Phase 3 Clinical Trials

If a drug makes it through a phase II clinical trial and enters a phase III clinical trial the number of participants generally increases again to between 300 – 3,000 participants. Phase III trials are randomized, controlled and often take place across several facilities. The goal of this phase of clinical testing is to determine if the new treatment is better than the best treatment currently available. In phase III clinical trials there is sometimes a phase called phase IIIB where participants continue to receive the drug until it is available to purchase.

At this point in the study sponsors are also looking at something called “label expansion”. This means that they are looking at new ways to potentially use the drug besides the original intention that it was tested for. This might also include using it on a new type of patient.
At the end of a phase III trial a “regulatory submission” is prepared. This is a document that outlines all of the research done on the drug up to that point. It also includes the pre-clinical trials research, the manufacturing procedures and requirements for the drugs as well as the drug’s shelf life. At this point the drug may even be marketed to the public. If the regulatory submission is approved the drug is made available for prescription to the general public.
As with all clinical studies, phase III trials are closely monitored by sponsors, government agencies and the clinical trials team throughout the process. Protocols are followed and patients are informed about what to expect every step of the way. Phase III trials may be conducted by a patient’s regular doctor or by members of the clinical trial team. If a new drug or treatment makes it through a phase III trial it is then available to the public either by prescription or over the counter (although there is one more phase of clinical trials).