Regorafenib Plus for third-line treatment in metastatic colorectal cancer: A real-world study.

e15562 Background: Regorafenib, approved as a monotherapy for refractory metastatic colorectal cancer (mCRC), is recognized for its potential immunomodulatory effects and ability to reverse chemotherapeutic resistance. In response to this, a combination regimen known as regorafenib Plus has been customized for specific patients. This study aims to evaluate the effectiveness and safety of regorafenib as a standalone treatment and in combination with other therapies (including concurrent/sequential chemotherapy, immunotherapy, transarterial chemoembolization TACE) in the real-world setting. The goal is to present viable treatment options for patients with mCRC. Methods: In this retrospective study, patients with chemo-refractory metastatic colorectal cancer (mCRC) who underwent regorafenib treatment at Beijing Chaoyang Hospital between January 2018 and October 2023 were stratified into two cohorts: monotherapy (Rego Mono) and concurrent/sequential combination therapy (Rego Plus). Index date was the initiation of regorafenib therapy in a sequence and median follow-up was 19.1 months. The clinical outcomes included progression-free survival (PFS), overall survival (OS), and 1/2-year OS rates. Results: A total of 67 pts were included (n = 39 Rego Mono; n = 28 Rego Plus). Baseline characteristics were comparable between cohorts. The median progression-free survival (PFS) was significantly extended in the Rego Plus group compared to Rego Mono (8.0 vs. 3.6 months, P = 0.000), and overall survival (OS) was also notably prolonged (24.4 vs. 19.1 months, P = 0.046). The 1/2-year OS rates were also improved by Rego Plus (63% vs 37.1%, 25.5% vs 11.4%). However, there were no statistical differences in PFS between concurrent and sequential combination therapies (8.4 vs 8.0 mont). Notably, under sequential therapy, after 3.7 months of PFS with regorafenib alone, an additional 4.7 months of PFS was observed when combined therapy was introduced. Regarding safety, Rego Plus was associated with an increased rate of adverse events (AEs) without an escalation in severity. Common AEs included rash, hand-foot syndrome, hypertension, and diarrhea. Conclusions: Rego Plus significantly prolonged PFS and OS in patients with chemo-refractory mCRC. Particularly when tumor stabilization is evident during monotherapy, the introduction of Rego Plus can offer a comparable or even longer PFS benefit, nearly doubling the PFS. Despite an elevated rate of AEs, the severity of these events did not increase, suggesting good tolerability. This approach has the potential to enhance the effectiveness of existing third-line therapies for mCRC, ultimately contributing to an improved prognosis for patients.