Early quantification of the therapeutic efficacy of the vascular disrupting agent, CKD-516, using dynamic contrast-enhanced ultrasonography in rabbit VX2 liver tumors

Thiazole, Isatin and Phthalimide Derivatives Tested in vivo against Cancer Models: A Literature Review of the Last Six Years

BACKGROUND

Cancer is a disease characterized by the abnormal multiplication of cells and is the second leading cause of death in the world. The search for new effective and safe anticancer compounds is ongoing due to factors such as low selectivity, high toxicity, and multidrug resistance. Thus, heterocyclic compounds derived from isatin, thiazole and phthalimide that have achieved promising in vitro anticancer activity have been tested in vivo and in clinical trials.

OBJECTIVE

This review focused on the compilation of promising data from thiazole, isatin, and phthalimide derivatives, reported in the literature between 2015 and 2022, with in vivo anticancer activity and clinical trials.

METHODS

A bibliographic search was carried out in the PUBMED, MEDLINE, ELSEVIER, and CAPES PERIODIC databases, selecting relevant works for each pharmacophoric group with in vivo antitumor activity in the last 6 years.

RESULTS

In our study, 68 articles that fit the scope were selected and critically analyzed. These articles were organized considering the type of antitumor activity and their year of publication. Some compounds reported here demonstrated potent antitumor activity against several tumor types.

CONCLUSION

This review allowed us to highlight works that reported promising structures for the treatment of various cancer types and also demonstrated that the privileged structures thiazole, isatin and phthalimide are important in the design of new syntheses and molecular optimization of compounds with antitumor activity.

Early response evaluation of doxorubicin-nanoparticle-microbubble therapy in orthotopic hepatocellular carcinoma rat model using contrast-enhanced ultrasound and intravoxel incoherent motion-diffusion MRI

Purpose

This study aimed to apply doxorubicin-loaded nanoparticle microbubble (Dox-NP-MB) therapy in an orthotopic rat model of hepatocellular carcinoma (HCC) and investigate the utility of contrast-enhanced ultrasound (CEUS) and intravoxel incoherent motion diffusion-weighted magnetic resonance imaging (IVIM-DWI) for response evaluation.

Methods

Twenty-eight N1S1 HCC model rats were treated with either Dox-NP-MB (group [G] 1, n=8), doxorubicin (Dox) alone (G2, n=7), nanoparticle microbubbles alone (G3, n=7), or saline (G4, control, n=6) on days 0 and 7, and were sacrificed on day 11. IVIM-DWI and CEUS were performed before each treatment and before euthanasia. Efficacy was estimated by the percentage of tumor volume growth inhibition compared with control. Toxicity was assessed by body weight changes and blood tests. Post-treatment changes in IVIM-DWI and CEUS parameters were analyzed.

Results

Tumor volume growth was inhibited by 48.4% and 90.2% in G1 and G2 compared to G4, respectively. Compared to G2, G1 had a significantly lower degree of body weight change (median, 91.0% [interquartile range, 88.5%-97.0%] vs. 88.0% [82.5%-88.8%], P<0.05) and leukopenia (1.75×10³ cells/μL [1.53-2.77] vs. 1.20×10³ cells/μL [0.89-1.51], P<0.05). After the first treatment, an increase in peak enhancement, wash-in rate, and wash-in perfusion index on CEUS was observed in G3 and G4 but suppressed in G1 and G2; the apparent diffusion coefficients, true diffusion coefficients, and perfusion fractions significantly increased in G1 and G2 compared to baseline (P<0.05).

Conclusion

Dox-NP-MB showed reduced Dox toxicity. Early changes in some CEUS and IVIM-DWI parameters correlated with the therapeutic response.

