Guide to 4 Clinical Trial Phases/Stages

There are a series of steps involved in a clinical trial. Each stage is designed for answering different questions related to the research. In this blog, we have explained the four stages of a clinical trial.

Phase 1

In the first phase, researchers test a new treatment or drug on small groups of people. It is meant for evaluating the safety of the drug and to determine a safe dosage range along with identification of side effects.

Phase 2

In this clinical trial phase, interventions are studied on a larger group of people for determining the efficacy. This stage is also meant for evaluating the safety of the drug or treatment further.

Phase 3

This stage is meant for studying the efficacy of a drug or treatment in large groups of participants. It is done by comparing the drug to other standard drugs. Phase 3 studies are used for monitoring the adverse effects and for collecting information that allow the safe use of the drug or treatment being studied.

Phase 4

The fourth phase is conducted after the drug has been marketed. It is designed for monitoring the effectiveness of the approved intervention in the general population. In the fourth phase, information is also collected about its adverse effects related to its widespread use. The collected information can also be used for investigating the potential use of the drug or treatment in a different condition with other types of therapies.

Pharmacovigilance services are also important in clinical research studies. Pharmacovigilance is the science related to detection, assessment, understanding and prevention of adverse effects of the drug or treatment. It plays an important role in ensuring that doctors have sufficient information for making a decision as far as choosing a drug for treatment is concerned.

What happens in phase 2 clinical trials

In clinical trials, phases are meant for researchers to conduct experiments with a health intervention. The aim is to find sufficient evidence for a process that might be useful as a medical treatment. For instance, if a pharmaceutical study is being conducted, the phases will start with drug design and discovery. The next step involves animal testing and if that is successful, they start the clinical phase of development. They test the safety of the drug in humans and expand the test for determining if the treatment is effective.

There are mainly four phases in a clinical trial that involves drugs. The drug development process normally proceeds through all four phases and continues for years. Once the drug being studied passes through phase 1, 2 and 3 successfully, it gets approved by the national regulatory authority for general use.

Phase 1 is designed for determining maximum amount of drug that can be given to a human before adverse effects become dangerous or intolerable. This phase is also referred to as ‘First-in-man Studies’. A group of 2-100 healthy volunteers participate in this phase. They are observed by the researchers in a clinical trial clinic.

In Phase 2 clinical trial, researchers evaluate whether the drug has any biological effect or activity in the human body. This is done once the dose or range of doses of the drug is determined from Phase 1. Larger group of volunteers participate in this second phase. This phase also continues the safety assessments of Phase 1. Some phase 2 trials are designed as case series. They demonstrate the activity and safety of the drug in selected patients.

Even BA/BE studies are important in clinical trials under which the test product is compared with the product already being sold in the market.

Companies Outsourcing Pharmacovigilance Services

There are many drug manufacturing companies that choose to outsource pharmacovigilance services to a third party. By gaining access to the expertise, flexibility and systems of a reliable service provider, pharma companies can benefit to a great extent. When it comes to the scale of outsourcing partnership, the size and needs of the pharmaceutical or biotech manufacturers needs to be taken into consideration.

Many large pharmaceutical companies outsource pharmacovigilance services even though they have the money and resources. Here’s how they benefit from outsourcing:

• It helps them save money because instead of hiring staff and managing everything in-house, they get instant access to trained professionals of the pharmacovigilance service provider. It eliminates the need for hiring, training and retaining staff. Ultimately, this not only helps in saving money but also allows their internal team to stay focused on the core business functions.
• The vendor gets to access the systems and standard operating procedures (SOPs) of the pharma company. This allows quick initiation of the programs, as per the client’s specifications. In such a case, the vendor acts as an extension of the pharma team. 
• Scalability is another benefit that pharma companies get to enjoy if they outsource pharmacovigilance. Since most large companies have some systems and staff in place for pharmacovigilance, the vendor can be leveraged for completing a subset of activities like, literature screening, safety writing, case processing.

When a small pharma company outsources, here are the benefits it enjoys:

• The company gets access to the service provider’s expertise and experience. Even they save money because they don’t have to hire, train and retain staff in-house. They get access to the SOPs and systems of the vendor.

Since many companies offer services related to pharmacovigilance and biologics in India, it is important to choose a reliable service provider.

Understanding Early Phase Clinical Trials

There are different phases of a clinical trial. In the early phase, a drug’s safety is tested whereas in the later phases, the effectiveness of a new treatment or a drug is compared to existing treatments. Mainly, there are three phases in a trial but some trials also have a phase 0 and phase 4 that is done once the drug is licensed.

Early phase in a clinical trial is the first step towards testing new medicines developed in a laboratory. The main purpose of this phase is to find out the correct dosage of a new medicine, how human body absorbs the drug, what are its side effects and toxicities and how often the drug can be given to ensure that its effect remains. The timely and strategic collection of data in the early phase clinical trial is necessary for the development process. It is also necessary for critical decision-making.

The early phase involves a small number of people. They are given only a small dose of the drug. The researchers mainly look for the following:

1. Has the effect of the drug reached the ailment
2. How the drug has been behaving with the human body
3. How the body is responding to the drug

In the first phase, a new treatment is tested on humans. It is done for establishing how a certain treatment is acting on humans and what are its safety limits? The treatment is tested on a small group of patients in increasing dosages. The researchers watch the patients carefully to see if there are any harmful side effects happening.

Phase 2 clinical study is done for testing the safety of the drug and in phase 3, the new treatment is compared to the existing treatment to assess the effectiveness.