Prep and OUD treatment extended combination therapy (protect)

The National Institute on Drug Abuse awarded RTI International $1.230918 million on July 1, 2026, under the Drug Use and Addiction Research Programs (CFDA 93.279) to develop the PREP and OUD Treatment Extended Combination Therapy (PROTECT) implant, a long-acting subcutaneous drug-delivery system for HIV prevention and opioid use disorder treatment.

The project will fabricate separate implants for sustained delivery of antiretroviral medications and medications for opioid use disorder, then integrate both into a single-rod platform capable of co-delivering both therapies. The PROTECT implant uses zero-order release kinetics to maintain consistent plasma drug levels over six months, eliminating adherence challenges associated with daily oral or on-demand regimens. The device is completely biodegradable yet retrievable if early removal becomes necessary due to adverse events, operates through a modular customizable polymer reservoir system, and incorporates user-centered design informed by iterative engagement with potential end users.

RTI International, a nonprofit research organization based in Durham, North Carolina, will conduct the work through April 30, 2031. The award funds research and development activities for adult populations at elevated risk for HIV and substance use disorder. The research builds on prior work conducted at RTI International on zero-order release delivery systems and addresses the pharmacokinetic stability limitations of current first-order release injectable products.

Abstract

The proposed program will advance an innovative and widely applicable long-acting therapeutic platform in the form of the prep and OUD treatment extended combination therapy (protect). The overarching goal is to advance the protect implant as a long-acting, highly effective, safe, and acceptable drug- delivery system for the prevention of HIV and substance use disorder (SUD), specifically OUD, in adult populations at elevated risk. Protect builds on significant prior research conducted at RTI international to deliver medications with zero-order release kinetics, providing consistent plasma drug levels for ≥6 months, thereby eliminating common adherence challenges associated with daily oral or on-demand regimens and first-order injectable therapies. The protect implant incorporates a number of beneficial product features that make IT uniquely suited for broad-scale implementation: IT is completely biodegradable, yet retrievable if early removal is needed due to adverse events; IT is discreet, user-independent, and capable of delivering single or combination therapy (e.g., antiretrovirals [arvs] and medications for OUD [mouds]) through a modular, customizable polymer reservoir system. Unlike current first-order release products, protect provides a stable pharmacokinetic profile throughout the dosing interval, mitigating the risk of subtherapeutic "tail" effects and treatment failure. The implant development process is guided by user-centered design, incorporating early and iterative engagement between product developers and potential end users to ensure that the final product is aligned with their needs, preferences, and lived experiences. The specific aims are to: (1) fabricate separate long-acting subcutaneous implants for the sustained delivery of ARV and moud, (2) integrate and optimize the implant form factor into a single-rod platform capable of CO-delivering both ARV and moud formulations; and (3) identify end-user preferences, inform implant development, and ensure future deployment of protect by conducting iterative socio-behavioral research. The proposed protect team is highly collaborative and multidisciplinary with complementary areas of expertise from key organizations, RTI international, magee-womens research institute, university of pittsburgh, and emory national primate research center, that can accelerate development of this innovative product. Our proposed protect program will follow a clear research strategy with expected deliverables to guide the progress of product development.