Regorafenib (BAY 73-4506) in advanced colorectal cancer: a phase I study

Targeting accelerated pulmonary ageing to treat chronic obstructive pulmonary disease-induced neuropathological comorbidities

Chronic obstructive pulmonary disease (COPD) is a major incurable health burden, ranking as the third leading cause of death worldwide, mainly driven by cigarette smoking. COPD is characterised by persistent airway inflammation, lung function decline and premature ageing with the presence of pulmonary senescent cells. This review proposes that cellular senescence, a state of stable cell cycle arrest linked to ageing, induced by inflammation and oxidative stress in COPD, extends beyond the lungs and affects the systemic circulation. This pulmonary senescent profile will reach other organs via extracellular vesicles contributing to brain inflammation and damage, and increasing the risk of neurological comorbidities, such as stroke, cerebral small vessel disease and Alzheimer's disease. The review explores the role of cellular senescence in COPD-associated brain conditions and investigates the relationship between cellular senescence and circadian rhythm in COPD. Additionally, it discusses potential therapies, including senomorphic and senolytic treatments, as novel strategies to halt or improve the progression of COPD.

Appropriate dose of regorafenib based on body weight of colorectal cancer patients: a retrospective cohort study

PURPOSE

Previous randomized studies have shown a survival benefit of using regorafenib but a high rate of adverse events in unresectable colorectal cancer patients. To reduce these adverse events and improve the tolerability, we examined the appropriate dose of regorafenib based on body weight.

METHODS

We used a nationwide claims database in Japan and examined the efficacy and safety of regorafenib for patients with metastatic colorectal cancer between groups divided by body weight (60 kg) and median average dose (120 mg) between 2013 and 2018. We also assessed overall survival (OS) and adverse events between these groups.

RESULTS

We identified 2530 Japanese patients (heavy weight/high dose: 513, light weight/low dose: 921, heavy weight/low dose: 452, and light weight/high dose: 644). There was no significant difference in the adverse events and OS after inverse probability treatment weighting (IPTW) adjustment between heavy weight/high dose group and light weight/low dose group (hazard ratio, HR=0.97). Among the light-weight patients, higher average dose was associated with shorter OS (IPTW adjusted HR=1.21, 95% CI 1.05 - 1.39, Table 3) while among the heavy-weight patients, there was no significant difference in OS between high and low dose groups (IPTW adjusted HR=1.14, 95% CI 0.95 - 1.37).

CONCLUSION

The findings suggest that a low dose of regorafenib for light-weight patients may be as safe and effective as high doses for heavy-weight patients. Further studies should be conducted to identify an appropriate dose based on each patient's physique and condition.

Regorafenib prevents the development of emphysema in a murine elastase model

Emphysema is a chronic obstructive lung disease characterized by inflammation and enlargement of the air spaces. Regorafenib, a potential senomorphic drug, exhibited a therapeutic effect in porcine pancreatic elastase (PPE)-induced emphysema in mice. In the current study we examined the preventive role of regorafenib in development of emphysema. Lung function tests and morphometry showed that oral administration of regorafenib (5 mg/kg/day) for seven days after instillation of PPE resulted in attenuation of emphysema. Mechanistically, regorafenib reduced the recruitment of inflammatory cells, particularly macrophages and neutrophils, in bronchoalveolar lavage fluid. In agreement with these findings, measurements using a cytokine array and ELISA showed that expression of inflammatory mediators including interleukin (IL)-1β, IL-6, and CXCL1/KC, and tissue inhibitor of matrix metalloprotease-1 (TIMP-1), was downregulated. The results of immunohistochemical analysis confirmed that expression of IL-6, CXCL1/KC, and TIMP-1 was reduced in the lung parenchyma. Collectively, the results support the preventive role of regorafenib in development of emphysema in mice and provide mechanistic insights into prevention strategies. [BMB Reports 2023; 56(8): 439-444].

Defining regorafenib as a senomorphic drug: therapeutic potential in the age-related lung disease emphysema

Senescence, a hallmark of aging, is a factor in age-related diseases (ARDs). Therefore, targeting senescence is widely regarded as a practicable method for modulating the effects of aging and ARDs. Here, we report the identification of regorafenib, an inhibitor of multiple receptor tyrosine kinases, as a senescence-attenuating drug. We identified regorafenib by screening an FDA-approved drug library. Treatment with regorafenib at a sublethal dose resulted in effective attenuation of the phenotypes of βPIX knockdown- and doxorubicin-induced senescence and replicative senescence in IMR-90 cells; cell cycle arrest, and increased SA-β-Gal staining and senescence-associated secretory phenotypes, particularly increasing the secretion of interleukin 6 (IL-6) and IL-8. Consistent with this result, slower progression of βPIX depletion-induced senescence was observed in the lungs of mice after treatment with regorafenib. Mechanistically, the results of proteomics analysis in diverse types of senescence indicated that growth differentiation factor 15 and plasminogen activator inhibitor-1 are shared targets of regorafenib. Analysis of arrays for phospho-receptors and kinases identified several receptor tyrosine kinases, including platelet-derived growth factor receptor α and discoidin domain receptor 2, as additional targets of regorafenib and revealed AKT/mTOR, ERK/RSK, and JAK/STAT3 signaling as the major effector pathways. Finally, treatment with regorafenib resulted in attenuation of senescence and amelioration of porcine pancreatic elastase-induced emphysema in mice. Based on these results, regorafenib can be defined as a novel senomorphic drug, suggesting its therapeutic potential in pulmonary emphysema.

Platform combining statistical modeling and patient-derived organoids to facilitate personalized treatment of colorectal carcinoma

BACKGROUND

We propose a new approach for designing personalized treatment for colorectal cancer (CRC) patients, by combining ex vivo organoid efficacy testing with mathematical modeling of the results.

METHODS

The validated phenotypic approach called Therapeutically Guided Multidrug Optimization (TGMO) was used to identify four low-dose synergistic optimized drug combinations (ODC) in 3D human CRC models of cells that are either sensitive or resistant to first-line CRC chemotherapy (FOLFOXIRI). Our findings were obtained using second order linear regression and adaptive lasso.

RESULTS

The activity of all ODCs was validated on patient-derived organoids (PDO) from cases with either primary or metastatic CRC. The CRC material was molecularly characterized using whole-exome sequencing and RNAseq. In PDO from patients with liver metastases (stage IV) identified as CMS4/CRIS-A, our ODCs consisting of regorafenib [1 mM], vemurafenib [11 mM], palbociclib [1 mM] and lapatinib [0.5 mM] inhibited cell viability up to 88%, which significantly outperforms FOLFOXIRI administered at clinical doses. Furthermore, we identified patient-specific TGMO-based ODCs that outperform the efficacy of the current chemotherapy standard of care, FOLFOXIRI.

CONCLUSIONS

Our approach allows the optimization of patient-tailored synergistic multi-drug combinations within a clinically relevant timeframe.

Effects of regorafenib on the mononuclear/phagocyte system and how these contribute to the inhibition of colorectal tumors in mice

BACKGROUND

Regorafenib was previously shown to reduce tumor-associated macrophages and potently inhibit colony-stimulating factor 1 receptor (CSF1R), also known as CD115, in biochemical assays. The CSF1R signaling pathway is essential in the biology of the mononuclear/phagocyte system, which can promote the development of cancer.

METHODS

A deeper investigation of regorafenib's effects on CSF1R signaling was performed using preclinical in vitro and in vivo studies with syngeneic CT26 and MC38 mouse models of colorectal cancer. Peripheral blood and tumor tissue were analyzed mechanistically by flow cytometry using antibodies against CD115/CSF1R and F4/80 and by ELISA for chemokine (C-C motif) ligand 2 (CCL2) levels. These read-outs were correlated with drug levels for the detection of pharmacokinetic/pharmacodynamic relationships.

