Development and Validation of a Novel Serum Prognostic Marker for Patients with Metastatic Colorectal Cancer on Regorafenib Treatment

Simple Summary

Regorafenib has proven its efficacy for later-line treatment of mCRC. However, treatment often brings substantial toxicities that lead clinicians to assess the risk-to-benefit ratio in heavily pretreated patients. Thus, it is crucial to develop a prognostic factor and model for guiding patient selection. In this study, we represent a new serum biomarker to serve as an independent prognostic factor for patients receiving regorafenib. All 4 factors of the prognostic model were employed with an excellent discriminatory ability. This result should be validated in further confirmatory studies.

Abstract

(1) Background: To investigate the prognostic value of cancer-inflammation prognostic index (CIPI) in patients with metastatic colorectal cancer (mCRC) on regorafenib treatment; (2) Methods: Patients with mCRC who were given regorafenib as later-line treatment at Kaohsiung and Linkou Chang-Gung Memorial Hospital between November 2014 and January 2021 were consecutively enrolled. All relevant clinicopathologic, laboratory data and survival status were recorded. Independent prognostic factors were determined by the multivariate Cox regression method; (3) Results: In total, 106 patients in the training cohort and 250 in the validation cohort were enrolled. The median OS for patients with CIPI ≥ 300 and < 300 in the training cohort was 3.8 and 9.0 months, respectively (hazard ratio (HR) 2.78, 95% confidence interval (CI) 1.82–4.23; p < 0.0001). Time to regorafenib, liver metastasis and CIPI were independent factors by multivariate Cox regression analyses. A new scoring model demonstrated a good discriminatory ability to risk stratification of a patient’s survival; (4) Conclusions: We identified CIPI as a novel serum marker highly associated with overall survival in patients with mCRC receiving regorafenib treatment. Further confirmatory studies are warranted.

Could the Inflammatory Prognostic Index Predict the Efficacy of Regorafenib in Patients with Metastatic Colorectal Cancer?

PURPOSE

To investigate the clinical importance of the inflammatory prognostic index (IPI) in patients with metastatic colorectal cancer treated with regorafenib.

METHODS

A retrospective analysis of 65 metastatic CRC patients treated with regorafenib between 2015 and 2020 was performed. The association between NLR, PNLR, IPI, and overall survival (OS) and progression-free survival (PFS) was evaluated.

RESULTS

According to the cut-off points, patients were divided into two groups. The patients in the high IPI group showed poorer OS compared to patients in the low IPI groups. The PFS was better in patients with low neutrophil-lymphocyte ratio (NLR) and platelet-neutrophil to lymphocyte ratio (PNLR), and the OS was better in patients with low IPI.

CONCLUSION

Among the immune inflammation scores analyzed in mCRC patients receiving regorafenib, NLR and PNLR were the best predictor of recurrence, whereas IPI was the best predictor of long-term survival. After being confirmed by better designed controlled trials, IPI can be used to identify the group of patients who will benefit more from regorafenib treatment.

Rapid Resistance of FGFR-driven Gastric Cancers to Regorafenib and Targeted FGFR Inhibitors can be Overcome by Parallel Inhibition of MEK

Amplification or overexpression of the FGFR family of receptor tyrosine kinases occurs in a significant proportion of gastric cancers. Regorafenib is a multikinase inhibitor of angiogenic and oncogenic kinases, including FGFR, which showed activity in the randomized phase II INTEGRATE clinical trial in advanced gastric cancer. There are currently no biomarkers that predict response to this agent, and whether regorafenib is preferentially active in FGFR-driven cancers is unknown. Through screening 25 gastric cancer cell lines, we identified five cell lines that were exquisitely sensitive to regorafenib, four of which harbored amplification or overexpression of FGFR family members. These four cell lines were also sensitive to the FGFR-specific inhibitors, BGJ398, erdafitinib, and TAS-120. Regorafenib inhibited FGFR-driven MAPK signaling in these cell lines, and knockdown studies confirmed their dependence on specific FGFRs for proliferation. In the INTEGRATE trial cohort, amplification or overexpression of FGFRs 1-4 was detected in 8%-19% of cases, however, this was not associated with improved progression-free survival and no objective responses were observed in these cases. Further preclinical analyses revealed FGFR-driven gastric cancer cell lines rapidly reactivate MAPK/ERK signaling in response to FGFR inhibition, which may underlie the limited clinical response to regorafenib. Importantly, combination treatment with an FGFR and MEK inhibitor delayed MAPK/ERK reactivation and synergistically inhibited proliferation of FGFR-driven gastric cancer cell lines. These findings suggest that upfront combinatorial inhibition of FGFR and MEK may represent a more effective treatment strategy for FGFR-driven gastric cancers.

