Regorafenib (BAY 73-4506): A new oral multikinase inhibitor of angiogenic, stromal and oncogenic receptor tyrosine kinases with potent preclinical antitumor activity

Regorafenib for the Treatment of Sarcoma

OPINION STATEMENT

Sarcomas are a rare group of tumors with many subtypes, conventionally classified into soft-tissue sarcomas and bone sarcomas. Chemotherapeutic regimens form the mainstay of systemic therapy but are not well defined beyond the first-line setting and clinical outcomes are variable. Tyrosine kinase inhibitors (TKIs), with a broad inhibition profile which have been shown to target tumor angiogenesis, have an established role in the treatment of sarcomas without characteristic driver alterations. One such TKI, regorafenib, has been evaluated in sarcomas and clinical data are discussed in this review. An overview of regorafenib data from five phase 2 and one phase 1b clinical trials in over 10 sarcoma subtypes (both soft-tissue and bone) in adult and pediatric patients is reviewed. Regorafenib demonstrated clinical benefit in patients with non-adipocytic soft-tissue sarcomas, osteosarcoma and Ewing sarcoma who had progressed on prior therapy. Patients with otherwise limited treatment options may therefore benefit from regorafenib therapy.

Eficácia e Segurança de Regorafenibe em Pacientes com Características de Bom Prognóstico no Tratamento do Câncer Colorretal Metastático: Análise de Subgrupo do Estudo CORRECT

Introdução: O câncer colorretal (CCR) e o segundo mais incidente e, quando metastático, apresenta taxa de sobrevida de 14% em cinco anos. Regorafenibe e um inibidor de tirosina-quinase (ITQ) aprovado para CCR metastático (CCRm) com aumento comprovado de sobrevida global (SG). Objetivo: Explorar resultados de eficácia e segurança de regorafenibe em pacientes com CCRm e características de bom prognostico (CBP). Método: Analise de subgrupo do estudo CORRECT, com participantes divididos de acordo com CBP, seguindo os critérios: Eastern Cooperative Oncology Group (ECOG) 0, tempo de doença metastática maior que 18 meses, até três sítios metastáticos e ausência de metástase hepática. Eficácia comparada com teste de log-rank estratificado e hazad ratios (HR) calculados com o modelo de Cox. Resultados: Dos 760 participantes randomizados, 292 (34,5%) apresentavam CBP; 185 (63,4%) receberam regorafenibe; 107 (35,6%), placebo. Para o grupo CBP, a mediana SG foi 10,9 meses (IC95%:8,8-12,3) para regorafenibe e 7,3 meses (IC95%:5,6-9,1) para placebo, com 39% de redução no risco de morte (HR 0,61; IC95%:0,43-0,88; p=0,0069). A mediana de sobrevida livre de progressão (SLP) foi de 3,5 meses (IC95%:3,0-3,9) versus 1,8 mês (IC95%:1,7-1,8) respectivamente, com 61% de redução no risco de progressão da doença ou morte (HR 0,39; IC95%:0,30-0,52; p<0,0001). Os eventos adversos graus 3 e 4 foram mais frequentes para regorafenibe. Após definição de valor basal para escores de qualidade de vida (EQ-5D), estes descaíram menos para regorafenibe comparados com placebo (0,687 versus 0,592) com diferença significativa de 0,09. Conclusão: Pacientes com CBP que receberam regorafenibe melhoraram SG e SLP com menor deterioração da qualidade de vida comparado com placebo.

Latest Advances in the Management of Pediatric Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumor is the most common mesenchymal neoplasm of the gastrointestinal tract, usually found in elderly adults. It is infrequent among pediatric patients and usually differs biologically from adult-type diseases presenting mutations of KIT and PDGFR genes. In this population, more frequent is the wild-type GIST possessing SDH, TRK, RAS, NF1 mutations, among others. Both tumor types require individualized treatment with kinase inhibitors that are still being tested in the pediatric population due to the different neoplasm biology. We review the latest updates to the management of pediatric gastrointestinal tumors with a particular focus on the advances in molecular biology of the disease that enables the definition of possible resistance. Emerging treatment with kinase inhibitors that could serve as targeted therapy is discussed, especially with multikinase inhibitors of higher generation, the effectiveness of which has already been confirmed in the adult population.

Current and emerging anti-angiogenic therapies in gastrointestinal and hepatobiliary cancers

Gastrointestinal tumours are a heterogeneous group of neoplasms that arise in the gastrointestinal tract and hepatobiliary system. Their incidence is rising globally and they currently represent the leading cause of cancer-related mortality worldwide. Anti-angiogenic agents have been incorporated into the treatment armamentarium of most of these malignancies and have improved survival outcomes, most notably in colorectal cancer and hepatocellular carcinoma. New treatment combinations with immunotherapies and other agents have led to unprecedented benefits and are revolutionising patient care. In this review, we detail the mechanisms of action of anti-angiogenic agents and the preclinical rationale underlying their combinations with immunotherapies. We review the clinical evidence supporting their use across all gastrointestinal tumours, with a particular emphasis on colorectal cancer and hepatocellular carcinoma. We discuss available biomarkers of response to these therapies and their utility in routine clinical practice. Finally, we summarise ongoing clinical trials in distinct settings and highlight the preclinical rationale supporting novel combinations.

Small-molecule inhibitors, immune checkpoint inhibitors, and more: FDA-approved novel therapeutic drugs for solid tumors from 1991 to 2021

The United States Food and Drug Administration (US FDA) has always been a forerunner in drug evaluation and supervision. Over the past 31 years, 1050 drugs (excluding vaccines, cell-based therapies, and gene therapy products) have been approved as new molecular entities (NMEs) or biologics license applications (BLAs). A total of 228 of these 1050 drugs were identified as cancer therapeutics or cancer-related drugs, and 120 of them were classified as therapeutic drugs for solid tumors according to their initial indications. These drugs have evolved from small molecules with broad-spectrum antitumor properties in the early stage to monoclonal antibodies (mAbs) and antibody‒drug conjugates (ADCs) with a more precise targeting effect during the most recent decade. These drugs have extended indications for other malignancies, constituting a cancer treatment system for monotherapy or combined therapy. However, the available targets are still mainly limited to receptor tyrosine kinases (RTKs), restricting the development of antitumor drugs. In this review, these 120 drugs are summarized and classified according to the initial indications, characteristics, or functions. Additionally, RTK-targeted therapies and immune checkpoint-based immunotherapies are also discussed. Our analysis of existing challenges and potential opportunities in drug development may advance solid tumor treatment in the future.

Atezolizumab plus bevacizumab treatment for unresectable hepatocellular carcinoma progressing after molecular targeted therapy: A multicenter prospective observational study

To evaluate the efficacy of atezolizumab plus bevacizumab treatment in patients with hepatocellular carcinoma (HCC) previously treated with molecular targeted agents (MTAs). Thirty-one patients treated with atezolizumab plus bevacizumab for unresectable HCC and previously treated with MTAs were enrolled in this study. The treatment lines ranged from second to sixth lines. The treatment effect on HCC differed from that during first-line treatment. The treatment effect was determined using the Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST. The treatment response was different for each MTA immediately prior to atezolizumab + bevacizumab treatment. Tumors treated with lenvatinib followed by atezolizumab + bevacizumab showed rapid growth for a short period of time followed by shrinkage. However, patients who received ramucirumab, sorafenib, and regorafenib did not show such changes. This was likely because of differences in the mechanism of action of the MTA administered immediately beforehand. The side-effect profile differed from that observed in the IMbrave150 phase 3 study of atezolizumab plus bevacizumab, which showed more adverse events related to hepatic reserve. Patients treated with the combination of atezolizumab and bevacizumab after lenvatinib therapy may experience rapid tumor growth and subsequent shrinkage.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Efficacy and Safety of Regorafenib with or without PD-1 Inhibitors as Second-Line Therapy for Advanced Hepatocellular Carcinoma in Real-World Clinical Practice

Background

Regorafenib is the first oral targeted drug as a second-line agent in patients with advanced hepatocellular carcinoma (HCC) who progressed on sorafenib treatment. Recently, several studies demonstrated that the combination of regorafenib and PD-1 inhibitors showed a synergistic effect. Our study aimed to evaluate the efficacy of regorafenib with PD-1 inhibitors (RP) and regorafenib alone (R) as second-line treatment for advanced HCC.

Methods

From October 2018 to January 2022, our retrospective study evaluated advanced HCC patients who received regorafenib with PD-1 inhibitors or regorafenib alone as a second-line treatment at the Second Affiliated Hospital of Nanchang University, China. The efficacy and safety were compared between RP and R groups.

