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Research and new methods

Phase I: first in people

Phase I trials are when a new medicine is tested in people for the first time. The main question is how safe it is and what amount is suitable.

Last updated: ~1 min read
Few participants
Figure 1.Few participants — Phase I: first in people

01Short answer

Only a small number of people take part, often no more than a few dozen. In cancer, they are usually patients for whom standard treatment no longer helps. The amount is raised cautiously, group by group, and side effects are watched very closely. Benefit is possible but is not the main aim. Some modern phase I trials show early promising results, but these must be confirmed in later phases.

02Simple explanation

First time in people.

Few participants.

Safety comes first.

Close monitoring.

03Scientific explanation

NCI: phase I trials study the safety, side effects and suitable amount of a new treatment.

NCI: new treatments are tested step by step, from the laboratory to clinical trials; only those proven safe and beneficial become standard care.

04What happens in the body?

Escalation

Each new group starts only after the previous group's safety is reviewed.

Small steps
Figure 2.Small steps — Phase I: first in people

Pharmacokinetics

How a medicine moves through the body.

A bedside monitor showing a patient's heart-rhythm trace
Figure 3.Close monitoring: a heart-rhythm monitor

How to read the news

Research news brings hope, but not every advance suits everyone. Look at who it was tested in, at what phase and in how many people.

Talk to your doctor

Show your doctor what you have read; they will explain how it relates to your diagnosis and treatment. Do not change your treatment on your own.

05From research news to a conversation: four steps

Read, check, ask, decide together.

Read — From a trusted source.1ReadFrom a trusted source.
Check — Phase, participants, result.2CheckPhase, participants, result.
Ask — Show your doctor.3AskShow your doctor.
Decide — Together, without rushing.4DecideTogether, without rushing.
SourceA trusted site.
DoctorA personal explanation.
SafetyNot changing treatment yourself.

06Key points at a glance

TopicIn brief
EscalationEach new group starts only after the previous group's safety is reviewed.
PharmacokineticsHow a medicine moves through the body.
How to read the newsResearch news brings hope, but not every advance suits everyone. Look at who it was tested in, at what phase and in how many people.
Talk to your doctorShow your doctor what you have read; they will explain how it relates to your diagnosis and treatment. Do not change your treatment on your own.

07Key terms

Maximum tolerated amount
The highest amount given without unacceptable side effects.
Pharmacokinetics
How a drug is absorbed and removed.
Clinical trial
Testing a new treatment with volunteers.
Evidence
A result confirmed by reliable research.

08Key points

  • Carefully.
  • With few.
  • Closely.
  • Check the source.
  • Talk to your doctor.

09Frequently asked questions

Will a phase I trial help me?

Possibly, but there is no guarantee; the main aim is safety.

How long does it last?

Usually months.

Is this advance right for me?

Only your treating doctor can say, based on your diagnosis, stage and condition.

10Questions for your doctor

Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.

  1. Will a phase I trial help me?

  2. How long does it last?

  3. Is this advance right for me?

My questions

12Sources

  1. National Cancer Institute. Phases of Clinical Trials
  2. National Cancer Institute. NCI Dictionary of Cancer Terms: phase I clinical trial
  3. National Cancer Institute. What Are Clinical Trials?
  4. National Cancer Institute. Using Trusted Resources
  5. National Cancer Institute. NCI Dictionary of Cancer Terms: phase II clinical trial
  6. National Cancer Institute. NCI Dictionary of Cancer Terms: phase III clinical trial
  7. National Cancer Institute. NCI Dictionary of Cancer Terms: phase IV clinical trial
  8. National Cancer Institute. Placebos in Cancer Clinical Trials
  9. National Cancer Institute. NCI Dictionary of Cancer Terms: control group
  10. National Cancer Institute. Randomization in Clinical Trials
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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