The use of regorafenib for patients with refractory metastatic colorectal cancer in clinical practice

The small molecule NLRP3 inhibitor RRx-001 potentiates regorafenib activity and attenuates regorafenib-induced toxicity in mice bearing human colorectal cancer xenografts

The multi-kinase inhibitor Regorafenib, approved for the treatment of metastatic colorectal cancer, is poorly tolerated with a Grade 3/4 drug related adverse event rate of 54% resulting in frequent dose reductions and discontinuations. RRx-001 is a minimally toxic NLRP3 inhibitor small molecule with macrophage-repolarizing properties in Phase 3 clinical trials. Studies have demonstrated the inhibitory impact of M2 macrophages on the activity of tyrosine kinases, suggesting that the repolarization of macrophages by RRx-001 may enhance the activity of TKIs. The purpose of these experiments was to determine whether RRx-001 demonstrated in vitro and in vivo synergy with regorafenib in colorectal cancer and whether RRx-001 attenuated the toxicity of regorafenib. Tumor-bearing mice were randomized into four cohorts: RRx-001 alone, regorafenib alone, RRx-001 + regorafenib and control. RRx-001 demonstrated in vitro and in vivo synergy with regorafenib with attenuation of toxicity in colorectal cancer cell lines. These results provide a rationale to treat colorectal cancer with RRx-001 plus another tyrosine kinase inhibitor like regorafenib.

Standard versus personalized schedule of regorafenib in metastatic gastrointestinal stromal tumors: a retrospective, multicenter, real-world study

Background

Despite its proven activity as third-line treatment in gastrointestinal stromal tumors (GIST), regorafenib can present a poor tolerability profile which often leads to treatment modifications and transient or permanent discontinuation; thus, in clinical practice physicians usually adopt various dosing and interval schedules to counteract regorafenib-related adverse events and avoid treatment interruption. The aim of this real-world study was to investigate the efficacy and safety of personalized schedules of regorafenib in patients with metastatic GIST, in comparison with the standard schedule (160 mg daily, 3-weeks-on, 1-week-off).

Patients and methods

Institutional registries across seven Italian reference centers were retrospectively reviewed and data of interest retrieved to identify patients with GIST who had received regorafenib from February 2013 to January 2021. The Kaplan–Meier method was used to estimate survival and the log-rank test to make comparisons.

Results

Of a total of 152 patients with GIST, 49 were treated with standard dose, while 103 received personalized schedules. At a median follow-up of 36.5 months, median progression-free survival was 5.6 months [95% confidence interval (CI) 3.73-11.0 months] versus 9.7 months (95% CI 7.9-14.5 months) in the standard-dose and the personalized schedule groups, respectively [hazard ratio (HR) 0.51; 95% CI 0.34-0.75; P = 0.00052]. Median overall survival was 16.6 months (95% CI 14.1-21.8 months) versus 20.5 months (95% CI 15.0-25.4 months), respectively (HR 0.75; 95% CI 0.49-1.22; P = 0.16).

Conclusions

Regorafenib-personalized schedules are commonly adopted in daily clinical practice of high-volume GIST expert centers and correlate with significant improvement of therapeutic outcomes. Therefore, regorafenib treatment optimization in patients with GIST may represent the best strategy to maximize long-term therapy.

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Regorafenib-personalized schedules are commonly adopted in daily clinical practice.

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Regorafenib-personalized schedules correlate with statistically significant improvement of therapeutic outcomes.

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A prompt personalization of regorafenib could help clinicians avoid early treatment discontinuation due to adverse events.

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A patient-tailored approach could be applied to other metastatic solid tumors treated with regorafenib.

A multi-institutional phase 2 trial of regorafenib in refractory advanced biliary tract cancer

BACKGROUND

Regorafenib is an oral multikinase inhibitor targeting angiogenesis, oncogenesis, and cancer proliferation/metastasis. This study evaluated the efficacy of regorafenib in refractory biliary tract cancer (BTC) in a multi-institutional phase 2 study.

METHODS

Patients with BTC who progressed on at least 1 line of systemic therapy received regorafenib at 160 mg daily for 21 days on and 7 days off. The primary endpoint was 6-month overall survival (OS), and the secondary endpoints were median OS, progression-free survival (PFS), and objective response rates. Pretreatment plasma was collected for cytokine evaluation.

RESULTS

A total of 39 patients were enrolled, and 33 were evaluable for efficacy. The median PFS and OS were 3.7 and 5.4 months, respectively, with survival rates of 46.2% at 6 months, 35.9% at 12 months, and 25.6% at 18 months for the intention-to-treat population. For the 33 evaluable patients who received regorafenib for at least 3 weeks, the median PFS and OS were 3.9 and 6.7 months, respectively, with survival rates of 51.5% at 6 months, 39.4% at 12 months, and 27.3% at 18 months. The objective response rate was 9.1%, and the disease control rate was 63.6%. Twenty-eight patients (71.8%) experienced grade 3/4 adverse events. Among the 23 cytokines analyzed, elevated baseline vascular endothelial growth factor D (VEGF-D) was associated with shorter PFS, whereas elevated baseline interleukin 6 (IL-6) and glycoprotein 130 (GP130) were associated with shorter OS.

CONCLUSIONS

Regorafenib demonstrated modest clinical efficacy in heavily pretreated patients with BTC. Further exploration of biomarkers is warranted to identify a group of patients with BTC who may benefit from regorafenib.

Factors Associated With Regorafenib Adherence With Metastatic Colorectal Cancer

INTRODUCTION

Regorafenib is an oral multikinase inhibitor for the treatment of metastatic colorectal cancer (mCRC). The clinical factors that may affect adherence to regorafenib remain unclear. The aim of this study was to evaluate adherence to regorafenib with mCRC and to identify factors that might affect adherence to regorafenib.

METHODS

A total of 108 consecutively enrolled Japanese patients with mCRC received regorafenib. Adherence was measured by pharmacists using pill counts and a self-reported treatment diary for patients at a pharmaceutical outpatient clinic. The median relative dose intensities of regorafenib and the factors adversely affecting adherence were retrospectively surveyed. Logistic regression analysis was then performed using patient socio-demographic factors and clinical factors.

RESULTS

A total of 96 patients were included in the analysis. The median adherence rate was 61.7% in the first cycle. The median relative dose intensity was 57.1%. The most common reason for non-adherence was a hand-foot-skin reaction (35.6%). On multivariate analysis, increased non-adherence to regorafenib was significantly associated with sex (female) [odds ratio (OR) = 4.36; 95% confidence interval (CI): 1.43-13.22, p = 0.01].

DISCUSSION

Hand-foot-skin reactions and female sex were associated with lower adherence to regorafenib. Since these factors could be associated with lower adherence to regorafenib, it would be useful to consider these factors when assessing adherence.