Results

In total, 78 patients were enrolled in our study and were separated into two groups – RP group (48) and R group (30) – according to the criteria. The ORR of RP group and R group was 18.8% and 10%, respectively, and the DCR was 66.7% and 43.3%, respectively. The RP group had a longer mPFS (5.9 months vs 3.0 months, P<0.001) and mOS (12.9 months vs 10.3 months, P=0.010) than the R group. Regorafenib monotherapy is an independent prognostic factor for OS and PFS. In OS, subgroup analysis showed that patients with AFP ≥ 400ng/mL, BCLC C stage and extrahepatic metastasis may benefit from RP, while in PFS, subgroup analysis showed that patients with BCLC C stage, AFP ≥ 400ng/mL, extrahepatic metastasis, ALBI ≥-2.60 and first-line treatment of sorafenib may benefit from RP. The incidence of grade 3/4 adverse reaction in the two groups was 22.9% and 23.3%, respectively, with no significant statistically difference (P=0.966).

Conclusion

In the second-line therapy of advanced HCC, compared to regorafenib alone, the combination of regorafenib and PD-1 inhibitors showed promising efficacy and tolerable drug toxicity.

Glioblastoma-Specific Strategies of Vascularization: Implications in Anti-Angiogenic Therapy Resistance

Angiogenesis has long been implicated as a crucial process in GBM growth and progression. GBM can adopt several strategies to build up its abundant and aberrant vasculature. Targeting GBM angiogenesis has gained more and more attention in anti-cancer therapy, and many strategies have been developed to interfere with this hallmark. However, recent findings reveal that the effects of anti-angiogenic treatments are temporally limited and that tumors become refractory to therapy and more aggressive. In this review, we summarize the GBM-associated neovascularization processes and their implication in drug resistance mechanisms underlying the transient efficacy of current anti-angiogenic therapies. Moreover, we describe potential strategies and perspectives to overcome the mechanisms adopted by GBM to develop resistance to anti-angiogenic therapy as new potential therapeutic approaches.

Clinical and NGS predictors of response to regorafenib in recurrent glioblastoma

Predictive factors for response to regorafenib in recurrent glioblastoma, IDH-wildtype, are scarcely recognized. The objective of this study was to identify molecular predictive factors for response to regorafenib using a clinically available platform. We analyzed a prospective cohort of 30 patients harboring recurrent glioblastoma, IDH-wildtype, and treated with regorafenib. Next-generation sequencing (NGS) analysis was performed on DNA extracted from paraffin-embedded tissues using a clinically available platform. Moreover, MGMT methylation and EGFRvIII expression analyses were performed. Six-month progression-free survival (PFS) was 30% and median overall survival (OS) was 7.5 months, in line with literature data. NGS analysis revealed a mutation in the EGFR pathway in 18% of cases and a mutation in the mitogen-activated protein-kinase (MAPK) pathway in 18% of cases. In the remaining cases, no mutations were detected. Patients carrying MAPK pathway mutation had a poor response to regorafenib treatment, with a significantly shorter PFS and a nonsignificantly shorter OS compared to EGFR-mutated patients (for PFS, 2.5 vs 4.5 months, p = 0.0061; for OS, 7 vs 9 months, p = 0.1076). Multivariate analysis confirmed that MAPK pathway mutations independently predicted a shorter PFS after regorafenib treatment (p = 0.0188). The negative prognostic role of MAPK pathway alteration was reinforced when we combined EGFR-mutated with EGFRvIII-positive cases. Recurrent glioblastoma tumors with an alteration in MAPK pathway could belong to the mesenchymal subtype and respond poorly to regorafenib treatment, while EGFR-altered cases have a better response to regorafenib. We thus provide a molecular selection criterion easy to implement in the clinical practice.

Analysis and Validation of Differentially Expressed Ferroptosis-Related Genes in Regorafenib-Induced Cardiotoxicity

Background

Although tyrosine kinase inhibitors (TKIs) constitute a type of anticancer drugs, the underlying mechanisms of TKI-associated cardiotoxicity remain largely unknown. Ferroptosis is a regulated cell death form that implicated in several tumors' biological processes. Our objective was to probe into the differential expression of ferroptosis-related genes in regorafenib-induced cardiotoxicity through multiple bioinformatics analysis and validation.

Methods and Materials

Four adult human cardiomyocyte cell lines treated with regorafenib were profiled using Gene Expression Omnibus (GEO) (GSE146096). Differentially expressed genes (DEGs) were identified using DESeq2 in R (V.3.6.3). Then, Gene Ontology (GO) Enrichment Analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) Enrichment Analysis, and Gene Set Enrichment Analysis (GSEA) were used to explore DEGs' bioinformatics functions and enriched pathways. We intersected DEGs with 259 ferroptosis-related genes from the FerrDb database. Finally, the mRNA levels of differentially expressed ferroptosis-related genes (DEFRGs) were validated in regorafenib-cultured cardiomyocytes to anticipate the link between DEFRGs and cardiotoxicity.

Results

747,1127,773 and 969 DEGs were screened out in adult human cardiomyocyte lines A, B, D, and E, respectively. The mechanism by which REG promotes cardiotoxicity associated with ferroptosis may be regulated by PI3K-Akt, TGF-beta, and MAPK. GSEA demonstrated that REG can promote cardiotoxicity by suppressing genes and pathways encoding extracellular matrix and related proteins, oxidative phosphorylation, or ATF-2 transcription factor network. After overlapping DEGs with ferroptosis-related genes, we got seven DEFRGs and found that ATF3, MT1G, and PLIN2 were upregulated and DDIT4 was downregulated. The ROC curve demonstrated that these genes predict regorafenib-induced cardiotoxicity well.

Conclusion

We identified four DEFRGs which may become potential predictors and participate in the regorafenib-induced cardiotoxicity. Our findings provide possibility that targeting these ferroptosis-related genes may be an alternative for clinical prevention and therapy of regorafenib-related cardiotoxicity.

FDA-Approved Inhibitors of RTK/Raf Signaling Potently Impair Multiple Steps of In Vitro and Ex Vivo Influenza A Virus Infections

Influenza virus (IV) infections pose a burden on global public health with significant morbidity and mortality. The limited range of currently licensed IV antiviral drugs is susceptible to the rapid rise of resistant viruses. In contrast, FDA-approved kinase inhibitors can be repurposed as fast-tracked host-targeted antivirals with a higher barrier of resistance. Extending our recent studies, we screened 21 FDA-approved small-molecule kinase inhibitors (SMKIs) and identified seven candidates as potent inhibitors of pandemic and seasonal IV infections. These SMKIs were further validated in a biologically and clinically relevant ex vivo model of human precision-cut lung slices. We identified steps of the virus infection cycle affected by these inhibitors (entry, replication, egress) and found that most SMKIs affected both entry and egress. Based on defined and overlapping targets of these inhibitors, the candidate SMKIs target receptor tyrosine kinase (RTK)-mediated activation of Raf/MEK/ERK pathways to limit influenza A virus infection. Our data and the established safety profiles of these SMKIs support further clinical investigations and repurposing of these SMKIs as host-targeted influenza therapeutics.

Changes in the Epidemiology of Hepatocellular Carcinoma in Asia

Simple Summary

The incidence and mortality of hepatocellular carcinoma (HCC) in Asia are among the world leaders. By understanding the changes in prevalence and influencing factors of HCC, we can better understand the current situation in Asia and take measures to reduce the incidence.

Abstract

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, with high morbidity and mortality, and the incidence is on the rise. HCC imposes a heavy healthcare burden on Asian countries due to the presence of multiple HCC risk factors in this area. Chronic hepatitis B virus (HBV) infection, chronic hepatitis C virus (HCV) infection, non-alcoholic liver disease (NAFLD), aflatoxin and alcohol intake are the causes of HCC that cannot be ignored. Compared with the pre-vaccination era, universal vaccination of newborns reduces the incidence of HCC. Anti-viral therapy with nucleos(t)ide analogues also causes a decline in HCC incidence. Early screening and direct-acting antiviral agent are beneficial to the prevention and treatment of HCV. For HCC caused by NAFLD and other reasons, lifestyle changes are imperative. This paper introduces the epidemiological trends of HCC in Asia and highlight future efforts. Focusing on prevention may be the most effective way to improve the prognosis of this hard-to-treat cancer.