RESULTS

Potent inhibition of CSF1R by regorafenib and its metabolites M-2, M-4, and M-5 was confirmed in vitro in RAW264.7 macrophages. The dose-dependent growth inhibition of subcutaneous CT26 tumors by regorafenib was associated with a significant reduction in both the number of CD115^hi monocytes in peripheral blood and the number of selective subpopulations of intratumoral F4/80^hi tumor-associated macrophages. CCL2 levels were not affected by regorafenib in blood but increased in tumor tissue, which may contribute to drug resistance and prevent complete tumor remission. An inverse relationship between regorafenib concentration and the number of CD115^hi monocytes and CCL2 levels was observed in peripheral blood, supporting the mechanistic involvement of regorafenib.

CONCLUSIONS

These findings may be clinically useful in optimizing drug dosing using blood-based pharmacodynamic markers and in identifying resistance mechanisms and ways to overcome them by appropriate drug combinations.

Phase II dose titration study of regorafenib in progressive unresectable metastatic colorectal cancer

Regorafenib has shown significant survival benefit as a salvage therapy for colorectal cancer; however, its starting dose has been controversial in recent studies. Therefore, we conducted a prospective study on the efficacy and safety of the dose reduction of regorafenib to 120 mg. Patients received 120 mg regorafenib once per day for 3 weeks, followed by a 1-week off-treatment period. The primary endpoint was the investigator-assessed disease control rate (DCR). Sixty patients were registered, and the DCR was 38.3% with a median progression-free survival of 2.5 months (95% confidence interval [CI] 1.9-3.7) and median overall survival of 10.0 months (95% CI 6.9-15.2). Common grade 3-4 adverse events were hand-foot skin reaction and hypertension (20.0% each). The results of administration of 120 mg regorafenib as the starting dose are consistent with reports from prior phase III trials, which used starting doses of 160 mg. This lower initiating dose of regorafenib may be beneficial to certain patient populations. This clinical trial was registered in the UMIN Clinical Trials Registry (UMIN-CTR number UMIN000018968, registration date: 10/09/2015).

1-[2-(1H-Pyrrole-2-carbonyl)phenyl]-3-(4-methoxyphenyl)urea

For the synthesis of 1-(2-(1H-pyrrole-2-carbonyl)phenyl)-3-(4-methoxyphenyl)urea, the final product, two different methods were used, in one or two steps, from (2-aminophenyl)(1H-pyrrol-2-yl)methanone. The one-step synthesis entailed a carbonylation reaction with 1/3 equivalent of triphosgene in the presence of two equivalents of trimethylamine, followed by the addition of 4-methoxyaniline to the in situ generated aryl isocyanate. The two-step synthesis required first the preparation of phenyl(2-(1H-pyrrole-2-carbonyl)phenyl)carbamate and then a substitution reaction by 4-methoxyaniline. The first method produced the final product in 72% yield, which was the best yield. The structure of the final product was confirmed by FTIR, UV-VIS, 1H and 13C NMR spectroscopy and high resolution mass spectrometry.

Continuous‐Flow Divergent Lithiation of 2,3‐Dihalopyridines: Deprotolithiation versus Halogen Dance

We describe herein the first halogen dance (HD) in continuous flow on 2-chloro-3-bromopyridine by selectively trapping a (pyridin-4-yl)lithium species that is known to undergo the halogen-dance process. In addition, this lithiated intermediate was trapped at lower temperature before the HD occurs. The HD process was extended to fluoro-iodopyridines by using various electrophiles to afford 28 examples with yields ranging from 42 to 97 % with very short residence times. Finally, scale up of the reaction was demonstrated, affording a promising space-time yield (STY) of 4.2 kg.h^-1 .L^-1 .

Modified Benzoxazole-Based VEGFR-2 Inhibitors and Apoptosis Inducers: Design, Synthesis, and Anti-Proliferative Evaluation

This work is one of our efforts to discover potent anticancer agents. We modified the most promising derivative of our previous work concerned with the development of VEGFR-2 inhibitor candidates. Thirteen new compounds based on benzoxazole moiety were synthesized and evaluated against three human cancer cell lines, namely, breast cancer (MCF-7), colorectal carcinoma (HCT116), and hepatocellular carcinoma (HepG2). The synthesized compounds were also evaluated against VEGFR-2 kinase activity. The biological testing fallouts showed that compound 8d was more potent than standard sorafenib. Such compound showed IC₅₀ values of 3.43, 2.79, and 2.43 µM against the aforementioned cancer cell lines, respectively, compared to IC₅₀ values of 4.21, 5.30, and 3.40 µM reported for sorafenib. Compound 8d also was found to exert exceptional VEGFR-2 inhibition activity with an IC₅₀ value of 0.0554 μM compared to sorafenib (0.0782 μM). In addition, compound 8h revealed excellent cytotoxic effects with IC₅₀ values of 3.53, 2.94, and 2.76 µM against experienced cell lines, respectively. Furthermore, compounds 8a and 8e were found to inhibit VEGFR-2 kinase activity with IC₅₀ values of 0.0579 and 0.0741 μM, exceeding that of sorafenib. Compound 8d showed a significant apoptotic effect and arrested the HepG2 cells at the pre-G1 phase. In addition, it exerted a significant inhibition for TNF-α (90.54%) and of IL-6 (92.19%) compared to dexamethasone (93.15%). The molecular docking studies showed that the binding pattern of the new compounds to VEGFR-2 kinase was similar to that of sorafenib.

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.

Impact of trough concentrations of regorafenib and its major metabolites M-2 and M-5 on overall survival of chemorefractory metastatic colorectal cancer patients: Results from a multicentre GERCOR TEXCAN phase II study

PURPOSE

This prospective pharmacokinetic (PK) ancillary study of the TEXCAN phase II GERCOR trial of patients with chemorefractory metastatic colorectal cancer and treated with regorafenib (REGO) investigated correlations between overall survival (OS) and concentrations (C) of REGO and its active metabolites, M-2 and M-5.

METHODS

55 patients received REGO 160 mg/day for 21 days of a 28-day cycle (NCT02699073). REGO, M-2, M-5 were measured by liquid chromatography-mass spectrometry assay on day 15 of cycle 1 (C1) and 2 (C2). We studied the association between OS and Cmin of REGO, M-2 and M-5 at C1 and their accumulations between C1 and C2.

RESULTS

Medians of C2/C1 M-2 and M-5 ratios were 0.82 (interquartile range 0.50-1.78) and 0.75 (interquartile range 0.41-1.93), respectively. Patients with C2/C1 M-2 ratio ≥ median had improved survival compared to those < median (12.6 versus 4.0 months, P = 0.023), corresponding to a 66% mortality risk reduction in multivariate analysis. The C2/C1 M-2 ratio correlated with C1 REGO+M-2+M-5 (Csum; P = 0.006). Restricted cubic spline analysis showed an increased OS benefit as the C2/C1 M-2 ratio raises and when C1 Csum ranged between 2.5 and 5.5 mg/L. Patients within the Csum range had a reduced incidence of serious adverse events and improved OS.

CONCLUSIONS

We identified PK parameters associated with a survival benefit in patients with metastatic colorectal cancer treated by REGO. OS and safety were favourable when C1 REGO+M-2+M-5 Csum ranged between 2.5 and 5.5 mg/L. These results pave the way for individual REGO dose modification strategies based on PK monitoring.

CLINICAL TRIAL REFERENCE

NCT02699073.

