Estimating the minimum antiretroviral adherence required for plasma HIV-1 RNA viral load suppression among people living with HIV who use unregulated drugs

B/F/TAF forgiveness to non-adherence

BACKGROUND

ART forgiveness is the ability of a regimen to maintain HIV-RNA suppression despite a documented imperfect adherence. We explored forgiveness of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF).

METHODS

In this retrospective cohort study pharmacy drug refills were used to calculate the proportion of days covered (PDC) as a proxy of adherence. Forgiveness was defined as the possibility to achieve a selected HIV-RNA threshold by a given level of imperfect adherence. A logistic model was applied to verify the impact of baseline variables and adherence on the virologic outcomes.

RESULTS

We enrolled 420 adults. From them, 787 one-year time-periods were derived for a median cohort follow-up of 873 person/years.Most of them were males (73.1%); the most frequent risk factor for HIV infection was heterosexual contacts (49.5% of cases), followed by 22.5% MSM and 22.5% intravenous drug users. The median age of enrolled persons with HIV was 51 years (IQR 45-57 years); the median duration of HIV infection was 7.9 years (IQR 4-18 years) and the median nadir of CD4 cells was 277 cells/mcL (IQR 100-513 cells/mcL).Adherence showed a median of 0.97 (IQR 0.91-1.00), consequently only 17 time-periods (2.2%) in 17 different individuals (4.0%) showed HIV-RNA blood levels above 200 copies/ml.A PDC of 0.75 was sufficient to obtain in > 90% of cases the virologic outcome for both 200 copies/ml or 50 copies/ml. An adherence value of 0.85 obtained a positive response in virtually all subjects either for a cut-off of 50 or 200 copies/ml.

CONCLUSIONS

Long-term success of ART needs effective, well tolerated, friendly regimens. Adherence remains a crucial determinant of long-term success, but suboptimal adherence levels are relatively common. Given this, an elevated forgiveness plays a relevant role to further improve long-term outcomes and should be considered a fundamental characteristic of any antiretroviral regimen. B/F/TAF has been proved to have all of these characteristics.

Cocaine regulates antiretroviral therapy CNS access through pregnane-x receptor-mediated drug transporter and metabolizing enzyme modulation at the blood brain barrier

BACKGROUND

Appropriate interactions between antiretroviral therapies (ART) and drug transporters and metabolizing enzymes at the blood brain barrier (BBB) are critical to ensure adequate dosing of the brain to achieve HIV suppression. These proteins are modulated by demographic and lifestyle factors, including substance use. While understudied, illicit substances share drug transport and metabolism pathways with ART, increasing the potential for adverse drug:drug interactions. This is particularly important when considering the brain as it is relatively undertreated compared to peripheral organs and is vulnerable to substance use-mediated damage.

METHODS

We used an in vitro model of the human BBB to determine the extravasation of three first-line ART drugs, emtricitabine (FTC), tenofovir (TFV), and dolutegravir (DTG), in the presence and absence of cocaine, which served as our illicit substance model. The impact of cocaine on BBB integrity and permeability, drug transporters, metabolizing enzymes, and their master transcriptional regulators were evaluated to determine the mechanisms by which substance use impacted ART central nervous system (CNS) availability.

RESULTS

We determined that cocaine had a selective impact on ART extravasation, where it increased FTC's ability to cross the BBB while decreasing TFV. DTG concentrations that passed the BBB were below quantifiable limits. Interestingly, the potent neuroinflammatory modulator, lipopolysaccharide, had no effect on ART transport, suggesting a specificity for cocaine. Unexpectedly, cocaine did not breach the BBB, as permeability to albumin and 4 kDa FITC-dextran, as well as tight junction proteins and adhesion molecules remained unchanged. Rather, cocaine selectively decreased the pregnane-x receptor (PXR), but not constitutive androstane receptor (CAR). Consequently, drug transporter expression and activity decreased in endothelial cells of the BBB, including p-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 4 (MRP4). Further, cytochrome P450 3A4 (CYP3A4) enzymatic activity increased following cocaine treatment that coincided with decreased expression. Finally, cocaine modulated adenylate kinases that are required to facilitate biotransformation of ART prodrugs to their phosphorylated, pharmacologically active counterparts.

CONCLUSION

Our findings indicate that additional considerations are needed in CNS HIV treatment strategies for people who use cocaine, as it may limit ART efficacy through regulation of drug transport and metabolizing pathways at the BBB.