Urea-based anticancer agents. Exploring 100-years of research with an eye to the future

Suramin was the first urea-based drug to be approved in clinic, and in the following century a number of milestone drugs based on this scaffold were developed. Indeed, urea soon became a privileged scaffold in medicinal chemistry for its capability to establish a peculiar network of drug-target interactions, for its physicochemical properties that are useful for tuning the druggability of the new chemical entities, and for its structural and synthetic versatility that opened the door to numerous drug design possibilities. In this review, we highlight the relevance of the urea moiety in the medicinal chemistry scenario of anticancer drugs with a special focus on the kinase inhibitors for which this scaffold represented and still represents a pivotal pharmacophoric feature. A general outlook on the approved drugs, recent patents, and current research in this field is herein provided, and the role of the urea moiety in the drug discovery process is discussed form a medicinal chemistry standpoint. We believe that the present review can benefit both academia and pharmaceutical companies' medicinal chemists to prompt research towards new urea derivatives as anticancer agents.

Chidamide plus Tyrosine Kinase Inhibitor Remodel the Tumor Immune Microenvironment and Reduce Tumor Progression When Combined with Immune Checkpoint Inhibitor in Naïve and Anti-PD-1 Resistant CT26-Bearing Mice

Combined inhibition of vascular endothelial growth factor receptor (VEGFR) and the programmed cell death protein 1 (PD-1) pathways has shown efficacy in multiple cancers; however, the clinical outcomes show limited benefits and the unmet clinical needs still remain and require improvement in efficacy. Using murine colon carcinoma (CT26) allograft models, we examined the efficacy and elucidated novel tumor microenvironment (TME) remodeling mechanisms underlying the combination of chidamide (a benzamide-based class l histone deacetylase inhibitor; brand name in Taiwan, Kepida®) with VEGF receptor tyrosine kinase inhibitor (TKIs; cabozantinib/regorafenib, etc.) and immune checkpoint inhibitors (ICIs; anti-PD-1/anti-PD-L1/anti-CTLA-4 antibodies). The TME was assessed using flow cytometry and RNA-sequencing to determine the novel mechanisms and their correlation with therapeutic effects in mice with significant treatment response. Compared with ICI alone or cabozantinib/regorafenib + ICI, combination of chidamide + cabozantinib/regorafenib + ICI increased the tumor response and survival benefits. In particular, treatment of CT26-bearing mice with chidamide + regorafenib + anti-PD-1 antibody showed a better objective response rate (ORR) and overall survival (OS). Similar results were observed in anti-PD-1 treatment-resistant mice. After treatment with this optimal combination, in the TME, RNA-sequencing revealed that downregulated mRNAs were correlated with leukocyte migration, cell chemotaxis, and macrophage gene sets, and flow cytometry analysis showed that the cell numbers of myeloid-derived polymorphonuclear suppressor cells and tumor-associated macrophages were decreased. Accordingly, chidamide + regorafenib + anti-PD-1 antibody combination therapy could trigger a novel TME remodeling mechanism by attenuating immunosuppressive cells, and restoring T-cell activation to enhance ORR and OS. Our studies also showed that the addition of Chidamide to the regorafenib + anti-PD-1 Ab combination could induce a durable tumor-specific response by attenuating immune suppression in the TME. In addition, this result suggests that TME remodeling, mediated by epigenetic immunomodulator combined with TKI and ICI, would be more advantageous for achieving a high objective response rate, when compared to TKI plus ICI or ICI alone, and maintaining long-lasting antitumor activity.

Immunomodulatory effects of regorafenib: Enhancing the efficacy of anti-PD-1/PD-L1 therapy

Anti-PD-1/PD-L1 therapy has shown significant benefits in the treatment of a variety of malignancies. However, not all cancer patients can benefit from this strategy due to drug resistance. Therefore, there is an urgent need for methods that can effectively improve the efficacy of anti-PD-1/PD-L1 therapy. Combining anti-PD-1/PD-L1 therapy with regorafenib has been demonstrated as an effective method to enhance its therapeutic effect in several clinical studies. In this review, we describe common mechanisms of resistance to anti-PD-1/PD-L1 therapy, including lack of tumor immunogenicity, T cell dysfunction, and abnormal expression of PD-L1. Then, we illustrate the role of regorafenib in modifying the tumor microenvironment (TME) from multiple aspects, which is different from other tyrosine kinase inhibitors. Regorafenib not only has immunomodulatory effects on various immune cells, but can also regulate PD-L1 and MHC-I on tumor cells and promote normalization of abnormal blood vessels. Therefore, studies on the synergetic mechanism of the combination therapy may usher in a new era for cancer treatment and help us identify the most appropriate individuals for more precise treatment.

Advantage of clinical colchicine concentration to promote sorafenib or regorafenib anti-cancer effects on hepatocellular carcinoma

The advantage of colchicine to promote sorafenib or regorafenib anti-cancer effects on hepatocellular carcinoma (HCC) was investigated. Four primary cultured HCC cell lines (S103, S143, S160, S176) were studied by clinically achievable plasma sorafenib (5, 10 μg/mL), regorafenib (2, 4 μg/mL) and colchicine (4 ng/mL) concentrations. Sorafenib and regorafenib target genes and cancer stem cell markers (NANOG, POU5F1) were selected for experiments. Colchicine inhibited proliferation in all cell lines. Sorafenib inhibited proliferation only in S143 (5 μg/mL). Combined colchicine with sorafenib reversed the sorafenib effect on cellular proliferation from promotive to inhibitory in S103, and demonstrated anti-proliferative effects on other cell lines. Regorafenib inhibited proliferation in S103 (2 μg/mL), S176 (2 μg/mL) and S160 (4 μg/mL). Combined colchicine with regorafenib demonstrated equal or stronger anti-proliferative effects than regorafenib alone in all cell lines except S160. Combined colchicine obliterated or reduced the number of up-regulated target genes induced by sorafenib, and demonstrated equal or increased number of down-regulated target genes as compared with regorafenib alone. However, combined colchicine with regorafenib increased one up-regulated target gene in three cell lines. Colchicine obliterated or decreased the magnitude of up-regulated NANOG induced by sorafenib (S103, S143, S176) or regorafenib (S143), and combined with regorafenib could down-regulate NANOG (S160, S176). Adding colchicine to sorafenib or regorafenib showed inconsistent influence on POU5F1 expression as compared with sorafenib or regorafenib alone. The above results suggest that the anti-cancer effects of combined sorafenib with colchicine may be better than sorafenib alone. Colchicine may be added to regorafenib non-responders.

A systematic comparison of anti-angiogenesis efficacy and cardiotoxicity of receptor tyrosine kinase inhibitors in zebrafish model

Pathological angiogenesis is fundamental to progression of cancerous tumors and blinding eye diseases. Anti-angiogenic receptor tyrosine kinase inhibitors (TKIs) are in broad use for the treatment of these diseases. With more and more TKIs available, it is a challenge to make an optimal choice. It remains unclear whether TKIs demonstrate similar anti-angiogenesis activities in different tissues. Many TKIs have shown varying degrees of toxic effects that should also be considered in clinical use. This study investigates the anti-angiogenic effects of 13 FDA-approved TKIs on the intersegmental vessels (ISVs), subintestinal vessels (SIVs) and retinal vasculature in zebrafish embryos. The results show that vascular endothelial growth factor receptor TKIs (VEGFR-TKIs) exhibit anti-angiogenic abilities similarly on ISVs and SIVs, and their efficacy is consistent with their IC₅₀ values against VEGFR2. In addition, VEGFR-TKIs selectively induces the apoptosis of endothelial cells in immature vessels. Among all TKIs tested, axitinib demonstrates a strong inhibition on retinal neovascularization at a low dose that do not strongly affect ISVs and SIVs, supporting its potential application for retinal diseases. Zebrafish embryos demonstrate cardiotoxicity after VEGFR-TKIs treatment, and ponatinib and sorafenib show a narrow therapeutic window, suggesting that these two drugs may need to be dosed more carefully in patients. We propose that zebrafish is an ideal model for studying in vivo antiangiogenic efficacy and cardiotoxicity of TKIs.

An overview of agents and treatments for PDGFRA-mutated gastrointestinal stromal tumors

Platelet-derived growth factor receptor A (PDGFRA) mutations occur in approximately 10-15% of gastrointestinal stromal tumors (GISTs). These tumors with PDGFRA mutations have a different pathogenesis, clinical characteristics, and treatment response compared to tumors with receptor tyrosine kinase protein (KIT) mutations (60-70%). Many clinical studies have investigated the use of tyrosine kinase inhibitors mainly in patients with KIT mutations; however, there is a lack of attention to the PDGFRA-mutated molecular subtype. The main effective inhibitors of PDGFRA are ripretinib, avapritinib, and crenolanib, and their mechanisms and efficacy in GIST (as confirmed in clinical trials) are described in this review. Some multi-targeted tyrosine kinase inhibitors with inhibitory effects on this molecular subtype are also introduced and summarized in this paper. This review focuses on PDGFRA-mutated GISTs, introduces their clinical characteristics, downstream molecular signaling pathways, and existing resistance mechanisms. We focus on the most recent literature that describes the development of PDGFRA inhibitors and their use in clinical trials, as well as the potential benefits from different combination therapy strategies.

