Surrogate endpoints in assessment of clinical efficacy and safety of oncology drugs — analysis of AHTAPol recommendations

Abstract

Treatments in oncology are assessed in terms of clinical efficacy and safety at the stage of therapeutic decisions made by oncologists, but also during reimbursement processes (by Health Technology Assessment bodies). Those assessments are based on analysis of clinical benefits measured by progression-related endpoints (progression free survival — PFS, time to progression — TTP) or by survival (overall survival — OS).

Therapeutic decisions in clinical practice are usually based on so called surrogate endpoints (PFS, TTP, response rate, partial response rate), as opposed to „hard” endpoints like survival (OS). This results from a fact that it is much harder to prove survival benefits in clinical trials, because it usually requires long-term follow-up studies and large numer of enrolled patients. This raises a question of whether surrogates are correlated with hard clinical enpoints, and how strong the correlation is. All those endpoints have different clinical meaning, different significance for patients and also different impact on reimbursement decisions.

The aim of this paper was to present definitions of the most commonly used oncology endpoints, show differences and similarities between them and to analyze what is their impact on reimbursement recommendations made by Polish Agency for Health Technology Assessment.