Sequential treatment with regorafenib and trifluridine/tipiracil in later-line refractory metastatic colorectal cancer: A real-world multicenter retrospective study.
Authors: Signorelli Carlo , Schirripa Marta , Chilelli Mario Giovanni , Calegari Maria Alessandra , Basso Michele , Anghelone Annunziato , Lucchetti Jessica , Minelli Alessandro , Angotti Lorenzo , Gemma Donatello , Dell'Aquila Emanuela , Cosimati Antonella , Arrivi Giulia , Morelli Cristina , Corsi Domenico Cristiano , Saltarelli Rosa , Morandi Maria Grazia , Zoratto Federica , Santamaria Fiorenza , Ruggeri Enzo Maria 
Published: January 2023

45 Background: Regorafenib (R) and Trifluridine/tipiracil (T) have been shown to prolong survival for patients (pts) with refractory metastatic colorectal cancer (mCRC) but it's to date unclear which agent should be administered first. Our analysis aimed to compare the efficacy and safety profiles of these drugs sequentially administered in daily clinical practice. Methods: Clinical data of pts diagnosed with mCRC who received R and/or T between July 2012 and March 2022, were retrospectively collected from 12 institutes in Lazio Region. Overall survival (OS), progression-free survival (PFS), overall response rate (ORR), disease control rate (DCR), and adverse events (AEs) were compared between the two groups. Results: 781 pts were included. Of these, 270 (34.5%) received T alone, 278 (35.5%) R alone, 124 (15.8%) T followed by R, and 109 (13.9%) the reverse sequence. M/F = 452/329; median age was 68 (42-86); median duration of follow-up was 24.7 months (mos) (95%CI = 19.7-81.1). The prevalent ECOG PS was 1 (54%). We focused our attention on 233 pts who received R/T (N = 110, 14%) or T/R sequence (N = 123, 15.7%). ≥2 metastatic sites prevailed in both groups (83% T/R, 88% R/T; p = 0.45). Drug dose reductions due to grade 3/4 AEs were carried out in 81.8% of the R/T-treated pts (the R dose reduction to 120 mg and the T dose reduction to 30 mg/m2 were both the most prevalent in 28.8% of the cases) vs. 77.2% of the reverse sequence (R dose reduction to 120 mg was the most prevalent in 34.7% of the events) (p = 0.42). 143 pts (61.3%) experienced grade 3-4 toxicities (50.3% in R/T vs. 49.6% in T/R). The most common grade 3/4 AEs related to the R/T group were non-haematologic like hand-foot syndrome (21.6%) and fatigue (15.4%); on the other hand, these were haematologic: neutropenia (36.4%) and anemia (13%) (p = 0.28). Only 1 pt discontinued T in the T/R group. No therapy-related death was reported. The median PFS and OS of R/T were longer than the T/R sequence: 11 vs. 8,5 mos (HR = 0,62; 95%CI = 0,46-0,83; p = 0.0014) and 14,9 vs. 13 mos (HR = 0,70; 95%CI = 0,51-0,96; p = 0.0296), respectively. The ORR did not differ significantly showing slightly higher in the T/R sequence (4.8% vs. 2.2%; p = 0.45). The DCR was in favor of the R/T group (44.4% vs. 33.9%; p = 0.14). Conclusions: In our real-world context, PFS and OS were significantly longer in the R/T group. R and T used sequentially could extend survival and stabilize cancer growth without acting on tumor shrinkage. Safety profiles are in line with published data. Dose reductions were more frequent in the R/T group. We suggest that prospective clinical trials directly comparing R and T are needed.