Targeted Therapy for Hepatocellular Carcinoma: Old and New Opportunities

Simple Summary

Hepatocellular carcinoma (HCC) is the most frequent primitive cancer of the liver, accounting for 90% of all recorded cases. HCC is the third most common cause of cancer-related death, with a 5-year survival rate of just 3%. In terms of the advanced stages, systemic treatments have allowed patients to achieve clinical benefits, although the prognosis remains very poor. In the past few decades, new molecular targeted therapies have been developed and clinically evaluated with interesting results. However, on the basis of the poor prognoses and the meager benefits deriving from the available systemic therapies, research into new treatments is extremely necessary. In this review, we focus on the available systemic therapies for advanced HCC, with a look toward the future.

Abstract

Hepatocellular carcinoma (HCC) is the most frequent primitive cancer of the liver, accounting for 90% of all recorded cases. HCC is the third most common cause of cancer-related death, with a 5-year survival rate of just 3%. In the advanced stages, systemic treatments allow doctors to obtain clinical benefits, although the prognosis remains very poor. In the past few decades, new molecular targeted therapies against receptor tyrosine kinases have been developed and clinically evaluated. Sorafenib was the first oral tyrosine kinase inhibitor (TKI) approved for the treatment of advanced HCC in 2007. Subsequently, other TKIs, including Cabozantinib, Regorafenib, Lenvatinib, and vascular endothelial growth factor receptor (VEGFR) inhibitors such as Ramucirumab and VEGF inhibitors such as Bevacizumab have been approved as first- or second-line treatments. More recently, the combination of immune checkpoint inhibitors and VEGF inhibitors (Atezolizumab plus Bevacizumab) have been analyzed and approved for the treatment of advanced HCC. On the basis of the poor prognoses and the meager benefits deriving from the available systemic therapies, research into new treatments is extremely necessary. In this review, we focus on the available systemic therapies for advanced HCC, with a look toward the future.

Studies on Biological and Molecular Effects of Small-Molecule Kinase Inhibitors on Human Glioblastoma Cells and Organotypic Brain Slices

Glioblastoma is the most common and aggressive primary brain tumor. Multiple genetic and epigenetic alterations in several major signaling pathways—including the phosphoinositide 3-kinases (PI3K)/AKT/mTOR and the Raf/MEK/ERK pathway—could be found. We therefore aimed to investigate the biological and molecular effects of small-molecule kinase inhibitors that may interfere with those pathways. For this purpose, patient-derived glioblastoma cells were challenged with dactolisib, ipatasertib, MK-2206, regorafenib, or trametinib. To determine the effects of the small-molecule kinase inhibitors, assays of cell proliferation and apoptosis and immunoblot analyses were performed. To further investigate the effects of ipatasertib on organotypic brain slices harboring glioblastoma cells, the tumor growth was estimated. In addition, the network activity in brain slices was assessed by electrophysiological field potential recordings. Multi-kinase inhibitor regorafenib and both MK-2206 and dactolisib were very effective in all preclinical tumor models, while with respect to trametinib, two cell lines were found to be highly resistant. Only in HROG05 cells, ipatasertib showed anti-tumoral effects in vitro and in organotypic brain slices. Additionally, ipatasertib diminished synchronous network activity in organotypic brain slices. Overall, our data suggest that ipatasertib was only effective in selected tumor models, while especially regorafenib and MK-2206 presented a uniform response pattern.

Recurrent Glioblastoma Treatment: State of the Art and Future Perspectives in the Precision Medicine Era

Current treatment guidelines for the management of recurrent glioblastoma (rGBM) are far from definitive, and the prognosis remains dismal. Despite recent advancements in the pharmacological and surgical fields, numerous doubts persist concerning the optimal strategy that clinicians should adopt for patients who fail the first lines of treatment and present signs of progressive disease. With most recurrences being located within the margins of the previously resected lesion, a comprehensive molecular and genetic profiling of rGBM revealed substantial differences compared with newly diagnosed disease. In the present comprehensive review, we sought to examine the current treatment guidelines and the new perspectives that polarize the field of neuro-oncology, strictly focusing on progressive disease. For this purpose, updated PRISMA guidelines were followed to search for pivotal studies and clinical trials published in the last five years. A total of 125 articles discussing locoregional management, radiotherapy, chemotherapy, and immunotherapy strategies were included in our analysis, and salient findings were critically summarized. In addition, an in-depth description of the molecular profile of rGBM and its distinctive characteristics is provided. Finally, we integrate the above-mentioned evidence with the current guidelines published by international societies, including AANS/CNS, EANO, AIOM, and NCCN.

Drug Treatment for Advanced Hepatocellular Carcinoma: First-Line and Beyond

Hepatocellular carcinoma (HCC) has high mortality. The option of systemic therapy has increased significantly over the past five years. Sorafenib was the first multikinase inhibitor, introduced in 2007, as a treatment option for HCC, and it was the only effective systemic treatment for more than ten years. It was not until 2017 that several breakthroughs were made in the development of systemic strategies. Lenvatinib, another multikinase inhibitor, stood out successfully after sorafenib, and has been applied to clinical use in the first-line setting. Other multikinase inhibitors such as regorafenib, ramucirumab and cabozantinib, were approved in quick succession as second-line therapies. Concurrently, immune checkpoint inhibitors (ICIs) have readily become established treatments for many solid tumors, including HCC. The most studied ICIs to date, target programmed cell death-1 (PD-1), its ligand PD-L1, and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). These ICIs have demonstrated efficacy in treating advanced HCC. More recently, combination of bevacizumab and atezolizumab (ICI targeting PD-L1) was approved as the gold-standard first-line therapy. Combination of ICIs with nivolumab and ipilimumab was also approved in the second-line setting for those who failed sorafenib. At the moment, numerous clinical trials in advanced HCC are underway, which will bring continuous change to the management, and increase the survival, for patients with advanced HCC. Our review article: (1) summarizes United States Food and Drug Administration (US FDA) approved systemic therapies in advanced HCC, (2) reports the evidence of currently approved treatments, (3) discusses potential drugs/drug combinations being currently tested in phase III clinical trials, and (4) proposes possible future directions in drug development for advanced HCC.

Two important factors affecting the prognosis of patients treated with sorafenib followed by regorafenib for advanced hepatocellular carcinoma

Objective

To investigate the effects of hand–foot syndrome (HFS) and fatigue on disease progression and survival in patients treated with sorafenib followed by regorafenib for advanced hepatocellular carcinoma.

Methods

A retrospective analysis of patients with advanced hepatocellular carcinoma treated with sorafenib in our hospital from 1 October 2018 to 31 October 2021 was performed, and clinical and pathological data and follow-up results were obtained. Patients were divided into groups according to the severity of HFS and fatigue. Survival analysis among the groups was performed using the Kaplan–Meier method, continuous variables were analyzed using the t-test, and factors associated with survival were evaluated using multivariate Cox regression analysis.

Results

The study included 150 men and 23 women with a mean age of 60.77 years (range: 40–85 years). The median overall survival (OS), progression-free survival (PFS), and time to tumor progression (TTP) increased with increasing severity of HFS. Conversely, the median OS, PFS, and TTP decreased with increasing severity of fatigue

Conclusion

HFS and fatigue were independent risk factors affecting TTP, PFS, and OS among patients treated with sorafenib followed by regorafenib for advanced hepatocellular carcinoma.

Paradigm shift in the treatment options of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is prevalent worldwide with suboptimal therapeutic outcomes. The advancement of therapeutic options and the development of new systemic therapies expand the armamentarium to tackle HCC. Treatment options should be provided based on the hierarchy of efficacy in a multidisciplinary perspective, instead of the traditional stage-guided scheme. In advanced HCC, lenvatinib has a comparable efficacy as sorafenib for the first-line therapy of HCC; while regorafenib, cabozantinib, and ramucirumab have been approved as second-line therapy after the failure of sorafenib. Immune checkpoint inhibitor therapy prolongs response rate and survival and enables long-term cure. Atezolizumab plus bevacizumab is superior to sorafenib as the first-line therapy for advanced HCC. Several emerging regimens by the combination of various systemic therapies are currently under clinical trials. Systemic therapy may be used in the neoadjuvant, adjuvant or even as initial therapy for intermediate-stage HCC. The paradigm shift of HCC treatment will improve patient outcomes.

