Diaphragm to Prevent Unintended Pregnancy (and Maybe Someday HIV)

September 18, 2014

While many contraceptive options are on offer for women in high-income countries, the choices are limited, or nonexistent, in low-income countries and communities around the world. Globally, 215 million women are in need of modern contraception. For millions of women worldwide, the existing method mix of contraceptives is not sufficient.1 Challenges to access and use include the need to reduce or eliminate side effects and removing the need for a doctor’s visit, among others. Ensuring the range of contraceptives available meet the needs of women in a variety of geographic and socio-economic settings and stages of life is key.

On September 9, 2014 the SILCS Diaphragm (brand name Caya®) was approved by the US Food and Drug Administration (FDA) for marketing in the US. Available in fourteen European countries since 2013, and also approved this year in Canada, women in the US can expect to see it available in 2015. Improving on other diaphragms currently on the market, the SILCS diaphragm is a one-size-fits-(nearly)-all product—eliminating the need for a woman’s cervix to be measured by her doctor before use. It is also easier to insert (like a tampon), and in Europe and Canada it is available without a prescription.

The SILCS Diaphragm is a non-hormonal form of contraception, which is preferred by some women. This is also key in that it relates to some of the major research questions under consideration in HIV prevention for women: whether hormonal contraception increases a women’s risk of HIV infection, and the importance of developing a multipurpose prevention option that could prevent pregnancy and sexually transmitted infections (STIs), including HIV. The potential use of the SILCS diaphragm as a non-hormonal contraceptive device to deliver anti-HIV drugs poses some intriguing possibilities.

Approval of the SILCS diaphragm expands the non-hormonal options women can use that do not necessarily require regular healthcare visits. PATH, the developer of the SILCS Diaphragm, is currently working to get this new diaphragm to low-income countries as it was designed with the settings and health systems of resource-limited countries in mind. They have licensed the technology to Kessel (Kessel medintim GmbH), a German company that markets the device in 14 countries throughout Europe, Canada, and soon, in the US (although not without a prescription in the US).

The Expanding Effective Contraceptive Options (EECO) project—led by WomanCare Global and funded by the USAID’s Office of Population and Reproductive Health, in partnership with Population Services International, Every1Mobile , the International Center for Research on Women and Evofem—is conducting pilot introductions of the SILCS diaphragm, along with four other woman-initiated reproductive health technologies. These pilots are in India, Malawi and Zambia. The EECO project works on the registration, marketing and distribution of the products, aiming to get them to the women who would like to use them.

Getting additional pregnancy prevention options to women in all settings is an important step to providing all women in need with a range of contraceptive options. It is of particular importance in areas where the injectable hormonal contraceptive Depo-Provera is the primary contraceptive option available and accessible and HIV infection rates are high.

The SILCS diaphragm may also play a future role in HIV prevention as research groups are considering how it could be combined with other products to provide protection against both HIV and unintended pregnancy. Multipurpose prevention technologies are drugs or devices that provide contraception and protection from HIV and/or other STIs. PATH and other partners are exploring the use of the SILCS diaphragm as a reusable microbicide gel delivery system where the gel could be applied to the diaphragm before insertion.

Studies are underway looking at the effectiveness of SILCS as a contraceptive when used with tenofovir gel, currently under study as a microbicide to reduce risk of HIV. This delivery system may be more acceptable to some women than the current microbicide applicator being tested, and it could hold gel higher in the vagina, closer to the cervix, possibly reducing the potential for leaking gel. In addition, SILCS is now an approved contraceptive method so it might reduce the stigma associated with use of a new product for HIV prevention alone; and, it is reusable for two years, reducing the cost of a potential delivery system for tenofovir gel.

The second way SILCS could be developed as a multipurpose prevention option is as a slow-release microbicide delivery system. By loading an ARV-based drug for prevention into the SILCS “spring” during the production process, it could allow for controlled release of the ARV over time. Researchers at PATH and Queens University Belfast completed a proof-of-concept study testing the device loaded with dapivirine (another ARV-drug currently being tested as a vaginal microbicide ring) where the drug was released at a constant rate over a period of at least 12 months. The next phase of preclinical study is not underway due to funding constraints, and it remains to be seen if this approach will continue through the pipeline.

It is critical that additional contraceptive options like SILCS continue to move towards rollout in settings with high HIV incidence. AVAC is working in partnership with groups and advocates in East and Southern Africa and on the global stage to bring the voices of women as the end-users to the conversation around hormonal contraception and HIV risk, and to the importance of expanding the range and choices in contraceptive and disease prevention methods.
AVAC will continue to track SILCS and other multipurpose prevention options in the research and development pipeline on our Prevention Research Database (PxRD).

To get involved, email avac@avac.org.

1Guttmacher Institute, 2011, 2012