OnCo
ideasIdea

Pre-specified crossover-adjusted survival in every trial that allows crossover

When control-arm patients switch to the new drug after their cancer grows, the survival comparison gets muddied. Trials should plan in advance how they will correct for this, and report both raw and corrected numbers.

Protocols permitting treatment switching pre-specify the adjustment method (rank-preserving structural failure time, inverse probability of censoring weighting, two-stage estimation), the assumptions, and sensitivity analyses, with the estimand defined under ICH E9(R1). Both intention-to-treat and adjusted OS are reported in the label and in HTA submissions. Health technology agencies already require this ad hoc; the idea is to make it a registration requirement.

Hypothesis
Mandatory pre-specified adjustment will reduce the frequency of OS results that are uninterpretable because of crossover, and will produce more consistent HTA decisions across countries for the same drug.
Rationale
Crossover is ethically necessary but currently destroys the OS signal in many trials, feeding disputes about value. Methods exist and are used inconsistently, often chosen after seeing the data.
What would test it
Audit recent oncology approvals with crossover for whether adjusted OS was pre-specified; then require it and re-audit after three years for interpretability and HTA discordance.
Maturity
early clinical
Who has to act
regulator
Cost to try
Small (under $1M)
Years to first evidence
1
Bottlenecks it attacks

Connected

4top