Fruquintinib: a novel antivascular endothelial growth factor receptor tyrosine kinase inhibitor for the treatment of metastatic colorectal cancer

Efficacy and Safety of Fruquintinib-Based Treatment in Patients with Refractory Bone and Soft Tissue Sarcoma after Developing Resistance to Several TKIs: A Multicenter Retrospective Study

OBJECTIVE

Multitargeted tyrosine kinase inhibitors (TKIs) have been approved as second-line therapy in refractory sarcoma, prolonging progression-free survival (PFS) but with short-lived duration of disease control. Fruquintinib is a TKI that specifically inhibits vascular endothelial growth factor receptor-1,2,3 with no metabolism by liver enzymes. In this retrospective study, we assessed the efficacy and safety of fruquintinib-based treatment in patients with refractory sarcoma after developing several lines of TKI resistance.

METHODS

We retrospectively analyzed the clinical data of patients with refractory sarcoma after they had developed several lines of resistance to TKIs and who received fruquintinib-based treatment from November 2021 to August 2023. The primary endpoint was the progression-free survival rate at 4 months (4m-PFSR). Secondary endpoints were the median PFS, overall survival (OS), objective response rate, disease control rate, and adverse effects (AEs). PFS and OS were estimated using the Kaplan-Meier method. A log-rank test was used to compare survival curves between different clinical and pathological factors. Cox proportional hazards analysis was performed to identify PFS-related prognostic factors.

RESULTS

We included 124 patients: 56 (45.2%) with osteosarcoma, 28 (22.6%) with Ewing sarcoma, seven (5.6%) with chondrosarcoma, and 33 (26.6%) with soft tissue sarcomas (STS). Only 18 (14.5%) patients received monotherapy with fruquintinib. With a median follow-up time of 6.8 (interquartile range [IQR], 4.6-9.4) months, 22 (17.7%) patients had partial response and 78 (62.9%) had stable disease. The 4m-PFSR was 58.4% (95% confidence interval [CI], 49.6%-67.1%). The median PFS and OS were 4.4 (95% CI, 3.9-5.0) months and 11.4 (95% CI, 10.3-12.5) months. In multivariate analysis, a high hazard ratio for progression was associated with target lesions located outside the lung and bone with 1.79 (95% CI, 1.10-2.93; p = 0.020). Eighty-eight AEs were recorded in 47 (37.9%) patients; the most common were pneumothorax (18/124, 14.5%), diarrhea (8/124, 6.5%), oral mucositis (7/124, 5.6%), and thrombocytopenia (7/124, 5.6%).

CONCLUSIONS

Fruquintinib may be a potential option for patients with refractory sarcoma after developing several lines of TKI resistance, with a satisfactory efficacy and safety profile in combination therapy. However, the degree of contribution of fruquintinib to results is unclear when combined with other effective substances. Additional prospective trials of fruquintinib should be conducted, especially involving different pathological types and combination regimens.

Discovery of novel thiophene-3-carboxamide derivatives as potential VEGFR-2 inhibitors with anti-angiogenic properties

VEGFR-2 is an attractive target for the development of anti-tumor drugs and plays a crucial role in tumor angiogenesis. This study reports a series of novel thiophene-3-carboxamide derivatives based on PAN-90806 as VEGFR-2 inhibitors, among which compound 14d exhibits excellent anti-proliferative activity against HCT116, MCF7, PC3, and A549 cell lines, and has effective VEGFR-2 inhibitory activity with an IC50 value of 191.1 nM. Additionally, CETSA results indicated that VEGFR-2 was a relevant target of compound 14d in the cell lines, and compound 14d could also inhibit VEGFR-2 protein phosphorylation in A549 cell line. Furthermore, compound 14d inhibited colony formation, cell migration, and HUVECs tube formation in a dose-dependent manner. The mechanism by which 14d induced cancer cell death involves blocking the cell cycle, increasing ROS production, inducing apoptosis, and dose-dependently reducing the levels of phosphorylated ERK and MEK. Molecular docking and molecular dynamics simulations had shown that compound 14d could stably bind to the active site of VEGFR-2. These results confirmed that compound 14d might be a promising lead compound for anti-angiogenesis.

Extended survival with metastatic pancreatic cancer under fruquintinib treatment after failed chemotherapy: Two case reports

BACKGROUND

Pancreatic cancer is a highly malignant disease. After decades of treatment progress, the current five-year survival rate for patients is still less than 10%. For later-line treatment, the treatment options are even more limited. Anti-angiogenic drugs can improve progression-free survival in patients with advanced pancreatic cancer. Preclinical data show that fruquintinib might improve the prognosis of advanced pancreatic cancer by targeting angiogenesis and lymphopoiesis, improving the abnormal vascular structure, and modulating the tumour immune microenvironment.

CASE SUMMARY

We present two cases of third-line fruquintinib monotherapy that brought an extraprolonged progress-free survival (PFS) of 10 months. Patient 1 took adjuvant gemcitabine-based and first-line nab-paclitaxel-based chemotherapy and then used local radiotherapy combined with programmed cell death 1 receptor (PD-1). Each line lasted approximately 7 months. Moreover, the patient took third-line fruquintinib, which was followed by stable disease for 10 months, during which no additional adverse effect was observed. The patient later refused to take fruquintinib due to difficulty urinating and lower abdominal pain after the coronavirus disease 2019 (COVID-19) infection. The patient died in February 2023. Patient 2 also took two prior lines of chemotherapy and then local radiotherapy combined with S-1. After confirmed disease progression, the patient experienced a continuous partial response after using fruquintinib monotherapy in the third line. After the patient had COVID-19 in December 2022, fruquintinib was discontinued. The patient died in January 2023 due to disease progression.

CONCLUSION

Both cases achieved a PFS benefit from later-line single-agent fruquintinib therapy. With its better safety profile, fruquintinib may be worth exploring and studying in more depth as a later-line treatment for pancreatic cancer patients.

Fruquintinib as new treatment option in metastatic colorectal cancer patients: is there an optimal sequence?

INTRODUCTION

Available treatments for colorectal cancer are limited. However, in the last few years several advances and new treatment options became available and expanded the continuum of care in metastatic colorectal cancer (mCRC).

