An Efficacy and Safety Comparison of Regorafenib and Nivolumab in Unresectable Hepatocellular Cancer Patients: A Systematic Review.

OBJECTIVE: This systematic review aimed to compare the efficacy and safety of regorafenib and nivolumab, two FDA-approved second-line treatments for unresectable Hepatocellular Carcinoma (HCC). METHODS: Literature comparing the efficacy and safety of regorafenib and nivolumab in unresectable HCC patients was systematically searched across seven databases, including: PubMed, SCOPUS, Cochrane Database of Systematic Reviews, ScienceDirect, EBSCOhost, EMBASE, and ProQuest, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The search was done on April 2nd, 2023. Study quality and risk of bias were assessed using the Agency for Healthcare Research and Quality (AHRQ) and ROBINS-1 tools. The selected studies were included in the qualitative data synthesis. RESULTS: Three trials found that HCC patients taking nivolumab had statistically insignificantly longer OS, TTP, and progression-free survival than those on regorafenib. Nivolumab increased ORR, with largely partial responses, and mixed DCR, with little statistical significance. All three studies showed that nivolumab had fewer side effects and improved tolerance. DISCUSSION: Three retrospective cohort studies with a total of 383 regorafenib-receiving cohorts and 230 nivolumab-receiving cohorts were included in the qualitative analysis. Nivolumab was found to be superior in regards of longer overall survival, longer time to progression, higher objective response rate, and lower adverse event occurrence. However, statistical significance was not achieved in most of the parameters. CONCLUSIONS: The use of nivolumab is preferable as the second-line systemic therapy for unresectable HCC. More high-quality studies are urgently needed to generate quantitative analysis, and to encourage the formation of guidelines for second-line systemic therapy.

CuET overcomes regorafenib resistance by inhibiting epithelial-mesenchymal transition through suppression of the ERK pathway in hepatocellular carcinoma.

BACKGROUND AND PURPOSE: Regorafenib was approved by the US Food and Drug Administration (FDA) for hepatocellular carcinoma (HCC) patients showing progress on sorafenib treatment. However, there is an inevitably high rate of drug resistance associated with regorafenib, which reduces its effectiveness in clinical treatment. Thus, there is an urgent need to find a potential way to solve the problem of regorafenib resistance. The metabolite of disulfiram complexed with copper, the Diethyldithiocarbamate-copper complex (CuET), has been found to be an effective anticancer drug candidate. In the present study, we aimed to evaluate the effect of CuET on regorafenib resistance in HCC and uncover the associated mechanism. EXPERIMENTAL APPROACH: Regorafenib-resistant HCC strains were constructed by applying an increasing concentration gradient. This study employed a comprehensive range of methodologies, including the cell counting kit-8 (CCK-8) assay, colony formation assay, cell cycle analysis, wound healing assay, Transwell assay, tumor xenograft model, and immunohistochemical analysis. These methods were utilized to investigate the antitumor activity of CuET, assess the combined effect of regorafenib and CuET, and elucidate the molecular mechanism underlying CuET-mediated regorafenib resistance. KEY RESULTS: The inhibitory effect of regorafenib on cell survival, proliferation and migration was decreased in regorafenib-resistant MHCC-97H (MHCC-97H/REGO) cells compared with parental cells. CuET demonstrated significant inhibitory effects on cell survival, proliferation, and migration of various HCC cell lines. CuET restored the sensitivity of MHCC-97H/REGO HCC cells to regorafenib in vitro and in vivo. Mechanistically, CuET reverses regorafenib resistance in HCC by suppressing epithelial-mesenchymal transition (EMT) through inhibition of the ERK signaling pathway. CONCLUSION AND IMPLICATIONS: Taken together, the results of this study demonstrated that CuET inhibited the activation of the ERK signaling pathway, leading to the suppression of the epithelial-mesenchymal transition (EMT) and subsequently reversing regorafenib resistance in HCC both in vivo and in vitro. This study provides a new idea and potential strategy to improve the treatment of regorafenib-resistant HCC.

Regorafenib synergizes with TAS102 against multiple gastrointestinal cancers and overcomes cancer stemness, trifluridine-induced angiogenesis, ERK1/2 and STAT3 signaling regardless of KRAS or BRAF mutational status.

