Seamless phase 2/3 oncology trial design with flexible sample size determination

Area of Science:

• Clinical Trial Design
• Oncology Drug Development
• Biostatistics

Background:

• Seamless phase 2/3 designs with fixed sample size determination (SSD) are popular in oncology for efficiency.
• However, fixed SSD can be problematic due to inaccurate treatment effect assumptions early in development.
• Limited efficacy data at the design stage poses a challenge for conventional fixed SSD.

Purpose of the Study:

• To propose an innovative seamless phase 2/3 study design with flexible SSD for oncology trials.
• To address the uncertainty in treatment effect estimations during the early stages of drug development.
• To offer an alternative to conventional fixed SSD designs by incorporating dynamic sample size adjustments.

Main Methods:

• The proposed design utilizes a distribution of treatment effects rather than a single assumption.
• Sample size for the phase 3 portion is determined dynamically based on observed phase 2 data.
• Practical sample size determination rules for the final analysis are discussed.

Main Results:

• The flexible SSD design can lead to a reduced sample size compared to conventional fixed SSD.
• The proposed design may offer improved statistical power.
• This approach enhances the efficiency of oncology drug development.

Conclusions:

• The innovative seamless phase 2/3 design with flexible SSD offers advantages over traditional fixed SSD methods.
• This design is particularly beneficial for aggressive development strategies aiming to expedite patient access to treatments.
• Dynamic sample size determination improves trial efficiency and reliability in oncology drug development.