Published online Apr 15, 2022. doi: 10.4251/wjgo.v14.i4.920
Peer-review started: October 9, 2021
First decision: December 12, 2021
Revised: January 4, 2022
Accepted: March 25, 2022
Article in press: March 25, 2022
Published online: April 15, 2022
The effectiveness of the combination therapy using regorafenib and programmed cell death-1 (PD-1) inhibitors in treating metastatic colorectal cancer (mCRC) in the REGONIVO trial in Japan and a retrospective study in the United States are inconsistent.
As the effectiveness of the combination therapy remains controversial, we evaluated the situation and data of the combination therapy including the efficacy and safety in our medical centre in order to provide more clinical evidence for this treatment.
The objectives of this study were to investigate the tumor response, progression-free survival, overall survival, and treatment-related adverse events of the treatment and explore a potential indicators predicting response and prognosis.
We identified patients with microsatellite stable (MSS) mCRC treated with regorafenib combined with PD-1 inhibitor at Henan Provincial People’s Hospital between December 2018 and December 2020. Collected data included age, sex, Eastern Cooperative Oncology Group (ECOG) performance status (PS), site of the primary tumor, site of the metastases, MSI/MMR, gene status, lines of treatment, and previous treatments. The blood routine examination and CEA results before treatment and after three and five cycles of combination therapy were longitudinally analyzed.
We included 30 patients with MSS mCRC treated with regorafenib combined with PD-1 inhibitor. The disease control rate was 60.0%. The median follow-up time was 12.0 mo, and median PFS was 3.4 mo [95% confidence interval (CI): 2.2-4.6 mo]. The median PFS in the low-PLR group was 4.2 mo (95%CI: 3.5-4.9 mo), compared with 2.8 mo (95%CI: 1.4-4.2 mo) in the high-PLR group (P = 0.005). Four (13.3%) patients experienced grade 3 TRAE.
We find that some patients can benefit from the combination therapy even after multi-line therapy and adverse events are generally tolerable. The PLR might be a potential indicator to predict patient response to this combination therapy.
This study provides experiences and could help to design a prospective trial for patients with MSS mCRC those who failure to standard therapy.