Single-agent TAS102 (trifluridine/tipiracil) and regorafenib are FDA-approved treatments for metastatic colorectal cancer (mCRC). We previously reported that regorafenib combined with a fluoropyrimidine can delay disease progression in clinical case reports of multidrug-resistant mCRC patients. We hypothesized that the combination of TAS102 and regorafenib may be active in CRC and other gastrointestinal (GI) cancers and may in the future provide a treatment option for patients with advanced GI cancer. We investigated the therapeutic effect of TAS102 in combination with regorafenib in preclinical studies employing cell culture, colonosphere assays that enrich for cancer stem cells, and in vivo. TAS102 in combination with regorafenib has synergistic activity against multiple GI cancers in vitro including colorectal and gastric cancer, but not liver cancer cells. TAS102 inhibits colonosphere formation and this effect is potentiated by regorafenib. In vivo anti-tumor effects of TAS102 plus regorafenib appear to be due to anti-proliferative effects, necrosis and angiogenesis inhibition. Growth inhibition by TAS102 plus regorafenib occurs in xenografted tumors regardless of p53, KRAS or BRAF mutations, although more potent tumor suppression was observed with wild-type p53. Regorafenib significantly inhibits TAS102-induced angiogenesis and microvessel density in xenografted tumors, as well inhibits TAS102-induced ERK1/2 activation regardless of RAS or BRAF status in vivo. TAS102 plus regorafenib is a synergistic drug combination in preclinical models of GI cancer, with regorafenib suppressing TAS102-induced increase in microvessel density and p-ERK as contributing mechanisms. The TAS102 plus regorafenib drug combination may be further tested in gastric and other GI cancers.

Large-scale, prospective observational study of regorafenib in Japanese patients with advanced gastrointestinal stromal tumors in a real-world clinical setting.

Background: Regorafenib improves overall survival (OS) of patients with advanced progressive gastrointestinal stromal tumors (GISTs) after standard chemotherapy in phase III trials in the 3rd-line setting. This large-scale, prospective observational study evaluated the safety and effectiveness of regorafenib in Japanese patients with GIST in a real-world clinical setting. Methods: Patients with GIST received oral regorafenib at a maximum daily dose of 160 mg for weeks 1-3 of each 4-week cycle (dose could be modified at investigator's discretion). The primary objective was to assess safety, particularly significant adverse drug reactions (ADRs), as well as the frequency of occurrence of ADRs, hand and foot syndrome (HFS), discontinuation of treatment due to disease progression and adverse events. A Cox proportional hazards model was used to evaluate associations between OS or time to treatment failure (TTF) and baseline characteristics or HFS. Results: Between August 2013 and March 2021, 143 evaluable patients were enrolled. ADRs occurred in 90.2% of patients and led to treatment discontinuation in 28.3%. The most frequent ADRs were HFS, hypertension, and liver injury. The overall response rate was 11.3% and disease control rate 56.5% (RECIST) based on investigators' assessments. Median OS was 17.4 months (95% CI 14.24-23.68). Median TTF was 5.3 (95% CI 4.0-6.5) months. Improved OS and TTF responses occurred in patients with an Eastern Cooperative Oncology Group performance status (ECOG-PS) of 0 or 1. Conclusion: The outcomes in this real-world study were consistent with those seen in clinical trials. No new safety concerns were identified. Clinical trial registration: https://clinicaltrials.gov, identifier NCT01933958.

Small molecule tyrosine kinase inhibitors approved for systemic therapy of advanced hepatocellular carcinoma: recent advances and future perspectives.

Liver cancer is the sixth most commonly diagnosed cancer and the third leading cause of cancer death in the world, and hepatocellular carcinoma (HCC) is the most common form of liver cancer. More than half of the HCC patients are diagnosed at an advanced stage and often require systemic therapy. Dysregulation of the activity of receptor tyrosine kinases (RTKs) is involved in the development and progress of HCC, RTKs are therefore the potential targets for systemic therapy of advanced HCC (aHCC). Currently, a total of six small molecule tyrosine kinase inhibitors (TKIs) have been approved for aHCC, including first-line sorafenib, lenvatinib, and donafenib, and second-line regorafenib, cabozantinib, and apatinib. These TKIs improved patients survival, which are associated with disease stage, etiology, liver function, tumor burden, baseline levels of alpha-fetoprotein, and treatment history. This review focuses on the clinical outcomes of these TKIs in key clinical trials, retrospective and real-world studies and discusses the future perspectives of TKIs for aHCC, with an aim to provide up-to-date evidence for decision-making in the treatment of aHCC.

