmacokinetic evaluation of long-acting cabotegravir in healthy adults for HIV preexposure prophylaxis.

AIMS: Cabotegravir is an integrase strand transfer inhibitor in clinical development as long-acting (LA) injectable HIV preexposure prophylaxis. METHODS: This phase I study assessed pharmacokinetics of cabotegravir in plasma and anatomical sites associated with sexual HIV-1 transmission after repeated oral and single intramuscular (IM) LA dosing in healthy adults. Following a 28-day oral lead-in period of cabotegravir 30 mg and a washout period of 14-42 days, participants were administered a single ultrasound-guided gluteal IM cabotegravir LA 600-mg injection. The study objective was to characterize cabotegravir concentrations in plasma, cervical, vaginal and rectal tissues, and cervicovaginal and rectal fluids and up to Week 12 after IM injection. RESULTS: Nineteen participants enrolled and 16 completed the study through Week 52. Cabotegravir was detected in plasma and all tissues and fluids. Median plasma cabotegravir concentrations exceeded the in vitro protein-adjusted 90% maximal inhibitory concentration through Week 12. Median tissue- and fluid-to-plasma cabotegravir concentration ratios across all visits were 0.32 for rectal fluid and 0.08-0.16 for other tissues and fluids. Adjusted R2 coefficients between cabotegravir concentrations in plasma and cervical, vaginal and rectal tissues were 0.78, 0.79 and 0.90, respectively. Injection-site reactions were common (88% of participants) and were mostly grade 1 in intensity (82%). Two participants reported 11 non-drug-related serious adverse events. CONCLUSION: Concentrations of cabotegravir in tissues and fluids were proportional to plasma over time, with strong correlations between tissue and plasma concentrations. Cabotegravir LA tissue-to-plasma ratios may be important for understanding its use as preexposure prophylaxis.

Pharmacokinetics and antiviral activity of cabotegravir and rilpivirine in cerebrospinal fluid following long-acting injectable administration in HIV-infected adults.

BACKGROUND: Long-acting (LA) formulations of cabotegravir, an HIV integrase inhibitor, and rilpivirine, an NNRTI, are in development as monthly or 2 monthly intramuscular (IM) injections for maintenance of virological suppression. OBJECTIVES: To evaluate cabotegravir and rilpivirine CSF distribution and HIV-1 RNA suppression in plasma and CSF in HIV-infected adults participating in a substudy of the Phase 2b LATTE-2 study (NCT02120352). METHODS: Eighteen participants receiving cabotegravir LA 400 mg + rilpivirine LA 600 mg IM [every 4 weeks (Q4W), n = 3] or cabotegravir LA 600 mg + rilpivirine LA 900 mg IM [every 8 weeks (Q8W), n = 15] with plasma HIV-1 RNA <50 copies/mL enrolled. Paired steady-state CSF and plasma concentrations were evaluable in 16 participants obtained 7 (±3) days after an injection visit. HIV-1 RNA in CSF and plasma were assessed contemporaneously using commercial assays. RESULTS: Median total CSF concentrations in Q4W and Q8W groups, respectively, were 0.011 µg/mL and 0.013 µg/mL for cabotegravir (0.30% and 0.34% of the paired plasma concentrations) and 1.84 ng/mL and 1.67 ng/mL for rilpivirine (1.07% and 1.32% of paired plasma concentrations). Cabotegravir and rilpivirine total CSF concentrations exceeded their respective in vitro EC50 for WT HIV-1 (0.10 ng/mL and 0.27 ng/mL, respectively). All 16 participants had HIV-1 RNA <50 copies/mL in plasma and CSF, and 15 of 16 participants had HIV-1 RNA <2 copies/mL in CSF. CONCLUSIONS: A dual regimen of cabotegravir LA and rilpivirine LA achieved therapeutic concentrations in the CSF resulting in effective virological control in CSF.

Cabotegravir + Rilpivirine Long-Acting: Overview of Injection Guidance, Injection Site Reactions, and Best Practices for Intramuscular Injection Administration.

Background: Cabotegravir (CAB) + rilpivirine (RPV) dosed monthly or every 2 months is a complete long-acting (LA) regimen for the maintenance of human immunodeficiency virus type 1 virologic suppression. Across the phase 3/3b trials, the most frequently reported adverse events were injection site reactions (ISRs). Methods: We present pooled ISR characteristics and outcomes for participants receiving CAB + RPV LA through week 96 of the FLAIR and ATLAS-2M studies, and survey results from healthcare providers (HCPs) giving injections (eg, injectors) in the ATLAS, FLAIR, and ATLAS-2M studies to determine optimal injection techniques. Surveys were anonymous, self-administered online questionnaires that queried provider demographics, injection experience, and techniques to minimize pre-/postinjection discomfort. Data were summarized using descriptive statistics. Results: Overall, 8453 ISRs were reported by 801 participants receiving ≥1 injection of CAB LA/RPV LA. Most ISRs were mild to moderate in severity (grade 1-2, 99%), with a median duration of 3 days (interquartile range, 2-4 days), and rarely led to withdrawal (2%). Surveys were completed by 181 HCPs across 113 sites. Pushing the intramuscular injection at slow speed (66%), bringing the medication to room temperature (58%), and relaxing the gluteus muscle before injecting (53%) were ranked as effective preinjection/injection procedure practices for minimizing pain. Most injectors (60%) indicated that a prone position provided optimal patient comfort, and 41% had no preference on injection medication order. Conclusions: Taken together, the data demonstrate favorable tolerability with CAB + RPV LA injections over the long term and simple techniques routinely used by injectors to help optimize the administration of CAB + RPV LA injections.