Prognostic implication of serum AFP in patients with hepatocellular carcinoma treated with regorafenib

Background: This multicenter study investigated the predictive value of baseline AFP and on-treatment AFP response for survival in hepatocellular carcinoma (HCC) patients with regorafenib. Materials & methods: A total of 578 patients with HCC treated with regorafenib from 12 institutions in South Korea and Italy were included. Baseline AFP (cutoff, 400 ng/ml) and AFP response (20% reduction from baseline) were analyzed for overall survival (OS) and progression-free survival (PFS). Results: Baseline AFP below 400 ng/ml was a significant factor that was independently associated with longer OS and PFS. AFP response was also a significant factor independently associated with longer OS and PFS. Conclusion: Baseline AFP and AFP response may be used as prognostic factors for survival in HCC treated with regorafenib.

RET signaling pathway and RET inhibitors in human cancer

Rearranged during transfection (RET) receptor tyrosine kinase was first identified over thirty years ago as a novel transforming gene. Since its discovery and subsequent pathway characterization, RET alterations have been identified in numerous cancer types and are most prevalent in thyroid carcinomas and non-small cell lung cancer (NSCLC). In other tumor types such as breast cancer and salivary gland carcinomas, RET alterations can be found at lower frequencies. Aberrant RET activity is associated with poor prognosis of thyroid and lung carcinoma patients, and is strongly correlated with increased risk of distant metastases. RET aberrations encompass a variety of genomic or proteomic alterations, most of which confer constitutive activation of RET. Activating RET alterations, such as point mutations or gene fusions, enhance activity of signaling pathways downstream of RET, namely PI3K/AKT, RAS/RAF, MAPK, and PLCγ pathways, to promote cell proliferation, growth, and survival. Given the important role that mutant RET plays in metastatic cancers, significant efforts have been made in developing inhibitors against RET kinase activity. These efforts have led to FDA approval of Selpercatinib and Pralsetinib for NSCLC, as well as, additional selective RET inhibitors in preclinical and clinical testing. This review covers the current biological understanding of RET signaling, the impact of RET hyperactivity on tumor progression in multiple tumor types, and RET inhibitors with promising preclinical and clinical efficacy.

Comparative Response of HCC Cells to TKIs: Modified in vitro Testing and Descriptive Expression Analysis

Introduction

Although the treatment paradigm for hepatocellular carcinoma (HCC) has recently shifted in favour of checkpoint inhibitor (CPI)-based treatment options, the tyrosine kinase inhibitors (TKI) currently approved for the treatment of HCC are expected to remain the cornerstone of HCC treatment alone or in combination with CPIs. Despite considerable research efforts, no biomarker capable of predicting the response to specific TKIs has been validated. Thus, personalized approaches to HCC may aid in determining optimal treatment lines for 2nd and 3rd lines. To identify new biomarkers, we examined differential sensitivity and investigated potential transcriptomic predictors.

Methods

To this aim, the sensitivity of nine HCC cell lines to sorafenib, lenvatinib, regorafenib, and cabozantinib was evaluated by a prolonged treatment scheme to determine their respective growth rate inhibition concentrations (GR50). Subgroups discriminated by GR50 values underwent differential expression and gene set enrichment analysis (GSEA).

Results

The nine cell lines showed broadly different sensitivities to different TKIs. GR50 values of sorafenib and regorafenib clustered closer in all cell lines, whereas treatments with lenvatinib and cabozantinib showed diversified GR50 values. GSEA showed the activation of specific pathways in sensitive vs non-sensitive cell lines. A signature consisting of 14 biomarkers (GAGE12H, GJB6, PTCHD3, PRH1-PRR4, C6orf222, HBB, C17orf99, GOLGA6A, CRYAA, CCL23, RP11-347C12.3, RP11-514O12.4, FAM180B, and TMPRSS4) discriminates the cell lines' response into three distinct treatment profiles: 1) equally sensible to sorafenib, regorafenib and cabozantinib, 2) sensible to lenvatinib, and 3) more sensible to regorafenib than sorafenib.

Conclusion

We observed diverse responses to either of the four TKIs. Subgroup analysis of TKI effectiveness showed distinct transcriptomic profiles and signaling pathways associated with responsiveness. This prompts more extensive studies to explore and validate pharmacogenomic and transcriptomic strategies for a personalized treatment approach, particularly after the failure of CPI treatment.

Glioblastoma: Current Status, Emerging Targets, and Recent Advances

Glioblastoma (GBM) is a highly malignant brain tumor characterized by a heterogeneous population of genetically unstable and highly infiltrative cells that are resistant to chemotherapy. Although substantial efforts have been invested in the field of anti-GBM drug discovery in the past decade, success has primarily been confined to the preclinical level, and clinical studies have often been hampered due to efficacy-, selectivity-, or physicochemical property-related issues. Thus, expansion of the list of molecular targets coupled with a pragmatic design of new small-molecule inhibitors with central nervous system (CNS)-penetrating ability is required to steer the wheels of anti-GBM drug discovery endeavors. This Perspective presents various aspects of drug discovery (challenges in GBM drug discovery and delivery, therapeutic targets, and agents under clinical investigation). The comprehensively covered sections include the recent medicinal chemistry campaigns embarked upon to validate the potential of numerous enzymes/proteins/receptors as therapeutic targets in GBM.

New fluorinated diarylureas linked to pyrrolo[2,3-d]pyrimidine scaffold as VEGFR-2 inhibitors: Molecular docking and biological evaluation

A series of pyrrolo[2,3-d]pyrimidine linked to diarylureas were previously discovered by our group as sorafenib fused congeners, which were endowed with more potent activity as inhibitors to vascular endothelial growth factor receptor (VEGFR2) than sorafenib. Based on these results and on the observation that the fluorinated regorafenib displayed higher VEGFR2 inhibitory activity relative to sorafenib. Therefore, in this study, we sought to develop more potent pyrrolopyrimidine surrogates through introduction of fluorine atom at the phenyl moiety near to the urea moiety mimicking regorafenib. We hypothesized that this would improve the compounds potency. Surprisingly, Compound9epossessed better VEGFR2 inhibitory activity (IC₅₀ = 52.4 nM) compared to standard drug sorafenib, whereas compounds (9b,d and f) showed moderate inhibitory activity. The newly synthesized compounds were tested on 60 human cancer cell lines. Field alignment and a molecular docking study of these compounds into the inactive conformation of VEGFR2 was performed, and theoretical ADME properties were determined.

Hepatic arterial infusion chemotherapy plus regorafenib in advanced colorectal cancer: a real-world retrospective study

Background

Hepatic arterial infusion chemotherapy delivers the drug directly to the liver. We aim to explore the benefits and tolerability of Hepatic arterial infusion chemotherapy plus regorafenib in advanced colorectal liver metastasis refractory to standard systemic chemotherapy.

Methods

This study analyzed 47 patients treated with hepatic arterial infusion chemotherapy plus regorafenib after standard systemic oxaliplatin and/or irinotecan in combination with bevacizumab or cetuximab between Jan 2017 and Jun 2020. Regorafenib was given for only 3 weeks in a 4-week cycle.

Results

Among 47 patients, 32 (68%) were males. The median age was 61 (29–75). With a median follow-up of 22.2 months (3.7–50.7 months). Before Hepatic arterial infusion chemotherapy administration in combination with regorafenib, 34 (72.3%) patients previously received ≥ 2 prior lines of systemic therapy and 37 (78.7%)patients previously received targeted biological treatment (anti-VEGF or anti-EGFR, or both). The initial doses of regorafenib were 40 mg/d (n = 1, 2.13%), 80 mg/d (n = 11, 23.43%), 120 mg/d (n = 2, 4.26%), and 160 mg/d (n = 23, 48.94%), while for 24.6% (n = 14) dose was unknown. Median Overall Survival was 22.2 months. Median Progression-Free Survival was 10.8 (95% CI: 9.0–13.7) months. Common Adverse Events were hand-foot skin reaction (12.77%), fatigue (6.38%), vomiting (6.38%), and decreased appetite (6.38%). Only 2 patients discontinued regorafenib due to Adverse Events.

Conclusions

Regorafenib combined with Hepatic arterial infusion was effective and tolerable in patients with liver predominant metastasis of colorectal cancer. Hence, this therapy can be considered as an alternative for second- or subsequent lines of therapy in patients refractory to standard systemic chemotherapy.

Impact of psoas muscle index assessed by a simple measurement method on tolerability and duration of continued treatment with sorafenib in hepatocellular carcinoma patients

BACKGROUND

In this study, we investigated the impact of simple measurement of psoas muscle index (PMI) on the tolerability of sorafenib treatment of switch from sorafenib to regorafenib.