Comparison between Nivolumab and Regorafenib as Second-line Systemic Therapies after Sorafenib Failure in Patients with Hepatocellular Carcinoma.

PURPOSE: Nivolumab and regorafenib are second-line therapies for patients with advanced hepatocellular carcinoma (HCC). We aimed to compare the effectiveness of nivolumab and regorafenib. MATERIALS AND METHODS: We retrospectively reviewed patients with HCC treated with nivolumab or regorafenib after sorafenib failure. Progression-free survival (PFS) and overall survival (OS) were analyzed. An inverse probability of treatment weighting using the propensity score (PS) was performed to reduce treatment selection bias. RESULTS: Among the 189 patients recruited, 137 and 52 patients received regorafenib and nivolumab after sorafenib failure, respectively. Nivolumab users showed higher Child-Pugh B patients (42.3% vs. 24.1%) and shorter median sorafenib maintenance (2.2 months vs. 3.5 months) compared to regorafenib users. Nivolumab users showed shorter median OS (4.2 months vs. 7.4 months, p=0.045) than regorafenib users and similar median PFS (1.8 months vs. 2.7 months, p=0.070). However, the median overall and PFS did not differ between the two treatment groups after the 1:1 PS matching (log-rank p=0.810 and 0.810, respectively) and after the stabilized inverse probability of treatment weighting (log-rank p=0.445 and 0.878, respectively). In addition, covariate-adjusted Cox regression analyses showed that overall and PFS did not significantly differ between nivolumab and regorafenib users after 1:1 PS matching and stabilized inverse probability of treatment weighting (all p>0.05). CONCLUSION: Clinical outcomes of patients treated with nivolumab and regorafenib after sorafenib treatment failure did not differ significantly.

Cost-Effectiveness Analysis of Regorafenib versus Other Third-Line Treatments for Metastatic Colorectal Cancer.

Background: Regorafenib, a novel multikinase inhibitor, has been approved by the US Food and Drug Administration as a standard treatment choice for metastatic colorectal cancer (mCRC). Nonetheless, its substantial cost places a significant burden on social health resources and patients. However, the cost-effectiveness (CE) of regorafenib compared to other third-line therapies is still undetermined. Objective: This study aims to assess the CE of regorafenib compared to other third-line therapies for the treatment of mCRC. Methods: We conducted a comprehensive literature search in PubMed, Medline, Scopus, Embase, Cochrane Library, as well as nine other databases to identify relevant studies published up to October 2023, focusing on patients with mCRC and examining the cost-effectiveness of regorafenib. Following the screening and extraction of pertinent data, the study quality was assessed using the Quality of Health Economic Studies (QHES) checklist. Results: The literature search yielded 751 records, and after applying the inclusion criteria, 13 studies from 7 different countries were included. Of these, 7 studies evaluated the cost-effectiveness of regorafenib compared to trifluridine/tipiracil (TAS-102), 3 studies compared regorafenib with best supportive care (BSC), and 3 studies compared regorafenib with fruquintinib, serplulimab, and regorafenib dose optimization (ReDo).The quality of the included studies was high with an average QHES scores of 85.62. Regorafenib standard dose proves to be less cost-effective than alternative third-line therapies. Implementing a dose optimization strategy could potentially rectify this disparity and enhance the cost-effectiveness of regorafenib. Conclusion: The use of the standard dose of regorafenib is generally regarded as not cost-effective when compared to other third-line therapies for patients with mCRC. However, implementing a dose-escalation strategy may enhance regorafenib's cost-effectiveness. Consequently, significant price reductions or optimizing the dose of regorafenib are required to achieve cost-effectiveness.

Regorafenib in patients with metastatic colorectal cancer in Spain: from clinical trials to real-world evidence.

Aim: To describe the evolution of regorafenib use, since its approval, in patients with previously treated metastatic colorectal cancer (mCRC) in routine clinical practice in Spain. Methods: We extracted patient characteristics, dosing, safety and efficacy data for the Spanish cohorts of the CORRECT and CONSIGN trials, and the real-world CORRELATE study. Results: The Spanish cohorts represented 10.7-13.8% of the global cohorts. Efficacy and safety in the Spanish cohorts reflected findings from the global cohorts, with evidence of a flexible dosing approach being adopted in routine clinical practice. Conclusion: Regorafenib use in patients with mCRC has evolved in the real-world setting, emphasizing the need for further research evaluating dosing patterns that can optimize clinical outcomes in these patients.Clinical trial registration: The CORRECT trial is registered at ClinicalTrials.gov, number NCT01103323; the CONSIGN trial is registered at ClinicalTrials.gov, number NCT01538680; the CORRELATE study is registered at ClinicalTrials.gov, number NCT02042144.

