Effect of HIV genotypic drug resistance testing on the management and clinical course of HIV-infected children and adolescents

Long-Term Safety and Efficacy of Dolutegravir in Treatment-Experienced Adolescents With Human Immunodeficiency Virus Infection: Results of the IMPAACT P1093 Study

BACKGROUND

P1093 is an ongoing phase I/II multicenter open-label study of dolutegravir plus an optimized background regimen in age-defined pediatric cohorts; here we report the long-term safety and virologic efficacy outcomes for the oldest cohort.

METHODS

The study enrolled human immunodeficiency virus type 1 (HIV-1)-infected treatment-experienced adolescents aged 12 to <18 years, with an HIV-1 RNA level ≥1000 copies/mL . Cumulative safety and HIV-1 RNA outcomes were assessed once the last enrolled participant reached 144 weeks of follow-up.

RESULTS

Among 23 adolescents enrolled, 16 remained in the study at least 144 weeks; the median follow-up was 153 weeks (range, 55-193 weeks). Dolutegravir was well tolerated, with grade 3 clinical adverse events in 5 participants, grade 3 laboratory abnormalities in 3, and grade 4 laboratory abnormalities in 1; none of the adverse events or abnormalities were judged to be treatment related. In an-intent-to-treat analysis, an HIV-1 RNA level <400 copies/mL at week 144 was achieved in 43% (10 of 23 participants; 95% confidence interval, 23.2%-65.5%); in addition, 35% (8 of 23; 16.4%-57.3%) had an HIV-1 RNA level <50 copies/mL. Nine participants (39%) discontinued study treatment before 144 weeks, but none because of adverse events or drug intolerance. All participants with sustained virologic control had excellent adherence; most who experienced virologic failure had adherence levels <90%. HIV-1 genotypic drug resistance testing was available at time of failure from 6 participants; 1 had evolution in integrase resistance with E138T, S147G, and R263K mutations at week 192 and phenotypic dolutegravir resistance of a 5.1-fold change.

CONCLUSIONS

Dolutegravir plus an optimized background regimen seemed safe, well tolerated, and efficacious in this cohort of treatment-experienced HIV-1-infected adolescents. Adherence remains problematic in this population.

CLINICAL TRIALS REGISTRATION

NCT01302847.

Safety, Pharmacokinetics and Efficacy of Dolutegravir in Treatment-experienced HIV-1 Infected Adolescents: Forty-eight-week Results from IMPAACT P1093

OBJECTIVE

To assess the pharmacokinetics (PK), safety and efficacy of dolutegravir plus optimized background regimen in HIV-infected treatment-experienced adolescents.

METHODS

Children older than 12 to younger than 18 years received dolutegravir weight-based fixed doses at approximately 1.0 mg/kg once daily in a phase I/II multicenter open label 48-week study. Intensive PK evaluation was done at steady state after dolutegravir was added to a failing regimen or started at the end of a treatment interruption. Safety and HIV RNA and CD4 cell count assessments were performed through week 48.

RESULTS

Twenty-three adolescents were enrolled and 22 (96%) completed the 48-week study visit. Median age and weight were 15 years and 52 kg, respectively. Median [interquartile range (IQR)] baseline CD4+ cell count was 466 cells/μL (297, 771). Median (IQR) baseline HIV-1 RNA log10 was 4.3 log10 copies/mL (3.9, 4.6). Dolutegravir geometric mean of the area under the plasma concentration-time curve from time of administration to 24 hours after dosing (AUC0-24) and 24 hour postdose concentration (C24) were 46.0 μg hours/mL and 0.90 μg/mL, respectively, which were within the study targets based on adult PK ranges. Virologic success with an HIV RNA <400 copies/mL was achieved in 74% [95% confidence interval (CI): 52-90%] at week 48. Additionally, 61% (95% CI: 39-80%) had an HIV RNA <50 copies/mL at week 48. Median (IQR) gain in CD4 cell count at week 48 was 84 cells/μL (-81, 238). Dolutegravir was well tolerated, with no grade 4 adverse events, serious adverse events or discontinuations because of serious adverse events.

CONCLUSIONS

Dolutegravir achieved target PK exposures in adolescents. Dolutegravir was safe and well tolerated, providing good virologic efficacy through week 48.

Explaining antiretroviral therapy adherence success among HIV-infected children in rural Uganda: a qualitative study

High adherence is critical for achieving clinical benefits of HIV antiretroviral therapy (ART) and particularly challenging for children. We conducted 35 qualitative interviews with caregivers of HIV-infected Ugandan children who were followed in a longitudinal study of real-time ART adherence monitoring; 18 participants had undetectable HIV RNA, while 17 had detectable virus. Interviews blinded to viral suppression status elicited information on adherence experiences, barriers and facilitators to adherence, and social support. Using an inductive content analytic approach, we identified 'lack of resources,' 'Lazarus effect,' 'caregiver's sense of obligation and commitment,' and 'child's personal responsibility' as categories of influence on adherence, and defined types of caregiver social support. Among children with viral suppression, high hopes for the child's future and ready access to private instrumental support appeared particularly important. These findings suggest clinical counseling should explore caregivers' views of their children's futures and ability to access support in overcoming adherence barriers.

Assessment of HIV antiretroviral therapy adherence by measuring drug concentrations in hair among children in rural Uganda

Current tools for measuring medication adherence have significant limitations, especially among pediatric populations. We conducted a prospective observational study to assess the use of antiretroviral (ARV) drug levels in hair for evaluating antiretroviral therapy (ART) adherence among HIV-infected children in rural Uganda. Three-day caregiver recall, 30-day visual analog scale (VAS), Medication Event Monitoring System (MEMS), and unannounced pill counts and liquid formulation weights (UPC) were collected monthly over a one-year period. Hair samples were collected quarterly and analyzed for nevirapine (NVP) levels, and plasma HIV RNA levels were collected every six months. Among children with at least one hair sample collected, we used univariable random intercept linear regression models to compare log transformed NVP concentrations with each adherence measure, and the child's age, sex, and CD4 count percentage (CD4%). One hundred and twenty-one children aged 2-10 years were enrolled in the study; 74 (61%) provided at least one hair sample, and the mean number of hair samples collected per child was 1.9 (standard deviation [SD] 1.0). Three-day caregiver recall, VAS, and MEMS were found to be positively associated with increasing NVP concentration in hair, although associations were not statistically significant. UPC was found to have a nonsignificant negative association with increasing hair NVP concentration. In conclusion, NVP drug concentrations in hair were found to have nonsignificant, although generally positive, associations with other adherence measures in a cohort of HIV-infected children in Uganda. Hair collection in this population proved challenging, suggesting the need for community education and buy-in with the introduction of novel methodologies.