Safety and Effectiveness From the Cabotegravir and Rilpivirine Implementation Study in European Locations Study: Phase 3b Hybrid Type III Implementation Study Integrating Cabotegravir + Rilpivirine Long-Acting Into European Clinical Settings.

BACKGROUND: Cabotegravir + rilpivirine long-acting (CAB + RPV LA) dosed every 2 months (Q2M) is a complete regimen for the maintenance of HIV-1 virologic suppression. In this study, we report month 12 clinical outcomes in patient study participants (PSPs) in the CAB and RPV Implementation Study in European Locations (CARISEL) study. SETTING: CARISEL is a phase 3b implementation-effectiveness study. METHODS: CARISEL was designed as a 2-arm, unblinded study with centers randomized to either enhanced or standard implementation arms. For PSPs, this study is single arm, unblinded, and interventional; all PSPs switched from daily oral therapy to CAB + RPV LA dosed Q2M. The primary objective was to evaluate the perceived acceptability, appropriateness, and feasibility of CAB + RPV LA implementation for staff participants (presented separately). Clinical secondary endpoints assessed through month 12 included the proportion of PSPs with plasma HIV-1 RNA ≥50 and <50 copies/mL (Snapshot algorithm), incidence of confirmed virologic failure (CVF; 2 consecutive plasma HIV-1 RNA levels ≥200 copies/mL), adherence to injection visit windows, and safety and tolerability. RESULTS: Four hundred thirty PSPs were enrolled and treated; the mean age was 44 years (30% ≥50 years), 25% were women (sex at birth), and 22% were persons of color. At month 12, 87% (n = 373/430) of PSPs maintained HIV-1 RNA <50 copies/mL, with 0.7% (n = 3/430) having HIV-1 RNA ≥50 copies/mL. One PSP had CVF. The safety profile was consistent with previous findings. Overall, the results were similar between implementation arms. CONCLUSION: CAB + RPV LA Q2M was well tolerated and highly effective in maintaining virologic suppression with a low rate of virologic failure.

Implementation of long-acting cabotegravir and rilpivirine: primary results from the perspective of staff study participants in the Cabotegravir And Rilpivirine Implementation Study in European Locations.

INTRODUCTION: Cabotegravir plus rilpivirine (CAB + RPV) is the first complete long-acting (LA) regimen recommended for maintaining HIV-1 virological suppression. Cabotegravir And Rilpivirine Implementation Study in European Locations (CARISEL) is an implementation-effectiveness study examining the implementation of CAB+RPV LA administered every 2 months (Q2M) in European HIV centres. We present staff study participant (SSP) perspectives on the administration of CAB+RPV LA over 12 months. METHODS: Eighteen clinics were randomized to one of two implementation support packages: standard arm (Arm-S) or enhanced arm (Arm-E). Arm-S included video injection training and provider/patient toolkits. Additionally, Arm-E included skilled wrap-around team meetings, face-to-face injection training and continuous quality improvement (CQI) calls. SSPs completed surveys on the acceptability, appropriateness and feasibility of CAB+RPV LA as an intervention and its implementation into their clinics, as well as barriers and facilitators to implementation. All surveys were completed at Month (M)1 (baseline), M5 and M12; data collection was completed by February 2022. Qualitative data were obtained from semi-structured interviews at M1, M5 and M12. The primary objective was assessed via formal statistical comparisons between study arms of the Acceptability of Implementation Measure, Implementation Appropriateness Measure and Feasibility of Implementation Measure surveys (1-5 Likert scale ranging from 1 = "completely disagree" to 5 = "completely agree"). Equivalent measures anchored to CAB+RPV LA as a therapy were also assessed. RESULTS: Seventy SSPs completed surveys and interviews at M1, 68 at M5 and 62 at M12. Mean acceptability/appropriateness/feasibility scores were ≥3.8 (out of 5) at M12 for implementation- and intervention-based measures. An analysis of covariance showed no significant differences between study arms for these outcomes. Although barriers were noted, most SSPs were not overly concerned that these would impact implementation; concern about these anticipated barriers also decreased over time. At M12, 90.3% (n = 56/62) of SSPs held a positive opinion about CAB+RPV LA implementation. Qualitative interviews and CQI calls highlighted three top practices that supported implementation: implementation planning; education about CAB+RPV LA clinical efficacy; and education around administering injections and managing pain/discomfort after injections. CONCLUSIONS: CARISEL demonstrated that CAB+RPV LA dosed Q2M was successfully implemented across a range of European locations, with SSPs finding implementation highly acceptable, appropriate and feasible. GOV NUMBER: NCT04399551.