Bowel cancer (also called colorectal cancer) affects the large bowel, including the colon and rectum. Approximately one in ten patients with advanced bowel cancer that has spread to other areas of the body (metastatic bowel cancer) survive 5 years after diagnosis or the start of treatment.Regorafenib is a treatment for patients with advanced bowel cancer that has continued to spread after receiving other treatments. It can slow down cancer growth, as shown in three international studies (CORRECT, CONSIGN and CORRELATE). In Spain, bowel cancer is the most common type of cancer and the cancer that causes the second most deaths. This study describes how the use of regorafenib in Spain has changed since it was approved in 2012, by looking at the patients from Spain who made up 11­14% of the participants in the three international studies.The CORRECT trial that compared regorafenib with a non-therapeutic placebo and the CONSIGN trial of regorafenib alone showed that treatment with regorafenib prolonged life and was well tolerated in patients with metastatic bowel cancer who had previously received or were not suitable to receive other treatments. The CORRELATE study showed that in the real world (i.e., outside of a controlled clinical trial), patients are sometimes prescribed regorafenib at lower starting doses than the recommended dose, without an apparent overall effect on how well regorafenib works or side effects. In the future, it will be important to continue researching how doctors prescribe regorafenib in daily clinical practice in Spain.

The cumulative antitumor effects of regorafenib and radiotherapy in hepatocellular carcinoma.

Regorafenib is a second-line standard treatment for hepatocellular carcinoma (HCC). However, the efficacy of regorafenib is often limited due to drug resistance, individual differences among patients, and irrational drug use. Radiotherapy (RT) is an important method of localized HCC treatment, and combining RT with other therapies may exert a synergetic antitumor effect. Platelet-derived growth factor receptor-like (PDGFRL) is a tumor suppressor in various solid tumors. However, the function of PDGFRL in HCC is still unknown. In this study, we explored whether regorafenib and RT exert a synergetic effect on the treatment of HCC. The antitumor effect and mechanisms of the combination of regorafenib and RT were verified in a xenograft mouse model in vivo and in HCC cells in vitro. The combination treatment significantly inhibited cell proliferation and promoted apoptosis both in vitro and in vivo. PDGFRL, a potential target of regorafenib, was increased after cumulative treatment in HCC cells, and PDGFRL suppressed HCC cell proliferation and promoted apoptosis by inhibiting STAT3 pathway activation. Furthermore, the cumulative antitumor effect was dependent on the upregulated expression of PDGFRL and inhibition of STAT3 signaling pathway activation in HCC cells. This study increased the understanding of the molecular mechanism underlying the effect of regorafenib plus RT on HCC and provided a theoretical basis for the clinical practice of HCC.

Regorafenib with immunotherapy versus regorafenib alone as second-line treatment for hepatocellular carcinoma: A multicenter real-world study.

INTRODUCTION: Regorafenib remains the standard and widely used second-line strategy for advanced hepatocellular carcinoma (HCC). There is still a lack of large-scale multicenter real-world evidence concerning the concurrent use of regorafenib with immune checkpoint inhibitors (ICI). This study aims to evaluate whether combining regorafenib with ICI provides greater clinical benefit than regorafenib monotherapy as second-line therapy for advanced HCC under real-world circumstances. PATIENTS AND METHODS: The study included 208 patients from five medical facilities. One hundred forty-three patients received regorafenib plus ICI combination therapy, while 65 patients received regorafenib monotherapy. Propensity score matching (PSM) analysis was employed. RESULTS: The regorafenib plus ICI group demonstrated significantly higher objective response rate (24.3% vs. 10.3%, after PSM, p = 0.030) and disease control rate (79.4% vs. 50.0%, after PSM, p < 0.001) compared to the regorafenib monotherapy group based on mRECIST criteria. Median progression-free survival (7.9 vs. 3.2 months, after PSM, p < 0.001) and overall survival (25.6 vs. 16.4 months, p = 0.010, after PSM) were also considerably longer in the regorafenib plus ICI group. The incidence of Grades 3-4 treatment-related adverse events (TRAEs) was marginally greater in the regorafenib plus ICI group than in the regorafenib group (23.8% vs. 20.0%, p = 0.546). Notably, there were no instances of treatment-related mortality or emergence of new TRAEs in any treatment group. CONCLUSION: The combination of regorafenib and ICI shows potential as a viable second-line treatment for advanced HCC, exhibiting favorable efficacy while maintaining a tolerable safety profile in contrast to regorafenib monotherapy.

