Clinical trials studying and evaluating new drugs evolve through a number of different stages known as ‘phases”. Early phase trials examine the safety and dosing of the candidate drugs, while later phase trials are concerned more with safety, tolerability and comparison against existing competitor drugs. In totality, it can take biopharmaceutical companies and medical device manufacturers up to 6-7 years to complete all clinical trials for a new therapy.

The four major clinical trial phases are phases I, II, III, and IV.

Phase I 

This is the first time a new therapy is tested on people. It studies the effects of the therapy on humans to establish a safe dosage range and identify and evaluate its side effects.

Phase I trials are usually small and involve around 20-50 volunteers. These could either be healthy members of the public or patients with the disease the therapy targets.

A trial can last several months, and their results are vital to the design of further trials. Once the new therapy has been found to be safe and well tolerated, it moves into phase II. The FDA reports that approximately 70% of drugs undergoing Phase I trials move to phase II.

Phase II 

Phase II clinical trials are usually bigger than Phase I and involve many more subjects than Phase I, some working with up to several hundred people. Clinical trials in this phase test the new therapy against potential disease profiles e.g., whether it shrinks a cancer tumor or improves blood test results. Phase II clinical trials may also provide more detailed information about the safety and side effects of the new therapy. 

Phase II trials subjects are sometimes randomized to receive the new drug, a standard treatment, or a placebo. This helps improve accuracy of the results by removing investigator bias.

Phase II trials can last anywhere from months to 2 years, with about 33% of drugs moving onto the next phase – Phase III.

If a clinical trial is unsuccessful, the sponsor must submit a written summary report of the results to the applicable governing body. In the U.S, many different regulations govern the retainment of records from clinical trials. The FDA also requires that records of failed trials be retained for a minimum of two years, while other involved bodies stipulate much longer.

Phase III 

By Phase III the drug has proved to be safe, well tolerated and effective against the target disease. Trials in this stage are usually quite large and can involve anywhere between hundreds and several thousands of people. The number of subjects required is based on the need to demonstrate statistical significance of the new therapy against existing standard therapies (if the drug is competing with an existing treatment). These studies are often multinational. 

More, a significant portion of safety data is derived in this phase, as the scale allows for visibility of less common side effects that may not appear in the preceding trails with smaller subject numbers. The reason is that uncommon side effects could have gone undetected in the preceding smaller trials. Phase III trials are randomized and can last for several years.

On completion of the Phase III studies, the sponsor can apply for approval to market their drug to the target populations defined through the preceding trials. Only  25-30% of drugs from Phase II gain marketing approval.


Phase IV

Phase IV trials are often called post-marketing surveillance studies. 

They are conducted after the new therapy has been approved for sale by the FDA (in the U.S) or an equivalent drug approval body. These look for side effects that were not seen in earlier trials and provide further information on the efficacy of the therapy over a long period of time They may also explore new indications or formulations of the newly approved drug as well as its cost-effectiveness. 

 The earlier clinical trials can be very complex and fraught with many challenges.Getting them right the first time around saves time and money both in that phase as well as informing following phases to be more focused and effective, decreasing the time to approval..

Encapsia supports the successful completion of all clinical trials including the more complex studies that current EDC vendors may struggle with. The encapsia software suite enables teams to collaborate in real-time, offers more flexibility, control, and more efficient/ streamlined processes. Encapsia of solutions cover you end-to-end clinical data capture, cleaning, analysis and management in a fully compliant, secure system. Encapsia also supports seamlessly integration with other system, further improving ease o adoption.

Take control of your clinical data and remove the barriers to trial continuity. Find out more about how encpasia can drive your clinical trial studies here.

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