Ash Bullement and Anthony Hatswell have had an original research article published in BMC Medical Research Methodology, concerning the use of multiple data cuts from a trial to iteratively fit and compare extrapolations as the data mature.
The research found that within the context of an immune-oncology treatment, more flexible parametric modelling approaches tended to yield more realistic extrapolations, and could be reasonably justified based on interim data.
You can read the open access article by following this link URL: https://bmcmedresmethodol.biomedcentral.com/articles/10.1186/s12874-020-00997-x