Multikinase inhibitors modulate non-constitutive proteasome expression in colorectal cancer cells.

Introduction: Proteasomes are multi-subunit protein complexes responsible for protein degradation in cells. Immunoproteasomes and intermediate proteasomes (together non-constitutive proteasomes) are specific forms of proteasomes frequently associated with immune response, antigen presentation, inflammation and stress. Expression of non-constitutive proteasome subunits has a prognostic value in several types of cancer. Thus, factors that modulate non-constitutive proteasome expression in tumors are of particular interest. Multikinase inhibitors (MKIs) demonstrate promising results in treatment of cancer. At the same time, their immunomodulatory properties and effects on non-constitutive proteasome expression in colorectal cancer cells are poorly investigated. Methods: Proteasome subunit expression in colorectal cancer was evaluated by bioinformatic analysis of available datasets. Two colorectal cancer cell lines, expressing fluorescent non-constitutive proteasomes were treated with multikinase inhibitors: regorafenib and sorafenib. The proteasome subunit expression was assessed by real-time PCR, Western blotting and flow cytometry. The proteasome activity was studied using proteasome activity-based probe and fluorescent substrates. Intracellular proteasome localization was revealed by confocal microscopy. Reactive oxygen species levels following treatment were determined in cells. Combined effect of proteasome inhibition and treatment with MKIs on viability of cells was estimated. Results: Expression of non-constitutive proteasomes is increased in BRAF-mutant colorectal tumors. Regorafenib and sorafenib stimulated the activity and synthesis of non-constitutive proteasomes in examined cell lines. MKIs induced oxidative stress and redistribution of proteasomes within cells. Sorafenib stimulated formation of cytoplasmic aggregates, containing proteolyticaly active non-constitutive proteasomes, while regorafenib had no such effect. MKIs caused no synergistic action when were combined with the proteasome inhibitor. Discussion: Obtained results indicate that MKIs might affect the crosstalk between cancer cells and immune cells via modulation of intracellular proteasome pool. Observed phenomenon should be considered when MKI-based therapy is applied.

Regorafenib plus programmed death­1 inhibitors vs. regorafenib monotherapy in second­line treatment for advanced hepatocellular carcinoma: A systematic review and meta­analysis.

The present study compared the efficacy and safety of regorafenib plus programmed death-1 inhibitors (R-P) with regorafenib monotherapy as second-line therapies for advanced hepatocellular carcinoma (HCC). A systematic search of relevant literature published in PubMed, Embase, Web of Science and Cochrane Library databases until October 2023 was conducted. Two authors independently performed data extraction and screening using standardized protocols. Stata/MP 17.0 was used for the meta-analysis to evaluate the impact of R-P treatment on major outcome indicators, including overall survival, progression-free survival (PFS), tumor response and adverse reactions, in patients with advanced HCC. The results indicated that five cohort studies involving 444 patients with advanced HCC were included. The results revealed that R-P treatment improved overall survival [hazard ratio (HR), 0.61; 95% confidence interval (CI) 0.48-0.77; I2=0.0%; P=0.663] and PFS (HR, 0.51; 95% CI 0.41-0.63; I2=17.5%; P=0.303). Additionally, it increased the objective response rate (risk ratio, 2.33; 95% CI, 1.49-3.64; I2=0.0%; P=0.994) and disease control rate (HR, 1.40; 95% CI, 1.20-1.63; I2=0.0%; P=0.892) compared with those of regorafenib. However, R-P treatment was associated with an increased incidence of adverse events, such as hypothyroidism, thrombocytopenia and rash, compared with that in regorafenib. In conclusion, R-P is superior to regorafenib monotherapy in terms of survival benefits and tumor response.

Regorafenib for patients with progression of advanced hepatocellular carcinoma after treatment with atezolizumab plus bevacizumab: a case series.

