Clinical Implication of Anti-Angiogenic Effect of Regorafenib in Metastatic Colorectal Cancer

Lung cavitation to pneumothorax: A case report of the multilayered respiratory challenges in oncology patients

INTRODUCTION

The management of patients with complex oncological histories poses unique challenges, particularly when they are on targeted chemotherapy agents known for specific side effects. This case report illuminates the multifaceted complexities encountered in such scenarios, with a focus on the rare complications associated with targeted therapies.

CASE PRESENTATION

We present a 50-year-old male with an extensive oncological background, including childhood retinoblastoma and radiation-induced leiomyosarcoma. Recently diagnosed with skull base osteosarcoma, he was undergoing treatment with Regorafenib. Admitted with sepsis due to Pseudomonas aeruginosa-induced community-acquired pneumonia, his clinical course was complicated by lung cavitation leading to a spontaneous pneumothorax. This report highlights the absence of empyema, a crucial differential in the diagnosis.

DISCUSSION

This case unravels the intricate interplay between targeted chemotherapy, concurrent medications like prednisone, and their potential to cause severe complications such as pneumonia and pneumothorax. It delves into the mechanisms by which Regorafenib can lead to lung cavitation and abscess formation, a rare but significant risk. The importance of a multidisciplinary approach for prompt diagnosis and treatment, including surgical intervention, is highlighted. The pathology of the surgically resected lobe revealed metastatic high-grade leiomyosarcoma, adding another layer of complexity to the case.

CONCLUSION

This case serves as a cautionary tale highlighting the need for vigilant monitoring of patients on targeted chemotherapy agents, especially those with complex medical histories. It highlights the importance of considering potential drug-related complications and the rationale behind therapeutic choices, including antibiotic selection and surgical decision-making, in the management of acute medical conditions in these patients.

Anti-metastatic effect of midazolam on melanoma B16F10 cells in the lungs of diabetic mice

Midazolam is an anesthetic agent commonly used for anesthesia and sedation in surgery. However, there is no information on the role of midazolam in hyperglycemia-induced cancer metastasis to date. In this study, we investigated the effects of midazolam on inhibiting metastases in the lungs of diabetic mice and on human pulmonary microvascular endothelial cells (HPMVECs). Subcutaneous injection of midazolam inhibited hyperglycemia-induced cancer metastasis in the lungs of diabetic mice. Midazolam also prevented the generation of ROS, activation of TGase, and subsequent vascular leakage in the lungs of diabetic mice. Furthermore, in vitro studies with HPMVECs confirmed that midazolam inhibited VEGF-induced intracellular events including ROS generation, TGase activation, and disruption of vascular endothelial-cadherins, thus preventing the permeability of endothelial cells. Notably, midazolam had no direct effect on the migration or proliferation of melanoma cells, instead acting upon endothelial cells. The midazolam-mediated inhibition of VEGF-induced intracellular events was reversed by treatment with the GABA_A receptor antagonist flumazenil. These findings suggest that midazolam prevents hyperglycemia-induced cancer metastasis by inhibiting VEGF-induced intracellular events and subsequent vascular leakage via the GABA_A receptors in the lungs of diabetic mice.

Imaging and clinical correlates with regorafenib in metastatic colorectal cancer

In colorectal cancer (CRC), imaging is important in determining tumor stage, selecting treatment strategies, and in assessing response to therapy. However, some challenges remain with established imaging techniques, such as computed tomography, and with some commonly used response criteria, such as Response Evaluation Criteria in Solid Tumors, which measures change in size of several target lesions instead of change in tumor morphology or metabolic function. In addition, these assessments are not typically conducted until after 8 weeks of treatment, meaning that potential non-responders are often not identified in a timely manner. Regorafenib, an oral tyrosine kinase inhibitor indicated for the treatment of metastatic CRC, blocks the activity of several protein kinases involved in angiogenesis, oncogenesis, metastasis, and tumor immunity. Timely differentiation of regorafenib responders from non-responders using appropriate imaging techniques that recognize not only changes in tumor size but also changes in tumor density or vasculature, may reduce unnecessary drug-related toxicity in patients who are unlikely to respond to treatment. This review discusses the latest developments in computed tomography, magnetic resonance imaging, and positron emission tomography tumor imaging modalities, and how these aid in identifying patients with metastatic CRC who are responders or non-responders to regorafenib treatment.