A phase 1 dose-escalation and dose-expansion study to assess the safety and efficacy of CKD-516, a novel vascular disrupting agent, in combination with Irinotecan in patients with previously treated metastatic colorectal cancer

Introduction The combination of an anti-angiogenic agent with cytotoxic chemotherapy is a standard treatment strategy for metastatic colorectal cancer. CKD-516 is an oral vascular disrupting agent that was preliminarily shown to be safe and efficacious as a monotherapy in refractory solid cancers. We evaluated the recommended phase 2 dose, safety, and preliminary efficacy of CKD-516 in combination with irinotecan in treatment-refractory metastatic colorectal cancer. Methods This phase 1 dose-escalation and dose-expansion study included patients with treatment-refractory metastatic colorectal cancer. CKD-516 tablets were administered for five consecutive days followed by two days off in combination with intravenous irinotecan (120 mg/m²) administered on day one of each treatment cycle every two weeks. A traditional 3 + 3 dose-escalation design was used. Results In total, 16 and 23 patients were enrolled in the dose-escalation and dose-expansion cohorts, respectively. The most common adverse events included diarrhea (79%), nausea (74%), vomiting (67%), and neutropenia (62%). No dose-limiting toxicity occurred, and the recommended phase 2 dose was determined at CKD-516/irinotecan doses of 11/120 mg/m². No cases of cardiac ischemia, cardiac dysfunction, or thromboembolism were reported. Among the 34 patients with available tumor response assessments, one patient achieved partial response (3%) and 26 patients achieved stable disease (76%). The median progression-free survival and overall survival were 4.1 and 11.6 months, respectively. Conclusion This phase 1 study showed that the combination of oral CKD-516 and irinotecan is safe and tolerable in metastatic, treatment-refractory colorectal patients and showed favorable efficacy outcomes. Further studies to confirm these preliminary findings are warranted. Trial registration number NCT03076957 (Registered at March 10, 2017).

Involvement of ER stress and reactive oxygen species generation in anti-cancer effect of CKD-516 for lung cancer

PURPOSE

CKD-516 (Valecobulin), a vascular-disrupting agent, inhibits microtubule elongation. We evaluated the effect of CKD-516 on lung cancer cells and the underlying molecular mechanisms.

METHODS

The effects of S516, an active metabolite of CKD-516, were evaluated in HUVECs and three lung cancer cell lines and by a microtubule polymerization assay. Tubulin cross-linking was used to identify the binding site of S516 on tubulin, and Western blotting was performed to identify the intracellular pathways leading to cell death. Subcutaneous lung cancer xenograft models were used to assess the in vivo effect of CKD-516 on tumor growth.

RESULTS

S516 targeted the colchicine binding site on β-tubulin. In lung cancer cells, S516 increased endoplasmic reticulum (ER) stress and induced reactive oxygen species (ROS) generation by mitochondria and the ER. In addition, CKD-516 monotherapy strongly inhibited the growth of lung cancer xenograft tumors and exerted a synergistic effect with carboplatin.

CONCLUSION

The findings suggest that CKD-516 exerts an anticancer effect in company with inducing ER stress and ROS production via microtubule disruption in lung cancer cells. CKD-516 may thus have therapeutic potential for lung cancer.

Enhanced efficacy of radiofrequency ablation for hepatocellular carcinoma using a novel vascular disrupting agent, CKD-516

BACKGROUND

CKD-516 is a novel vascular disrupting agent that shuts down intratumoral blood flow. We therefore hypothesized that concomitant administration of CKD-516 would enhance the therapeutic efficacy of radiofrequency ablation (RFA) by reducing heat sink effects. We assessed the effects of the combination of CKD-516 and RFA in a rat orthotopic hepatocellular carcinoma (HCC) model.

METHODS

Rat HCC cells (N1-S1) were engrafted into the hepatic lobe of Sprague-Dawley (SD) rats. Mice were randomly divided into two groups: RFA-only and CKD-RFA. In the CKD-RFA group, CKD-516 was administered by intraperitoneal injection 2 h before RFA. Ablation zone size was measured on triphenyltetrazolium chloride-stained specimens. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to evaluate the area of apoptosis/necrosis in the ablation zone. Immunohistochemistry with anti-CD31 antibody was performed to evaluate the effect of CKD-516 on tumor vessels.

RESULTS

Ablation zone size was significantly larger in the CKD-RFA group than in the RFA-only group (243.10 ± 74.39 versus 123.30 ± 28.17 mm², p < 0.001). On TUNEL staining, the area of apoptosis/necrosis was also significantly larger in the CKD-RFA group than in the RFA-only group (274.44 ± 140.78 versus 143.74 ± 90.13 mm²; p = 0.006). Immunohistochemistry with anti-CD31 antibody revealed patent tumor vessels in the RFA-only group, while collapsed vessels were seen in the CKD-RFA group, indicating a vascular shutdown effect of CKD-516.

