4CPS-294 Efficacy and safety profile of trifluridine–tipiracil and regorafenib in the treatment of metastatic colorectal cancer

Background and importance Regorafenib (REG) and trifluridine–tipiracil (TAS-102) are used in metastatic colorectal cancer (mCRC) after failure of conventional therapy based on fluorouracil (5-FU) schemes. Aim and objectives To evaluate the efficacy and safety of TAS-102 and regorafenib drugs in patients with mCRC. Material and methods A retrospective single centre study was conducted from January 2010 to August 2020, which included all patients diagnosed with CRBM treated with TAS-102/REG. Clinical and demographic variables were collected, corresponding to age, sex, time of disease follow-up, time of treatment with the drug, previous adjuvant/neoadjuvant, presence of RAS type mutation and number of previous metastatic lines. Efficacy was determined by calculating progression free survival (PFS) applying the Kaplan–Meyer statistic with SPSS V.15. Progression was analysed according to the radiological criteria response evaluation criteria in solid tumours (RECIST V.1.1). The occurrence of grade III/IV adverse effects (AEs) leading to early dose reduction/suspension of treatment was determined. AEs were classified according to the common terminology criteria for adverse effects (CTCAE V.6.0). Results 104 patients were included, 57.7% (n=60) treated with REG (66.3%, n=69); mean age was 63.9 years (41–83)). Mean follow-up time of the disease was 3.9 years (0.1–15.5). Mean duration of treatment was 3.9 months for TAS-102 and 4.2 for REG. 46% (n=48) of patients received adjuvant therapy and 16.3% (n=17) neoadjuvant. 48.1% presented RAS mutation (n=50). Mean of previous metastatic lines was 2.4 (1–7). 84% (n=37) of patients progressed with TAS-102 versus 72% (n=43) with REG. 11.5% (n=12) discontinued treatment due to toxicity. Median PFS was the same for both: 3.8 months (p=0.86). A reduction in drug doses due to the appearance of AEs was carried out in 25% of cases (n=11) with TAS-102 versus 61.7% with REG (n=37). The most common grade III/IV AEs with TAS-102 were haematological toxicity (20.5%, n=9), gastrointestinal (2.3%, n=1) and other (2.3%, n=1); for REG, gastrointestinal (16.7%, n=10), asthenia (13.3%, n=8), skin toxicity (11.7%, n=7), mucositis (6.7%, n=4), plaquetopenia (3.3%, n=2) and other (13.3%, n=8). Conclusion and relevance The study showed that there were no significant differences between PFS values between TAS-102 and REG. However, treatment with REG was tolerated worse, with AEs in more than 60% of cases compared with 25% with TAS-102. References and/or acknowledgements Conflict of interest No conflict of interest