Scientists Explore Monoclonal Antibodies as Contraception

With the overturning of Roe v. Wade early in 2022, the year has become a landmark for expanding access and options for reproductive care, especially contraception. Shortly after this policy change, researchers at the University of North Carolina Chapel Hill (UNC) revealed data on how they have weaponized monoclonal antibodies as a form of female contraception.

Monoclonal antibodies have been used for treating and preventing various diseases. Over the past few years, monoclonal antibodies have been used throughout the pandemic to treat severe cases of COVID-19. With traditional use focused on targeted therapies for cancer, researchers have repurposed this critical healthcare tool to address yet another healthcare concern, unintended pregnancy.

According to the CDC, approximately 45% of pregnancies in the United States are unintended, with 75% of those unintended pregnancies being in people ages 15–19. Additionally, marginalized communities, such as low-income and minority individuals, are affected at higher rates. Despite the availability of female contraceptives, hormonal options — usually the most effective — come with many side effects and contraindications.

The paper published by UNC researchers in Science Translational Medicine identifies a care gap for people with female reproductive anatomy who are looking for non-hormonal birth control options. Their solution was to engineer potent antibodies to immobilize sperm so that it cannot reach the egg, a process they refer to as "stopping sperm in its tracks." According to the UNC School of Pharmacy, this idea is based on cases of infertility that arise when a child-bearing partner develops antibodies to their partner’s sperm.

This early study showed that, in animal models, monoclonal antibodies were roughly 99.9% effective in preventing sperm from reaching the egg. Despite efficacy in animal models, additional studies and clinical trials in human participants are necessary before giving this contraceptive method the stamp of approval. Upon approval, this form of contraception could be delivered via an intravaginal ring.

Although this form of contraception has potential, many are concerned that it will be an expensive, thus, inaccessible, method of care. With this in mind, researchers are looking to incorporate information collected from antibodies in infertile women.

In an article for the UNC School of Pharmacy, Samuel Lai, professor in the Division of Pharmacoengineering and Molecular Pharmaceutics at the UNC Eshelman School of Pharmacy, said, “we think these second-generation molecules will provide not only greater potency but will translate to lower costs that make the approach cost-effective.”