Synergistic Anti-Angiogenic Effect of Combined VEGFR Kinase Inhibitors, Lenvatinib, and Regorafenib: A Therapeutic Potential for Breast Cancer

Background: Breast cancer currently affects more than two million women worldwide, and its incidence is steadily increasing. One of the most essential factors of invasion and metastasis of breast cancer cells is angiogenesis and non-angiogenic vascularization. Lenvatinib and Regorafenib share the same anti-angiogenic effect by inhibiting vascular endothelial growth factor receptors (VEGFRs subtypes 1 to 3) and have been approved for treating different types of cancer. Methods: We investigated Lenvatinib and Regorafenib effects on a well-established in-vitro model of breast cancer using MCF-7 (estrogen, progesterone receptor-positive, and HER2-negative), MDA-MB-231 (triple negative), as well as Human Umbilical Vascular Endothelial Cell line (HUVEC) cell lines. We performed the cell viability assay on four groups of cells, which included a control group, a Lenvatinib treated only group, a Regorafenib treated only group, and a group treated with a combination of both drugs at 24, 48, and 72 h. Data were analyzed as means ± standard deviation, and the drug−drug interactions with Compusyn software. Cellular migration assay, tube formation assay, and Western blots were conducted to determine the functional and the protein expression of downstream signals such as Caspase-9, anti-apoptotic Survivin, P-ERK, and total-ERK in the control and treatment groups. Results: MCF-7 cells showed a reduction in cell survival rates with higher dosing and longer incubation periods with each drug and with the combination of drugs. A synergistic interaction was identified (CI < 1) with both drugs on MCF7 at different dose combinations and at a higher dose in MDA-MB-231 cells. Furthermore, there was a marked decrease in the anti-angiogenic effect of both drugs in tube formation assay using MDA-MB-231 cells and survivin protein expression in MCF-7, and those antitumor markers showed a better outcome in drug combination than the use of each drug alone. Conclusion: Our result is the first to report the synergistic anti-angiogenic potential of combination therapy of Lenvatinib and Regorafenib. Therefore, it shows their therapeutic potential in breast cancer, including the aggressive types. Further studies are warranted to confirm and explore this therapeutic approach.

New Series of VEGFR-2 Inhibitors and Apoptosis Enhancers: Design, Synthesis and Biological Evaluation

Background

Cancer is still a major world health threat, causing a high rate of mortality. VEGFR-2 inhibitor anticancer agents are of great significance. However, they showed some serious side effects.

Purpose

To discover new effective and safer anticancer agents, a new series of piperazinylquinoxaline-based derivatives was designed and synthesized on the basis of the pharmacophoric features of VEGFR-2 inhibitor drugs.

Methods

The new candidates were evaluated against A549 lung cancer cells, HepG-2 hepatoma cells, Caco-2 colon cancer cells, MDA breast cancer cells, and VEGFR-2 kinase. Moreover, cell cycle kinetics and apoptosis rates were studied in HepG-2 cells treated with compound 11, which was the most promising candidate.

Results

The new derivatives revealed better antitumor results (IC₅₀ from 6.48 to 38.58 µM) against the aforementioned cancer cell lines than sorafenib. Also, the new candidates showed VEGFR-2 inhibition with IC₅₀ values ranging from 0.19 to 0.60 µM compared to 0.08 µM for sorafenib. Compound 11, meanwhile, showed IC₅₀ values equal to 10.61, 9.52, 12.45, 11.52, and 0.19 µM against the cancer cell lines and VEGFR-2, respectively. Moreover, compound 11 raised the apoptosis rate in HepG-2 cells from 5% to 44% and caused 4, 2.3, and 3-fold increases in BAX/Bcl-2 ratio, caspase-3 level, and P53 expression, respectively, compared to control untreated cells. Finally, the new derivatives displayed the correct binding mode into VEGFR-2 kinase pocket, giving interactions with the essential residues.

Conclusion

This work suggests that compound 11 is a very significant anticancer candidate, and piperazinylquinoxaline is an important scaffold in the development of new potential effective and safer VEGFR-2 inhibitor agents.

Discrimination of hand-foot skin reaction caused by tyrosine kinase inhibitors based on direct keratinocyte toxicity and vascular endothelial growth factor receptor-2 inhibition

Tyrosine kinase inhibitors (TKIs) are molecular-targeted anticancer drugs. Their benefits are limited by dermal toxicities, including hand-foot skin reaction (HFSR), which is commonly found in skin areas subjected to friction. The present study aimed to explain the incidence of HFSR in patients treated with TKIs by focusing on keratinocyte toxicity and inhibition of vascular endothelial growth factor receptor (VEGFR), which plays an essential role in angiogenesis. Mice with gene knockout for the immunosuppressive cytokine interleukin-10 exhibited HFSR-like phenotypes, such as cytotoxicity in keratinocytes and increased number and size of blood vessels after repeated doses of regorafenib, sorafenib, and pazopanib, all of which cause high incidence of HFSR, in combination with tape-stripping mimicking skin damage at the friction site. Comprehensive examination of the direct cytotoxic effects of 21 TKIs on primary cultured human keratinocytes revealed that 18 of them reduced the cell viability dose-dependently. Importantly, the ratio of the trough concentration in patients (C_trough) to the LC₅₀ values of cell viability reduction was higher than unity for four HFSR-inducing TKIs, suggesting that these TKIs cause keratinocyte toxicity at clinically relevant concentrations. In addition, eight HFSR-inducing TKIs caused inhibition of VEGFR-2 kinase activity, which was validated by their ratios of C_trough to the obtained IC_50,VEGFR-2 of more than unity. All 12 TKIs with no reported incidence of HFSR exhibited less than unity values for both C_trough/LC_{50,keratinocytes} and C_trough/IC_50,VEGFR-2. These results suggested that a combination of keratinocyte toxicity and VEGFR-2 inhibition may explain the incidence of HFSR upon TKI usage in humans.

Synthesis, biological evaluation, and molecular docking of new series of antitumor and apoptosis inducers designed as VEGFR-2 inhibitors

Based on quinazoline, quinoxaline, and nitrobenzene scaffolds and on pharmacophoric features of VEGFR-2 inhibitors, 17 novel compounds were designed and synthesised. VEGFR-2 IC₅₀ values ranged from 60.00 to 123.85 nM for the new derivatives compared to 54.00 nM for sorafenib. Compounds 15_a, 15_b, and 15_d showed IC₅₀ from 17.39 to 47.10 µM against human cancer cell lines; hepatocellular carcinoma (HepG2), prostate cancer (PC3), and breast cancer (MCF-7). Meanwhile, the first in terms of VEGFR-2 inhibition was compound 15_d which came second with regard to antitumor assay with IC₅₀ = 24.10, 40.90, and 33.40 µM against aforementioned cell lines, respectively. Furthermore, Compound 15_d increased apoptosis rate of HepG2 from 1.20 to 12.46% as it significantly increased levels of Caspase-3, BAX, and P53 from 49.6274, 40.62, and 42.84 to 561.427, 395.04, and 415.027 pg/mL, respectively. Moreover, 15_d showed IC₅₀ of 253 and 381 nM against HER2 and FGFR, respectively.

TAS-102 Monotherapy and Combination Therapy with Bevacizumab for Metastatic Colorectal Cancer

Objective

To evaluate the effectiveness and safety of TAS-102 monotherapy and combination therapy with bevacizumab in the treatment of metastatic colorectal cancer.

Methods

The PubMed, Web of Science, MEDLINE, and Cochrane Library databases were searched for the literature on TAS-102 treatment of metastatic colorectal cancer. Extracted data include median overall survival (mOS), median progression-free survival (mPFS), and the incidence of adverse events for meta-analysis.

Results

Our study found that the mOS of patients treated with TAS-102 monotherapy was 6.95 (95% CI: 6.26-7.72) months and the mPFS was 2.53 (95% CI: 2.31-2.78) months. The mOS in patients treated by TAS-102 combined with bevacizumab was 10.41 (95% CI: 8.40-12.89) months, and the mPFS is 4.35 (95% CI: 3.05-6.20) months. In the control experiment, the patients' mOS and mPFS were improved. TAS-102+B vs. TAS-102 (OR = 0.41, 95% CI: 0.18-0.93; OR = 0.72, 95% CI: 0.63-0.83) and TAS-102 vs. placebo (OR = 0.44, 95% CI: 0.29-0.67; OR = 0.51, 95% CI: 0.42-0.62) were studied to actively prevent the occurrence of neutropenia, leukopenia, febrile neutropenia, anemia, and vomiting.

