Bringing Microbicides to Market

The process of testing a new product for safety and effectiveness is long and complex. It generally takes many clinical trials—some involving leads that prove to have problems or don't work—before finding a safe and effective product that can address a health need.

Candidate products pass through rigorous laboratory and animal testing before testing in people begins. There are three phases of human clinical trials:

• Phase I trials determine whether the product is safe (does not cause immediate harm) when used by a small number of healthy volunteers over a few weeks
  

• Phase II trials test for safety and effectiveness of the product, but over a longer time and with a larger number of volunteers, some of whom may have higher risk factors
  

• Phase III trials enroll thousands of people in several sites and frequently in several countries. These trials evaluate overall safety and effectiveness
  

If the candidate product appears to cause harm or is not effective, research is stopped and that lead is dropped from consideration.

Even when a clinical trial suggests that a product is effective, there are many more steps that must be completed before it can be made available to consumers, including:

• Review and licensing for use by a drug regulatory agency 
  

• Manufacture in large quantities and introduction in different settings 
  

Even if a clinical trial does not yield convincing results of effectiveness, it nonetheless advances the scientific field. Each trial builds the evidence base and strengthens the field's ability to plan and mount successful trials in the future