A population pharmacokinetic model based on HPTN 077 of long-acting injectable cabotegravir for HIV PrEP

the HPTN 077 Study Team

Research output: Contribution to journalArticlepeer-review


Aims: Cabotegravir delivered as a long-acting intramuscular injection has shown superior efficacy to oral tenofovir-emtricitabine as pre-exposure prophylaxis (PrEP) for HIV. Cabotegravir pharmacokinetics (PK), like those of other long-acting depot preparations, exhibit variability between individuals and between injection occasions. The aim of this study is to describe the population pharmacokinetics of long-acting cabotegravir (CAB-LA). Methods: Using available PK measurements from 133 participants in the HIV Prevention Trials Network (HPTN) 077 trial, we analysed CAB-LA PK data using nonlinear mixed-effects modelling to develop a population PK model. Results: A two-compartment model with first order absorption best described the CAB-LA PK. The analysis identified between-occasion variability (BOV, i.e., differences in PK within one individual from one injection to the next) as a significant covariate affecting the absorption rate, with an estimated contribution of BOV to PK variability on the absorption rate (ka) of 38.5%. Sex and body weight were identified as significant covariates influencing the absorption rate and apparent clearance of CAB-LA after intramuscular injection at various doses and frequencies. Male participants had 67% higher ka than female participants. Serially adding to the model body weight on clearance, sex on ka, and BOV on ka led to a decrease in the objective function value (OFV) of 24.4, 36 and 321.4, respectively. Conclusion: The public availability of this model will facilitate and enable a wide variety of future clinically relevant simulations to inform the optimal use of CAB-LA.

Original languageEnglish (US)
JournalBritish Journal of Clinical Pharmacology
StatePublished - Oct 2022


  • antiretrovirals
  • infectious diseases
  • pharmacometrics

ASJC Scopus subject areas

  • Pharmacology (medical)
  • Pharmacology


Dive into the research topics of 'A population pharmacokinetic model based on HPTN 077 of long-acting injectable cabotegravir for HIV PrEP'. Together they form a unique fingerprint.

Cite this