Prognostic and Predictive Biomarkers in Patients with Metastatic Colorectal Cancer Receiving Regorafenib

Regorafenib is a tyrosine kinase inhibitor approved by the FDA for the treatment of patients with chemotherapy refractory metastatic colorectal cancer (mCRC). Regorafenib inhibits signaling through multiple receptors associated with angiogenesis, metastasis, and tumor immunity. Here, we report biomarker results from LCCC1029, a randomized, placebo-controlled, phase II trial of chemotherapy ± regorafenib in patients with second-line mCRC. A panel of 20 soluble protein biomarkers (termed the Angiome) was assessed in the plasma of 149 patients from the LCCC1029 trial both at baseline and along the treatment continuum. Baseline protein levels were analyzed for prognostic and predictive value for progression-free survival (PFS) and overall survival (OS). Changes in protein levels during treatment were analyzed for potential pharmacodynamic effects. Six markers (HGF, IL6, PlGF, VEGF-R1, OPN, and IL6R) were found to be prognostic for PFS. Nine markers (IL6, TIMP-1, PlGF, VCAM-1, ICAM-1, OPN, TSP-2, HGF, and VEGF-R1) were prognostic for OS. Higher baseline levels of OPN (P _intx = 0.0167), VCAM-1 (P _intx = 0.0216), and PDGF-AA (P _intx = 0.0435) appeared to predict for PFS benefit from regorafenib compared with placebo. VCAM-1 was also potentially predictive of OS benefit from regorafenib compared with placebo (P _intx = 0.0124). On-treatment changes of six markers reflected potential on-target effect of regorafenib. Consistent results were observed in an Italian cohort where 105 patients with late-stage mCRC received regorafenib monotherapy. The key findings of this study suggest that VCAM-1 may be a predictive biomarker for regorafenib benefit, while multiple protein markers may be prognostic of outcome in patients with mCRC.

Molecular insight of regorafenib treatment for colorectal cancer

Regorafenib is a multi-targeting kinase inhibitor approved for the treatment of metastatic colorectal cancer patients in refractory to standard chemotherapy. Similarly to sorafenib, this agent was originally developed as a RAF1 inhibitor. However, the kinase inhibitory profile is distinct from sorafenib. A broad-spectrum of kinase inhibition induces wide-range drug sensitivity, irrespective of mutation status of major oncogenes. This agent's main therapeutic effects are anti-angiogenesis and the remodeling of tumor microenvironment through several mechanisms of action. The dual blockade of VEGF receptors and TIE2 can lead to both additive anti-angiogenesis effects and the suggestive unique regulation of vessel stability. Additionally, it inhibits molecular escape pathways to VEGF inhibition (e.g., FGF, PIGF, and PDGF signaling), enabling its continuous antiangiogenic effect even in tumors resistant to VEGF inhibitors. Furthermore, regorafenib has the important effect of enhancing anti-tumor immunity via macrophage modulation. Based on this concept, clinical trials have been recently launched for the development of a combination strategy with immune checkpoint inhibitors. Contrary to regorafenib induced clinical benefits and advances in the novel strategy, currently no predictive biomarkers have been identified. In the present review, we revisit and summarize regorafenib's unique mechanisms of action. The review could highlight molecular insights and provide some perspective for the search of predictive biomarkers used in metastatic colorectal cancer patients treated with regorafenib.

Regorafenib: A Review in Metastatic Colorectal Cancer

Regorafenib (Stivarga^®) is an oral small-molecule multiple kinase inhibitor. It is indicated worldwide for patients with metastatic colorectal cancer (mCRC). In the EU and USA it is indicated for patients with mCRC who have been previously treated with, or are not considered candidates for available therapies, including fluoropyrimidine-based chemotherapy, an anti-VEGF therapy and, if RAS wild-type, an anti-EGFR therapy. In Japan, it is indicated for the treatment of unresectable, advanced/recurrent CRC. The addition of regorafenib to best supportive care prolonged median overall survival (OS; by up to 2.5 months) and progression-free survival (PFS; by up to 1.5 months) relative to the addition of placebo in double-blind phase 3 studies (CORRECT and CONCUR) in patients with mCRC who had progressed after failure of standard therapy. Health-related quality of life was not adversely affected with regorafenib relative to placebo. A large open-label phase 3 study (CONSIGN) and several large real-world studies supported the efficacy of regorafenib in this setting. Regorafenib had a generally manageable tolerability profile, which was consistent with the profile of a typical small-molecule multiple kinase inhibitor. Treatment-related adverse events (AEs), mostly of mild or moderate severity, were reported in the majority of patients receiving regorafenib, with dermatological toxicities and liver enzyme elevations among the most common AEs. Although identification of biomarkers/parameters predicting efficacy outcomes with regorafenib will help to individualize therapy, current evidence indicates that regorafenib is a valuable treatment option for patients with refractory mCRC who have a very poor prognosis.