AREAS COVERED

Fruquintinib, a tyrosine kinase inhibitor, has been shown to be effective in heavily pretreated mCRC progressing to trifluridine-tipiracil (FTD/TPI) or regorafenib or both. Preclinical studies have shown that fruquintinib inhibits with high selectivity VEGFR 1-2-3, leading to a blockade in angiogenesis process, but also acts, with weak inhibition, on RET, FGFR-1, and c-kit kinases. Fruquintinib demonstrated good efficacy and tolerance in chemorefractory mCRC in two phase III trial: FRESCO and FRESCO 2. These results led to FDA approval of fruquintinib for pretreated mCRC patients who received prior fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy.

EXPERT OPINION

Fruquintinib is a valid therapeutic option for heavily pretreated mCRC patients. However, an optimal sequence of treatments is yet to be defined. In this review, we propose an algorithm for later lines of treatment to integrate fruquintinib as a standard of care together with the new therapeutic combinations that recently showed clinical benefit for chemorefractory mCRC, in both molecularly selected (e.g. KRASG12C or HER2 amplification) and in non-oncogenic driven patients.

Blood Vessel-Targeted Therapy in Colorectal Cancer: Current Strategies and Future Perspectives

The vasculature is a key player and regulatory component in the multicellular microenvironment of solid tumors and, consequently, a therapeutic target. In colorectal carcinoma (CRC), antiangiogenic treatment was approved almost 20 years ago, but there are still no valid predictors of response. In addition, treatment resistance has become a problem. Vascular heterogeneity and plasticity due to species-, organ-, and milieu-dependent phenotypic and functional differences of blood vascular cells reduced the hope of being able to apply a standard approach of antiangiogenic therapy to all patients. In addition, the pathological vasculature in CRC is characterized by heterogeneous perfusion, impaired barrier function, immunosuppressive endothelial cell anergy, and metabolic competition-induced microenvironmental stress. Only recently, angiocrine proteins have been identified that are specifically released from vascular cells and can regulate tumor initiation and progression in an autocrine and paracrine manner. In this review, we summarize the history and current strategies for applying antiangiogenic treatment and discuss the associated challenges and opportunities, including normalizing the tumor vasculature, modulating milieu-dependent vascular heterogeneity, and targeting functions of angiocrine proteins. These new strategies could open perspectives for future vascular-targeted and patient-tailored therapy selection in CRC.

Efficacy, safety and genomic analysis of SCT200, an anti-EGFR monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type metastatic colorectal cancer: a phase Ⅱ study

BACKGROUND

Limited therapeutic options are available for metastatic colorectal cancer (mCRC) patients after failure of first- and second-line therapies, representing an unmet medical need for novel therapies.

METHODS

This is an open-label, single arm, multicenter, phase Ⅱ study aiming to perform the efficacy, safety and genomic analysis of SCT200, a noval fully humanized IgG1 anti-epidermal growth factor receptor (EGFR) monoclonal antibody, in patients with fluorouracil, irinotecan and oxaliplatin refractory RAS and BRAF wild-type mCRC. SCT200 (6 mg/kg) was given weekly for the first six weeks, followed by a higher dose of 8 mg/kg every two weeks until disease progression or unacceptable toxicity. Primary endpoint was independent review committee (IRC)-assessed objective response rate (ORR) and secondary endpoints included ORR in patients with left-sided tumor, disease control rate (DCR), duration of response (DoR), time to response (TTR), progression-free survival (PFS), overall survival (OS) and safety.

FINDINGS

From February 12, 2018 to December 1, 2019, a total of 110 patients aged between 26 and 77 years (median: 55; interquartile range [IQR]: 47-63) with fluorouracil, oxaliplatin, and irinotecan refractory RAS and BRAF wild-type mCRC were enrolled from 22 hospitals in China. As the data cut-off date on May 15, 2020, the IRC-assessed ORR and DCR was 31% (34/110, 95% confidence interval [CI] 22-40%) and 75% (82/110, 95% CI 65-82%), respectively. Thirty one percent (34/110) patients achieved confirmed partial response (PR). The median PFS and median OS were 5.1 months (95% CI 3.4-5.2) and 16.2 months (95% CI 11.1-not available [NA]), respectively. The most common ≥ grade 3 treatment-related adverse events (TRAEs) were hypomagnesemia (17%, 19/110) and acneiform dermatitis (11%, 12/110). No deaths occurred. Genomic analysis suggested positive association between MYC amplification and patients' response (P = 0.0058). RAS/RAF mutation and MET amplification were the most frequently detected resistance mechanisms. Patients with high circulating tumor DNA (ctDNA) at baseline or without ctDNA clearance at the 7th week after the first dose of SCT200 administration before receiving SCT200 had worse PFS and OS.

INTERPRETATION

SCT200 exhibited promising clinical efficacy and manageable safety profiles in RAS and BRAF wild-type mCRC patients progressed on fluorouracil, irinotecan and oxaliplatin treatment. The baseline ctDNA and ctDNA clearance status at the 7th week after the first dose of SCT200 administration before receiving SCT200 could be a potential prognostic biomarker for RAS and BRAF wild-type mCRC patients with SCT200 therapy.

FUNDING

This study was sponsored by Sinocelltech Ltd., Beijing, China and partly supported by the National Science and Technology Major Project for Key New Drug Development (2019ZX09732001-006, 2017ZX09304015).

A perspective on emerging therapies in metastatic colorectal cancer: Focusing on molecular medicine and drug resistance

The majority of cancer cases are colorectal cancer, which is also the second largest cause of cancer-related deaths worldwide. Metastasis is the leading cause of death for patients with colorectal cancer. Metastatic colorectal cancer incidence are on the rise due to a tiny percentage of tumors developing resistant to medicines despite advances in treatment tactics. Cutting-edge targeted medications are now the go-to option for customized and all-encompassing CRC care. Specifically, multitarget kinase inhibitors, antivascular endothelial growth factors, and epidermal growth factor receptors are widely used in clinical practice for CRC-targeted treatments. Rare targets in metastatic colorectal cancer are becoming more well-known due to developments in precision diagnostics and the extensive use of second-generation sequencing technology. These targets include the KRAS mutation, the BRAF V600E mutation, the HER2 overexpression/amplification, and the MSI-H/dMMR. Incorporating certain medications into clinical trials has significantly increased patient survival rates, opening new avenues and bringing fresh viewpoints for treating metastatic colorectal cancer. These focused therapies change how cancer is treated, giving patients new hope and better results. These markers can significantly transform and individualize therapy regimens. They could open the door to precisely customized and more effective medicines, improving patient outcomes and quality of life. The fast-growing body of knowledge regarding the molecular biology of colorectal cancer and the latest developments in gene sequencing and molecular diagnostics are directly responsible for this advancement.