Background: Immunotherapy has reshaped the systemic treatment of hepatocellular carcinoma (HCC), with atezolizumab plus bevacizumab (TA) regimen and regorafenib being the first-line and second-line treatment options for advanced HCC, respectively. However, the efficacy of using the second-line therapeutic agent regorafenib in patients with HCC that has progressed after TA regimen treatment is unknown, and there is a lack of supporting clinical data. The purpose of this case series was to evaluate the clinical efficacy of the second-line therapeutic agent regorafenib in patients with advanced HCC who progressed after treatment with a first-line TA regimen. Case Description: This case series included five patients with intermediate to advanced HCC treated with regorafenib after progression on a TA regimen. We retrospectively report the clinical data, clinical outcomes, and adverse events of these five patients. According to modified Response Evaluation Criteria in Solid Tumors (mRECIST), one patient achieved partial response (PR), three patients achieved stable disease (SD), and one patient experienced progressive disease (PD); the disease control rate (DCR) reached 80%, and the objective response rate (ORR) reached 20%. Conclusions: In patients with intermediate to advanced HCC who experience disease progression after TA therapy, second-line treatment with regorafenib may be effective in delaying progression and may be associated with better disease control. However, these findings need to be further confirmed in prospective studies with larger cohorts.

Formulation, development and evaluation of hyaluronic acid-conjugated liposomal nanoparticles loaded with regorafenib and curcumin and their in vitro evaluation on colorectal cancer cell lines.

Colorectal cancer is one of the major causes of global cancer, with chemotherapy and radiation therapy being effective but limited due to low specificity. Regorafenib, a multikinase inhibitor, provides hope to patients with metastatic colorectal cancer and was approved by the FDA in 2012. However, due to resistance issues and adverse events, its efficacy is compromised, necessitating further refinement. Meanwhile, curcumin, a compound of turmeric, exhibits anticancer effects through antioxidant and anti-inflammatory actions, induction of the apoptosis, arrest of cell cycle, inhibition of angiogenesis, and modulation of signaling pathways. Unfortunately, its clinical utility is limited by its poor bioavailability, pointing towards innovative drug delivery strategies for enhanced efficacy in colorectal cancer treatment. Hyaluronic acid (HA)-decorated liposomes (LIPO) have been developed to target colorectal cells through an overexpressed CD44 receptor, increasing antitumor and antimetastasis efficacy. This study investigates the possibility of loading curcumin (CUR) or regorafenib (REGO) into a liposomal formulation for passive and HA-actively targeted treatment, evaluating its critical quality attributes (CQA) (size, zeta potential, polydispersity index) and cytotoxic activity in the HT29 colorectal cancer cell line. The average particle size of the plain liposomes and those decorated with HA was 144.00 ± 0.78 nm and 140.77 ± 1.64 nm, respectively. In contrast, curcumin-loaded plain liposomes and HA-decorated liposomes had 140 ± 2.46 nm and 164.53 ± 15.13 nm, respectively. The prepared liposomes had a spherical shape with a narrow size distribution and an acceptable zeta potential of less than -30 mV. The encapsulation efficiency was 99.2 % ± 0.3 and 99.9 ± 0.2 % for HA-decorated and bare regorafenib loaded. The % EE was 98.9 ± 0.2 % and 97.5 ± 0.2 % for bare liposomal nanoparticles loaded with curcumin and coated with curcumin. The IC50 of free REGO, CUR, REGO-LIPO, CUR-LIPO, REGO-LIPO-HA and CUR-LIPO-HA were 20.17 ± 0.78, 64.4 ± 0.33, 224.8 ± 0.06, 49.66 ± 0.22, 73.66 ± 0.6, and 27.86 ± 0.49 µM, respectively. The MTT assay in HT29 cells showed significant cytotoxic activity of the HA-decorated liposomal formulation compared to the base uncoated formulation, indicating that hyaluronic acid-targeted liposomes loaded with regorafenib or curcumin could be a promising targeted formulation against colorectal cancer cells.

COL5A2 drives regorafenib resistance-induced metastatic phenotype via reducing LIFR expression in hepatocellular carcinoma.

