What are Microbicides? The term “microbicide” refers to a range of experimental products such as gels, creams, rings, and films that aim to prevent the sexual transmission of HIV. Current microbicide trials are evaluating candidates that are applied vaginally or rectally using an applicator. In most of these studies volunteers are asked to use the candidate microbicide before, and sometimes after, every sex act. There is also work underway to explore other types of “delivery” systems, such as a vaginal ring that would release the microbicide that could be worn for long periods of time and wouldn’t require application before sex.
An effective microbicide would reduce the risk of HIV infection at the site of sexual exposure. There is a range of ways that a microbicide might provide this protection. It might contain an active ingredient that blocks HIV activity directly; it might provide a more general enhancement of naturally-occurring mucosal defenses and/or physical barrier at the mucosal surfaces.
Microbicide Investment In 2009, total global investment in microbicide R&D was US$236 million, a 3% decrease over 2008. Public-sector funders provided US$223 million (94%), the philanthropic sector US$11.8 million (6%) and the commercial sector US$1 million (<1%). Of the public sector funders, the US continued to maintain the largest presence, providing US$173 million (73%) of total investment, an increase of 12% over 2008 due in part to a US$4.7 million infusion of in American Recovery and Reinvestment Act (ARRA) stimulus funds. European national governments and the European Commission together accounted for US$44 million, an increase of 11% from 2008. The commercial sector contributes to the development of microbicide research in a number of ways through pharmaceutical company support. A number of companies have provided ARV compounds for development as potential microbicides along with technical support to product developers. From 2004 to 2009, IPM obtained non-exclusive royalty-free licenses for ARVs from GileadSciences (NRTI), Johnson & Johnson subsidiary Tibotec (NNRTI), Pfizer (CCR5 blocker), Merck & Co. (CCR5 blocker & gp41 binder), and Bristol-Myers Squibb Co. (gp120 binder). The microbicide field has also benefited over this period from the active participation of the following biotechnology companies for the following products: Endo Biopharmaceuticals (PRO2000), ImQuest Biosciences (pyrimidinediones), Mapp Biopharmaceuticals (monoclonal antibodies), Osel (probiotics), ReProtect (BufferGel), and Starpharma Holdings (VivaGel)—many companies with support for follow-on development through a variety of NIH grant and contract mechanisms.
Microbicide Expenditures. A subset of investments in microbicide R&D in 2009 was analyzed to provide a breakdown of global funding allocations by type of activity or product development stage: 9% was devoted to basic mechanisms of mucosal transmission, 36% to pre-clinical research, 11% to product formulation, 34% to clinical trials, 4% to social science research, 4% to infrastructure, and 2% to policy and advocacy. Basic mechanisms of mucosal transmission, formulations and preclinical work each saw increased investment from 2008 to 2009.
N.B. Figures and Tables are taken from the report Advancing the Science in a Time of Fiscal Constraint: Funding for HIV Prevention Technologies in 2009.