Conclusion

TAS-102 monotherapy and combination therapy with bevacizumab can significantly improve the survival of patients and prevent specific adverse events from happening.

Regorafenib outcomes from the population based South Australian Metastatic Colorectal Cancer Registry

AIM

Reviewing outcomes of regorafenib use in metastatic colorectal cancer using real-world data from the South Australian Metastatic Colorectal Cancer Registry.

METHODS

A retrospective review of the characteristics and outcomes of patients who received regorafenib in the Registry up to December 2018. The registry started in February 2006.

RESULTS

Fifty-three patients received regorafenib therapy since approved by the therapeutic goods administration in November 2013. The median age was 66 (range 34-82). 66% were male, 66% had stage IV disease at diagnosis, 53% had liver only involvement, whereas 13% had liver and lung disease and 6% had lung only involvement. 75% had left-sided primary. KRAS was available in 35/53 patients with 49% of them being WT. BRAF status was known in 8/53 with 25% of them having a mutated variant. MSI testing was known in 14 patients in whom 21% of them had MSI-High tumors. Prior lines of treatment received: one line 4%, two 9%, three 23%, four 26%, >four 37%. Prior biological use: bevacizumab 72%, anti-EGFR 100% (for RAS WT). Median survival from diagnosis was 3.3 years (95% CI, 2.8-3.8 years). Median survival from the start of regorafenib was 7.1 months (95% CI, 4.8-9.4 months) and the 12-month survival rate was 28%.

CONCLUSION

The survival outcome for those patients from our population-based registry who access regorafenib is in keeping with reports from large, randomized trials. Thus, clinicians can quote local real world data when discussing efficacy and access to regorafenib therapy for mCRC patients.

MYO1B enhances colorectal cancer metastasis by promoting the F-actin rearrangement and focal adhesion assembly via RhoA/ROCK/FAK signaling

Background

Colorectal cancer (CRC) has a high worldwide incidence and mortality. Tumor metastasis is one of the primary reasons for the poor prognosis of CRC patients. However, the mechanism underlying CRC metastasis is still unclear. Myosin 1B (MYO1B) is important for cell migration and motility and is part of the myosin superfamily that contains various myosins. Studies of prostate, cervical, and head and neck cancer have revealed preliminary findings concerning the effect of MYO1B on tumor metastasis. However, the role of MYO1B in CRC metastasis, as well as its underlying mechanism, remains unknown.

Methods

Quantitative real-time PCR and immunohistochemical staining methods were used to analyze the expression of MYO1B in human CRC and normal mucosa tissues. Lentivirus vector-based MYO1B oligonucleotides and short hairpin RNA (shRNA) were used to examine the functional relevance of MYO1B in CRC cells. Co-immunoprecipitation, western blotting, and immunofluorescence assays were used to investigate the underlying mechanism of MYO1B-mediated cell migration.

Results

The expression of MYO1B was increased in most CRC tissues and was positively associated with a greater risk of tumor metastasis and poor prognosis for patients. MYO1B was significantly associated with the migration and invasion properties of CRC cells in vitro and in vivo. MYO1B promoted F-actin rearrangement through the ROCK2/LIMK/Cofilin axis by enhancing the activation of RhoA. MYO1B also promoted the assembly of focal adhesions by targeting RhoA.

Conclusions

MYO1B plays a vital role in CRC metastasis by promoting the activation of RhoA. MYO1B may not only be a valid biomarker for predicting the risk of metastasis and poor prognosis in CRC but may also be a potential therapeutic target for patients with a high risk of tumor metastasis.

Identification of Novel Potential VEGFR-2 Inhibitors Using a Combination of Computational Methods for Drug Discovery

The vascular endothelial growth factor receptor 2 (VEGFR-2) is largely recognized as a potent therapeutic molecular target for the development of angiogenesis-related tumor treatment. Tumor growth, metastasis and multidrug resistance highly depends on the angiogenesis and drug discovery of the potential small molecules targeting VEGFR-2, with the potential anti-angiogenic activity being of high interest to anti-cancer research. Multiple small molecule inhibitors of the VEGFR-2 are approved for the treatment of different type of cancers, with one of the most recent, tivozanib, being approved by the FDA for the treatment of relapsed or refractory advanced renal cell carcinoma (RCC). However, the endogenous and acquired resistance of the protein, toxicity of compounds and wide range of side effects still remain critical issues, which lead to the short-term clinical effects and failure of antiangiogenic drugs. We applied a combination of computational methods and approaches for drug design and discovery with the goal of finding novel, potential and small molecule inhibitors of VEGFR2, as alternatives to the known inhibitors’ chemical scaffolds and components. From studying several of these compounds, the derivatives of pyrido[1,2-a]pyrimidin-4-one and isoindoline-1,3-dione in particular were identified.

18F-FDG-PET/CT as an imaging biomarker for regorafenib efficacy in metastatic colorectal cancer (JACCRO CC-12)

Introduction

Regorafenib is a multikinase inhibitor approved for the treatment of metastatic colorectal cancer (mCRC). Despite providing a statistically significant survival benefit, a substantial number of patients fail to respond to or continue with treatment, which has resulted in an unmet clinical need for a biomarker of regorafenib efficacy.

Methods

The JACCRO CC-12 study was a prospective, multicenter, single-arm phase II trial designed to evaluate the usefulness of [¹⁸F]fluorodeoxyglucose positron emission tomography (FDG-PET) as an imaging biomarker of regorafenib in patients with mCRC that progressed after standard chemotherapies. FDG-PET and contrast-enhanced computed tomography (CT) were performed before and after treatment with regorafenib 160 mg once daily 3 weeks on/1 week off. The primary end point was the change in the maximum standardized uptake value in the lesion with the highest uptake at pre-treatment FDG-PET. The secondary end points included overall survival (OS), progression-free survival (PFS), the objective response rate (ORR), safety, and the correlation between FDG-PET and CT.

Results

Twenty patients were enrolled from November 2014 to March 2016, 17 of whom were evaluated for metabolic and morphological changes. Metabolic response with FDG-PET was partial response (PR) in one case (5.9%), stable disease (SD) in four (23.5%), and progressive disease (PD) in 12 (70.6%). The metabolic response rate was 5.9%. On CT imaging, no complete response or PR was observed, and the ORR was 0%. Median PFS and OS were 1.7 and 9.8 months, respectively. The median PFS of patients who achieved PR or SD by FDG-PET was 3.7 months, whereas that of those assessed as PD was 1 month (p = 0.13). The median OS of patients who achieved PR or SD by FDG-PET was 13.0 months, whereas that of patients assessed as PD was 10.6 months (p = 0.43). Frequent adverse events were palmar–plantar erythrodysesthesia syndrome, hypertension, loss of appetite, and fatigue.

Conclusions

In this study, FDG-PET failed to demonstrate usefulness as an early imaging biomarker of regorafenib in patients with mCRC.

Bioequivalence and Pharmacokinetic Evaluation of Two Oral Formulations of Regorafenib: An Open-Label, Randomised, Single-Dose, Two-Period, Two-Way Crossover Clinical Trial in Healthy Chinese Volunteers Under Fasting and Fed Conditions

Background

Regorafenib is an oral multi-kinase inhibitor approved for the treatment of solid tumours, but the pharmacokinetic profile of regorafenib in the Chinese population is unclear.

Objective

The aim of this study was to examine the pharmacokinetics, bioequivalence, and safety of two formulations of regorafenib 40 mg in healthy Chinese volunteers under fed and fasting conditions.

Methods

A single-centre, randomised, open-label, two-period, two-way crossover phase 1 trial was conducted by randomising a single oral dose of test (T) or reference (R, Stivarga^®) regorafenib (40 mg) to healthy Chinese volunteers under both fasting and fed conditions (high-fat and high-calorie diet). Pharmacokinetic parameters were calculated using non-compartmental methods. Adverse events were recorded to assess drug safety.