CONCLUSION

Concomitant administration of CKD-516 during RFA can increase the ablation zone of tumors due to its vascular disrupting effect.

Comparison of tumor vascularity and hemodynamics in three rat hepatoma models

PURPOSE

To compare tumor vascularity and hemodynamics in three rat hepatoma models: N1-S1 cells in Sprague-Dawley rats, McA-RH7777 cells in Sprague-Dawley rats, and 13762 MAT B III cells in F344 rats.

METHODS

The three rat hepatoma models were induced in five rats per group. After confirming that the tumors grew up to 10 mm on magnetic resonance imaging, the rats underwent dynamic contrast-enhanced ultrasonography (DCE-US). Afterward, the rats were euthanized for histologic analyses. The Kruskal-Wallis test was used to compare the rat hepatoma models. Correlation coefficients were calculated between the microvessel density (MVD) and DCE-US parameters.

RESULTS

On DCE-US imaging, arterial enhancement and washout were demonstrated in all N1-S1 tumors, while persistent peripheral enhancement on arterial to portal phases was shown in all 13762 MAT B III tumors. The McA-RH7777 tumors presented diverse enhancement patterns on arterial and portal phases. There were no significant differences in DCE-US parameters among the three hepatoma groups, while MVD was correlated with peak intensity (r = 0.565, p = 0.044), mean transit time (r = -0.559, p = 0.047), and time to peak (r = - 0.617, p = 0.025) of individual rats. The necrosis ratio was significantly different between the models (p = 0.031); 13762 MAT B III showed a significantly higher necrosis ratio than N1-S1 (p < 0.050 by post hoc test).

CONCLUSION

The N1-S1 tumor may be suitable as a model to investigate hypervascular hepatic tumors of the liver in DCE-US such as hepatocellular carcinoma among the three tumors.

Feasibility of Using Volumetric Contrast-Enhanced Ultrasound with a 3-D Transducer to Evaluate Therapeutic Response after Targeted Therapy in Rabbit Hepatic VX2 Carcinoma

The aim of this study was to assess the feasibility of using dynamic contrast-enhanced ultrasound (DCE-US) with a 3-D transducer to evaluate therapeutic responses to targeted therapy. Rabbits with hepatic VX2 carcinomas, divided into a treatment group (n = 22, 30 mg/kg/d sorafenib) and a control group (n = 13), were evaluated with DCE-US using 2-D and 3-D transducers and computed tomography (CT) perfusion imaging at baseline and 1 d after the first treatment. Perfusion parameters were collected, and correlations between parameters were analyzed. In the treatment group, both volumetric and 2-D DCE-US perfusion parameters, including peak intensity (33.2 ± 19.9 vs. 16.6 ± 10.7, 63.7 ± 20.0 vs. 30.1 ± 19.8), slope (15.3 ± 12.4 vs. 5.7 ± 4.5, 37.3 ± 20.4 vs. 15.7 ± 13.0) and area under the curve (AUC; 1004.1 ± 560.3 vs. 611.4 ± 421.1, 1332.2 ± 708.3 vs. 670.4 ± 388.3), had significantly decreased 1 d after the first treatment (p = 0.00). In the control group, 2-D DCE-US revealed that peak intensity, time to peak and slope had significantly changed (p < 0.05); however, volumetric DCE-US revealed that peak intensity, time-intensity AUC, AUC during wash-in and AUC during wash-out had significantly changed (p = 0.00). CT perfusion imaging parameters, including blood flow, blood volume and permeability of the capillary vessel surface, had significantly decreased in the treatment group (p = 0.00); however, in the control group, peak intensity and blood volume had significantly increased (p = 0.00). It is feasible to use DCE-US with a 3-D transducer to predict early therapeutic response after targeted therapy because perfusion parameters, including peak intensity, slope and AUC, significantly decreased, which is similar to the trend observed for 2-D DCE-US and CT perfusion imaging parameters.

Dynamic Contrast-Enhanced MRI Using a Macromolecular MR Contrast Agent (P792): Evaluation of Antivascular Drug Effect in a Rabbit VX2 Liver Tumor Model

Objective

To evaluate the utility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using macromolecular contrast agent (P792) for assessment of vascular disrupting drug effect in rabbit VX2 liver tumor models.