Systemic therapies, the ultimate strategies for patients with advanced hepatocellular carcinoma (HCC), are suffering from serious clinical challenges, such as the occurrence and development of drug resistance. Treatment resistance aggravates tumor progression partly by inducing tumor metastasis. Regorafenib-resistant HCC cells exhibit a highly striking metastatic phenotype, but the detailed mechanisms underlying these aggressive behaviors remain elusive. Here, we conduct transcriptome sequencing analysis to identify COL5A2 as a crucial driver of the metastatic characteristics of regorafenib-resistant HCC cells. COL5A2 is aberrantly highly expressed in resistant cells, and its genetic depletion significantly suppresses proliferation, migration, invasion, vasculogenic mimicry (VM) formation and lung metastasis in vitro and in vivo, concomitant with the downregulation of VE-cadherin, EphA2, Twist1, p-p38 and p-STAT3 expressions. LIFR is confirmed to be an essential downstream molecule of COL5A2, and its expression is observably elevated by COL5A2 depletion. Ectopic overexpression of LIFR drastically attenuates the proliferation, migration, invasion and VM of regorafenib-resistant cells and represses the expressions of VM-related molecules and the activation of p38/STAT3 signaling pathway. Interestingly, rescue experiments show that the inhibition of the above aggressive features of resistant cells by COL5A2 loss is clearly alleviated by silencing of LIFR. Collectively, our results reveal that COL5A2 promotes the ability of regorafenib-resistant HCC cells to acquire a metastatic phenotype by attenuating LIFR expression and suggest that therapeutic regimens targeting the COL5A2/LIFR axis may be beneficial for HCC patients with therapeutic resistance.

Pharmacokinetic interaction between regorafenib and atorvastatin in rats.

BACKGROUND: Regorafenib is used in the treatment of colorectal cancer and hepatocellular carcinoma. Due to the co-morbidity of hyperlipidemia in these conditions, statins, including atorvastatin, are used as potential adjuvant therapy agents. Both regorafenib and atorvastatin are metabolized by CYP3A4. In addition, atorvastatin is a P-gp and BCRP substrate, whereas regorafenib and its active metabolites M-2 and M-5 are inhibitors of these transporters. Hence, the concomitant use of both drugs may increase the risk of a clinically significant drug-drug interaction. Therefore, the present study aimed to assess the pharmacokinetic interactions of atorvastatin and regorafenib and their active metabolites. METHODS: Male Wistar rats were assigned to three groups (eight animals in each) and were orally administered: regorafenib and atorvastatin (IREG+ATO), a carrier with regorafenib (IIREG), and atorvastatin with a carrier (IIIATO). Blood samples were collected for 72 h. UPLC-MS/MS was the method of measurement of regorafenib and atorvastatin concentrations. The pharmacokinetic parameters were calculated with a non-compartmental model. RESULTS: A single administration of atorvastatin increased the exposure to regorafenib and its active metabolites. In the IREG+ATO group, the Cmax, AUC0-t, and AUC0-∞ of regorafenib increased 2.7, 3.2, and 3.2-fold, respectively. Atorvastatin also significantly increased the Cmax, AUC0-t, and AUC0-∞ of both regorafenib metabolites. Regorafenib, in turn, decreased the AUC0-t and AUC0-∞ of 2-OH atorvastatin by 86.9% and 67.3%, and the same parameters of 4-OH atorvastatin by 45.0% and 46.8%, respectively. CONCLUSIONS: This animal model study showed a significant pharmacokinetic interaction between regorafenib and atorvastatin. While this interaction may be clinically significant, this needs to be confirmed in clinical trials involving cancer patients.

CHOP regulated by METTL14-m6A affects cell cycle arrest and regorafenib sensitivity in HCC cells.

BACKGROUND: Regorafenib, a multi-targeted kinase inhibitor, has been used in the treatment of Hepatocellular carcinoma (HCC). The purpose of this study is to investigate the mechanism of Regorafenib in HCC. METHODS: Regorafenib's impact on the sensitivity of HCC cells was assessed using CCK8. Differential gene expression analysis was performed by conducting mRNA sequencing after treatment with Regorafenib. The m6A methylation status of CHOP and differential expression of m6A methylation-related proteins were assessed by RIP and Western Blot. To explore the molecular mechanisms involved in the therapeutic effects of Regorafenib in HCC and the impact of METTL14 and CHOP on Regorafenib treatment, we employed shRNA/overexpression approaches to transfect METTL14 and CHOP genes, as well as conducted in vivo experiments. RESULTS: Treatment with Regorafenib led to a notable decrease in viability and proliferation of SK-Hep-1 and HCC-LM3 cells. The expression level of CHOP was upregulated after Regorafenib intervention, and CHOP underwent m6A methylation. Among the m6A methylation-related proteins, METTL14 exhibited the most significant downregulation. Mechanistic studies revealed that Regorafenib regulated the cell cycle arrest in HCC through METTL14-mediated modulation of CHOP, and the METTL14/CHOP axis affected the sensitivity of HCC to Regorafenib. In vivo, CHOP enhanced the anticancer effect of Regorafenib. CONCLUSION: The inhibition of HCC development by Regorafenib is attributed to its modulation of m6A expression of CHOP, mediated by METTL14, and the METTL14/CHOP axis enhances the sensitivity of HCC to Regorafenib. These findings provide insights into the treatment of HCC and the issue of drug resistance to Regorafenib.