METHOD

This retrospective study enrolled 109 patients with Child-Pugh A hepatocellular carcinoma (HCC) treated with sorafenib. Pretreatment PMI was calculated by measuring and multiplying the greatest anterior/posterior and transverse diameters of the psoas muscles on axial computed tomography images at the L3 vertebral level, and normalizing the sum of bilateral psoas muscle areas by the square of the height in meters. We, then, statistically analyzed the association between PMI and adverse events (AEs) to treatment, tolerability of sorafenib, time to treatment failure (TTF), and prognosis in patients stratified according to PMI.

RESULT

Patients were divided into high PMI (n = 41) and low PMI (n = 68) groups based on the cutoff PMI values (men: 7.04 cm2/m2; women: 4.40 cm2/m2) determined by receiver operating characteristic curve analysis to determine sorafenib tolerability. Frequencies of all types of severe AEs were higher in the low PMI group (50.0%) than in the high PMI group (29.3%; P = 0.045). The high PMI group (51.2%) had greater tolerance to sorafenib than the low PMI group (25.0%; P = 0.007). Moreover, in multivariable analysis, PMI was associated with sorafenib tolerability (odds ratio 0.26; P = 0.008) and was a prognostic factor affecting TTF (hazard ratio 1.77; P = 0.021).

CONCLUSION

PMI might be a predictive marker of tolerance to treatment and TTF in HCC patients receiving sorafenib treatment.

Second-line treatment of advanced hepatocellular carcinoma: Time for more individualized treatment options?

Hepatocellular carcinoma (HCC) is the most frequently diagnosed primary tumor of the liver and is usually detected as advanced disease. It is an aggressive disease that often progresses rapidly when it fails to respond to treatment. As such, patients have limited opportunities to try different subsequent-line treatment regimens. In the last 5 years, the number of agents and/or regimens available for the treatment of advanced HCC has significantly increased, which has made treatment choices for this patient population increasingly complex. In the second-line setting, several phase III trials of regorafenib (RESORCE), ramucirumab (REACH/REACH-2), and cabozantinib (CELESTIAL) have demonstrated clinically meaningful survival benefits in patients with the disease. However, the median overall survival of patients with advanced HCC remains unchanged at approximately 12 mo from the start of systemic second-line therapy, with a limited duration of response. Evidence from the REACH/REACH-2 trials demonstrated for the first time that baseline alpha-fetoprotein (AFP) levels can be used as an identification factor to select those who are likely to benefit the most from ramucirumab treatment. Ramucirumab is both well tolerated and efficacious and has a clinically acceptable safety profile. Therefore, it should be considered an option for patients with AFP levels ≥ 400 ng/mL.

Efficacy and tolerability of regorafenib in pretreated patients with progressive CNS grade 3 or 4 gliomas

Background

The phase 2 REGOMA trial suggested an encouraging overall survival benefit in glioblastoma patients at first relapse treated with the multikinase inhibitor regorafenib. Here, we evaluated the efficacy and side effects of regorafenib in a real-life setting.

Methods

From 2018 to 2021, 30 patients with progressive WHO CNS grade 3 or 4 gliomas treated with regorafenib (160 mg/day; first 3 weeks of each 4-week cycle) with individual dose adjustment depending on toxicity were retrospectively identified. Side effects were evaluated according to the Common Terminology Criteria for Adverse Events (version 5.0). MRI was obtained at baseline and after every second cycle. Tumor progression was assessed according to RANO criteria. After regorafenib initiation, the median PFS and OS were calculated.

Results

The median number of treatment lines before regorafenib was 2 (range 1–4). Most patients (73%) had two or more pretreatment lines. At first relapse, 27% of patients received regorafenib. A total of 94 regorafenib cycles were administered (median 2 cycles; range 1–9 cycles). Grade 3 and 4 side effects were observed in 47% and 7% of patients, respectively, and were not significantly increased in patients with two or more pretreatments (P > 0.05). The most frequent grade 3 or 4 side effects were laboratory abnormalities (62%). PFS was 2.6 months (range 0.8–8.2 months), and the OS was 6.2 months (range 0.9–24 months).

Conclusions

In patients with progressive WHO grade 3 or 4 gliomas, predominantly with two pretreatment lines or more, regorafenib seems to be effective despite considerable grade 3 or 4 side effects.

Design, synthesis and biological evaluation of a series of novel pyrrolo[2,3-d]pyrimidin/pyrazolo[3,4-d]pyrimidin-4-amine derivatives as FGFRs-dominant multi-target receptor tyrosine kinase inhibitors for the treatment of gastric cancer

Gastric cancer is the second most lethal cancer across the world. With the progress in therapeutic approaches, the 5-year survival rate of early gastric cancer can reach > 95%. However, the prognosis and survival time of advanced gastric cancer is still somber. Therefore, more effective targeted therapies for gastric cancer treatment are urgently needed. FGFR, VEGFR and other receptor tyrosine kinases have recently been suggested as potential targets for gastric cancer treatment. We herein report the discovery of pyrrolo[2,3-d]pyrimidin/pyrazolo[3,4-d]pyrimidin-4-amine derivatives as a new class of FGFRs-dominant multi-target receptor tyrosine kinase inhibitors. SAR assessment identified the most active compounds 8f and 8k, which showed excellent inhibitory activity against a variety of receptor tyrosine kinases. Moreover, 8f and 8k displayed excellent potency in the SNU-16 gastric cancer cell line. Furthermore, 8f and 8k could inhibit FGFR1 phosphorylation and downstream signaling pathways as well as induce cell apoptosis. In vivo, 8f and 8k suppress tumor growth in the SNU-16 xenograft model without inducing obvious toxicity. These findings raise the possibility that compounds 8f and 8k might serve as potential agents for the treatment of gastric cancer.

An Observational Study of Trifluridine/Tipiracil-Containing Regimen Versus Regorafenib-Containing Regimen in Patients With Metastatic Colorectal Cancer

Background

There are no randomized control trials comparing the efficacy of trifluridine/tipiracil and regorafenib in patients with metastatic colorectal cancer (mCRC). Herein, we conducted an observational study to compare the oncologic outcomes of trifluridine/tipiracil-containing regimen (TAS-102) and regorafenib-containing regimen (REG) in patients with mCRC.

Material and method

Patients who were diagnosed to have mCRC in 2015 to 2021 and treated with TAS-102-containing regimen or REG-containing regimen were recruited. Monotherapy or combination therapy were all allowed in this study. Oncologic outcomes were presented with progression-free survival (PFS), overall survival (OS), overall response rate (ORR) and disease control rate (DCR).

Results

A total of 125 patients were enrolled into our study, accounting for 50 patients with TAS-102 and 75 patients with REG. Of these patients, 64% were treated with TAS-102 or REG monotherapy, while the remaining were treated with TAS-102 combination or REG combination. In general, the median PFS and OS were 3.7 versus 2.0 months (P = 0.006) and 9.2 versus 6.8 months (P = 0.048) in TAS-102 and REG, respectively. The ORR and DCR were 44% versus 20% (P < 0.001) and 72% versus 43% (P < 0.001) in TAS-102 and REG, respectively. As for treatment strategies, the survival were significantly longer in combination than in monotherapy, no matter in TAS-102 or REG group. Multivariate analysis showed TAS-102 and combination therapy were independent predictor associated with better survival.

Conclusions

Our results suggested that TAS-102 had better oncologic outcomes than REG in patients with mCRC, especially in combination. Further prospective trials are warranted to confirm our results.

Real-Life Experience of Regorafenib in Patients With Advanced Hepatocellular Carcinoma

Background: The RESORCE trial reported that regorafenib was effective as the second-line treatment for patients with hepatocellular carcinoma (HCC) after progression on sorafenib. Real-world data are needed to assess clinical outcomes and adverse events in the setting of daily practice.

Objective: We aimed to evaluate the efficacy and safety of regorafenib after disease progression with sorafenib in Chinese patients with advanced HCC.

Patients and Methods: A total of 41 patients with advanced HCC who did not respond to sorafenib and followed a regorafenib regimen were enrolled in this retrospective study. Overall survival (OS), progression-free survival (PFS), radiological responses, and adverse events (AEs) were evaluated. Survival curves were compared by using the log-rank test and constructed with the Kaplan–Meier method.

Results: The median PFS with regorafenib was 6.6 months (range: 5.0–8.2 months), and the median OS with regorafenib was not reached. The 1-year OS rate of regorafenib was 66.4%. The median OS of sequential sorafenib to regorafenib treatment was 35.3 months [95% confidence interval (CI), 24.3–46.3], and the 2-year OS rate of sequential sorafenib to regorafenib treatment was 74.4%. The most common AEs of regorafenib treatment were elevated aspartate aminotransferase [17/41 patients (41.5%)], elevated alanine aminotransferase [16/41 patients (39%)] and hand-foot syndrome [14/41 patients (34.1%)].