Assessment of tumor enhancement by contrast-enhanced CT in solid tumor-bearing dogs treated with toceranib phosphate

In humans, contrast-enhanced CT (CECT) has been used to indirectly assess the antiangiogenic effects demonstrated by a number of tyrosine kinase inhibitors. This retrospective, cross-sectional study aimed to quantitatively evaluate changes in tumor contrast-enhancement (CE) using CECT in solid tumor-bearing dogs treated with toceranib phosphate (TOC). The changes in tumor size and CE were measured using the Hounsfield unit (HU) scale in CECT images before TOC treatment and between 30 and 90 days after initiating the treatment. Among the 36 dogs treated with TOC, eight (22.2%) showed a partial response, 22 (61.1%) showed stable disease, and six (16.7%) showed progressive disease. Thirty (83.3%) of 36 dogs showed a decrease in tumor CE (median: -20%, range: -1% to -48%) after initiating the treatment. The results indicated that tumor CE and size changes were observed in tumor-bearing dogs that were treated with TOC; however, tumor CE was not significantly correlated with tumor regression. We suggest that these results could serve as pilot data to evaluate the antiangiogenic effects associated with TOC.

Efficacy of regorafenib in acute pulmonary carcinomatous lymphangitis as a manifestation of rectal cancer: A case report

Recent therapeutic advancements have prolonged the survival duration of patients with metastatic or recurrent colorectal cancer even during salvage treatment. Although treatment with regorafenib and trifluridine/tipiracil combination has exhibited apparent survival benefits, clear and objective evidence of a response to these drugs is scarce. Herein, the present study reports the case of a patient with rectal cancer refractory to multiple surgical interventions and standard chemotherapy. Treatment with regorafenib resulted in immediate improvement of respiratory failure caused by pulmonary lymphangitic carcinomatosis. This improvement persisted for over 3 months and was confirmed by radiology. Our findings suggest that regorafenib can reduce peritumoral edema via its interaction with the vascular endothelial growth factor receptor. Thus, regorafenib functions as a multityrosine kinase inhibitor to alleviate symptoms of lymphangitic carcinomatosis despite the low potency of the drug.

Computed tomography densitometric study of anti-angiogenic effect of regorafenib in colorectal cancer liver metastasis

Aim: Regorafenib induces radiological changes in liver metastasis among patients with metastatic colorectal cancer (mCRC). The standard criteria used to evaluate solid tumor response (Response Evaluation Criteria in Solid Tumors) may be limited in assessing response to biologic agents with anti-angiogenic action. Patients & methods: A total of 67 hepatic lesions in 32 selected patients were analyzed to evaluate tumor attenuation as measured by Hounsfield unit (HU) and size changes. Results: Following two cycles of regorafenib, tumor HU values decreased in the in 73.1% (49/67) of lesions (average HU changes -25.6%) while tumor size increased in 64.2% (43/67) of them (average size changes +25.4%). Conclusion: The computed tomography density changes evaluation may be an additional tool, in combination with tumor sizing, to evaluate tumor response in patients treated with regorafenib.

Tumoral cavitation in colorectal cancer patients with unresectable lung metastasis treated with bevacizumab and chemotherapy

PURPOSE

Efficacy and the frequency of tumor cavitation have not been investigated in patients with metastatic colorectal cancer (mCRC) and lung metastases (LMs) treated with chemotherapy in combination with bevacizumab. This study was aimed to evaluate the efficacy and safety of bevacizumab for unresectable mCRC with LM and to determine the frequency of tumor cavitation, and its correlation with clinical outcomes in patients receiving bevacizumab plus chemotherapy.

