ZB-06, a vaginal film containing an engineered human contraceptive antibody (HC4-N), demonstrates safety and efficacy in a phase 1 postcoital test and safety study

BACKGROUND

With an unplanned pregnancy rate of 50% or more in many countries, there is an urgent need for contraceptives that are more accessible and acceptable. To meet the growing demand for new contraceptives, ZabBio developed ZB-06, a vaginal film containing HC4-N, a human contraceptive antibody (HCA) that inactivates sperm.

OBJECTIVES

To assess the potential contraceptive activity of the ZB-06 film using a surrogate assessment for contraceptive efficacy, the postcoital test (PCT). We also assessed clinical safety of film use among healthy heterosexual couples. Serum, cervical mucus (CM) and vaginal fluid HC4-N antibody concentrations and sperm agglutination potency were determined after single film use. Changes in the concentration of soluble pro-inflammatory cytokines and vaginal Nugent score after film use were measured as sub-clinical safety endpoints.

STUDY DESIGN

Phase I first-in-woman, open-label, proof-of-concept, PCT and safety study.

RESULTS

Twenty healthy women were enrolled in the study and 8 heterosexual couples completed all study visits. The product was safe for both female participants and their male sexual partners. The PCT performed on ovulatory CM at baseline (no product use), revealed a mean of 25.9 (± 30.6) progressively motile sperm (PMS) per high power field (hpf). After use of a single ZB-06 film prior to intercourse, this number dropped to 0.04 (± 0.06) PMS/hpf (p<0.0001). At the follow up PCT visit approximately one month later (no product use), a mean of 47.4 (± 37.4) PMS/hpf was observed, indicating contraceptive reversibility.

CONCLUSIONS

A single dose of the ZB-06 film applied prior to intercourse was safe and met efficacy surrogate benchmarks of excluding progressively motile sperm from ovulatory CM. These data indicate that ZB-06 is a viable contraceptive candidate warranting further development and testing.

Development of an auxotrophic, live-attenuated Brucella suis vaccine strain capable of expressing multimeric GnRH

Feral swine cost around $1.5 billion each year in agricultural, environmental, and personal property damages. They are also the most widespread carriers of the zoonotic disease brucellosis, which threatens both livestock bio-security and public health. Currently, there is no approved vaccine against brucellosis in pigs. This is a preliminary report on the development of a live-attenuated B. suis vaccine that could be employed to deliver heterologous antigens to control swine populations. An attenuated vaccine strain provided significant protection against B. suis challenge in mice. Leucine auxotrophy in the vaccine strain allowed the over-expression of heterologous antigens without the use of antibiotic resistant markers. Vaccinated mice showed the development of antibodies against expressed antigen. Further evaluation is required to assess its ability to cause infertility using the mouse model prior to further testing for use as a tool for feral swine population and disease control.