# A short pre-surgery drug window as the default early test of new agents

Source: https://onco.cc/ideas/idea-tr1-window-of-opportunity-default/  
OnCo record `idea-tr1-window-of-opportunity-default` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Between diagnosis and surgery there are usually a few weeks. Giving a new drug in that window and comparing the tumour before and after surgery shows whether it hits its target in real people, quickly and cheaply.

## Summary

Window-of-opportunity trials give a short course of an investigational agent between diagnostic biopsy and definitive surgery, with paired tissue for pharmacodynamic, proliferation (Ki-67) and immune readouts, and ctDNA dynamics. The proposal is to make a window study a standard early step for agents with a tissue biomarker, with cancer centres maintaining a standing window-trial pathway (consent, scheduling, sample handling) that any agent can slot into.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Agents showing target modulation in a window study will succeed in later phases at a higher rate than agents without such evidence, and window studies will kill inactive agents earlier and cheaper.
- Rationale: Pre-surgical endocrine and CDK4/6 window studies predicted later trial outcomes through Ki-67 change; the design gives human pharmacodynamic proof-of-mechanism with 20-40 patients.
- Proposed test: Fund a standing window-trial pathway at five centres and track the correlation between window-study pharmacodynamic outcomes and subsequent phase 2 success for the agents tested.
- Maturity: early-clinical
- Actor: research

## Sources

- Bottleneck evidence (Trial design, endpoints and cost): Davis et al., Availability of evidence of benefits on survival and quality of life of cancer drugs approved by EMA 2009-13 (BMJ 2017): https://doi.org/10.1136/bmj.j4530

## Connected records

- cancers: [Head and neck squamous cell carcinoma](https://onco.cc/cancers/head-and-neck/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Prostate cancer](https://onco.cc/cancers/prostate/)
- technologies: [Histopathology & immunohistochemistry](https://onco.cc/technologies/histopathology-ihc/), [Single-cell & spatial profiling](https://onco.cc/technologies/single-cell-spatial/)
- terms: [Circulating tumour DNA (ctDNA)](https://onco.cc/terms/ctdna/), [Neoadjuvant / adjuvant / perioperative](https://onco.cc/terms/neoadjuvant-adjuvant/)
- bottlenecks: [Biomarkers are not validated or standardised](https://onco.cc/bottlenecks/b-biomarker-validation/), [The valley of death between lab and product](https://onco.cc/bottlenecks/b-translational-valley/), [Trial design, endpoints and cost](https://onco.cc/bottlenecks/b-trial-design/)
- key papers: [Availability of evidence of benefits on overall survival and quality of life of cancer drugs approved by European Medicines Agency: retrospective cohort study of drug approvals 2009-13](https://onco.cc/key-papers/paper-davis-bmj/)
- roadmaps: [Surgery roadmap: radical operations → less surgery → no surgery when a drug has done the work](https://onco.cc/roadmaps/surgery-roadmap/), [Trial modernisation roadmap: the randomised trial → platforms and adaptive designs → decentralised, pragmatic and always-on](https://onco.cc/roadmaps/trial-modernisation-roadmap/)

---
JSON: https://onco.cc/api/v1/entities/idea-tr1-window-of-opportunity-default.json