Small-molecule drugs of colorectal cancer: Current status and future directions

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the world's fourth most deadly cancer. CRC, as a genetic susceptible disease, faces significant challenges in optimizing prognosis through optimal drug treatment modalities. In recent decades, the development of innovative small-molecule drugs is expected to provide targeted interventions that accurately address the different molecular characteristics of CRC. Although the clinical application of single-target drugs is limited by the heterogeneity and high metastasis of CRC, novel small-molecule drug treatment strategies such as dual/multiple-target drugs, drug repurposing, and combination therapies can help overcome these challenges and provide new insights for improving CRC treatment. In this review, we focus on the current status of a range of small molecule drugs that are being considered for CRC therapy, including single-target drugs, dual/multiple-target drugs, drug repurposing and combination strategies, which will pave the way for targeting CRC vulnerabilities with small-molecule drugs in future personalized treatment.

Fruquintinib in combination with sintilimab or TAS-102 as third-line or above treatment in patients with metastatic colorectal cancer: a real-world study

Background

For metastatic colorectal cancer (mCRC), the efficacy of third-line or above treatments is not ideal. Combining targeted vascular endothelial growth factor (VEGF) or vascular endothelial growth factor receptor (VEGFR) biological agents with chemotherapy or anti-programmed death receptor 1 (PD-1) treatment can bring longer survival benefits to patients with mCRC compared with the application of a single drug. In this study, fruquintinib was used as the research drug, and the main purpose was to compare the efficacy and safety of fruquintinib in combination with sintilimab (FS) or trifluridine and tipiracil (TAS-102) (FT) in the third-line or above treatment in mCRC patients.

Methods

Based on real-world clinical practice, mCRC patients who progressed after second-line or higher-line chemotherapy regimens and received FS or FT as third-line or above treatment from December 2020 to November 2022 were analyzed. Progression-free survival (PFS) was the primary endpoint. Safety, disease control rate (DCR) and objective response rate (ORR) were secondary end points.

Results

In the FS group, 47 patients received FS, and in the FT group, 45 patients received FT. The DCR values in the FS and FT groups were 80.9% (38/47) and 55.6% (25/45), respectively (P<0.05). The median PFS (mPFS) in the FS group was 6.0 months, and the mPFS in the FT group was 3.5 months (P<0.05). Most adverse events (AEs) were grade 1-2 in severity.

Conclusions

As a third-line or above regimen in mCRC patients, compared to FT, treatment with FS provides a higher DCR and longer mPFS and is better tolerated. The combination of fruquintinib and sintilimab may become a new treatment option for mCRC patients.

Case report: PRES associated with fruquintinib in a patient with metastatic colon cancer

Posterior reversible encephalopathy syndrome (PRES) is a rare, reversible neurological disease that is frequently associated with the use of targeted therapy agents. In this case study, we examine the development of posterior reversible encephalopathy syndrome (PRES) in a 44-year-old woman with metastatic colon cancer following 1 month of treatment with the vascular endothelial growth factor receptor (VEGFR) inhibitor, fruquintinib. The occurrence of PRES after 1 month of VEGFR inhibitor administration is a common phenomenon. However, it is noteworthy that this is the first reported case of PRES associated with fruquintinib. The patient's neurological function improved upon discontinuing the drug for a week, but worsening was observed following a lower-dose fruquintinib treatment. This patient's experience highlights the potential for neurological deterioration in those treated with fruquintinib, prompting physicians to consider the possibility of PRES. Notably, this may be the first reported case linking fruquintinib to the syndrome, underscoring the importance of recognizing the association between PRES and fruquintinib.

Novel biomarkers used for early diagnosis and tyrosine kinase inhibitors as targeted therapies in colorectal cancer

Colorectal cancer (CRC) is the third most common and second most lethal type of cancer worldwide, presenting major health risks as well as economic costs to both people and society. CRC survival chances are significantly higher if the cancer is diagnosed and treated early. With the development of molecular biology, numerous initiatives have been undertaken to identify novel biomarkers for the early diagnosis of CRC. Pathological disorders can be diagnosed at a lower cost with the help of biomarkers, which can be detected in stool, blood, and tissue samples. Several lines of evidence suggest that the gut microbiota could be used as a biomarker for CRC screening and treatment. CRC treatment choices include surgical resection, chemotherapy, immunotherapy, gene therapy, and combination therapies. Targeted therapies are a relatively new and promising modality of treatment that has been shown to increase patients' overall survival (OS) rates and can inhibit cancer cell development. Several small-molecule tyrosine kinase inhibitors (TKIs) are being investigated as potential treatments due to our increasing awareness of CRC's molecular causes and oncogenic signaling. These compounds may inhibit critical enzymes in controlling signaling pathways, which are crucial for CRC cells' development, differentiation, proliferation, and survival. On the other hand, only one of the approximately 42 TKIs that demonstrated anti-tumor effects in pre-clinical studies has been licensed for clinical usage in CRC. A significant knowledge gap exists when bringing these tailored medicines into the clinic. As a result, the emphasis of this review is placed on recently discovered biomarkers for early diagnosis as well as tyrosine kinase inhibitors as possible therapy options for CRC.

Evaluation of Fruquintinib in the Continuum of Care of Patients with Colorectal Cancer

The management of patients with metastatic colorectal cancer (mCRC) has the continuum of care as the treatment paradigm. To date, trifluridine/tipiracil, a biochemically modulated fluoropyrimidine, and regorafenib, a multi-kinase inhibitor, remain the main options for the majority of patients who progressed to standard doublet- or triplet-based chemotherapies, although a tailored approach could be indicated in certain circumstances. Being highly selective for vascular endothelial growth factor receptor (VEGFR)-1, -2 and -3, fruquintinib demonstrated a strong anti-tumor activity in preclinical models and received approval from China's National Medical Products Administration (NMPA) in 2018 for the treatment of patients with chemo-refractory mCRC. The approval was based on the results of the phase III FRESCO trial. Then, in order to overcome geographic differences in clinical practice, the FRESCO-2 trial was conducted in the US, Europe, Japan, and Australia. In a heavily pretreated patient population, the study met its primary endpoint, demonstrating an advantage of fruquintinib over a placebo in overall survival (OS). Here, we review the clinical development of fruquintinib and its perspectives in gastrointestinal cancers. Then, we discuss the introduction of fruquintinib in the continuum of care of CRC paying special attention to unmet needs, including the identification of cross-resistant and potentially susceptible populations, evaluation of radiological response, and identification of novel biomarkers of clinical benefit.

