Oncolytics Biotech Inc T.ONC

Validating surrogate end points

[westcoast1000]

Published online 2016 May 10. doi: 10.1016/j.mayocp.2016.02.012

PMCID: PMC5104665

NIHMSID: NIHMS763236

PMID: 27236424

Strength of Validation for Surrogate End Points Used in the US Food and Drug Administration’s Approval of Oncology Drugs

Chul Kim, MD, MPH and Vinay Prasad, MD, MPH

The paper noted above from 2016 has this paragraph  in the intro:

The validation of surrogate end points in oncology is an increasingly important field, with different statistical methods used.8–12 We favor a clear and simple hierarchy to grade the strength of surrogate-survival correlations.7,13 In this model, level 3—the lowest level—requires the surrogate-survival correlation to be only biologically plausible. Level 2 and level 1 analyses require clinical data. Although level 2 analysis shows that the surrogate is associated with the final outcome across groups, level 1 analysis addresses the clinically relevant question of whether improving the surrogate end point is associated with improvements in survival across many randomized studies. Typically, regression analysis is performed in level 1 studies. The x coordinate reflects the change in surrogate end point, and the y coordinate reflects the change in final end point. Correlation coefficients (r) closer to 1 signify stronger associations. As such, the validation of surrogate-survival associations in oncology exists along an established hierarchy.


Back to ONCY, clearly there are studies, regressions and history linking PFS and ORR to OS in broad terms. For pela the other issue is the genetic and other testing that is done to identify the status of the immune system of the patient as an indicator of potential response. Clearly for an immunoloical therapy like pela the status of the immune system is conceptally and practically an important indicator of being able to stimulate the immune system.

The vanished post from Q does point out that ONCY has never stated how it uses the biomarkers it found in its multi year quest to find them. We do not know if they can or will use the biomarkers for recruiting patients for trials. We could expect they would be used for future precision medicine.

My thoughts anyway.