After working on drugs for fibromyalgia and rheumatoid arthritis — both conditions that disproportionately affect women — Sabrina Johnson, now the Chief Executive Officer and President of Daré Bioscience, realized that she wanted to work for a company that developed products specifically for women’s health.

But when she went looking for those places, “I was very, very disappointed,” she said. Some large pharmaceutical companies had women’s health products that they’d commercialized or had acquired through company mergers, but none of them were developing anything new internally. When she looked at drugs coming out of academic labs or startups, she saw that they had trouble getting their products into development because there was no drug developer solely focused on women’s health indications.

“Instead of asking, why is no one doing it? Why don't I just step up and do it?” Johnson said. In 2015, Johnson founded Daré Bioscience, which, to her knowledge, is currently the only publicly traded company whose sole focus is on developing therapies for women’s health.

“We work in contraception, all the way through menopause, and everything in between,” Johnson added.

One of the company’s most advanced products is Ovaprene, a monthly, non-hormonal birth control option. This drug-device combination is currently in the middle of a Phase 3 clinical trial. Johnson and her team hope that Ovaprene will give women a much sought-after new option for contraception.

What motivated you to work on a new form of birth control?

We really wanted to start with an unmet need and then develop a target product profile to solve it. We saw a few gaps specifically in the contraceptive category, and one of them was around non-hormonal options. On the non-hormonal side of the equation, there hasn't been as much innovation. There is the male condom, which is not even a female product. There is the female condom and spermicides. There are diaphragms, which actually work really well, but they're hard to get and can be cumbersome to use. Then, there's the copper intrauterine device (IUD), which is incredibly effective, but unfortunately a large proportion of women don’t choose it because it has to be inserted and can have a challenging side effect profile for some women.

In the hormonal category, there is the daily pill, an implant, and the hormonal IUD. There have also been a lot of innovations in less frequent dosing, and one that really caught our attention — and lasts for a time period that people like — was the monthly hormone-releasing vaginal ring. When we looked at the literature and market research, women were interested in having something that was non-hormonal and something they would just have to do once per month. That was our target profile, and we found Ovaprene.

What is Ovaprene, and how does it work?

Ovaprene is a small ring that has a physical barrier in the center made of a knitted polymer. It's a three-dimensional weave that is designed to inhibit sperm’s progression through it. The ring also releases an active pharmaceutical ingredient that’s a form of iron that interferes with sperm motility through a lipid peroxidation reaction. Women would replace the device with a new one every month.

When we found Ovaprene, it had already been through a small human proof-of-concept study showing that it could block progressively motile sperm from getting into the cervix (1). It really caught our interest because it checked all those boxes of what we were looking for in a monthly non-hormonal contraceptive. When we got Daré Bioscience up and going, it was the first product that we brought into our portfolio to advance.

What has Ovaprene’s development process been like?

Ovaprene was my first time working on a contraceptive product, and because it's non-hormonal, that added some nuances to the program. It actually is a lot more challenging to develop a non-hormonal contraceptive method than a hormonal method for a few reasons that we really didn’t think about until we were in the nitty gritty of it.

When people are on a hormonal method — the pill, a ring, a patch — their cycle lengths are pretty regulated. That removes a lot of variability from a clinical study. When it's a non-hormonal method, there are complexities because cycle lengths are different. Some women may have a 21-day or a 35-day cycle; not everyone has the perfect 28-day menstrual cycle. That posed some challenges in terms of even just simple things, like when do we tell someone to put Ovaprene in? What if she doesn't get her next period, and it's already been 30 days? We had to think through those things.

What were some other challenges you encountered designing a clinical trial for a non-hormonal contraceptive?

We needed to show that Ovaprene worked in people the way it was supposed to. For a hormonal product, we could do a study with healthy volunteers and show there are high enough blood levels of the hormone that it should be effective. Because Ovaprene is non-hormonal, our study was much more complicated. The first study we had to do for the Food and Drug Administration (FDA) was in women who are not at risk of getting pregnant; in this case, we chose women who had a tubal ligation. They would insert the device once per month and take an ovulation predictor test. When they were ovulating, we instructed them to have intercourse. Within two hours of that sex act, they would come into the clinic to be evaluated to see if there were progressively motile sperm getting into the cervix.

We showed that across all the women and all the cycles an average of only 0.48 progressively motile sperm got into the cervix (2). Those are really good findings. In pregnancy rate studies, Ovaprene has had 86 to 91 percent contraceptive effectiveness with typical use at six months (3). That's the same range as diaphragms, and it's at the low range of hormonal pills. So, those studies were a great proof-of-concept.

How has Ovaprene advanced since then?

We had those data in 2019, and then there was the COVID-19 pandemic, which was a bit of a disruption. Because Ovaprene is a drug-device combination product, it’s a complicated product from a regulatory perspective. The device division of the FDA leads our review, but both the drug and device divisions of the FDA are involved. We got our protocol for a Phase 3 study lined up, and we started the study in December 2023. We're running the study right now through a collaborative research agreement with the National Institutes of Health. There are 20 sites actively recruiting people across the country, and we’ve seen a lot of interest in a non-hormonal method. We haven’t projected when we will have our final data to release yet, but we do expect that by the summer of 2025 we will have about half of the target number of women in the study having completed six months of the study — basically, we’ll be halfway through.

What has been the most rewarding part of developing Ovaprene?

It's a proud time to be working on a contraceptive for women. Quite frankly, there's a lot going on in the world, and over the last couple years there have been changes around reproductive access. Half of all pregnancies, even in the US, are still unintended. If there's not something that is going to work for someone in their lifestyle, they're not going to opt for it. So, it's very rewarding to be working on something that hopefully just puts another option out there for people and just gives one more choice that maybe is going to be the perfect method for someone. It's nice to be making a difference in that way.

Also, just being a woman, it's fun getting to work on products that I can imagine my 25-year-old self would have thought were really cool or what a fun option this would have been to have. I’ve worked in a lot of therapeutic areas, and mostly I was working on diseases. There is something really invigorating about getting to work on something that is not about being ill and is about how we can solve this social challenge.

This interview has been condensed and edited for clarity.

References

1. Del Priore, G., Malanowska-Stega, J., Shalaby, S.W. & Richman, S. A pilot safety and tolerability study of a nonhormonal vaginal contraceptive ring. J Reprod Med  54, 685-690 (2009).
2. Mauck, C. et al. Successful postcoital testing of Ovaprene: An investigational non-hormonal monthly vaginal contraceptive. Contraception  132, 110373 (2024).
3. Mauck, C. & Vincent, K.L. The postcoital test in the development of new vaginal contraceptives. Biol Reprod  103, 437–444 (2020).