Cocaine Regulates Antiretroviral Therapy CNS Access Through Pregnane-X Receptor-Mediated Drug Transporter and Metabolizing Enzyme Modulation at the Blood Brain Barrier

Background

Appropriate interactions between antiretroviral therapies (ART) and drug transporters and metabolizing enzymes at the blood brain barrier (BBB) are critical to ensure adequate dosing of the brain to achieve HIV suppression. These proteins are modulated by demographic and lifestyle factors, including substance use. While understudied, illicit substances share drug transport and metabolism pathways with ART, increasing the potential for adverse drug:drug interactions. This is particularly important when considering the brain as it is relatively undertreated compared to peripheral organs and is vulnerable to substance use-mediated damage.

Methods

We used an in vitro model of the human BBB to determine the extravasation of three first-line ART drugs, emtricitabine (FTC), tenofovir (TFV), and dolutegravir (DTG), in the presence and absence of cocaine, which served as our illicit substance model. The impact of cocaine on BBB integrity and permeability, drug transporters, metabolizing enzymes, and their master transcriptional regulators were evaluated to determine the mechanisms by which substance use impacted ART central nervous system (CNS) availability.

Results

We determined that cocaine had a selective impact on ART extravasation, where it increased FTC's ability to cross the BBB while decreasing TFV. DTG concentrations that passed the BBB were below quantifiable limits. Interestingly, the potent neuroinflammatory modulator, lipopolysaccharide, had no effect on ART transport, suggesting a specificity for cocaine. Unexpectedly, cocaine did not breach the BBB, as permeability to albumin and tight junction proteins and adhesion molecules remained unchanged. Rather, cocaine selectively decreased the pregnane-x receptor (PXR), but not constitutive androstane receptor (CAR). Consequently, drug transporter expression and activity decreased in endothelial cells of the BBB, including p-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 4 (MRP4). Further, cytochrome P450 3A4 (CYP3A4) enzymatic activity increased following cocaine treatment that coincided with decreased expression. Finally, cocaine modulated adenylate kinases are required to facilitate biotransformation of ART prodrugs to their phosphorylated, pharmacologically active counterparts.

Conclusion

Our findings indicate that additional considerations are needed in CNS HIV treatment strategies for people who use cocaine, as it may limit ART efficacy through regulation of drug transport and metabolizing pathways at the BBB.

Efficacy of an mHealth self-management intervention for persons living with HIV: the WiseApp randomized clinical trial

IMPORTANCE

Progression of HIV disease, the transmission of the disease, and premature deaths among persons living with HIV (PLWH) have been attributed foremost to poor adherence to HIV medications. mHealth tools can be used to improve antiretroviral therapy (ART) adherence in PLWH and have the potential to improve therapeutic success.

OBJECTIVE

To determine the efficacy of WiseApp, a user-centered design mHealth intervention to improve ART adherence and viral suppression in PLWH.

DESIGN, SETTING, AND PARTICIPANTS

A randomized (1:1) controlled efficacy trial of the WiseApp intervention arm (n = 99) versus an attention control intervention arm (n = 101) among persons living with HIV who reported poor adherence to their treatment regimen and living in New York City.

INTERVENTIONS

The WiseApp intervention includes the following components: testimonials of lived experiences, push-notification reminders, medication trackers, health surveys, chat rooms, and a "To-Do" list outlining tasks for the day. Both study arms also received the CleverCap pill bottle, with only the intervention group linking the pill bottle to WiseApp.

RESULTS

We found a significant improvement in ART adherence in the intervention arm compared to the attention control arm from day 1 (69.7% vs 48.3%, OR = 2.5, 95% CI 1.4-3.5, P = .002) to day 59 (51.2% vs 37.2%, OR = 1.77, 95% CI 1.0-1.6, P = .05) of the study period. From day 60 to 120, the intervention arm had higher adherence rates, but the difference was not significant. In the secondary analyses, no difference in change from baseline to 3 or 6 months between the 2 arms was observed for all secondary outcomes.

CONCLUSIONS

The WiseApp intervention initially improved ART adherence but did not have a sustained effect on outcomes.

Real World Data on Forgiveness to Uncomplete Adherence to Bictegravir/ Emtricitabine/Tenofovir Alafenamide

Background: forgiveness is the ability of a given regimen to maintain complete viral suppression despite a documented imperfect adherence. We explored forgiveness of bictegravir/emtricitabine/tenofovir alafenamide. Methods: drug refills were used to calculate the percent day covered (PDC) as a proxy of adherence. Forgiveness was calculated as the achieved rate of a selected HIV-RNA threshold by a given level of imperfect adherence. Results: 281 adult PLWH were followed for 343 patient/years. Adherence was very high with a median of 98% (IQR 95-100%). A PDC as low as 70% was sufficient to obtain 100% and maintain virologic suppression. According to probit analysis adherence was not related to the possibility to maintain an HIV-RNA TND or < 50 copies/ml. Conclusions: Long-term success of ART needs effective regimens that are the least intrusive of the patient's lifestyle, an elevated forgiveness may be considered as an additional feature that can further improve long-term outcomes.