METHODS

Patients with mCRC and LMs treated with bevacizumab as first- or second-line therapy at West China Hospital, Sichuan University Cancer Center from September 2010 to November 2016 were included in this retrospective study. Data on clinicopathological characteristic were collected and overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and disease control rate (DCR) were determined.

RESULTS

Among 60 patients included in the study, response rate (RR), stable disease (SD), and DCR were 43.6% (17/39), 51.3% (20/39) and 94.9% (37/39) in patients receiving bevacizumab as first-line treatment. Median OS and PFS of the first-line treatment group were 32.4 and 15.5 months, respectively. Among 60, 12 patients (20%) developed cavitation after bevacizumab therapy initiation. Median OS was longer in patients with cavitation than those without cavitation (42.1 vs 30.8 months; p = 0.042) in the first-line treatment group.

CONCLUSION

Bevacizumab in combination with chemotherapy exhibited promising efficacy in mCRC patients LMs. Moreover, our findings reveal that OS might be affected by new tumor cavitation during antiangiogenic agent treatment.

Evolution of regorafenib from bench to bedside in colorectal cancer: Is it an attractive option or merely a "me too" drug?

Colorectal cancer (CRC) is a major public health problem in the United States with an estimated 50,260 deaths in 2017. Over the past two decades, several agents have been approved by the US Food and Drug Administration (FDA) for the treatment of patients with metastatic CRC (mCRC). Regorafenib (BAY 73-4506) is a small-molecule multikinase inhibitor that was approved for the treatment of mCRC in 2012. This agent is a novel oral diphenylurea-based multikinase inhibitor that is active against several angiogenic receptor tyrosine kinases (RTKs; VEGFR-1, VEGFR-2, VEGFR-3, TIE-2), oncogenic RTKs (c-KIT, RET), stromal RTKs (PDGFR-B, FGFR-1), and intracellular signaling kinases (c-RAF/RAF-1, BRAF, BRAF^V600E). Preclinical studies have documented its broad-spectrum activity against different solid tumor types including CRC. Phase I studies showed that it had an acceptable safety profile in advanced refractory mCRC. A subsequent Phase III trial (CORRECT) demonstrated significant clinical efficacy of regorafenib in patients with refractory or advanced mCRC, which eventually led to its FDA approval for the treatment of mCRC in September 2012. However, the drug was associated with significant toxicity in clinical practice when administered at the approved doses, which necessitated a thorough reassessment of its dosing schedule and toxicity profile. This review summarizes the development of regorafenib from the initial preclinical studies to the Phase III trials and critically examines the current clinical space occupied by regorafenib in the treatment of mCRC, at 5 years after its initial FDA approval.

Early morphological change for predicting outcome in metastatic colorectal cancer after regorafenib

Background and Objective

It is unclear whether early morphological change (EMC) is a predictive marker for regorafenib in metastatic colorectal cancer (mCRC). Therefore, the present study investigated whether EMC can predict the outcome of mCRC patients receiving regorafenib.

Results

This study evaluated 68 patients. Among 52 patients with lung metastasis, 16 (31%) had cavity formation (CF). The median progression-free survival (PFS) and overall survival (OS) in patients with/without CF were 4.2/2.4 months (p<0.01) and 9.2/6.5 months (p=0.09), respectively. Among 45 patients with liver metastasis, 14 (31%) had active morphological response (MR). The median PFS and OS in patients with/without active MR were 5.3/2.4 months (p<0.01) and 13.6/6.9 months (p=0.02), respectively. Overall, 25 patients (37%) had EMC. The median PFS and OS in patients with/without EMC were 5.3/2.1 months (p<0.01) and 13.3/6.1 months (p<0.01), respectively.