Results

Sixty-six participants were enrolled for both fasting and fed treatments. The 90% CIs geometric least-square means of ratio_T/R for regorafenib were completely contained within the equivalence margin of 80–125% under both fasting and fed conditions. Both formulations displayed similar and generally good safety profiles.

Conclusion

Single oral dose of the T (40 mg) and R (40 mg) regorafenib was bioequivalent under fasting and fed conditions and had similar favourable safety profiles among healthy Chinese volunteers.

Efficacy and safety of anlotinib in patients with advanced malignancy: a single-center, single-arm, phase 2 trial

BACKGROUND

For advanced tumors that lack specific oncogenic alteration and are resistant to chemotherapy, anti-angiogenesis therapy or immunotherapy or a combination of the two are the most important treatments. Anlotinib is a newly developed oral small molecule receptor tyrosine kinases inhibitor with the potency of inhibiting tumor angiogenesis. This was an open-label, single-arm, phase 2 study to validate the efficacy and safety of anlotinib in patients with various cancer types.

METHODS

Patients with advanced malignancy who have failed previous therapies or lack effective treatment choices received daily oral administration of 12 mg anlotinib on days 1-14 every 3 weeks until disease progression, intolerable toxicity or physician decision. The primary endpoint was objective response rate (ORR).

RESULTS

A total of 93 eligible patients with 26 different cancer types were enrolled. The overall ORR was 21.5%. The median PFS was 5.7 months and median OS was 12.0 months. The most common treatment-related AE of all grades and of grade 3 was both hypertriglyceridemia at an incidence of 40.9% and 5.4%, respectively.

CONCLUSIONS

Anlotinib exhibits objective efficacy and safety in advanced malignancy and might be a possible treatment option for many types of cancer patients who have failed prior treatment and with no optimal therapy regimen.

Phase 1 dose-escalation and pharmacokinetic study of regorafenib in paediatric patients with recurrent or refractory solid malignancies

BACKGROUND

This phase 1 study evaluated safety, pharmacokinetics (PK), maximum tolerated dose (MTD), and antitumour activity of regorafenib in paediatric patients with solid tumours.

PATIENTS AND METHODS

Patients (aged 6 months to <18 years) with recurrent/refractory solid tumours received oral regorafenib once daily for 3 weeks on/1 week off. The starting dose (60 mg/m²) was derived from an adult physiology-based PK model and scaled to children; dose escalation was followed by safety expansion of the MTD cohort. Treatment-emergent adverse events (TEAEs) were evaluated using National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0. Regorafenib PK was evaluated using a population PK model.

RESULTS

Forty-one patients (median age 13 years) received regorafenib (four cohorts: 60-93 mg/m²). Five of 23 evaluable patients experienced dose-limiting toxicities (Grade 4 thrombocytopenia, Grade 3 maculopapular rash, pyrexia, hypertension, and exfoliative dermatitis [each n = 1]). The MTD was defined as 82 mg/m². The most common Grade ≥3 drug-related TEAE was thrombocytopenia (10%). The incidence and severity of hypertension, diarrhoea, fatigue, hypothyroidism, and hand-foot skin reaction were lower than reported in adults. Regorafenib exposure increased with dose, with substantial overlap because of moderate-to-high interpatient variability. One patient with rhabdomyosarcoma experienced an unconfirmed partial response; 15 patients had stable disease, five for >16 weeks.

CONCLUSIONS

The recommended phase 2 dose of single-agent regorafenib in paediatric patients with solid malignancies is 82 mg/m². Regorafenib demonstrated acceptable tolerability and preliminary antitumour activity, supporting further investigation in paediatric patients.

CLINICAL TRIAL NUMBER

NCT02085148.

Small molecules in targeted cancer therapy: advances, challenges, and future perspectives

Due to the advantages in efficacy and safety compared with traditional chemotherapy drugs, targeted therapeutic drugs have become mainstream cancer treatments. Since the first tyrosine kinase inhibitor imatinib was approved to enter the market by the US Food and Drug Administration (FDA) in 2001, an increasing number of small-molecule targeted drugs have been developed for the treatment of malignancies. By December 2020, 89 small-molecule targeted antitumor drugs have been approved by the US FDA and the National Medical Products Administration (NMPA) of China. Despite great progress, small-molecule targeted anti-cancer drugs still face many challenges, such as a low response rate and drug resistance. To better promote the development of targeted anti-cancer drugs, we conducted a comprehensive review of small-molecule targeted anti-cancer drugs according to the target classification. We present all the approved drugs as well as important drug candidates in clinical trials for each target, discuss the current challenges, and provide insights and perspectives for the research and development of anti-cancer drugs.

Regorafenib Combined with Other Systemic Therapies: Exploring Promising Therapeutic Combinations in HCC

Regorafenib was the first drug to demonstrate a survival benefit as a second-line agent after sorafenib failure in patients with unresectable hepatocellular carcinoma (HCC). Recent studies have shown that its mechanism of action is not only limited to its very broad spectrum of inhibition of angiogenesis, tumor proliferation, spread, and metastasis, but also to its immunomodulatory properties that have favorable effects on the very intricate role that the tumor microenvironment plays in carcinogenesis and tumor growth. In this review, we discuss rationale and evidence supporting regorafenib efficacy in HCC and that led to its approval as a second-line treatment, after sorafenib failure. We also discuss the evidence from clinical practice studies that confirm the results previously achieved in clinical trials. Finally, we analyze the potential role of regorafenib in emerging combined treatment approach with immunotherapy strategies using immune checkpoint blockade and its potential extension to patient categories not included in the registrative study.

Molecularly targeted therapy for advanced gastrointestinal noncolorectal cancer treatment: how to choose? Past, present, future

Gastrointestinal cancer is a leading cause of death worldwide. Conventional cytotoxic chemotherapy has been the backbone of advanced gastrointestinal cancer treatment for decades and still represents a key element of the therapeutic armamentarium. However, only small increments in survival outcomes have been reached. New clinical trials are designed, including classic chemotherapy in association with either small-molecule inhibitors or mAb. During the past few years, remarkable progress in molecular biology of gastrointestinal noncolorectal cancers, the discovery of specific targets and the resulting development of systemic drugs that block critical kinases and several molecular pathways have all contributed to progress. New biological agents with molecularly targeted therapies are now available or currently included in clinical trials (EGFR inhibitors (i), antiangiogenic agents, c-METi, IDHi, FGFR2i, BRAFi, Pi3Ki/AKTi/mTORi, NTRKi). When we focus on the current state of precision medicine for gastrointestinal malignancies, it becomes apparent that there is a mixed history of success and failure. The aim of this review is to focus on the studies that have been completed to date with target therapies and to understand which of these are currently the accepted choice in clinical practice and which need further confirmation and approval for inclusion in guidelines. All these findings will enable to guide clinical practice for oncologists in the design of the next round of clinical trials.

Precision Oncology, Signaling and Anticancer Agents in Cancer Therapeutics

BACKGROUND

The global alliance for genomics and healthcare facilities provides innovational solutions to expedite research and clinical practices for complex and incurable health conditions. Precision oncology is an emerging field explicitly tailored to facilitate cancer diagnosis, prevention and treatment based on patients' genetic profile. Advancements in "omics" techniques, next-generation sequencing, artificial intelligence and clinical trial designs provide a platform for assessing the efficacy and safety of combination therapies and diagnostic procedures.

METHOD

Data were collected from Pubmed and Google scholar using keywords: "Precision medicine", "precision medicine and cancer", "anticancer agents in precision medicine" and reviewed comprehensively.

RESULTS

Personalized therapeutics including immunotherapy, cancer vaccines, serve as a groundbreaking solution for cancer treatment. Herein, we take a measurable view of precision therapies and novel diagnostic approaches targeting cancer treatment. The contemporary applications of precision medicine have also been described along with various hurdles identified in the successful establishment of precision therapeutics.