Sequential-delivery nanocomplex for combined anti-angiogenesis and gene therapy against colorectal cancer

Neovascularization can provide tumors with essential nutrients and oxygen, as well as maintain a microenvironment for tumor cell growth. In this study, we combined anti-angiogenic therapy and gene therapy for synergistic anti-tumor therapy. We co-delivered the vascular endothelial growth factor receptor inhibitor fruquintinib (Fru) and small interfering RNA CCAT1 (siCCAT1) inhibiting epithelial-mesenchymal transition using 1,2-distearoyl-snglycero-3-phosphoethanolamine-N- [methoxy (polyethylene glycol)] with a pH-responsive benzoic imine linker bond (DSPE-Hyd-mPEG) and polyethyleneimine-poly (d, l-lactide) (PEI-PDLLA) nanocomplex (Fru and siCCAT1 co-delivery NP, FCNP). Due to the characteristics of pH-response, DSPE-Hyd-mPEG removed from FCNP after enrichment at the tumor site, which had a protective effect in the body. Meanwhile, Fru acting on the peritumor blood vessels was rapidly released, and then the nanoparticles loaded with siCCAT1 (CNP) was engulfed by cancer cells and facilitate the successful lysosomal escape of siCCAT1 in, playing the role of silencing CCAT1. Efficient silencing of CCAT1 by FCNP was observed, and simultaneously, the expression of VEGFR-1 was also down-regulated. Furthermore, FCNP elicited significant synergistic antitumor efficacy via anti-angiogenesis and gene therapy in the SW480 subcutaneous xenograft model with favorable biosafety and biocompatibility during the treatment. Overall, FCNP was considered a promising strategy for the combined anti-angiogenesis-gene treatment against colorectal cancer.

Using a combination of fruquintinib, raltitrexed, and S-1 as a third-line treatment for metastatic colorectal cancer with co-existence of Hodgkin lymphoma: a case report

Background

Patients with metastatic colorectal cancer (mCRC) beyond second line treatment have a poor prognosis. Fruquintinib, regorafenib, trifluridine/tipiracil (TAS-102), panitumumab and cetuximab combined with single-agent chemotherapy regimens are currently recommended as third-line therapies for patients exhibiting disease progression. Effective late-line therapies for mCRC are urgently needed. The FRESCO randomized clinical trial (RCT) prompts fruquintinib as a third-line treatment in advanced colorectal cancer (CRC). A phase II study in our center reported the efficacy and safety of S-1 plus raltitrexed for the treatment of chemo-refractory mCRC. The combination of the fruquintinib, raltitrexed, and S-1 has not been reported in mCRC.

Case Description

This case report presents a patient with mCRC who received third-line treatment with fruquintinib, raltitrexed, and S-1. A 54-year-old male presenting with hematochezia was admitted to West China Hospital of Sichuan University in June 2017 and underwent surgery for a tumor between the rectum and sigmoid colon. Postoperative pathology identified adenocarcinoma (wild-type RAS/RAF, no PIK3CA mutation), and the patient was diagnosed with mCRC (pathological stage, pT3pN1apM0). The mFOLFOX6 regimen was administered. The patient was subsequently diagnosed with Hodgkin lymphoma in May 2018 and treated with the ABVD regimen after multidisciplinary discussions. Liver metastases (intestinal-type adenocarcinoma) were detected in November 2018, and second-line therapy with the FOLFIRI regimen was initiated in January 2019. Lung metastases were identified in September 2019, so the patient was treated with a combination of raltitrexed, S-1, and fruquintinib. A partial response (PR) was detected in November 2019, and the patient underwent resection of the hepatic lesion on November 5, 2020. Computed tomography (CT) images in November 2021 revealed a stable disease; thus, raltitrexed was discontinued, and S-1 and fruquintinib were maintained. The treatment is still responding until the last follow-up (December 2022).

Conclusions

The case was characterized by the simultaneous existence of mCRC and Hodgkin lymphoma, which required management by a multidisciplinary team. Third-line therapy with fruquintinib, raltitrexed, and S-1 achieved a PR that permitted surgical resection and enabled a relatively long progression-free survival. The findings suggest that the three agents regimen might be clinically effective as late-line therapy for mCRC.

Nitrogen Containing Heterocycles as Anticancer Agents: A Medicinal Chemistry Perspective

Cancer is one of the major healthcare challenges across the globe. Several anticancer drugs are available on the market but they either lack specificity or have poor safety, severe side effects, and suffer from resistance. So, there is a dire need to develop safer and target-specific anticancer drugs. More than 85% of all physiologically active pharmaceuticals are heterocycles or contain at least one heteroatom. Nitrogen heterocycles constituting the most common heterocyclic framework. In this study, we have compiled the FDA approved heterocyclic drugs with nitrogen atoms and their pharmacological properties. Moreover, we have reported nitrogen containing heterocycles, including pyrimidine, quinolone, carbazole, pyridine, imidazole, benzimidazole, triazole, β-lactam, indole, pyrazole, quinazoline, quinoxaline, isatin, pyrrolo-benzodiazepines, and pyrido[2,3-d]pyrimidines, which are used in the treatment of different types of cancer, concurrently covering the biochemical mechanisms of action and cellular targets.