Materials and Methods

This retrospective study included mCRC patients with lung and/or liver metastases receiving regorafenib. CF in lung metastasis and MR in liver metastasis were evaluated at the first post-treatment computed tomography scan. EMC was determined as CF and/or active MR. We compared PFS and OS between patients with and those without EMC.

Conclusions

EMC could be a useful predictive marker for regorafenib in mCRC.

Efficacy and safety of regorafenib in the treatment of metastatic colorectal cancer: A systematic review

PURPOSE

Despite advances in the treatment of colorectal cancer, third-line treatment options are still limited. Regorafenib was approved in 2012 for the treatment of patients with metastatic colorectal cancer previously treated with approved standard therapy. The purpose of this review is to present existing clinical data on regorafenib.

METHOD

We systematically searched the PubMed and Embase databases, as well as ASCO and ESMO conference abstracts, for studies in English including ≥30 patients, evaluating the efficacy and safety of regorafenib in patients with metastatic colorectal cancer. A meta-analysis was conducted on the published, randomized phase III trials.

RESULTS

24 eligible studies were included. In two phase III trials, regorafenib significantly increased overall survival (OS), progression free survival (PFS), and disease control rate when compared to placebo. Survival benefits of 1.4 and 2.5 months were presented. The meta-analysis indicated a significant greater treatment effect on OS (hazard ratio 0.67) and PFS (hazard ratio 0.40), compared to placebo. The non-randomized studies mostly supported these results. The most frequently reported adverse events were hand-foot-skin reaction (25%-86%), hypertension (11%-47%) and fatigue (2%-73%).

CONCLUSION

Large phase III randomized trials indicate that regorafenib provides a benefit in OS and PFS when compared to placebo. Adverse events were common, but manageable and typical of multi-target tyrosine kinase inhibitors. Further research is needed to investigate alternative approaches to the dosing of regorafenib and to explore clinical and molecular biomarkers that can guide patient selection.

Comparison of Quantitative Methods on FDG PET/CT for Treatment Response Evaluation of Metastatic Colorectal Cancer

PURPOSE

FDG PET is effective in treatment response evaluation of cancer. However, there is no standard method for quantitative evaluation of FDG PET, particularly regarding cytostatic drugs. We compared various FDG PET quantitative methods in terms of response determination.

METHODS

A total of 39 refractory metastatic colorectal cancer patients who received a multikinase inhibitor treatment were included. Baseline and posttreatment FDG PET/CT scans were performed before and two cycles after treatment. Standardized uptake value (SUV) and total lesion glycolysis (TLG) values using various margin thresholds (30-70 % of maximum SUV with increment 10 %, twice mean SUV of blood pool, SUV 3.0, and SUV 4.0) were measured, with measurement target of the hottest lesion or a maximum of five hottest lesions. Treatment response by the PERCIST criteria was also determined. Predictive values of the PET indexes were evaluated in terms of the treatment response determined by the RECIST 1.1 criteria.

RESULTS

The agreement rate was 38 % between response determined by the PERCIST and the RECIST criteria (κ = 0.381). When patients were classified into disease control group (PR, SD) and non-control group (PD) by the RECIST criteria, percent changes of TLG with various margin thresholds (particularly, 30-50 % of maximum SUV) exhibited significant differences between the two groups, and high diagnostic power for the response by the RECIST criteria. TLG-based criteria, which used a margin threshold of 50 % of maximum SUV, exhibited a high agreement with the RECIST criteria compared with the PERCIST criteria (κ = 0.606).

CONCLUSION

In metastatic colorectal cancer, FDG PET/CT could be effective for treatment response evaluation by using TLG measured by margin thresholds of 30-50 % of maximum SUV. Further studies are warranted regarding the optimal cutoff values for this method.

