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A healthcare worker provides treatment to a smiling young patient seated in a clinic chair in a colourful paediatric treatment room.

Types of clinical trials

There are two main types of clinical trials: therapeutic trials and non-therapeutic trials.

Therapeutic trials test new or improved treatments to determine their safety and effectiveness for specific disease. Each study builds on earlier research to improve the best available therapies and undergoes rigorous clinical and scientific review.

Non-therapeutic trials focus on improving our understanding of childhood cancer. By studying how cancer develops and the effects of treatment, including side effects, researchers aim to reduce long-term impact and improve quality of life, while also exploring how genetics can influence cancer risks and treatment options. 

Phases of clinical trials

Clinical trials are completed in phases. Each phase of a clinical trial builds upon the previous phase, with the overall goal of improving childhood cancer treatments.

The clinical trials pathway usually begins with preclinical research, where treatments are investigated in the laboratory to ensure they are ready for human testing. Phase 1 trials involve small groups of participants to understand safety and dosage. Phase 2 trials look at how well the treatment works for specific cancers. Phase 3 trials compare the new approach with the current best treatment in larger groups. Phase 4 trials continue to monitor long‑term safety and benefits once the treatment is approved. 

Phase I clinical trials

  • Phase I trials aim to identify the safest dose of a new treatment and understand how the body responds to it.
  • They begin with very low doses, which are gradually increased in small groups of participants to assess tolerance.
  • These trials are offered only when standard treatments are no longer effective or suitable.
  • Most participants do not receive direct benefit, though a small number may respond positively.

Phase II clinical trials

  • Phase II trials evaluate whether a new treatment works for specific types of cancer and gather more information on how it affects the body.
  • Patients receive the dose that was shown to be safe in Phase I and are monitored for side effects and for whether the cancer shrinks or disappears.
  • These trials are offered when standard treatments have not worked or when no standard treatment exists for the disease.
  • A small number of patients may respond to the new treatment, and the knowledge gained helps improve future therapies for children.

Phase III clinical trials

  • Phase III trials test whether a new treatment, already shown to work for a specific cancer, is better than the current standard therapy, such as offering higher cure rates, longer disease control, fewer side effects, or reduced time in hospital.
  • Patients are randomly assigned to receive either the standard treatment or the new treatment, a process called randomisation.
  • These trials include patients with the same type of cancer who are eligible for standard therapy.
  • Phase III studies may identify new treatments that provide greater benefits than current standard care.