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ABOUT contains imputed individual participant data (IPD) from previously published oncology research clinical trials (RCTs). The site also contains various types of analysis performed on these data. Data and analysis can be downloaded or viewed interactively using R-Shiny.

Public domain license. All data are are available under a permissive CC BY4.0 license; software is released under an MIT License.

Individual participant data. IPD in oncology trials is the time (relative to the start of the trial) at which events such as progression, death and censoring occur for individual (anonymous) trial participants. This is the most useful form of survival data for meta-analysis and retrospective investigation of trial outcomes [1,2].

Data imputation. The Kaplan Meir estimators [3] for survival universally published as part of Phase 3 clinical trial reports are plotted using IPD but the underlying values are rarely published. The International Committee of Medical Journal Editors (ICMJE) has stated release of IPD from clinical trials is an ethical necessity but compliance remains poor: less than 1% of papers published in the last three actually comply [4]. To overcome this problem we have developed methods we have developed image processing methods to impute IPD values from published plots of the Kaplan-Meier estimator [5–7]. Our approach is consistent with the Institute of Medicine’s reports on best practices for sharing data from published clinical trials, including crediting the sources of the data and sharing all code used in the analyses [8]. However, primary data with associated demographic information would be superior to imputed data; we welcome data contributions from individuals with access to the primary data. Contact us at CancerIPD [at]


CT1.v1 Imputed IPD from ~150 trial publications in breast, colorectal, lung, and prostate cancer, which in aggregate comprise ~220,000 overall survival OS) or event-free survival events (e.g. progression free survival, PFS).

Citations: “Cancer patient survival can be parametrized to improve trial precision and reveal time-dependent therapeutic effects” by Deborah Plana, Geoffrey Fell, Brian M. Alexander, Adam C. Palmer, Peter K. Sorger. Nat Commun 13, 873 (2022).

Plana, D., Fell, G., Alexander, B. M., Palmer, A. C. & Sorger, P. K. Imputed individual participant data from oncology clinical trials. Synpase repository. (2021).

CT2.v1 Imputed IPD from combination therapies with immune-checkpoint inhibitors across six cancer types including breast, gastric, head and neck, lung, melanoma, and renal.

Citation: “Predictable clinical benefits without evidence of synergy in trials of combination therapies with immune-checkpoint inhibitors” by Adam C. Palmer, Benjamin Izar , Haeun Hwangbo and Peter K. Sorger. Clin Cancer Res (2022) 28 (2): 368–377.


Harvard MIT Program in Regulatory Sciences.

Dana-Farber Cancer Institute

Palmer Laboratory at University of North Carolina at Chapel Hill


  1. Stewart, L. A. & Tierney, J. F. To IPD or not to IPD?: Advantages and Disadvantages of Systematic Reviews Using Individual Patient Data. Eval Health Prof 25, 76–97 (2002).
  2. Riley, R. D., Lambert, P. C. & Abo-Zaid, G. Meta-analysis of individual participant data: rationale, conduct, and reporting. BMJ 340, c221 (2010).
  3. Kaplan, E. L. & Meier, P. Nonparametric Estimation from Incomplete Observations. 53, (1958).
  4. Danchev, V., Min, Y., Borghi, J., Baiocchi, M. & Ioannidis, J. P. A. Evaluation of Data Sharing After Implementation of the International Committee of Medical Journal Editors Data Sharing Statement Requirement. JAMA Netw Open 4, e2033972 (2021).
  5. Alexander, B. M., Schoenfeld, J. D. & Trippa, L. Hazards of Hazard Ratios - Deviations from Model Assumptions in Immunotherapy. N. Engl. J. Med. 378, 1158–1159 (2018).
  6. Guyot, P., Ades, A., Ouwens, M. J. & Welton, N. J. Enhanced secondary analysis of survival data: reconstructing the data from published Kaplan-Meier survival curves. BMC Med Res Methodol 12, 9 (2012).
  7. Rahman, R. et al. Deviation from the Proportional Hazards Assumption in Randomized Phase 3 Clinical Trials in Oncology: Prevalence, Associated Factors, and Implications. Clin Cancer Res 25, 6339–6345 (2019).
  8. Committee on Strategies for Responsible Sharing of Clinical Trial Data, Board on Health Sciences Policy, & Institute of Medicine. Discussion Framework for Clinical Trial Data Sharing: Guiding Principles, Elements, and Activities. (National Academies Press (US), 2014).


This project was supported by NIH grant U54-CA225088 to Peter Sorger. Deborah Plana is supported by NIGMS training grants T32-GM007753 and F30-CA260780.