University of Pittsburgh scientists have developed a novel approach to human immunodeficiency virus (HIV) and sexually transmitted infection (STI) prevention. Using a medicated enema specifically formulated to deliver combinations of tenofovir (TFV) and Q-Griffithsin (Q-GRFT) this approach can offer pre-exposure prophylaxis (PrEP) against HIV and other STIs in men who have sex with other men (MSM).
Description
Enema use (or douching) is common among MSM before and/or after anal intercourse for hygiene and other purposes. This enema utilizes this behavior to deliver a combination of TFV and Q-GRFT, two anti-HIV drugs with different mechanisms of action known to have a synergistic effect. This first-of-its-kind enema solution has the potential to revolutionize efforts to reduce the spread of HIV and STIs.
Applications
• HIV PrEP
• STI prevention
Advantages
PrEP has changed the landscape of HIV treatment. The discovery and subsequent approval of PrEP, an oral tablet taken either daily or as required prior to sexual activity, prevents HIV infection through interruption of viral replication. However, to be effective it must be taken regularly, and adherence can be a challenge to some. Additional, douching (enema use) is common in the MSM community, but it can be a risk factor for HIV/STIs due to damage of the anal endothelium.
Given this is a common behavior among MSM, this group is an ideal target for intervention to include HIV/STI prevention strategies with a view to improve adherence to a treatment regimen. This enema, developed to deliver PrEP through existing behaviors should improve adherence and in turn reduce HIV/STI transmission.
Invention Readiness
Previous research has suggested the inclusion of HIV/STI prevention strategies can be incorporated into enemas with the expectation of increased user adherence. Two different enema formulations have been produced. Both were clear, colorless, pH neutral, hypotonic (ca. 140 mOsm/kg), and contained TFV and Q-GRFT. These formulations remained stable under controlled storage conditions (4 °C; 25 °C / 60% RH; 40 °C / 75% RH) for two years. The formulation method was designed to be simple, robust and reproducible for large-scale manufacturing.
In vitro testing in a Caco-2 monolayer cell model demonstrated a good safety profile with high cell viability of both formulations. Drug absorption studies (apparent permeability) showed Q-GRFT and excipients in the enema formulation did not impact on TFV absorption. Ex vivo testing using a human colon tissue model found TFV permeated into tissues and Q-GRFT adhered to the tissue surface, with no damage to the colon endothelium observed. Further development required.
IP Status
https://patents.google.com/patent/WO2023031884A1