Conclusion: Regorafenib appears to be safe and clinically effective in patients with advanced HCC who progressed on first-line sorafenib.

Influence of precedent drug on the subsequent therapy in the sequence of trifluridine/tipiracil with/out bevacizumab and regorafenib for unresectable or recurrent colorectal cancer

Background

Trifluridine/tipiracil (TFTD), with or without bevacizumab (Bev), and regorafenib are salvage chemotherapy options for metastatic colorectal cancer (mCRC). Here, we examined the influence of precedent drug on the efficacy of subsequent drug.

Method

The subjects were patients with mCRC who received salvage chemotherapy with TFTD (with/without Bev) followed by regorafenib (TFTD→Rego group/TFTD+Bev→Rego group), or reverse sequence (Rego→TFTD group) at the National Cancer Center Hospital between November 2013 and December 2020. The overall survival (OS), progression-free survival (PFS), disease control rate (DCR), tumor growth rate (TGR), and tumor growth kinetics (TGK) in the first evaluation were assessed in the three groups.

Results

A total of 69 patients, including 27 in the TFTD→Rego group, 13 in the TFTD+Bev→Rego group, and 29 in the Rego→TFTD group, were identified. There were no significant differences in the OS among the three groups, and in the PFS and DCR between the precedent and subsequent therapies in any of the groups. The median TGR (%/month) and TGK (mm/month) in the precedent→subsequent therapy were 50.9→32.7 (p = 0.044) and 8.76→7.79 in the TFTD→Rego group, 25.4→36.1 and 7.49→9.92 in the TFTD+Bev→Rego group, and 40.8→24.4 (p = 0.027) and 8.02→7.20 in the Rego→TFTD group, respectively.

Conclusion

In crossover use of TFTD with/without Bev and regorafenib, both agents showed similar efficacy in terms of the conventional parameters, but the differences observed in the TGR and TGK might suggest some influence of prior regorafenib treatment on the efficacy of subsequent TFTD therapy, and vice versa.

Emerging drugs for the treatment of hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) remains a leading cause of liver related mortality. Cirrhosis of any etiology is the major risk factor although HCC can develop in its absence in patients with Hepatitis B and increasingly in those with non-alcoholic fatty liver disease. When detected at an early stage, curative options include surgical resection, liver transplantation and/or ablative therapies. Unfortunately, most cases of HCC are recognized at an advanced state when options are limited and non-curative. However new systemic therapies with tyrosine kinase inhibitors and immunotherapy have expanded therapeutic options in advanced HCC. Advances in systemic therapy have given patients with advanced HCC hope and prolonged their survival. Ongoing trials addressing different combination therapies with checkpoint inhibitors, tyrosine kinase inhibitors (TKI) or anti-VEGF therapies are expected to further enhance the management of advanced HCC.

AREAS COVERED

We discuss recent data and ongoing research efforsts to improve the treatment of hepatocellular carcinoma with discussion of current and upcoming systemic therapy combining agents of different classes.

EXPERT OPINION

Sustemic therapy for HCC is in evolution. The inclusion of immunotherapy to systemic therapy has revolutionalized the field of HCC treatment. Identificantion of the appropriate combination and sequence of systemic therapy coupled with discovery of reliable HCC biomarkers will lead to improved survival and inidividulized HCC therapy.

The Release of a Highly Cytotoxic Paullone Bearing a TEMPO Free Radical from the HSA Hydrogel: An EPR Spectroscopic Characterization

This study shows the potential of a thermally induced human serum albumin (HSA) hydrogel to serve as a drug depot for sustained release of a highly cytotoxic modified paullone ligand bearing a TEMPO free radical (HL). The binding of HL to HSA was studied by electron paramagnetic resonance (EPR) spectroscopy and imaging. The EPR protocol was also implemented for the study of matrix degradation, and ligand diffusion rate, in two additional spin-labeled hydrogels, containing 5-doxylstearate and 3-carbamoyl-proxyl. The results showed that the hydrogel is an efficient HL reservoir as it retained 60% of the ligand during 11 days of dialysis in physiological saline. Furthermore, upon incubation with Colo 205 human colon adenocarcinoma cells for 3 days, the HL/HSA hydrogel did not exhibit cytotoxic activity, demonstrating that it is also an efficient ligand depot in the presence of living cells. It was observed that the percentage of HL release is independent of its initial concentration in the hydrogel, suggesting that HSA possesses a specific binding site for the ligand, most likely Sudlow site 2, as predicted by molecular docking. The intrinsic property of albumin to bind and transport various substances, including hydrophobic drugs, may be fine-tuned by appropriate physical/chemical hydrogel preparation procedures, providing optimal drug delivery.

Efficacy and safety of regorafenib dose-escalation therapy for Japanese patients with refractory metastatic colorectal cancer (RECC study)

BACKGROUND

Regorafenib significantly improves overall survival in previously treated metastatic colorectal cancer patients. However, various toxicities, such as hand-foot skin reaction (HFSR), fatigue, and liver dysfunction have limited the use of regorafenib. These toxicities appear soon after treatment initiation. The ReDOS study demonstrated the effectiveness of a weekly dose-escalation therapy of regorafenib starting with a lower daily dose; however, its usefulness in Asian subjects is unknown. We conducted a phase II study to evaluate the safety and survival benefit of regorafenib dose-escalation therapy for Japanese patients.

METHODS

Patients with sufficient organ function, who had previously received more than two lines of chemotherapy were included. Regorafenib was started at 80 mg/day and escalated to 120 mg/day in Week 2 and 160 mg/day in Week 3, if no severe drug-related toxicities were observed. The primary endpoint was cancer progression-free survival (PFS). Tumor response and progression were assessed radiologically every 8 weeks. This study was registered in the University Hospital Medical Information Network (UMIN#UMIN000028933).

RESULTS

57 patients were enrolled and all started regorafenib at 80 mg/day. 32 patients (56.1%) were subsequently escalated to 120 mg/day and 19 (33.3%) to 160 mg/day. Only 8 patients (14.0%) discontinued treatment because of adverse events. Median PFS was 1.9 months. Median overall survival was 8.9 months, the response rate was 0%, and the disease control rate was 31.6%. The most frequent adverse event greater than grade 3 was hypertension (19.3%), followed by HFSR (14.0%).

CONCLUSIONS

Regorafenib dose-escalation therapy is well tolerated with PFS-like regorafenib standard therapy.

Sprouting Angiogenesis in Human Pituitary Adenomas

Introduction

Angiogenesis in pituitary tumors is not fully understood, and a better understanding could help inform new pharmacologic therapies, particularly for aggressive pituitary tumors.

Materials and Methods

219 human pituitary tumors and 12 normal pituitary glands were studied. Angiogenic genes were quantified by an angiogenesis qPCR array and a TaqMan probe-based absolute qPCR. Angiogenesis inhibition in pituitary tumors was evaluated in vitro with the endothelial tube formation assay and in vivo in RbΔ19 mice.

Results

71 angiogenic genes, 40 of which are known to be involved in sprouting angiogenesis, were differentially expressed in pituitary tumors. Expression of endothelial markers CD31, CD34, and ENG was significantly higher in pituitary tumors, by 5.6, 22.3, and 8.2-fold, respectively, compared to in normal pituitary tissue. There was no significant difference in levels of the lymphatic endothelial marker LYVE1 in pituitary tumors compared with normal pituitary gland tissue. Pituitary tumors also expressed significantly higher levels of angiogenesis growth factors, including VEGFA (4.2-fold), VEGFB (2.2), VEGFC (19.3), PGF (13.4), ANGPT2 (9.2), PDGFA (2.7), PDGFB (10.5) and TGFB1 (3.8) compared to normal pituitary tissue. Expression of VEGFC and PGF was highly correlated with the expression of endothelial markers in tumor samples, including CD31, CD34, and ENG (endoglin, a co-receptor for TGFβ). Furthermore, VEGFR inhibitors inhibited angiogenesis induced by human pituitary tumors and prolonged survival of RbΔ19 mice.

Conclusion

Human pituitary tumors are characterized by more active angiogenesis than normal pituitary gland tissue in a manner consistent with sprouting angiogenesis. Angiogenesis in pituitary tumors is regulated mainly by PGF and VEGFC, not VEGFA and VEGFB. Angiogenesis inhibitors, such as the VEGFR2 inhibitor cabozantinib, may merit further investigation as therapies for aggressive human pituitary tumors.