Fruquintinib/HMPL-013 ameliorates cognitive impairments and pathology in a mouse model of cerebral amyloid angiopathy (CAA)

Cerebral amyloid angiopathy (CAA) is characterized by the cerebrovascular amyloid-β (Aβ) accumulation, and always accompanied by Alzheimer's disease (AD). The mechanisms revealing CAA pathogenesis are still unclear, and it is challenging to develop an efficient therapeutic strategy for its treatment. Vascular endothelial growth factor (VEGF) and its receptors including VEGFR-1,-2,-3 activation are involved in Aβ processing, and modulate numerous cellular events associated with central nervous system (CNS) diseases. In the present study, we attempted to explore the regulatory function of fruquintinib (also named as HMPL-013), a highly selective inhibitor of VEGFR-1,-2,-3 tyrosine kinases, on CAA progression in Tg-SwDI mice. Here, we found that HMPL-013-rich diet consumption for 12 months significantly improved the behavioral performances and cerebral blood flow (CBF) of Tg-SwDI mice compared with the vehicle group. Importantly, HMPL-013 administration considerably reduced Aβ_1-40 and Aβ_1-42 burden in cortex and hippocampus of Tg-SwDI mice through regulating Aβ metabolism process. Congo red staining confirmed Aβ deposition in vessel walls, reflecting CAA formation, which was, however, strongly ameliorated after HMPL-013 treatment. Neuron death, aberrant glial activation and pro-inflammatory response in brain tissues of Tg-SwDI mice were dramatically alleviated after HMPL-013 consumption. More studies showed that the protective effects of HMPL-013 against CAA might be partially attributed to its regulation on the expression of genes associated with blood vasculature. Intriguingly, VEGF and phosphorylated VEGFR-1,-2 protein expression levels were remarkably decreased by HMPL-013 in cortex and hippocampus of Tg-SwDI mice, which were validated in HMPL-013-treated brain vascular endothelial cells (BVECs) under hypoxia. Finally, we found that VEGF-induced human umbilical vein endothelial cells (HUVEC) proliferation and tube formation were strongly abolished upon HMPL-013 exposure. Collectively, all these findings demonstrated that oral administration of HMPL-013 had therapeutic potential against CAA by reducing Aβ deposition, inflammation and neuron death via suppressing VEGF/VEGFR-1,-2 signaling.

Using a zebrafish xenograft tumor model to compare the efficacy and safety of VEGFR-TKIs

PURPOSE

We constructed a zebrafish xenograft tumor model to compare and quantify the antiangiogenic efficacy and safety of nine vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs), axitinib, lenvatinib, pazopanib, apatinib, cabozantinib, sunitinib, semaxanib, sorafenib, and regorafenib, in parallel.

METHODS

CT26 and GL261 tumor cells were implanted into the perivitelline space of Tg (flk1: eGFP) zebrafish to construct a xenograft tumor model. VEGFR-TKIs' antiangiogenic efficacy was quantified using AngioTool software, and the median effective dose (ED50) was calculated. The toxicity was evaluated by calculating the median lethal dose (LD50) and gross morphological changes. Cardiac toxicity was further assessed by heart rate, heart rhythm, the distance between the sinus venosus (SV) and bulbus arteriosus (BA), and pericardial edema.

RESULTS

Using the zebrafish xenograft tumor model, we found that all nine VEGFR-TKIs exhibited antiangiogenic abilities, but the effectiveness of semaxanib was worse than that of other VEGFR-TKIs. Meanwhile, the zebrafish toxicity assay showed that all tested VEGFR-TKIs were associated with cardiac-related toxicity, especially apatinib and axitinib, which caused serious pericardial edema in zebrafish at relatively low concentrations. A narrow therapeutic window was found for most VEGFR-TKIs, and the simultaneous occurrence of toxic effects of semaxanib was recognized.

CONCLUSION

Our findings showed the potential of using a zebrafish xenograft tumor model to accelerate VEGFR-TKI screening and further the development of more efficient and less toxic VEGFR-TKIs.

Emerging Therapeutic Agents for Colorectal Cancer

There are promising new therapeutic agents for CRC patients, including novel small-molecule inhibitors and immune checkpoint blockers. We focused on emerging CRC’s therapeutic agents that have shown the potential for progress in clinical practice. This review provides an overview of tyrosine kinase inhibitors targeting VEGF and KIT, BRAF and MEK inhibitors, TLR9 agonist, STAT3 inhibitors, and immune checkpoint blockers (PD1/PDL-1 inhibitors), for which recent advances have been reported. These new agents have the potential to provide benefits to CRC patients with unmet medical needs.

Discovery of new VEGFR-2 inhibitors based on bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives as anticancer agents and apoptosis inducers

Herein, a new wave of bis([1, 2, 4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives have been successfully designed and synthesised. The synthesised derivatives were biologically investigated for their cytotoxic activities against HepG2 and MCF-7. Also, the tested compounds were further examined in vitro for their VEGFR-2 inhibitory activity. The most promising derivative 23j was further investigated for its apoptotic behaviour in HepG2 cell lines using flow cytometric and western-plot analyses. Additional in-silico studies were performed to predict how the synthesised compounds can bind to VEGFR-2 and to determine the drug-likeness profiling of these derivatives. The results revealed that compounds 23a, 23i, 23j, 23l, and 23n displayed the highest antiproliferative activities against the two cell lines with IC50 values ranging from 6.4 to 19.4 µM. Furthermore, compounds 23a, 23d, 23h, 23i, 23j, 23l, 23 m, and 23n showed the highest VEGFR-2 inhibitory activities with IC50 values ranging from 3.7 to 11.8 nM, comparing to sorafenib (IC50 = 3.12 nM). Moreover, compound 23j arrested the HepG2 cell growth at the G2/M phase and induced apoptosis by 40.12% compared to the control cells (7.07%). As well, such compound showed a significant increase in the level of caspase-3 (1.36-fold), caspase-9 (2.80-fold), and BAX (1.65-fold), and exhibited a significant decrease in Bcl-2 level (2.63-fold).

Small Molecule Kinase Inhibitor Drugs (1995-2021): Medical Indication, Pharmacology, and Synthesis

The central role of dysregulated kinase activity in the etiology of progressive disorders, including cancer, has fostered incremental efforts on drug discovery programs over the past 40 years. As a result, kinase inhibitors are today one of the most important classes of drugs. The FDA approved 73 small molecule kinase inhibitor drugs until September 2021, and additional inhibitors were approved by other regulatory agencies during that time. To complement the published literature on clinical kinase inhibitors, we have prepared a review that recaps this large data set into an accessible format for the medicinal chemistry community. Along with the therapeutic and pharmacological properties of each kinase inhibitor approved across the world until 2020, we provide the synthesis routes originally used during the discovery phase, many of which were only available in patent applications. In the last section, we also provide an update on kinase inhibitor drugs approved in 2021.

