The i3+3 design for phase I clinical trials

Area of Science:

• Clinical Trials
• Biostatistics
• Pharmacology

Background:

• Traditional 3+3 designs often fail to meet dose-finding trial objectives.
• Model-based designs show improved performance but can be complex.
• There is a need for improved rule-based designs balancing simplicity and efficacy.

Purpose of the Study:

• To introduce and evaluate a novel rule-based design, i3+3, for early-phase clinical trials.
• To compare the operating characteristics of the i3+3 design against traditional and model-based designs.
• To assess the safety and accuracy of the i3+3 design in identifying the maximum tolerated dose (MTD).

Main Methods:

• The study proposes the i3+3 design, incorporating advanced rules to handle data variability.
• Operating characteristics were evaluated through extensive simulations.
• The i3+3 design was compared with the standard 3+3 design and popular model-based designs.

Main Results:

• The i3+3 design demonstrated superior safety and accuracy in identifying the MTD compared to the 3+3 design.
• Simulations indicated that i3+3 offers comparable performance to established model-based phase I designs.
• The proposed design effectively accounts for data variabilities, enhancing trial outcomes.

Conclusions:

• The i3+3 design represents a significant advancement over the traditional 3+3 approach for dose-finding studies.
• It offers a robust and reliable alternative to model-based designs, balancing performance with operational simplicity.
• The i3+3 design enhances patient safety and the precision of MTD determination in early-phase trials.