What Clinicians Need to Know About the Development of Long-Acting Formulations

Advancing Toward a Human Immunodeficiency Virus Cure: Initial Progress on a Difficult Path

Therapies to eradicate human immunodeficiency virus (HIV) infection, sparing lifelong antiviral therapy, are a still-distant goal. But significant advances have been made to reverse HIV latency while antiretroviral therapy (ART) is maintained to allow targeting of the persistent viral reservoir, to test interventions that could clear cells emerging from latent infection, and to improve HIV cure research assays and infrastructure. Steady progress gives hope that future therapies to clear HIV infection may relieve individuals and society of the burden of HIV.

Physiologically based Pharmacokinetic Model Validated to Enable Predictions Of Multiple Drugs in a Long-acting Drug-combination Nano-Particles (DcNP): Confirmation with 3 HIV Drugs, Lopinavir, Ritonavir, and Tenofovir in DcNP Products

Drug-Combination Nanoparticles (DcNP) are a novel drug delivery system designed for synchronized delivery of multiple drugs in a single, long-acting, and targeted dose. Unlike depot formulations, slowly releasing drug at the injection site into the blood, DcNP allows multiple-drug-in-combination to collectively distribute from the injection site into the lymphatic system. Two distinct classes of long-acting injectables products are proposed based on pharmacokinetic mechanisms. Class I involves sustained release at the injection site. Class II involves a drug-carrier complex composed of lopinavir, ritonavir, and tenofovir uptake and retention in the lymphatic system before systemic access as a part of the PBPK model validation. For clinical development, Class II long-acting drug-combination products, we leverage data from 3 nonhuman primate studies consisting of nine PK datasets: Study 1, varying fixed-dose ratios; Study 2, short multiple dosing with kinetic tails; Study 3, long multiple dosing (chronic). PBPK validation criteria were established to validate each scenario for all drugs. The models passed validation in 8 of 9 cases, specifically to predict Study 1 and 2, including PK tails, with ritonavir and tenofovir, fully passing Study 3 as well. PBPK model for lopinavir in Study 3 did not pass the validation due to an observable time-varying and delayed drug accumulation, which likely was due to ritonavir's CYP3A inhibitory effect building up during multiple dosing that triggered a mechanism-based drug-drug interaction (DDI). Subsequently, the final model enables us to account for this DDI scenario.

Preferences and feasibility of long-acting technologies for treatment of hepatitis C virus in low- and middle-income countries: A survey of providers and policymakers

Long-acting technologies (LATs) for hepatitis C virus (HCV) are under development as a strategy to improve linkage to care, treatment adherence and outcomes. We conducted a survey of HCV treatment prescribers and HCV policymakers in low- and middle-income countries (LMICs) regarding acceptability and feasibility of HCV LATs. We included one-time intramuscular injection, subdermal implant and transdermal patch as potential LAT options. We surveyed participants regarding optimal health system and patient characteristics, concerns, potential barriers, overall feasibility and preferences for HCV LAT as compared to daily oral medication. Overall, 122 providers and 50 policymakers from 42 LMICs completed the survey. Among providers, 93% (113/122) expressed willingness to prescribe LAT and 72% (88/120) of providers preferred LAT if provided at comparable efficacy, safety and cost as current oral treatments. Of providers preferring HCV LAT to daily oral medication, 67% (59/88) preferred injection, 24% (21/88) preferred patch and 9% (8/88) preferred implant. Only 20% (24/122) would prescribe LAT if it were more costly than oral treatment. In regression analysis, no provider characteristics were associated with preference for LAT over oral treatment. Policymakers reported high likelihood that LAT would be included in treatment guidelines (42/50; 84%) and national drug formularies (39/50; 78%) if efficacy, safety and cost were similar to oral treatment. HCV LATs could advance progress to HCV elimination in LMICs by diversifying treatment options to improve treatment coverage and outcomes. Provider preferences from LMICs are a critical consideration in the development of HCV LATs to ensure its early and equitable availability in LMICs.

The New Era of Long-Acting Antiretroviral Therapy: When and Why to Make the Switch

PURPOSE OF REVIEW

Despite the availability of safe and effective oral combination antiretroviral therapy, barriers to maintaining viral suppression remain a challenge to ending the HIV epidemic. Long-acting injectable antiretroviral therapy was developed as an alternative to daily oral therapy. This review summarizes the current literature on the efficacy of long-acting cabotegravir plus rilpivirine for the treatment of HIV-1, reasons to switch to injectable therapy, and barriers to switching.

RECENT FINDINGS

Long-acting cabotegravir plus rilpivirine is safe and effective in maintaining HIV-1 virologic suppression. Ideal candidates for switching to long-acting cabotegravir plus rilpivirine are virologically suppressed on oral regimens with good adherence and no history of virologic failure or baseline resistance. Indications to switch to injectable therapy include patient preference, the potential for improved adherence, and avoidance of adverse effects. Implementation research is needed to assess and overcome system barriers. Long-acting cabotegravir plus rilpivirine is a novel alternative to oral antiretrovirals, with the potential to improve adherence and quality of life in people with HIV.