STIs continue to affect a significant proportion of patients despite available antibiotics which have been proven to cure many of these conditions. Vaccine coverage is lacking in many regions for Hepatitis A and Hepatitis B, and cures do not yet exist for herpes simplex virus (HSV) types1 and 2 and the human immunodeficiency virus type 1 (HIV-1).
HSV impacts over 700 million people worldwide and HIV impacts 39 million. While transmission is reduced by antiviral drugs, infection remains common. Unintended pregnancies are also common, with nearly 50% of pregnancies being unintended. MPTs can protect individuals against HIV and other STIs, along with unintended pregnancies.
MAbs were first developed in 1975, providing a safer option for passive immunization compared to antisera which was associated with severe side effects. At least 137 mAbs have been approved for clinical use by the FDA or EU, and over 570 are in early commercial development.
The World Health Organization has recognized the importance of mAbs for preventing HIV. They provide broadly neutralizing antibodies (bnAbs), which can neutralize a significant proportion of HIV strands. Multiple bnAbs are currently being evaluated for the prevention and management of HIV in clinical trials.
Antiviral effects against HSV infection have been observed in at least 50 mAbs, with 3 having progressed to human clinical trials. The first, 2C (HDIT101) has been deemed safe through escalating doses taken intravenously.
The second mAb being evaluated in human trials, E317 (UB-621), has neutralizing effects against HSV-1 and HSV-2. It has shown positive safety and efficacy results after a single dose in a phase 1 analysis. The final mAb, HSV8, also displayed antiviral neutralization and no severe adverse events in a phase 1 clinical trial.
Many mAbs are also being evaluated for use against other STI pathogens. Additionally, an antisperm mAb has displayed promising results as an immunocontraception. In a phase 1 clinical trial, safety and efficacy against progressively motile sperm in cervical mucus was observed in female participants.
Combining mAbs may also allow useful MPT while providing a specific safety profile. However, barriers to mAb access must be reduced. These include manufacturing challenges, limited delivery methods, and high cost. Overall, mAB-based MPTs show safety, efficacy, and combinatorial flexibility, according to investigators.
Reference
Dohadwala S, Geib MT, Politch JA, Anderson DJ. Innovations in monoclonal antibody-based multipurpose prevention technology (MPT) for the prevention of sexually transmitted infections and unintended pregnancy. Front Reprod Health. 2024;5:1337479. doi:10.3389/frph.2023.1337479
