Surrogate Endpoints in Second-Line Trials of Targeted Agents in Metastatic Colorectal Cancer: A Literature-Based Systematic Review and Meta-Analysis.

Abstract

PURPOSE:

The purpose of this study was to evaluate progression-free survival (PFS) and objective response rate (ORR) as surrogate endpoints of overall survival (OS) in modern clinical trials investigating the efficacy of targeted agents in the second-line treatment of metastatic colorectal cancer (mCRC).

MATERIALS AND METHODS:

A systematic search of literature pertaining to randomized phase II and III trials evaluating targeted agents as second-line treatments for mCRC was performed. The strength of the correlation between both PFS and ORR and OS was assessed based on the Pearson's correlation coefficient (R) and the coefficient of determination (R2).

RESULTS:

Twenty trials, including a total of 7,571 patients, met the search criteria. The median duration of post-progression survival (PPS) was 7.6 months. The median differences between experimental and control arms were 0.65 months (range, -2.4 to 3.4) for the median PFS and 0.7 months (range, -5.8 to 3.9) for the median OS. PFS and ORR showed moderate (R=0.734, R2=0.539, p < 0.001) and poor correlation (R=0.169, R2=0.029, p=0.476) with OS, respectively. No differences between anti-angiogenic agents and other drugs were evident.

CONCLUSION:

Targeted agents investigated in the second-line treatment of mCRC provided minimal PFS gains translating into modest OS improvements. Considering both the moderate correlation between PFS and OS and the short duration of PPS, the OS should remain the preferred primary endpoint for randomized clinical trials in the second-line treatment of mCRC.

• Authors: Chiara Cremolini, Carlotta Antoniotti, Filippo Pietrantonio, Rosa Berenato, Marco Tampellini, Chiara Baratelli, Lisa Salvatore, Federica Marmorino, Beatrice Borelli, Federico Nichetti, Paolo Bironzo, Cristina Sonetto, Maria Di Bartolomeo, Filippo de Braud, Fotios Loupakis, Alfredo Falcone, M Di Maio
• Journal: Cancer research and treatment (Cancer Res Treat) Vol. 49 Issue 3 Pg. 834-845 (07 2017) ISSN: 2005-9256 [Electronic] Korea (South)
• PMID: 27857020 (Publication Type: Journal Article, Meta-Analysis, Review, Systematic Review)

Chemical References

• Biomarkers

Topics

• Antineoplastic Combined Chemotherapy Protocols (adverse effects, therapeutic use)
• Biomarkers
• Clinical Trials as Topic
• Colorectal Neoplasms (drug therapy, metabolism, mortality, pathology)
• Humans
• Odds Ratio
• Proportional Hazards Models
• Treatment Outcome