Broad spectrum of regorafenib activity on mutant KIT and absence of clonal selection in gastrointestinal stromal tumor (GIST): correlative analysis from the GRID trial

BACKGROUND

In the phase 3 GRID trial, regorafenib improved progression-free survival (PFS) independent of KIT mutations in exons 9 and 11. In this retrospective, exploratory analysis of the GRID trial, we investigated whether a more comprehensive KIT mutation analysis could identify mutations that impact treatment outcome with regorafenib and a regorafenib-induced mutation pattern.

METHODS

Archived tumor samples, collected at any time prior to enrollment in GRID, were analyzed by Sanger sequencing (n = 102) and next-generation sequencing (FoundationONE; n = 47). Plasma samples collected at baseline were analyzed by BEAMing (n = 163) and SafeSEQ (n = 96).

RESULTS

In archived tumor samples, 67% (68/102) had a KIT mutation; 61% (62/102) had primary KIT mutations (exons 9 and 11) and 12% (12/102) had secondary mutations (exons 13, 14, 17, and 18). At baseline, 81% of samples (78/96) had KIT mutations by SafeSEQ, including the M541L polymorphism (sole event in 6 patients). Coexisting mutations in other oncogenes were rare, as were mutations in PDGFR, KRAS, and BRAF. Regorafenib showed PFS benefit across all primary and secondary KIT mutational subgroups examined. Available patient-matched samples taken at baseline and end of treatment (n = 41; SafeSEQ), revealed heterogeneous KIT mutational changes with no specific mutation pattern emerging upon regorafenib treatment.

CONCLUSION

These data support the results of the GRID trial, and suggest that patients may benefit from regorafenib in the presence of KIT mutations and without the selection of particular mutation patterns that confer resistance. The study was not powered to address biomarker-related questions, and the results are exploratory and hypothesis-generating.

Gastrointestinal Stromal Tumor

Over the past 20 years, gastrointestinal stromal tumor (GIST) has evolved into an increasingly complex clinical entity with ever more challenges. While surgical resection is the gold standard, advancements in genetic testing, therapeutic options, immunotherapy, and management of metastatic disease necessitate a comprehensive, multimodal approach for these tumors. This chapter highlights the importance of genomic testing of GIST, the use of neoadjuvant and adjuvant therapy for localized disease, surgical principles for GIST, as well as current and new approaches for addressing metastatic disease.

Baseline soluble MICA levels act as a predictive biomarker for the efficacy of regorafenib treatment in colorectal cancer

Background

To evaluate the effect of regorafenib on soluble MHC class I polypeptide-related sequence A (MICA) (sMICA) level in vitro. In addition, we clinically examined whether its plasma levels were associated with regorafenib activity in terms of progression-free survival (PFS) in patients with CRC.

Methods

Human CRC cell line HCT116 and HT29 cells were treated with regorafenib and its pharmacologically active metabolites, M2 or M5 at the same concentrations as those in sera of patients. We also examined the sMICA levels and the area under the plasma concentration–time curve of regorafenib, M2 and M5.

Results

Regorafenib, M2, and M5 significantly suppressed shedding of MICA in human CRC cells without toxicity. This resulted in the reduced production of sMICA. In the clinical examination, patients with CRC who showed long median PFS (3.7 months) had significantly lower sMICA levels than those with shorter median PFS (1.2 months) (p = 0.045).

Conclusions

MICA is an attractive agent for manipulating the immunological control of CRC and baseline sMICA levels could be a predictive biomarker for the efficacy of regorafenib treatment.

Regorafenib in Refractory Metastatic Colorectal Cancer: A Multi-Center Retrospective Study

Background

Regorafenib improves progression-free survival (PFS) and overall survival (OS) in patients with refractory metastatic colorectal cancer (mCRC). Here, we report the treatment patterns of regorafenib in the third- or late-line setting for mCRC in four centers in China.

Patients and Methods

Patients with refractory mCRC in four centers in China administered regorafenib from February 1, 2018 to June 31, 2021 were enrolled. Patients were grouped into 3 cohorts, namely, the monotherapy (regorafenib alone), chemo (regorafenib plus chemotherapy), and immune [regorafenib plus anti-PD1 (programmed cell death 1) antibodies] groups. Demographic, clinical, survival and safety data were retrospectively analyzed.

Results

A total of 177 patients were included in this study. Of them, 116 (65.5%) were treated with regorafenib alone, while 28 (15.9%) and 33 (18.6%) were administered regorafenib plus chemotherapy and anti-PD1 antibodies, respectively. The median followed-up time was 9.2 months. The disease control rate (DCR) was 40.7%. The median PFS (mPFS) was 2.43 months and the median OS (mOS) was 12.2 months. The immune group had longer median PFS (3.5 m vs. 2.2 m, p = 0.043) compared with the monotherapy group. Patients administered regorafenib plus chemotherapy had longer median OS (15.9 m vs. 8.4 m, p = 0.032) compared with the monotherapy group. Patients who began regorafenib treatment at 120 mg had longer median PFS and OS compared with those who began at 80 mg (PFS: 3.7 m vs. 2.0 m; p <0.001; OS: 13.4 m vs. 10.2 m; p = 0.005). Patients with a final dose of 120 mg had longer median PFS and OS compared with the 80 mg or less group (PFS: 5.0 m vs. 2.3 m; p = 0.045; OS: UR (unreach) vs. 10.9 m; p = 0.003). There were 87.0% (154/177) patients who experienced AEs. Three groups had similar rates of AEs (86.2% vs. 89.3% vs. 87.9%; p = 0.89).

Conclusion

Patients administered regorafenib alone or regorafenib in combination with other agents were relieved to some extent, with a disease control rate of 40.7%. Regorafenib plus anti-PD1 antibodies showed better PFS, while regorafenib plus chemotherapy had the most benefit in OS. There was no significant difference among three groups in terms of AEs.

Efficacy and safety of regorafenib in Japanese patients with advanced gastrointestinal stromal tumors

BACKGROUND

Regorafenib is an oral multi-kinase inhibitor that has been established as third-line treatment for patients after the failure of imatinib and sunitinib. However, since clinical data of regorafenib in the Japanese population are still lacking, the management of regorafenib is mainly based on the clinical experience of each oncologist. The aim of this study was to evaluate the efficacy and safety of regorafenib in a Japanese population.

METHODS

Thirty-three patients treated with regorafenib for metastatic and recurrent gastrointestinal stromal tumors were retrospectively enrolled. This study investigated the anti-tumor effect, including overall survival, progression-free survival, and safety, which was evaluated based on the incidence of adverse events.

RESULTS

The median overall survival of patients treated with regorafenib was 23.8 months and the 1-year overall survival rate was 80.0%, the median progression-free survival was 7.1 months and the 1-year progression-free survival rate was 40.2%. The responses to regorafenib were partial response in 3 cases (9.1%), stable disease in 17 (51.5%), progressive disease in 10 (30.3%), and non-evaluable in 3 (9.1%). The disease control rate was 54.0%. Treatment-related adverse events were reported in all patients, with the most common being hand-foot syndrome (72.7%), followed by liver damage (36.4%) and diarrhea (27.3%), and six patients (20.0%) were discontinued due to adverse events.

CONCLUSION

This is the first report of Japanese patients with gastrointestinal stromal tumors treated with regorafenib. Regorafenib showed efficacy and a manageable safety profile in Japanese patients with advanced gastrointestinal stromal tumors, which was comparable with previous studies.

Antiangiogenic Strategies in Epithelial Ovarian Cancer: Mechanism, Resistance, and Combination Therapy

Angiogenesis is one of the hallmarks of cancer and plays a crucial role in carcinogenesis and progression of epithelial ovarian cancer. Antiangiogenic agent is the first approved targeted agent in ovarian cancer. Anti-angiogenic agents mainly include agents target VEGF/VEGFR pathway, such as bevacizumab and agents target receptor tyrosine kinase, and non-VEGF/VEGFR targets of angiogenesis. Antiangiogenic agents demonstrate certain effects in ovarian cancer treatment either as monotherapy or combined with chemotherapy. Unfortunately, antiangiogenic agents, such as bevacizumab, integrated into the ovarian cancer treatment paradigm do not increase cures. Thus, the benefits of anti-angiogenic agents must be carefully weighed against the cost and associated toxicities. Antiangiogenic agents drug resistance and short of predictive biomarkers are main obstacles in ovarian cancer treatment. A combination of poly (ADP-ribose) polymerase inhibitors or immune checkpoint inhibitors might be great strategies to overcome resistance as well as enhance anti-tumor activity of anti-angiogenic drugs. Predictive biomarkers of antiangiogenic agents are in urgent need.