Determination of Regorafenib monohydrate (colorectal anticancer drug) solubility in supercritical CO2: Experimental and thermodynamic modeling.

In this study, the solubilities of Regorafenib monohydrate (REG), a widely used as a colorectal anticancer drug, in supercritical carbon dioxide (ScCO2) were measured under various pressures and temperature conditions, for the first time. The minimum value of REG in mole fraction was determined to be 3.06×10-7, while the maximum value was found to be 6.44×10-6 at 338 K and 27 MPa. The experimental data for REG were correlated through the utilization of two types of models: (1) a set of 25 existing empirical and semi-empirical models that incorporated 3-8 parameters according to functional dependencies, (2) a model that relied on solid-liquid equilibrium (SLE) and the newly improved association models. All of the evaluated models were capable of generating suitable fits to the solubility data of REG, however, the average absolute relative deviation (AARD) of Gordillo et al. model (AARD=13.2%) and Reddy et al. model (AARD=13.5%) indicated their superiority based on AARD%. Furthermore, solvation and sublimation enthalpies of REG drug were estimated for the first time.

Locoregional treatment improves overall survival for liver cancer during second-line regorafenib or immune checkpoint inhibitor.

For advanced hepatocellular carcinoma (HCC), the best second-line treatment after first-line treatment with sorafenib is unclear. This study aimed to compared the efficacy of second-line regorafenib (a tyrosine kinase inhibitor) and immune checkpoint inhibitors (ICIs) in patients with advanced HCC after sorafenib therapy. This retrospective study included 89 patients with HCC treated with sorafenib, and then regorafenib (n = 58) or an ICI (n = 31). Treatment response, overall survival (OS) and progression-free survival (PFS) of the 2 groups were compared, and factors associated with post-treatment mortality or disease progression were evaluated. During follow-up period, compared to regorafenib, treatment with an ICI results in a slight increase in a 20% decrease of AFP (35.7% vs. 31.8%), complete response rate (6.5% vs. 0%), objective response rate (16.1% vs. 6.9%), median overall survival (13.3 vs. 5 months), and median PFS (3.0 vs. 2.6 months). Combined locoregional treatment (LRT) (hazard ratio [HR] = 0.40, 95% confidence interval [CI]: 0.15-0.99) during second-line treatment was associated with a decreased risk of post-treatment mortality. After propensity scoring matching, combined LRT during second-line treatment had longer post-treatment OS than patients without combined LRT. A 20% decrease of AFP (HR = 0.54, 95% CI: 0.31-0.94) was associated with a decreased risk of post-treatment disease progression. In conclusions, second-line treatment with regorafenib or ICI prolongs OS in patients with advanced HCC treated with sorafenib. Combined LRT during second-line treatment is associated with decreased post-treatment mortality. A 20% decrease of AFP level may be predictive of a lower rate of disease progression.

Allosteric SHP2 inhibition enhances regorafenib's effectiveness in colorectal cancer treatment.

Colorectal cancer (CRC) is the third most common cancer globally. Regorafenib, a multi-target kinase inhibitor, has been approved for treating metastatic colorectal cancer patients who have undergone at least two prior standard anti-cancer therapies. However, regorafenib efficacy as a single agent remains suboptimal. A promising target at the crossroads of multiple signaling pathways is the Src homology 2 domain-containing protein tyrosine phosphatase (SHP2). However, a combination approach using SHP2 inhibitors (SHP099) and anti-angiogenic drugs (Regorafenib) has not been reported in current research. In this study, we conducted in vitro experiments combining SHP099 and regorafenib and established an MC-38 colon cancer allograft mouse model. Our results revealed that co-treatment with SHP099 and regorafenib significantly inhibited cell viability and altered the biological characteristics of tumor cells compared with treatment alone in vitro. Furthermore, the combination strategy demonstrated superior therapeutic efficacy compared to monotherapy with either drug. This was evidenced by reduced tumor size, decreased proliferation, increased apoptosis, normalized tumor microvasculature, and improved antitumor immune response in vivo. These findings suggest that the combination of an SHP2 inhibitor and regorafenib is a promising therapeutic approach for patients with colorectal cancer.