Radiological imaging markers predicting clinical outcome in patients with metastatic colorectal carcinoma treated with regorafenib: post hoc analysis of the CORRECT phase III trial (RadioCORRECT study)

OBJECTIVE

To identify imaging markers predicting clinical outcomes to regorafenib in metastatic colorectal carcinoma (mCRC).

METHODS

The RadioCORRECT study is a post hoc analysis of a cohort of patients with mCRC treated within the phase III placebo-controlled CORRECT trial of regorafenib. Baseline and week 8 contrast-enhanced CT were used to assess response by RECIST 1.1, changes in the sum of target lesion diameters (ΔSTL), lung metastases cavitation and liver metastases density. Primary and secondary objectives were to develop ex novo univariable and multivariable models to predict overall survival (OS) and progression-free survival (PFS), respectively.

RESULTS

202 patients were enrolled, 134 (66.3%) treated with regorafenib and 68 (33.7%) with placebo. In the univariate analysis, PFS predictors were lung metastases cavitation at baseline (HR 0.50, 95% CI 0.27 to 0.92, p=0.03) and at week 8 (HR 0.58, 95% CI 0.36 to 0.93, p=0.02). Baseline cavitation (HR 0.23, 95% CI 0.08 to 0.66, p=0.007), RECIST 1.1 (HR 0.23, 95% CI 0.14 to 0.4, p <0.0001) and ΔSTL (HR 1.16, 95% CI 1.06 to 1.27, p=0.002) predicted OS. We found an increase of 9% of diameter as the best threshold for discriminating OS (HR 2.64, 95% CI 1.61 to 4.34, p <0.001). In the multivariate analysis, baseline and week 8 cavitation remained significant PFS predictors. Baseline cavitation, RECIST 1.1 and ΔSTL remained predictors of OS in exploratory multivariable models. Assessment of liver metastases density did not predict clinical outcome.

CONCLUSIONS

RECIST 1.1 and ΔSTL predict favourable outcome to regorafenib. In contrast to liver metastases density that failed to be a predictor, lung metastases cavitation represents a novel radiological marker of favourable outcome that deserves consideration.

Antiangiogenic therapy for refractory colorectal cancer: current options and future strategies

Even though significant improvements in the treatment of colorectal cancer (CRC) have been made in recent years, survival rates for metastatic colorectal cancer (mCRC) are poor. Effective treatment options for metastatic colorectal cancer remain limited, and new therapeutic strategies are desperately needed. Several tyrosine kinase inhibitors (TKIs) and monoclonal antibodies (mAbs) that target angiogenesis, a critical process for facilitating tumor cell growth, invasion, and metastasis, are either approved or in clinical development for the treatment of mCRC. Many of these agents have shown efficacy in mCRC, both as single agents and in combination with standard chemotherapy regimens. However, there is a need for predictive markers of response to identify those patients most likely to benefit from antiangiogenic therapy, and, to date, no markers of this type have been validated in patients. Additionally, because antiangiogenic agents typically cause cytostatic as opposed to cytotoxic antitumor effects, it is important to determine the best strategies for evaluating therapeutic response in mCRC to ensure maximum clinical benefit. In this review, we summarize the efficacy and tolerability of approved and investigational antiangiogenic agents for the treatment of mCRC. We also discuss potential markers of response to antiangiogenic agents and how these markers, along with appropriate endpoint selection, can improve clinical trial design.

Recent Developments in Regorafenib Treatment for Gastrointestinal Cancers: Presentations at the Meeting of the European Society for Medical Oncology (ESMO) Congress 2016

