Longer-acting intravaginal formulation of buprenorphine

PROJECT SUMMARY The broad, long-term goal of this research program is to empower women suffering from opioid use disorder (OUD) through the development of a long-acting intravaginal ring (IVR) formulation of the opioid partial agonist -buprenorphine (BUP). This proposal is in response to RFA-DA-19-019 which calls for solutions to develop “Longer-acting formulations of existing addiction medications”. The current armamentarium of BUP-based drug products for the treatment of OUD includes daily sublingual, monthly injectable, and bi-annual implantable formulations. The year-over-year increase in these prescriptions suggest that improved BUP medications hold significant potential for improving patient retention, and overall healthcare outcomes. Despite their usefulness, both immediate-release and long-acting BUP formulations demonstrate sub-optimal pharmacokinetic (PK) profiles displaying an initial burst release followed by plateauing. The daily formulations often suffer from adherence/compliance issues and contain 5-10X more drug loading than required, creating diversion potential. Long-acting injectable and implantable medications are invasive, and require HCP visits for administration. To address this unmet need, we propose a “fast-track” IND-enabling approach to develop a monthly IVR delivering BUP using our established drug delivery technology. The commercial success of the contraceptive IVR Nuvaring® provides an applicable case study. More than 1 million women choose IVRs over traditional methods: more than long-acting implants or patches. We expect that a BUP ring will be chosen by a significant percentage of women seeking treatment for OUD. Our team has experience formulating IVRs to deliver a wide variety of small and large molecules using our “pod” technology. This work has resulted in three IND approvals in the fields of HIV pre-exposure prophylaxis (PrEP) and the treatment of genital herpes. In preliminary work, we developed a pilot BUP pod-IVR and tested it in vitro to confirm its formulation feasibility. We confirmed that BUP is vaginally bioavailable in a sheep model. PK modeling indicates that our pod-IVR can maintain therapeutic plasma levels at a substantially reduced dose and diversion potential. The specific aims of Phase 1 are to develop lead formulations across a broad range of release targets and to perform safety and PK testing in sheep. The milestone for successful completion of Phase 1 will be the demonstration of safety and clinically relevant drug concentrations from the animal study. In Phase 2, the specific aims will be: to carry out all of the necessary work in chemistry, manufacturing and controls (CMC); pre-clinical animal studies; and protocol development to allow the milestone: Investigational New Drug (IND) allowance from the FDA allowing the first-in-human testing of a BUP pod-IVR. Following successful completion of this project, we will seek funding to carry out a series of clinical studies to further demonstrate safety, PK, and efficacy. The development of this product will provide women a novel, private and improved therapeutic adjunct in the treatment of opiate addiction with reduced risk for diversion.