Subgroup Analysis by Liver Metastasis in the FRESCO Trial Comparing Fruquintinib versus Placebo Plus Best Supportive Care in Chinese Patients with Metastatic Colorectal Cancer

Objective

The aim of the present subgroup analysis of the FRESCO trial is to determine the efficacy and hepatotoxicity of fruquintinib in Chinese patients with metastatic CRC with liver metastasis (CRLM) who were receiving third-line or posterior-line therapy.

Methods

Overall survival (OS) and progression-free survival (PFS) were evaluated by Kaplan–Meier method. Hazard ratio (HR) was estimated through Cox proportional hazards model. Hepatotoxicity was coded using the standardized MedDRA queries of hepatic failure, fibrosis, cirrhosis, and other liver injury-related conditions and graded using the Common Terminology Criteria Adverse Events grades. The efficacy of fruquintinib in patients with CRLM was evaluated in various subgroups.

Results

A total of 287 (69.0%) patients with metastatic CRC had liver metastasis (LM, fruquintinib: 185 and placebo: 102). Median OS in patients with CRLM was significantly prolonged with fruquintinib compared with placebo (8.61 months vs 5.98 months; HR=0.59, 95% CI, 0.45–0.77, P<0.001). In patients with CRLM, the incremental median PFS for patients in the fruquintinib-treated group was significantly higher than in the placebo group (median PFS: 3.71 vs.1.84 months; HR=0.22, 95% CI: 0.17–0.30; P<0.001). Compared with placebo, significant improvements in OS were observed with fruquintinib in LM patients regardless of lung metastasis, prior target therapy, and K-RAS status. In patients with CRLM, treatment-emergent hepatotoxicities of any grade occurred in 7 (3.8%) patients in the fruquintinib group vs 2 (2.0%) in the placebo group.

Conclusion

Fruquintinib demonstrated a statistically significant increase in OS and PFS as compared with placebo in Chinese patients with CRLM. The hepatotoxicity of fruquintinib was less reported, and comparable with placebo in patients with CRLM.

ClinicalTrials.gov Identifier

NCT02314819.

Fruquintinib beneficial in elderly patient with neoplastic pericardial effusion from rectal cancer: A case report

BACKGROUND

Neoplastic pericardial effusion (NPE) is a rare consequence of rectal cancer and carries a poor prognosis. Optimal management has yet to be determined. Fruquintinib is an oral anti-vascular endothelial growth factor receptor tyrosine kinase inhibitor approved by the China Food and Drug Administration in September 2018 as third-line treatment of metastatic colorectal cancer.

CASE SUMMARY

Herein, we report an elderly patient with NPE from rectal cancer who responded to the use of fruquintinib. In March 2015, a 65-year-old Chinese woman diagnosed with KRAS-mutated adenocarcinoma of the rectum was subjected to proctectomy, adjuvant concurrent chemoradiotherapy, and adjuvant chemotherapy. By October 2018, a mediastinal mass was detected via computed tomography. The growth had invaded parietal pericardium and left hilum, displaying features of rectal adenocarcinoma in a bronchial biopsy. FOLFIRI and FOLFOX chemotherapeutic regimens were administered as first- and second-line treatments. After two cycles of second-line agents, a sizeable pericardial effusion resulting in tamponade was drained by pericardial puncture. Fluid cytology showed cells consistent with rectal adenocarcinoma. Single-agent fruquintinib was initiated on January 3, 2019, as a third-line therapeutic. Ten cycles were delivered before the NPE recurred and other lesions progressed. The recurrence-free interval for NPE was 9.2 mo, attesting to the efficacy of fruquintinib. Ultimately, the patient entered a palliative care unit for best supportive care.

CONCLUSION

Fruquintinib may confer good survival benefit in elderly patients with NPEs due to rectal cancer.

Case Report: Severe Rashes Associated With Fruquintinib in a Patient With Metastatic Colorectal Cancer

Metastatic colorectal cancer (mCRC) is a common and high-risk malignant tumor. Fruquintinib is a novel small-molecule compound with high selective inhibition of vascular endothelial growth factor (VEGF) receptor (VEGFR) for mCRC for which second-line or higher standard chemotherapy has been ineffective. A female patient with mCRC developed severe rashes after 2 weeks of taking fruquintinib. Considering the relationship between fruquintinib and the rashes, she discontinued taking the drug, and her condition improved. Although fruquintinib has shown good safety and manageable toxicity in previous trials, the patient in the present case developed severe rashes after 2 weeks of taking fruquintinib. The common skin reactions of hand and foot are erythema and paresthesia of hand and foot. Because few people have reported a severe rash caused by fruquintinib, which is different from the common hand foot skin reaction. We hope the case attracts the attention of oncologists.

Molecular-targeted therapy toward precision medicine for gastrointestinal cancer: Current progress and challenges

Gastrointestinal (GI) cancer remains the deadliest cancer in the world. The current standard treatment for GI cancer focuses on 5-fluorouracil-based chemotherapeutic regimens and surgery, and molecular-targeted therapy is expected to be a more effective and less toxic therapeutic strategy for GI cancer. There is well-established evidence for the use of epidermal growth factor receptor-targeted and vascular endothelial growth factor-targeted antibodies, which should routinely be incorporated into treatment strategies for GI cancer. Other potential therapeutic targets involve the PI3K/AKT pathway, tumor growth factor-β pathway, mesenchymal-epithelial transition pathway, WNT pathway, poly (ADP-ribose) polymerase, and immune checkpoints. Many clinical trials assessing the agents of targeted therapy are underway and have presented promising and thought-provoking results. With the development of molecular biology techniques, we can identify more targetable molecular alterations in larger patient populations with GI cancer. Targeting these molecules will allow us to reach the goal of precision medicine and improve the outcomes of patients with GI cancer.

Influence of KDR Genetic Variation on the Efficacy and Safety of Patients with Chemotherapy Refractory Metastatic CRC Who Received Apatinib Treatment

Background

The aim of the present study was to investigate the influence of kinase insert domain containing receptor (KDR) genetic variation on the efficacy of treatment and safety of patients with chemotherapy-refractory metastatic colorectal cancer (CRC) receiving apatinib.

