Phase I clinical trial

Phase I Clinical Trial

Study Type
Scope
Participants	20-100
Conducted by
Location
Duration
Results published in
Key findings
Related articles

A Phase I clinical trial is the first stage of clinical trials conducted to assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of a new biomedical intervention in humans. These trials are a critical step in the development of new drugs and therapies, providing initial data on the intervention's effects and side effects in a small group of healthy volunteers or patients.

Overview

Phase I trials are primarily concerned with assessing the safety of a drug. The main goal is to determine the drug's most frequent and serious adverse events and the dose at which these effects occur. This is often referred to as the maximum tolerated dose (MTD). Unlike later-phase trials, the primary focus is not on the efficacy of the drug.

Design

The design of Phase I trials is typically an open-label, non-randomized study. Participants are usually under close supervision, and the trial often takes place in specialized clinical settings. These trials may use a single ascending dose (SAD) or multiple ascending dose (MAD) design to gradually increase the dose administered to groups of participants.

Participants

Participants in Phase I trials are usually healthy volunteers, although some trials may include patients, particularly when the drug is anticipated to have severe or irreversible side effects. The number of participants typically ranges from 20 to 100.

Ethical Considerations

Given the risks involved, Phase I trials are closely regulated and require extensive ethical oversight. Informed consent is a critical component, ensuring that participants are fully aware of the potential risks and benefits.

Regulatory Aspects

In the United States, the Food and Drug Administration (FDA) oversees the conduct of Phase I trials, requiring an Investigational New Drug (IND) application before the trial can commence. Similar regulatory bodies exist in other countries, such as the European Medicines Agency (EMA) in the European Union.

Challenges and Criticisms

Phase I trials face several challenges, including ethical concerns about exposing participants to potential harm without direct therapeutic benefit. There is also the challenge of recruiting participants willing to undergo such trials.

See Also

• Clinical trial
• Drug development
• Pharmacokinetics
• Pharmacodynamics