IPM Approach to Clinical Trials
IPM’s clinical trials are carried out sequentially: first to determine the safety of the product (ensuring that no significant side effects occurred among participants) and then to test its longer-term safety and efficacy (the ability of the product to prevent HIV infection).
Initial Safety Trials
Phase I trials involve small numbers of women who participate under carefully controlled clinical conditions over several days or weeks.
Expanded Safety Trials
Phase I/II trials, in which a microbicide is administered to a wider range of women over longer periods, are then conducted to gain additional safety and acceptability data.
Only when the safety trials have been completed can efficacy trials begin to test the safety of the microbicide over a longer time period and the ability of the microbicide to prevent HIV infection.
Much larger trials, usually Phase III, need to be conducted in locations where new HIV infections are occurring at a relatively high rate, so that researchers can see if there is a difference in infection rates between those women who use the active microbicide product and those who use a placebo product (without the active drug).
If significantly fewer women become infected in the group that used the microbicide, then researchers know that the microbicide helps reduce the risk of HIV infection.
Thousands of volunteers are usually enrolled in HIV prevention efficacy trials. In some cases, researchers may conduct Phase IIB trials, which can yield initial efficacy data and usually enroll fewer participants than a Phase III trial, typically up to 1,000 participants and sometimes many more.