Methods

A total of 108 patients with chemotherapy refractory metastatic CRC who were treated with apatinib participated in this study retrospectively. Efficacy of the patients' treatment was evaluated. Prognosis was carried out and safety profile was documented, respectively. Blood specimens and peripheral blood mononuclear cells (PBMC) of the patients were obtained for the analysis of genetic variation and KDR gene mRNA expression, respectively. The association between genotype status and clinical outcomes was presented.

Results

Objective response rate (ORR) and disease control rate (DCR) of the 108 patients with metastatic CRC receiving apatinib treatment were 5.6% and 69.4%, respectively. Survival analysis results exhibited that the median progression-free survival (PFS) and overall survival (OS) of the 108 patients with metastatic CRC was 3.6 months (95% confidence interval (CI): 3.03-4.17 months) and 8.9 months (95% CI: 7.57-10.23 months), respectively. Subsequently, the analysis of KDR genetic variation indicated that rs2071559 was of clinical significance. The minor allele frequency of rs2071559 was 0.22 and the genotype status corresponded with Hardy-Weinberg equilibrium (P=0.949). Prognosis analysis in a dominant inheritance manner through the combination of patients with TC and CC genotype showed that the median PFS of patients with TT genotype and TC/CC genotype was 4.1 and 3.0 months, respectively (P=0.012). Furthermore, the median OS of patients with the two genotypes was 10.5 and 6.1 months, respectively (P=0.007). Additionally, multivariate Cox regression analysis of OS showed that TC/CC genotype was an independent factor for OS (Hazard ratio (HR)=0.65, P=0.021). Interestingly, mRNA expression analysis suggested that the mRNA expression of KDR in PBMC differed significantly according to rs2071559 genotype status (P<0.001).

Conclusion

Apatinib demonstrated a potentially superior clinical outcome for patients with chemotherapy-refractory metastatic CRC. KDR polymorphism rs2071559 could be used as a potential biomarker for the prognosis evaluation of patients with CRC receiving apatinib therapy.

New quinoxaline derivatives as VEGFR-2 inhibitors with anticancer and apoptotic activity: Design, molecular modeling, and synthesis

New series of [1,2,4]triazolo[4,3-a]quinoxalin-4(5H)-one and [1,2,4]triazolo[4,3-a]quinoxaline derivatives have been designed, synthesized, and biologically assessed for their anti-proliferative activities against two selected tumor cell lines MCF-7 and HepG2. Comparing to sorafenib (IC₅₀ = 2.17 ± 0.13 and 3.51 ± 0.21 µM against MCF-7 and HepG2, respectively), compound 25d, 25e, 25i, and 27e exhibited the highest activities against the examined cell lines with IC₅₀ values extending from 4.1 ± 0.4 to 11.7 ± 1.1 µM. Furthermore, VEGFR-2 inhibitory activities were assessed for all the synthesized compounds as potential mechanisms for their anti-proliferative activities. Compounds 25d, 25e, 25i, and 27e displayed prominent inhibitory efficiency versus VEGFR-2 kinase with IC₅₀ value ranging from 3.4 ± 0.3 to 6.8 ± 0.5 nM. Fascinatingly, the results of VEGFR-2 inhibitory assays were matched with that of the cytotoxicity data, where the most potent anti-proliferative derivatives exhibited promising VEGFR-2 inhibitory activities. Further studies displayed the ability of compound 25d to induce apoptosis in HepG2 cells and can arrest the growth of such cells at the G2/M phase. Also, compound 25d produced a significant increase in the level of BAX/Bcl-2 ratio (3.8-fold), caspase- 3 (1.8-fold), and caspase-9 (1.9-fold) compared to the control cells. Molecular docking studies were carried out to investigate the possible binding interaction inside the active site of the VEGFR-2.

Fruquintinib with gefitinib as first-line therapy in patients carrying EGFR mutations with advanced non-small cell lung cancer: a single-arm, phase II study

Background

Fruquintinib is an oral vascular endothelial growth factor receptor inhibitor. Previous gefitinib studies with anti-angiogenics show promising efficacy. This phase II trial assessed efficacy and safety of fruquintinib in combination with gefitinib, in patients with advanced non-small cell lung cancer (NSCLC).

Methods

Fifty patients with stage IIIB/IV NSCLC and an epidermal growth factor receptor (EGFR) exon-19 deletion or exon-21 L858R mutation were enrolled between January 2017 and June 2019. Per protocol (version 1.0), patients received 4 mg fruquintinib once daily (qd) Days 1–21 of Cycle 1, using a 3-week-on/1-week-off schedule, plus continuous gefitinib 250 mg qd. If tolerated, patients proceeded to fruquintinib 5 mg qd (fruquintinib 5 mg group, n=26). Following protocol updates, dose escalation of fruquintinib from 4 mg qd to 5 mg qd was not allowed. The primary efficacy endpoint was objective response rate (ORR); secondary endpoints included progression-free survival (PFS), disease control rate (DCR), time to response, duration of response and adverse events (AEs).

Results

ORR was 73.5% (95% CI, 58.9–85.1) and DCR was 98.0% (95% CI, 89.2–100.0). Median PFS was 14.7 months for both groups; PFS was highest for patients with exon-19 deletion (16.5 months; 95% CI, 12.9–21.2). Grade ≥3 treatment-emergent AEs occurred in 17 (65.3%; fruquintinib 5 mg,) and 11 patients (45.8%; 4 mg). Serious AEs were recorded for nine patients (fruquintinib 5 mg, six patients; 4 mg, three).

Conclusions

Fruquintinib and gefitinib treatment showed an acceptable safety profile and promising efficacy in patients with NSCLC.

