EXECUTIVE SUMMARY

Researchers now are focusing on an investigational multipurpose prevention technology comprised of griffithsin in a carrageenan gel. While research is in the early stages, the combination approach may lead to a new option to prevent HIV and STIs in an on-demand or sustained use format.

  • Griffithsin is a potent anti-HIV agent that has been found to be safe and effective when tested against HIV and herpes simplex virus-2 (HSV-2) in animal studies.
  • Research scientists at the Population Council plan to pursue multiple delivery methods for griffithsin, including inserts that dissolve quickly and intravaginal rings, to provide on-demand and sustained protection.

Researchers now are focusing on an investigational multipurpose prevention technology comprised of griffithsin, a naturally occurring algae protein, in a carrageenan gel. While research is in the early stages, the combination approach may lead to a new option to prevent HIV and STIs in an on-demand or sustained use format.

Scientists at the New York City-based Population Council have begun enrolling women in a Phase I trial, conducted at the Albert Einstein College of Medicine in the Bronx, NY. A total of 27 women ages 18-49 will be enrolled. Seven women will take part in an open-label period and will receive a single dose of the griffithsin/carrageenan gel formulation. Data from this initial trial will inform the randomized, placebo-controlled safety, pharmacokinetics, and pharmacodynamics assessment of the formulation. Twenty women will be randomized to receive either the formulation or a placebo gel; all will use a gel product once daily for 14 days. Results are expected in 2018.

Initially discovered by scientists at the Center for Cancer Research at the National Cancer Institute, griffithsin is a potent anti-HIV agent that has been found to be safe and effective when tested against HIV and herpes simplex virus-2 (HSV-2) in animal studies.1

“Griffithsin’s mode of action and the fact that it is not used in HIV treatment means there is no risk that users of a griffithsin-prevention product could develop cross-resistance to ARVs [antiretroviral drugs] that are used for treatment,” said George Creasy, MD, medical director at the Population Council’s Center for Biomedical Research, in a press statement. “This may increase the possibility that a griffithsin multipurpose prevention technology could become an over-the-counter product and increase access for people in high-demand, low-resource settings.”

The Population Council plans to pursue multiple delivery methods for griffithsin, including inserts that dissolve quickly and intravaginal rings, to provide on-demand and sustained protection. Additional methods of delivery may be developed by agency scientists in the future.

“Multipurpose products that prevent sexually transmitted infections, including HIV, must be a research and development priority,” said James Sailer, MPP, vice president and executive director of the Center for Biomedical Research at the Population Council. “We are excited to be enrolling participants in the first trial of a griffithsin-containing multipurpose prevention technology, which could be an important addition to the HIV and STI prevention toolbox.”

HIV prevention efforts have proven effective in the United States: The number of new infections has dropped since the peak of the epidemic in the mid-1980s, and an overall stabilization of new infections has been seen in recent years.2 Currently, methods to prevent HIV include abstinence, condoms, and pre- and post-exposure prophylaxis with antiretrovirals.

However, there is concern that using ARV-based products for HIV prevention could promote the development or spread of drug-resistant HIV strains that would compromise subsequent treatment with ARVs.3 High rates of drug resistance in a population could make the spread of drug resistance easier and eventually reduce the effectiveness of ARVs in treatment and prevention.

Griffithsin is one product in the early stages of development as a multipurpose option. Other potential products include protection against unintended pregnancy/HIV/HSV-2 (herpes), unintended pregnancy/chlamydia/gonorrhea/HIV/ HSV-2 (herpes), and HIV/HSV-2 (herpes)/human papillomavirus, formulated in vaginal rings, gels, and fast-dissolving vaginal inserts and films. (See all methods now under development at the Initiative for MPTs’ website, http://www.theimpt.org.)

Young women in the United States are interested in multipurpose prevention technology (MPT) options that are safe and effective, with a preference for protection against HIV and HSV, according to results from a recent cross-sectional online survey.4

Women who participated in the survey were ages 18-29, U.S. residents, and had engaged in sexual activity with a male partner in the past three months. Results of the survey indicate that women desired protection from HIV (86.6%), followed by herpes simplex virus (HSV, 41.1%) and human papillomavirus (21.9%). Protection from gonorrhea (10.8%) and chlamydia (12.7%) were seen as least important.

What type of prevention options would women like? Survey findings indicate that many women would prefer injectables (45.6%), followed by vaginal gels (33.7%), vaginal rings (26.3%), and diaphragms (17.3%). Safety and efficacy in preventing pregnancy were the most important factors when choosing a multi-purpose prevention option.4

“While injectables are most highly desired, many women would use vaginal/topical methods,” researchers say. “These preferences must be considered as MPT development continues to ensure acceptance among young women, an important target demographic, in the United States.”

REFERENCES

  1. Levendosky K, Mizenina O, Martinelli E, et al. Griffithsin and carrageenan combination to target herpes simplex virus 2 and human papillomavirus. Antimicrob Agents Chemother 2015;59:7290-7298.
  2. Hall HI, Song R, Rhodes P, et al. Estimation of HIV incidence in the United States. JAMA 2008;300:520-529.
  3. Chirenje ZM, Marrazzo J, Parikh UM. Antiretroviral-based HIV prevention strategies for women. Expert Rev Anti Infect Ther 2010;8:1177-1186.
  4. Schreier J, Sheth AN, Lathrop E, et al. Multipurpose prevention technology product preferences among young women in the United States. Contraception 2017;96;302.