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# Comments on ICH Statistical Principles Addendum
- URL: https://www.fdaweb.com/comments-on-ich-statistical-principles-addendum/
- Published: 2018-04-30T12:00:00.000Z
- Updated: 2026-09-15T00:01:50.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5141333

UCB BioPharma says it appears that an International Conference for Harmonization draft guidance on statistical principles for clinical trials addendum on estimands and sensitivity analysis in clinical trials “still does not give real guidance on which estimands (specifically, handling strategies for intercurrent events) are to be used. The company’s comment [letter](https://www.regulations.gov/document?D=FDA-2017-D-6113-0011&ref=fdaweb.com) also says the document should include guidance on wording of study objectives so that estimand construction is properly supported.

Pfizer’s [comment](https://www.regulations.gov/document?D=FDA-2017-D-6113-0016&ref=fdaweb.com) asks that the term “post-randomization” be substituted for “intercurrent” throughout the document and makes other general and specific recommendations.

In its letter, Alexion [asks](https://www.regulations.gov/document?D=FDA-2017-D-6113-0010&ref=fdaweb.com) FDA to consider clarifying the scope of additional variables required to meaningfully define a population summary; the population summary attribute of estimand in the context of time-to-event analysis; whether imputation strategy as opposed to observed data should be part of estimand definition, and other general and specific comments.