Angiogenesis-Related Functions of Wnt Signaling in Colorectal Carcinogenesis

Simple Summary

Angiogenesis belongs to the most clinical characteristics of colorectal cancer (CRC) and is strongly linked to the activation of Wnt/β-catenin signaling. The most prominent factors stimulating constitutive activation of this pathway, and in consequence angiogenesis, are genetic alterations (mainly mutations) concerning APC and the β-catenin encoding gene (CTNNB1), detected in a large majority of CRC patients. Wnt/β-catenin signaling is involved in the basic types of vascularization (sprouting and nonsprouting angiogenesis), vasculogenic mimicry as well as the formation of mosaic vessels. The number of known Wnt/β-catenin signaling components and other pathways interacting with Wnt signaling, regulating angiogenesis, and enabling CRC progression continuously increases. This review summarizes the current knowledge about the role of the Wnt/Fzd/β-catenin signaling pathway in the process of CRC angiogenesis, aiming to improve the understanding of the mechanisms of metastasis as well as improvements in the management of this cancer.

Abstract

Aberrant activation of the Wnt/Fzd/β-catenin signaling pathway is one of the major molecular mechanisms of colorectal cancer (CRC) development and progression. On the other hand, one of the most common clinical CRC characteristics include high levels of angiogenesis, which is a key event in cancer cell dissemination and distant metastasis. The canonical Wnt/β-catenin downstream signaling regulates the most important pro-angiogenic molecules including vascular endothelial growth factor (VEGF) family members, matrix metalloproteinases (MMPs), and chemokines. Furthermore, mutations of the β-catenin gene associated with nuclear localization of the protein have been mainly detected in microsatellite unstable CRC. Elevated nuclear β-catenin increases the expression of many genes involved in tumor angiogenesis. Factors regulating angiogenesis with the participation of Wnt/β-catenin signaling include different groups of biologically active molecules including Wnt pathway components (e.g., Wnt2, DKK, BCL9 proteins), and non-Wnt pathway factors (e.g., chemoattractant cytokines, enzymatic proteins, and bioactive compounds of plants). Several lines of evidence argue for the use of angiogenesis inhibition in the treatment of CRC. In the context of this paper, components of the Wnt pathway are among the most promising targets for CRC therapy. This review summarizes the current knowledge about the role of the Wnt/Fzd/β-catenin signaling pathway in the process of CRC angiogenesis, aiming to improve the understanding of the mechanisms of metastasis as well as improvements in the management of this cancer.

Previous Use of Anti-Vascular Endothelial Growth Factor Receptor Agents Decreases Efficacy of Fruquintinib in Metastatic Colorectal Cancer Refractory to Standard Therapies

Purpose

Fruquintinib is an anti-vascular endothelial growth factor receptor (VEGFR) agent. The FRESCO trial demonstrated that patients with metastatic colorectal cancer (mCRC) refractory to standard therapies could benefit from fruquintinib with tolerable adverse events (AEs). However, the efficacy and safety of fruquintinib in clinical practice has scarcely been reported, especially in patients with previous use of anti-VEGFR agents.

Methods

This retrospective study investigated the efficacy and safety of fruquintinib in patients with mCRC between January 2019 and December 2019. Progression-free survival (PFS) and overall survival (OS) were assessed by a Kaplan-Meier analysis and log-rank test. A Cox regression model was performed to identify independent prognostic factors.

Results

A total of 46 patients were included. The median PFS and OS were 3.1 months (95% confidence interval [CI], 1.9–4.3 months) and 9.0 months (95% CI, 7.2–10.8 months), respectively. Patients previously treated with anti-VEGFR agents had shorter median PFS compared with those without previous use of anti-VEGFR agents (1.9 vs. 3.7 months, P = 0.006), while the median OS was similar between the two groups (8.5 vs. 9.0 months, P = 0.992). Multivariate analysis revealed that the neutrophil-lymphocyte ratio (NLR) was an independent prognostic factor in PFS (hazard ratio [HR], 2.230; 95% CI, 1.191–4.517, P = 0.014) and OS (HR, 4.221; 95% CI, 1.683–10.586; P = 0.002). The most common non-hematological and hematological AEs were hand-foot syndrome (37.0%) and anemia (39.1%), respectively.

Conclusion

Fruquintinib was an effective third-line therapy in mCRC with tolerable AEs. Efficacy of fruquintinib was decreased in patients with previous use of anti-VEGFR agents. NLR was an independent prognostic factor in PFS and OS in patients treated with fruquintinib.

Tyrosine Kinase Receptors in Oncology

Tyrosine kinase receptors (TKR) comprise more than 60 molecules that play an essential role in the molecular pathways, leading to cell survival and differentiation. Consequently, genetic alterations of TKRs may lead to tumorigenesis and, therefore, cancer development. The discovery and improvement of tyrosine kinase inhibitors (TKI) against TKRs have entailed an important step in the knowledge-expansion of tumor physiopathology as well as an improvement in the cancer treatment based on molecular alterations over many tumor types. The purpose of this review is to provide a comprehensive review of the different families of TKRs and their role in the expansion of tumor cells and how TKIs can stop these pathways to tumorigenesis, in combination or not with other therapies. The increasing growth of this landscape is driving us to strengthen the development of precision oncology with clinical trials based on molecular-based therapy over a histology-based one, with promising preliminary results.

Combination of Fruquintinib and Anti-PD-1 for the Treatment of Colorectal Cancer

Identification of effective therapies for colorectal cancer (CRC) remains an urgent medical need, especially for the microsatellite-stable (MSS) phenotype. In the current study, a combination of fruquintinib plus anti-PD-1 for MSS CRC therapy was investigated. First, a case of advanced MSS CRC was reported. After failure of multiline therapy, the patient finally achieved rapid response after receiving fruquintinib plus anti-PD-1 treatment. Then the effect of fruquintinib plus anti-PD-1 was verified using a murine syngeneic model of CT26 cells (MSS). The results showed that cotreatment significantly inhibited tumor growth and promote survival time for tumor-bearing mice compared with the single drug alone. In addition, fruquintinib/anti-PD-1 cotreatment decreased angiogenesis, enhanced normalization of the vascular structure, and alleviated tumor hypoxia. Moreover, the combination therapy reprogrammed the immune microenvironment by enhancing chemotactic factor release, increasing CD8⁺ T cell infiltration and activation, decreasing ration of regulatory T cells, and promoting M1/M2 ratio of macrophage. Finally, the enhanced antitumor effect of fruquintinib/anti-PD-1 cotreatment was significantly reversed in CD8 knockout mice compared with that in the wild-type mice. Our study indicated that combination of fruquintinib and anti-PD-1 could synergistically suppress CRC progression and altered the tumor microenvironment in favor of antitumor immune responses.