CONCLUSION

This review highlights the key breakthroughs related to immunotherapies, targeted anticancer agents, and target interventions related to cancer signaling mechanisms. The success story of this field in context to drug resistance, safety, patient survival and in improving quality of life is yet to be elucidated. We conclude that, in the near future, the field of individualized treatments may truly revolutionize the nature of cancer patient care.

Design, synthesis and molecular modeling of new quinazolin-4(3H)-one based VEGFR-2 kinase inhibitors for potential anticancer evaluation

Globally cancer is the second leading cause of death. So that this work is an attempt to develop new effective anti-cancer agents. In line with pharmacophoric features of VEGFR-2 kinase inhibitors, new nineteen quinazolin-4-one derivatives were designed, synthesized and biologically evaluated for their potential anticancer activity. All target compounds were evaluated in vitro for VEGFR-2 tyrosine kinase inhibition. Then, nine compounds of best results were further investigated by in vitro assay against three human cancer cell lines, namely HepG2, PC3 and MCF. N^'-{2-](3-Ethyl-6-nitro-4-oxo-3,4-dihydroquinazoline-2-yl)thio[acetyl}benzohydrazide (36) was found to be the most potent candidate as it showed IC₅₀ = 4.6 ± 0.06 µM against VEGFR-2 kinase. It also exhibited IC₅₀ = 17.23 ± 1.5, 26.10 ± 2.2 and 30.85 ± 2.3 µg/mL against HepG2, PC3 and MCF, respectively. At the same time it showed IC₅₀ = 145.93 ± 1.1 µg/mL against the normal human lung fibroblasts cell line (WI-38), indicating good selectivity index. Further investigation into HepG2 cell cycle showed the ability of compound 36 to induce apoptosis and arrest cell growth at G2/M phase. Moreover, docking studies demonstrated the ability of compound 36 to bind VEGFR-2 in a correct manner making three essential hydrogen bonds with the key residues Glu885, Asp1046 and Cys919. In sum, this work suggests that compound 36 can serve as a lead for development of effective anticancer agents targeting VEGFR-2.

Diarylureas as Antitumor Agents

The diarylurea is a scaffold of great importance in medicinal chemistry as it is present in numerous heterocyclic compounds with antithrombotic, antimalarial, antibacterial, and anti-inflammatory properties. Some diarylureas, serine-threonine kinase or tyrosine kinase inhibitors, were recently reported in literature. The first to come into the market as an anticancer agent was sorafenib, followed by some others. In this review, we survey progress over the past 10 years in the development of new diarylureas as anticancer agents.

Experience with regorafenib in the treatment of hepatocellular carcinoma

Regorafenib is a diphenylurea oral multikinase inhibitor, structurally comparable to sorafenib, which targets a variety of kinases implicated in angiogenic and tumor growth-promoting pathways. Regorafenib was the first agent to positively show significant survival advantage as a second-line therapy in patients with unresectable hepatocellular carcinoma (HCC) who had previously failed first-line treatment with sorafenib. Recent evidence has shown that its antitumor efficacy is due to a comprehensive spectrum of tumor neo-angiogenesis and proliferation inhibition and immunomodulatory effects on the tumor microenvironment, which plays a crucial role in tumor development. This review addresses the rationale and supporting evidence for regorafenib's efficacy in HCC that led to regorafenib's approval as a second-line therapy. In addition, we review proof from clinical practice studies that validate the RESORCE trial results. We discuss regorafenib's potential role in the newly emerging therapeutic strategy based on combination with immune checkpoint blockade and its possible extensibility to patient categories not enrolled in the registrative study.

Cocrystals of regorafenib with dicarboxylic acids: synthesis, characterization and property evaluation

Three cocrystals of regorafenib were synthesized, and two of them demonstrate significantly improved solubility and tabletability without compromising physicochemical stability.

The recent advancement of low-dimensional nanostructured materials for drug delivery and drug sensing application: A brief review

In this review article, we have presented a detailed analysis of the recent advancement of quantum mechanical calculations in the applications of the low-dimensional nanomaterials (LDNs) into biomedical fields like biosensors and drug delivery systems development. Biosensors play an essential role for many communities, e.g. law enforcing agencies to sense illicit drugs, medical communities to remove overdosed medications from the human and animal body etc. Besides, drug delivery systems are theoretically being proposed for many years and experimentally found to deliver the drug to the targeted sites by reducing the harmful side effects significantly. In current COVID-19 pandemic, biosensors can play significant roles, e.g. to remove experimental drugs during the human trials if they show any unwanted adverse effect etc. where the drug delivery systems can be potentially applied to reduce the side effects. But before proceeding to these noble and expensive translational research works, advanced theoretical calculations can provide the possible outcomes with considerable accuracy. Hence in this review article, we have analyzed how theoretical calculations can be used to investigate LDNs as potential biosensor devices or drug delivery systems. We have also made a very brief discussion on the properties of biosensors or drug delivery systems which should be investigated for the biomedical applications and how to calculate them theoretically. Finally, we have made a detailed analysis of a large number of recently published research works where theoretical calculations were used to propose different LDNs for bio-sensing and drug delivery applications.

Current Treatment Options for HCC: From Pharmacokinetics to Efficacy and Adverse Events in Liver Cirrhosis

BACKGROUND

Hepatocellular carcinoma (HCC) is among the world's most common cancers. For over ten years, the only medical treatment for it has been the multikinase inhibitor Sorafenib. Currently, however, other first or second-line therapeutic options have also shown efficacy against HCC, such as multikinase inhibitors (Regorafenib, Lenvatinib, and Cabozantinib), a monoclonal antibody against the vascular endothelial growth factor receptor 2 (Ramucirumab), and immune-checkpoint inhibitors (Nivolumab, Pembrolizumab, Ipilimumab).

AIM

The aim of this paper is to review the metabolic pathways of drugs that have been tested for the treatment of HCC and the potential influence of liver failure over those pathways.

METHODS

The Food and Drug Administration (FDA)'s and European Medicines Agency (EMA)'s datasheets, results from clinical trials and observational studies have been reviewed.

RESULTS

This review summarizes the current knowledge regarding targets, metabolic pathways, drug interactions, and adverse events of medical treatments for HCC in cirrhotic patients.

CONCLUSION

The new scenario of systemic HCC therapy includes more active drugs with different metabolic pathways and different liver adverse events. Clinical and pharmacological studies providing more data on the safety of these molecules are urgently needed.

Clinical Pharmacokinetics and Pharmacodynamics of Transarterial Chemoembolization and Targeted Therapies in Hepatocellular Carcinoma

The management of hepatocellular carcinoma (HCC) is based on a multidisciplinary decision tree. Treatment includes loco-regional therapy, mainly transarterial chemoembolization, for intermediate-stage HCC and systemic therapy with oral tyrosine kinase inhibitors (TKIs) for advanced HCC. Transarterial chemoembolization involves hepatic intra-arterial infusion with either conventional procedure or drug-eluting-beads. The aim of the loco-regional procedure is to deliver treatment as close as possible to the tumor both to embolize the tumor area and to enhance efficacy and minimize systemic toxicity of the anticancer drug. Pharmacokinetic studies applied to transarterial chemoembolization are rare and pharmacodynamic studies even rarer. However, all available studies lead to the same conclusions: use of the transarterial route lowers systemic exposure to the cytotoxic drug and leads to much higher tumor drug concentrations than does a similar dose via the intravenous route. However, reproducibility of the procedure remains a major problem, and no consensus exists regarding the choice of anticancer drug and its dosage. Systemic therapy with TKIs is based on sorafenib and lenvatinib as first-line treatment and regorafenib and cabozantinib as second-line treatment. Clinical use of TKIs is challenging because of their complex pharmacokinetics, with high liver metabolism yielding both active metabolites and their common toxicities. Changes in liver function over time with the progression of HCC adds further complexity to the use of TKIs. The challenges posed by TKIs and the HCC disease process means monitoring of TKIs is required to improve clinical management. To date, only partial data supporting sorafenib monitoring is available. Results from further pharmacokinetic/pharmacodynamic studies of these four TKIs are eagerly awaited and are expected to permit such monitoring and the development of consensus guidelines.

