Chemotherapy Rechallenge or Reintroduction Compared to Regorafenib or Trifluridine/Tipiracil for Pretreated Metastatic Colorectal Cancer Patients: A Propensity Score Analysis of Treatment Beyond Second Line (Proserpyna Study).

ABSTRACT

BACKGROUND: The optimal treatment for metastatic colorectal cancer (mCRC) beyond second line is still questioned. Besides the standard of care agents (regorafenib, REG, or trifluridine/tipiracil, FTD/TPI), chemotherapy rechallenge or reintroduction (CTr/r) are commonly considered in clinical practice, despite weak supporting evidence. The prognostic performance of CTr/r, REG and FTD/TPI in this setting are herein evaluated. PATIENTS AND METHODS: PROSERpYNa is a multicenter, observational, retrospective study, in which patients with refractory mCRC, progressing after at least 2 lines of CT, treated with CTr/r, REG or FTD/TPI, are considered eligible and were enrolled in 2 independent data sets (exploratory and validation). Primary endpoint was overall survival (OS); secondary endpoints were investigator-assessed progression-free survival (PFS), objective response rate (RR) and safety. A propensity score adjustment was accomplished for survival analyses. RESULTS: Data referring to patients treated between Jan-10 and Jan-19 from 3 Italian institutions were gathered (341 and 181 treatments for exploratory and validation data sets respectively). In the exploratory cohort, median OS (18.5 vs. 6.5 months), PFS (6.1 vs. 3.5 months) and RR (28.6% vs. 1.4%) were significantly longer for CTr/r compared to REG/FTD/TPI. Survival benefits were retained at the propensity score analysis, adjusted for independent prognostic factors identified at multivariate analysis. Moreover, these results were confirmed within the validation cohort analyses. CONCLUSIONS: Although the retrospective fashion, CTr/r proved to be a valuable option in this setting in a real-world context, providing superior outcomes compared to standard of care agents at the price of a moderate toxicity.