Phase III Immunotherapy RECIST and iRECIST

Challenge

Immunotherapy trials present a distinctive interpretive challenge: apparent radiographic progression may reflect treatment-related inflammation rather than true tumor growth. The sponsor required central reviewers to distinguish pseudoprogression from genuine disease progression with consistency across more than 90 sites in 18 countries, while applying two response frameworks—RECIST 1.1 and iRECIST—in parallel. Any variability in how unconfirmed progression was identified, confirmed, or dated threatened to distort the trial's efficacy conclusions and invite regulatory scrutiny.

Our Solution

Intrinsic Imaging assigned subspecialty oncologic radiologists to perform dual independent assessments under both response frameworks, with each reader blinded to the other's determinations. Automated discordance triggers within our reading platform flagged unconfirmed progression findings and routed them immediately to adjudication, ensuring that no progression event was finalized without the confirmatory review iRECIST demands. Standardized reader training and ongoing calibration sessions maintained uniform application of both criteria sets throughout the trial's duration.

Results

• Consistent central assessment of 12500+ timepoints
• Full audit trail supported the BLA submission
• Zero Form 483 observations during the sponsor inspection