Regorafenib is effective against neuroblastoma in vitro and in vivo and inhibits the RAS/MAPK, PI3K/Akt/mTOR and Fos/Jun pathways

BACKGROUND

Regorafenib is an inhibitor of multiple kinases with aberrant expression and activity in neuroblastoma tumours that have potential roles in neuroblastoma pathogenesis.

METHODS

We evaluated neuroblastoma cells treated with regorafenib for cell viability and confluence, and analysed treated cells for apoptosis and cell cycle progression. We evaluated the efficacy of regorafenib in vivo using an orthotopic xenograft model. We evaluated regorafenib-mediated inhibition of kinase targets and performed reverse-phase protein array (RPPA) analysis of neuroblastoma cells treated with regorafenib. Lastly, we evaluated the efficacy and effects of the combination of regorafenib and 13-cis-retinoic acid on intracellular signalling.

RESULTS

Regorafenib treatment resulted in reduced neuroblastoma cell viability and confluence, with both induction of apoptosis and of cell cycle arrest. Regorafenib treatment inhibits known receptor tyrosine kinase targets RET and PDGFRβ and intracellular signalling through the RAS/MAPK, PI3K/Akt/mTOR and Fos/Jun pathways. Regorafenib is effective against neuroblastoma tumours in vivo, and the combination of regorafenib and 13-cis-retinoic acid demonstrates enhanced efficacy compared with regorafenib alone.

CONCLUSIONS

The effects of regorafenib on multiple intracellular signalling pathways and the potential additional efficacy when combined with 13-cis-retinoic acid represent opportunities to develop treatment regimens incorporating regorafenib for children with neuroblastoma.

Regorafenib in Chinese patients with metastatic colorectal cancer: Subgroup analysis of the phase 3 CONCUR trial

BACKGROUND AND AIM

In the phase 3 CONCUR trial (NCT01584830), regorafenib improved overall survival (OS) versus placebo in Asian patients with treatment-refractory metastatic colorectal cancer (mCRC). We conducted a post hoc subgroup analysis of Chinese patients in CONCUR.

METHODS

Adults with mCRC progressing despite at least two prior treatment regimens and Eastern Cooperative Oncology Group performance status 0-1 were randomized 2:1 to regorafenib 160 mg once daily or placebo for the first 3 weeks of each 4-week cycle. Dose modifications were permitted. The primary endpoint was OS. Secondary endpoints included progression-free survival, objective overall response, disease control rate, and safety.

RESULTS

A total of 172 Chinese patients were randomized and treated (regorafenib n = 112, placebo n = 60). OS was significantly improved with regorafenib versus placebo (8.4 vs 6.2 months, respectively; hazard ratio [HR] 0.56, 95% CI 0.39-0.80; one-sided P = 0.000632), as was progression-free survival (HR 0.32, 95% CI 0.22-0.47; one-sided P < 0.000001). The most common drug-related grade ≥ 3 treatment-emergent adverse events (TEAEs; regorafenib, placebo) were hand-foot skin reaction (19%, 0%), hypertension (13%, 3%), hypophosphatemia (7%, 0%), increased alanine aminotransferase (6%, 0%), and increased aspartate aminotransferase (5%, 0%). In patients receiving regorafenib and placebo, respectively, TEAEs led to treatment discontinuation in 14% and 7%, dose reduction in 39% and 0%, and dose interruption in 64% and 20%.

CONCLUSIONS

This retrospective analysis showed that regorafenib provided an OS benefit over placebo for Chinese patients with previously treated mCRC. TEAEs were consistent with the regorafenib safety profile and manageable with treatment modifications.

Efficacy and safety of regorafenib as beyond second-line therapy in patients with metastatic colorectal cancer: an adjusted indirect meta-analysis and systematic review

Background:

The evidence base for optimum third-line therapy for metastatic colorectal cancer (mCRC) is not conclusive. Recent studies have demonstrated the efficacy of regorafenib as third-line therapy in mCRC. This indirect meta-analysis compared the efficacy and safety of regorafenib with other available third-line therapies for mCRC.

Methods:

A literature search for randomized controlled trials (RCTs) was conducted in PubMed, Embase, and Cochrane Library for studies evaluating the efficacy and safety of fruquintinib, regorafenib, TAS-102, and nintedanib as third-line therapies in patients with mCRC. Overall survival (OS) and progression-free survival (PFS) were the primary outcomes, while objective response rate (ORR) and safety were the secondary outcomes. Hazard ratio (HR) and relative risk (RR) with their respective 95% confidence interval (CI) were used for analysis of survival, clinical response, and safety data. An adjusted indirect meta-analysis with placebo as the common comparator was performed.

Results:

We identified eight RCTs comparing regorafenib (two studies), fruquintinib (two studies), TAS-102 (three studies), and nintedanib (one study) against placebo. The OS with regorafenib was significantly better when compared with nintedanib (HR = 0.66; 95% CI: 0.45, 0.95, p = 0.02) but was similar to that of fruquintinib (HR = 1.01; 95% CI: 0.67, 1.52, p = 0.94) and TAS-102 (HR = 0.97; 95% CI: 0.68, 1.38, p = 0.88). The PFS and ORR for regorafenib were slightly better than those of TAS-102 (PFS: HR = 0.86, 95% CI: 0.54, 1.37, p = 0.5; ORR: RR = 1.13, 95% CI: 0.11, 11.05, p = 0.92) and nintedanib (PFS: HR = 0.68, 95% CI: 0.42, 1.10, p = 0.12; ORR: not reported) but were lower than those for fruquintinib (PFS: HR = 1.53, 95% CI: 0.93, 2.52, p = 0.08; ORR: RR = 0.68269, 95% CI: 0.045, 10.32, p = 0.79). Safety analysis showed that the RR of adverse events (AEs) was lesser in patients treated with regorafenib in comparison with that in patients treated with fruquintinib, but was similar to that in patients treated with nintedanib and TAS-102.

Conclusion:

Regorafenib has efficacy similar to that of TAS-102 and better safety when compared with fruquintinib. Considering the mechanism of action of regorafenib, which targets multiple factors in the angiogenic pathway, it could be an ideal option for treatment in the beyond second-line setting.

A meta-analysis comparing regorafenib with TAS-102 for treating refractory metastatic colorectal cancer

Objective

We performed this meta-analysis to compare the efficacy and toxicity of regorafenib and TAS-102.

Methods

Electronic databases were searched to identify studies comparing the efficacy and safety of regorafenib and TAS-102 in patients with chemotherapy-refractory metastatic colorectal cancer using pooled analyses.

Results

Three clinical trials were included in this analysis. Regarding the reasons for treatment discontinuation, regorafenib was significantly associated with disease progression (odds ratio [OR] = 0.33, 95% confidence interval [CI] = 0.21–0.50) and adverse events (OR = 4.38, 95% CI = 2.69–7.13). However, overall (OR = 0.97, 95% CI = 0.81–1.17) and progression-free survival (OR = 1.01, 95% CI = 0.86–1.18) did not significantly differ between the groups. The most common treatment-related adverse events in the regorafenib group were neutropenia (OR = 0.06, 95% CI = 0.03–0.11), hand–foot syndrome (OR = 50.34, 95% CI = 10.44–242.84), and liver dysfunction (OR = 34.51, 95% CI = 8.30–143.43). Conversely, the incidence of thrombocytopenia did not differ between the two groups.