Practical dosing guidance for the management of clinician-administered injections of long-acting cabotegravir and rilpivirine.

Cabotegravir (CAB) and rilpivirine (RPV) is the first complete long-acting (LA) injectable regimen recommended by treatment guidelines for the maintenance of HIV-1 virologic suppression in people with HIV-1 who are virologically suppressed on a stable antiretroviral regimen that is administered monthly (Q1M) or every 2 months (Q2M). As an alternative regimen to lifelong daily oral antiretroviral therapy, Q1M or Q2M dosing schedules are associated with increased patient satisfaction and treatment preference. In addition, it may address challenges associated with daily oral dosing, including fear of treatment disclosure or stigma, anxiety related to oral dosing adherence, and the daily reminder of HIV disease status. Cabotegravir + RPV LA is administered by clinical staff as two intramuscular injections dosed Q1M or Q2M. In this review, we share practical dosing guidance for CAB+RPV LA injectable therapy, including how to initiate therapy, schedule injection visits, manage dosing interruptions due to missed or delayed injection visits, manage errors in dosing, and transition to alternative antiretroviral therapy after discontinuation. Practical guidance on the clinical management of CAB+RPV LA dosing, including a detailed discussion using case-based scenarios that may be encountered in clinical practice, is provided. The clinician-administered CAB+RPV LA regimen has dosing management considerations that are flexible and considerate of the patient and has the potential to provide a highly desirable and efficacious alternative to daily oral antiretroviral therapy for many people with HIV-1.

Guidance for clinicians on the management of long-acting Cabotegravir and Rilpivirine Injectable Therapy for HIV-1 Cabotegravir (CAB) and rilpivirine (RPV) is the first long-acting (LA) injectable therapy for people with HIV-1 who previously achieved undetectable virus levels using other HIV-1 medications. People with HIV-1 receive CAB+RPV LA as two injections given by their clinician every 1 month or every 2 months, providing an alternative treatment option to lifelong daily oral medications. People with HIV-1 receiving CAB+RPV LA every 1 or 2 months have higher levels of treatment satisfaction and often prefer CAB+RPV LA compared with daily oral medications. Cabotegravir+RPV LA may also address challenges associated with daily oral medications, including fear of inadvertently sharing HIV status, anxiety related to taking daily medications, and having a daily reminder of HIV. In this review, we provide guidance for clinicians on how to administer CAB+RPV LA injectable therapy, including how to start patients on CAB+RPV LA injections, schedule injection visits, manage missed or delayed injection visits, manage dosing errors, and switch patients to a different treatment if CAB+RPV LA is discontinued. This review also includes a detailed discussion of potential scenarios related to the administration and scheduling of CAB+RPV LA injections that may occur in clinical practice. Overall, this review serves as a practical guide for managing CAB+RPV LA injectable therapy in clinical practice that will be useful for HIV clinicians.

Factors Associated with Health Care Providers' Preference for Forgoing an Oral Lead-In Phase When Initiating Long-Acting Injectable Cabotegravir and Rilpivirine in the SOLAR Clinical Trial.

Cabotegravir and rilpivirine long-acting (LA) antiretroviral therapy (ART) demonstrated similar safety and efficacy in maintaining viral suppression among participants switching from daily oral to LA ART in the Extension Phase of the FLAIR trial. The Phase IIIb SOLAR study comparing efficacy and safety of daily oral versus LA ART every 2 months allowed participants and health care providers (HCPs) to choose an oral lead-in (OLI) before LA initiation or proceed by immediately starting with injections (SWI). We conducted an online survey among SOLAR HCPs (n = 110) in 13 countries to assess reasons for choosing OLI versus SWI. Logistic regression was used to identify factors influencing this decision. Thirty-two percent of HCPs reported a future preference to use OLI, whereas 54% reported a future preference for SWI. HCPs had greater odds of reporting future intentions for SWI if they were from Continental Europe versus North America [adjusted odds ratio (aOR): 3.83, p < 0.05], from sites with a greater number of participants who initiated LA ART without OLI (aOR: 1.56, p < 0.01), and those who reported comfort with the medication safety profile (aOR: 6.39, p < 0.01). HCPs who participated in LA ART trials before SOLAR had decreased odds of reporting a preference for SWI compared to those with no prior LA ART trial experience (aOR: 0.11; p < 0.01). Results indicated higher intentions to SWI over OLI among HCPs initiating participants on LA ART. A major factor associated with SWI was provider comfort with safety data, reinforcing the role of continued training regarding an SWI approach.