Materials and Methods

This study was approved by our Institutional Animal Care and Use Committee. DCE-MRI was performed with 3-T scanner in 13 VX2 liver tumor-bearing rabbits, before, 4 hours after, and 24 hours after administration of vascular disrupting agent (VDA), using gadomelitol (P792, n = 7) or low molecular weight contrast agent (gadoterate meglumine [Gd-DOTA], n = 6). P792 was injected at a of dose 0.05 mmol/kg, while that of Gd-DOTA was 0.2 mmol/kg. DCE-MRI parameters including volume transfer coefficient (K^trans) and initial area under the gadolinium concentration-time curve until 60 seconds (iAUC) of tumors were compared between the 2 groups at each time point. DCE-MRI parameters were correlated with tumor histopathology. Reproducibility in measurement of DCE-MRI parameters and image quality of source MR were compared between groups.

Results

P792 group showed a more prominent decrease in K^trans and iAUC at 4 hours and 24 hours, as compared to the Gd-DOTA group. Changes in DCE-MRI parameters showed a weak correlation with histologic parameters (necrotic fraction and microvessel density) in both groups. Reproducibility of DCE-MRI parameters and overall image quality was not significantly better in the P792 group, as compared to the Gd-DOTA group.

Conclusion

Dynamic contrast-enhanced magnetic resonance imaging using a macromolecular contrast agent shows changes of hepatic perfusion more clearly after administration of the VDA. Gadolinium was required at smaller doses than a low molecular contrast agent.

Phase I Study of CKD-516, a Novel Vascular Disrupting Agent, in Patients with Advanced Solid Tumors

PURPOSE

CKD-516 is a newly developed vascular disrupting agent. This phase I dose-escalation study of CKD-516 was conducted to determine maximum-tolerated dose (MTD), safety, pharmacokinetics, and preliminary antitumor efficacy in patients with advanced solid tumors.

MATERIALS AND METHODS

Patients received CKD-516 intravenously on D1 and D8 every 3 weeks, in a standard 3+3 design. Safety was evaluated by National Cancer Institute Common Terminology Criteria for Adverse Events ver. 4.02 and response was assessed by Response Evaluation Criteria in Solid Tumor ver. 1.1.

RESULTS

Twenty-three patients were treated with CKD-516 at seven dosing levels: 1 mg/m(2)/day (n=3), 2 mg/m(2)/day (n=3), 3.3 mg/m(2)/day (n=3), 5 mg/m(2)/day (n=3), 7 mg/m(2)/day (n=3), 9 mg/m(2)/day (n=6), and 12 mg/m(2)/day (n=2). Mean age was 54 and 56.5% of patients were male. Two dose-limiting toxicities, which were both grade 3 hypertension, were observed in two patients at 12 mg/m(2)/day. The MTD was determined as 12 mg/m(2)/day. Most common adverse events were gastrointestinal adverse events (diarrhea, 34.8% [30.4% grade 1/2, 13.0% grade 3]; nausea, 21.7% [all grade 1/2]; vomiting, 21.7% [all grade 1/2]), myalgia (17.4%, all grade 1/2), and abdominal pain (21.7% [21.7% grade 1/2, 4.3% grade 3]). The pharmacokinetic study showed the dose-linearity of all dosing levels. Among 23 patients, six patients (26.1%) showed stable disease. Median progression-free survival was 39 days (95% confidence interval, 37 to 41 days).

CONCLUSION

This study demonstrates feasibility of CKD-516, novel vascular disrupting agent, in patients with advanced solid tumor. MTD of CKD-516 was defined as 12 mg/m(2)/day on D1 and D8 every 3 weeks.

Dynamic contrast-enhanced magnetic resonance imaging of the liver: Applications in treatment of hepatic malignancies with vascular targeting agents

Dynamic contrast-enhanced magnetic resonance (DCE-MR) imaging of the liver as a trendy technique can be applied in various kinds of liver diseases to evaluate perfusion and vascular characteristics of liver tissue and tumor. It has been proved that DCE-MR imaging plays an important role in the treatment of liver malignancies with vascular targeting agents. This review aims to give an overview of DCE-MR imaging of the liver in terms of semi-quantitative analysis methods, common quantitative analysis models and contrast agents and discuss its application value in the treatment of liver malignancies with vascular targeting agents.