Conclusions

Regorafenib and TAS-102 have similar efficacy but different adverse event profiles. Differences in the toxicity profiles of the two drugs will help guide treatment selection.

Regorafenib Regulates AD Pathology, Neuroinflammation, and Dendritic Spinogenesis in Cells and a Mouse Model of AD

The oral multi-target kinase inhibitor regorafenib, which targets the oncogenic receptor tyrosine kinase (RTK), is an effective therapeutic for patients with advanced gastrointestinal stromal tumors or metastatic colorectal cancer. However, whether regorafenib treatment has beneficial effects on neuroinflammation and Alzheimer’s disease (AD) pathology has not been carefully addressed. Here, we report the regulatory function of regorafenib in neuroinflammatory responses and AD-related pathology in vitro and in vivo. Regorafenib affected AKT signaling to attenuate lipopolysaccharide (LPS)-mediated expression of proinflammatory cytokines in BV2 microglial cells and primary cultured microglia and astrocytes. In addition, regorafenib suppressed LPS-induced neuroinflammatory responses in LPS-injected wild-type mice. In 5x FAD mice (a mouse model of AD), regorafenib ameliorated AD pathology, as evidenced by increased dendritic spine density and decreased Aβ plaque levels, by modulating APP processing and APP processing-associated proteins. Furthermore, regorafenib-injected 5x FAD mice displayed significantly reduced tau phosphorylation at T212 and S214 (AT100) due to the downregulation of glycogen synthase kinase-3 beta (GSK3β) activity. Taken together, our results indicate that regorafenib has beneficial effects on neuroinflammation, AD pathology, and dendritic spine formation in vitro and in vivo.

Population pharmacokinetics of regorafenib in solid tumours: Exposure in clinical practice considering enterohepatic circulation and food intake

Aim

Regorafenib is an oral multikinase inhibitor with clinical efficacy in a range of advanced solid tumours. A population pharmacokinetic (PK) model was developed to evaluate the variability of the PK of regorafenib and its pharmacologically active metabolites M‐2 and M‐5 in solid tumours.

Methods

The model was initially developed using densely sampled phase 1 data and information on food intake to incorporate enterohepatic circulation (EHC) that was identified to considerably contribute to the PK of regorafenib. This was then applied to sparsely sampled data from four phase 3 studies in patients with advanced solid tumours. The need for exact food intake data to estimate individual drug exposure was evaluated.

Results

By incorporating EHC, the model adequately described the PK profiles of regorafenib, M‐2 and M‐5 after single and multiple doses in patients from phase 1 studies. Individual exposure in phase 3 studies was adequately described based on assumptions on the time and frequency of food intake, although exact food intake data are recommended to improve the estimation. Covariate analysis identified sex and body mass index (BMI) as impacting exposure to regorafenib, and sex as strongly impacting exposure to M‐2 and M‐5 (also influenced by the BMI effect on parent regorafenib in the joint model developed); however, these factors accounted for a small portion of the overall variability in exposure.

Conclusions

The adequate description of regorafenib PK after multiple dosing requires the incorporation of EHC. Neither single nor combined covariates predicted exposures that would warrant a priori regorafenib dose adjustment.

The Synergistic Anti-Cancer Effects of NVP-BEZ235 and Regorafenib in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of liver cancer worldwide. Regorafenib is a multi-kinase inhibitor and the second-line treatment for HCC. Since the PI3K/Akt/mTOR signaling pathway is dysregulated in HCC, we evaluated the therapeutic effects of regorafenib combined with a dual PI3K/mTOR inhibitor BEZ235 in the human HCC cell lines (n = 3). The combined treatment with BEZ235 and regorafenib enhanced the inhibition of cell proliferation and increased the expression of cleaved caspase-3 and cleaved PARP in HCC cells. Moreover, the combined treatment suppressed HCC cell migration and invasion in the transwell assay. Further, the Western blot analyses confirmed the involvement of epithelial-mesenchymal transition (EMT)-related genes such as slug, vimentin, and matrix metalloproteinase (MMP)-9/-2. Additionally, the proteinase activity of MMP-9/-2 was analyzed using gelatin zymography. Furthermore, the inhibition of phosphorylation of the Akt, mTOR, p70S6K, and 4EBP1 after combined treatment was validated using Western blot analysis. Therefore, these results suggest that the combined treatment with BEZ235 and regorafenib benefits patients with HCC.

Comparison of Standard Initial Dose and Reduced Initial Dose Regorafenib for Colorectal Cancer Patients: A Retrospective Cohort Study

BACKGROUND

The benefit of regorafenib for colorectal cancer patients was demonstrated in previous randomized studies. However, these studies showed a high rate of treatment-related adverse events, and adverse events were more common in Japanese patients. Some studies showed fewer adverse events and a longer survival time with a reduced initial dose. However, the benefits of a reduced initial dose of regorafenib have only been evaluated in small samples.

OBJECTIVE

Our objective was to analyze the efficacy of initial regorafenib dose reduction compared with a standard dose for colorectal cancer patients.

PATIENTS AND METHODS

We used a hospital-based nationwide claims database. Patients who received regorafenib for metastatic colorectal cancer between June 2013 and July 2017 were included in this study. We divided the patients into a standard initial dose group (standard group) and a reduced initial dose group (reduced group). Overall survival (OS) and adverse events were compared between the two groups. We performed propensity score matching for sensitivity analysis.

RESULTS

We included 2376 patients (1208 in the standard group and 1168 in the reduced group). The median OS was 12.3 months (95% confidence interval (CI): 11.0-13.3) in the standard group and 12.6 months (95% CI: 11.7-13.6) in the reduced group. A log-rank test showed no significant difference between the two groups (p = 0.41). Most adverse events occurred less frequently in the reduced group. In the sensitivity analysis, there was no significant difference for OS.

CONCLUSIONS

No significant difference was observed for OS between the standard group and the reduced group. However, there were fewer adverse events in the reduced group. The optimal initial dose of regorafenib should be identified in further studies.

Therapeutic drug monitoring of regorafenib and its metabolite M5 can predict treatment efficacy and the occurrence of skin toxicities

BACKGROUND

Regorafenib is a multiple tyrosine kinase inhibitor, and the use of this drug is approved for the treatment of cancers that are resistant to chemotherapy, which include advanced colorectal cancer, gastrointestinal stromal tumor, and hepatocellular carcinoma. However, the drug causes adverse events, including skin toxicities that require dose modification in approximately 75% of cases. At present, the blood concentration of regorafenib is not assessed in clinical settings; thus, we recently developed a method that can assess the blood concentration of the drug using high-performance liquid chromatography.

METHODS

We measured the trough blood concentrations (C_trough) of regorafenib and its metabolites (M2 and M5) in 14 and 4 patients with advanced colorectal cancer and gastrointestinal stromal tumor, respectively, using high-performance liquid chromatography. Then, the correlation between the C_trough and therapeutic outcomes of regorafenib was analyzed.

RESULTS

In patients who were receiving regorafenib 40-160 mg/day, the C_trough values of regorafenib, M2, and M5 were 318-9467, 34-3594, and 38-3796 ng/mL, respectively. The difference in the values was significant. Although the specific factors influencing this difference were not elucidated, the C_trough of regorafenib was extremely lower in some patients, even though the drug was administered at a standard dose, which may explain the lower response rate. Moreover, the C_trough value of M5 was significantly correlated to the incidence of skin toxicities, which is the most frequent cause of dose modification.

CONCLUSIONS

The use of regorafenib may not be suitable in patients with a low C_trough value. To prevent skin toxicities, the C_trough value of M5 should be monitored.

Long-term survival of an advanced colorectal cancer patient treated with Regorafenib: Case report and literature review

Two phase 3 trials reported a prolonged survival in the third-line setting of colorectal cancer patients treated with regorafenib with the longest duration of treatment of 16 months. Herein, we reported a unique case of a patient refractory to conventional chemotherapy who showed a prolonged stable disease with regorafenib.