The European Society for Medical Oncology (ESMO) Congress was held in Copenhagen, Denmark from 7th–11th October 2016. The use of the promiscuous multikinase inhibitor regorafenib (Stivarga®, BAY 73-4506) in the treatment of cancers of the gastrointestinal (GI) tract was strongly featured at this meeting. Regorafenib targets multiple kinases involved in oncogenesis and angiogenesis, and is US Food and Drug Administration (FDA)-approved for the treatment of advanced metastatic colorectal cancer and GI stromal tumours, following progression on standard therapies. In this review, we summarise the results of completed clinical trials on the use of regorafenib alone or in combination with other therapies for the treatment of GI cancers. We highlight the results of the Phase III RESORCE study which demonstrated the efficacy of regorafenib as a second-line therapy in patients with advanced hepatocellular carcinoma who have progressed on sorafenib. We review some promising preliminary data on the use of regorafenib in other GI cancers, such as gastric cancer, oesophageal cancer, pancreatic cancer, and soft tissue carcinomas, and provide a brief overview of ongoing and planned trials. Finally, we discuss the incidence and management of regorafenib-related toxicities and summarise attempts to identify predictive biomarkers of regorafenib sensitivity.

Total lesion glycolysis (TLG) as an imaging biomarker in metastatic colorectal cancer patients treated with regorafenib

PURPOSE

This study was performed to evaluate whether fluorine-18 fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) could predict treatment outcome of regorafenib in metastatic colorectal cancer (mCRC).

METHODS

Previously treated refractory mCRC patients were enrolled into a prospective biomarker study of regorafenib. For this sub-study, the results of FDG PET/CT scans at baseline and after two cycles of treatment were analyzed. Various metabolic parameters obtained from PET images were analyzed in relation to treatment outcome.

RESULTS

A total of 40 patients were evaluable for PET image analysis. Among various PET parameters, total lesion glycolysis (TLG) measured in the same target lesions for RECIST 1.1 analysis were the most significant in predicting prognosis, with the lowest p-value observed in TLG calculated using the margin threshold of 40 % (TLG_{40 %}). Further analysis using TLG_{40 %} showed significantly longer overall survival (OS) in patients with lower baseline TLG_{40 %} (<151.8) (p = 0.003, median 14.2 vs. 9.1 months in <151.8 and ≥151.8, respectively). Patients showing higher decrease in TLG_{40 %} after treatment showed significantly longer progression-free survival (PFS) (p = 0.001, median 8.0 vs. 2.4 months in %ΔTLG_{40 %} < -9.6 % and ≥ -9.6 %, respectively) and OS (p = 0.002, median 16.4 vs. 9.1 months in %ΔTLG_{40 %} < -9.6 % and ≥ -9.6 %, respectively). The same cutoff could discriminate patients with longer survival among the patients who were under the stable disease category according to RECIST 1.1 (median PFS 8.4 vs. 6.8 months, p = 0.020; median OS 18.3 vs. 11.5 months, p = 0.049).

CONCLUSION

Measurement of TLG can predict treatment outcome of regorafenib in mCRC.

Repositioning Bevacizumab: A Promising Therapeutic Strategy for Cartilage Regeneration

Drug discovery and development has been garnering an increasing trend of research due to the growing incidence of the diverse types of diseases. Recently, drug repositioning, also known as drug repurposing, has been emerging parallel to cancer and tissue engineering studies. Drug repositioning involves the application of currently approved or even abandoned drugs as alternative treatments to other diseases or as biomaterials in other fields including cell therapy and tissue engineering. In this review, the advancement of the antiangiogenesis drugs that were used as treatment for cancer and other diseases, with particular focus on bevacizumab, will be described. This will include an overview of the nature and progression of osteoarthritis (OA), one of the leading global degenerative diseases that cause morbidity, and the development of its therapeutic strategies. In addition, this will also feature the nonsteroidal anti-inflammatory drugs that are commonly prescribed for OA and the benefits of repositioning bevacizumab as alternative treatments for other diseases and as biomaterials for cartilage regeneration. To date, a few number of studies, employing different modes of administration and varying dosages in diverse animal models, have shown that bevacizumab can be used as a signal and can promote both in vitro and in vivo cartilage regeneration. However, other antiangiogenesis drugs and their effects in chondrogenesis and cartilage regeneration are also worth investigating.