In vitro characterization of cisplatin-loaded superabsorbent polymer microspheres designed for chemoembolization

In Vitro Characterization of Drug-Loaded Superabsorbent Polymer Microspheres: Absorption and Release Capacity of Contrast Material, Antibiotics and Analgesics

PURPOSE

To examine the characteristics of drug-loaded superabsorbent polymer microspheres (SAP-MS) such as drug absorption, drug release, diameter, and visibility.

MATERIALS AND METHODS

SAP-MS (HepaSphere150-200 µm; Merit Medical, South Jordan, UT, USA) were suspended in drug solutions: (a) cefazolin, (b) lidocaine, (c) iopamidol and cefazolin, (d) iopamidol and lidocaine, and (e) iopamidol, cefazolin, and lidocaine. The concentrations of drugs were measured, and the amount of each drug absorbed was calculated. Filtered drug-loaded SAP-MS were mixed with saline, and the drug release rates were calculated. The diameter changes of SAP-MS during absorption were observed. Radiography of drug-loaded SAP-MS was evaluated as radiopacity by contrast-to-noise ratio (CNR).

RESULTS

The drug concentration did not change during absorption. The release rates increased for 10 min and then came to an equilibrium. The mean amounts of drug absorbed at 180 min and mean release rates at 24 h were (a) cefazolin: 265.4 mg, 64.2%; (b) lidocaine: 19.6 mg, 75.6%; (c) iopamidol: 830.2 mg, 22.5%; cefazolin: 137.6 mg, 21.2%; (d) iopamidol: 1620.6 mg, 78.5%; lidocaine: 13.5 mg, 81.4%; and (e) iopamidol: 643.7 mg, 52.9%; cefazolin: 194.0 mg, 51.6%; lidocaine: 5.3 mg, 58.4%. The diameter of SAP-MS increased for approximately 15 min. Finally, the diameters of SAP-MS were (a) 3.9 times, (b) 5.0 times, (c) 2.2 times, (d) 5.5 times, and (e) 3.6 times larger than the original size. Drug-loaded SAP-MS containing iopamidol were visible under X-ray imaging, with CNRs of (c) 3.0, (d) 9.0, and (e) 4.5.

CONCLUSION

SAP-MS can absorb and release iopamidol, cefazolin, and lidocaine.

Emerging Polymer Materials in Trackable Endovascular Embolization and Cell Delivery: From Hype to Hope

Minimally invasive endovascular embolization is a widely used clinical technique used for the occlusion of blood vessels to treat various diseases. Different occlusive agents ranging from gelatin foam to synthetic polymers such as poly(vinyl alcohol) (PVA) have been commercially used for embolization. However, these agents have some drawbacks, such as undesired toxicity and unintended and uncontrolled occlusion. To overcome these issues, several polymer-based embolic systems are under investigation including biocompatible and biodegradable microspheres, gelling liquid embolic with controlled occlusive features, and trackable microspheres with enhanced safety profiles. This review aims to summarize recent advances in current and emerging polymeric materials as embolization agents with varying material architectures. Furthermore, this review also explores the potential of combining injectable embolic agents and cell therapy to achieve more effective embolization with the promise of outstanding results in treating various devastating diseases. Finally, limitations and challenges in developing next-generation multifunctional embolic agents are discussed to promote advancement in this emerging field.

Five-Years Outcome Analysis of 142 Consecutive Hepatocellular Carcinoma Patients Treated with Doxorubicin Eluting Microspheres 30-60 μm: Results from a Single-Centre Prospective Phase II Trial

PURPOSE

To assess prospectively long-term results of doxorubicin-loaded HepaSphere 30-60 μm in consecutive patients with hepatocellular carcinoma (HCC) not amenable to curative treatments.

PATIENTS AND METHODS

Single-center study from June 2011 to December 2015 in 151 patients treated with 75 mg of doxorubicin per HepaSphere vial. Baseline: Barcelona Clinic Liver Cancer BCLC A/B was 49.3%/50.7%, and median diameter 6.1 cm (mean 6.7 ± 2.0). Liver function, local response (mRECIST), liver time to progression (LTTP), progression-free survival (PFS), overall survival (OS) and adverse events (AEs) were recorded.

RESULTS

Final analysis included 142 patients with median follow-up of 46.8 months (range 4-72) without grade 4/5 AEs, and 30-day mortality was 0%. Mean number of scheduled treatments was 2.6 (range 1-3) and on demand 3 (range 1-8). Complete response for single tumor ≤ 5 cm was 75.0% and 66.7% for Child A and Child B, while for > 5 cm was 28.6% and 11.8%, respectively. OS was 31.0 months (mean 33.3 ± 15.2; range 8-69), notably for BCLC A 41 months (mean 41.1 ± 15.3; range 13-69) and for BCLC B 26.0 (mean 26.0 ± 10.5; range 8-51). OS at 1, 3 and 5 years: 95.8%, 75.7% and 21.4% for BCLC A, and 94.4%, 36.1% and 2.7% for BCLC B. Median LTTP for BCLC A was 11 months (mean 11.9 ± 4.7; range 3-24) and 7.5 for BCLC B (mean 7.9 ± 2.9). Local response was significant for OS and LTTP (p < 0.0001), while size and lesion number affected LPFS and OS (p < 0.001).

CONCLUSIONS

HepaSphere 30-60 μm loaded with doxorubicin provides a safe and effective treatment option for patients with HCC.

Chemoembolization of hepatocellular carcinoma with HepaSphere™

This review discusses the current data on Hepasphere™ in the treatment of hepatocellular carcinoma. HepaSphere is a drug-loadable microsphere that can be bound with doxorubicin, epirubicin, cisplatin or oxaliplatin. In vitro and in vivo studies confirm lower systemic exposure to the drug and fewer systemic doxorubicin-related side effects. Studies suggest that this technique is better tolerated than conventional lipiodol-based chemoembolization (c-TACE). In intermediate and early stage hepatocellular carcinoma - nonresponsive to curative treatments - complete response and partial response rates range from 22.2 to 48% and 43.7 to 51%, respectively. Studies with survival as an end-point are needed and head-to-head comparisons with other drug-eluting beads are necessary.

Does drug-eluting bead transcatheter arterial chemoembolization improve the management of patients with hepatocellular carcinoma? A meta-analysis

BACKGROUND

Drug eluting beads (DEB) are relatively new embolic agents that allow sustained release of chemotherapeutic agents in a localized fashion to the tumor. This technique is associated with reduced systemic side effects relative to systemic chemotherapy and an increase in the dose of antineoplastic agent delivered to the lesion. The meta-analysis was undertaken to assess the effectiveness of DEB-transcatheter arterial chemoembolization (TACE) in the management of hepatocellular cancer.

METHODS

We searched the Web of Science, PubMed, EBSCO, EMBASE, the Wiley Library and Google Scholar for studies on DEB-TACE in the management of hepatocellular cancer from 1979 to April 2013. The risk of bias was assessed using RevMan 5 · 1. Random and fixed-effects meta-analytical models were used where indicated, and between-study heterogeneity was assessed. Disease control, complications and severe complications were recorded.

RESULTS

Five studies met the selection criteria, three RCTs and two case-control studies, published from 2010 to 2012, included 217 patients in the DEB-TACE group and 237 in the conventional-TACE group. There was no significance over disease control (OR 2.27, 95% CI 0.78-6.63) with moderate between-study heterogeneity (χ(2) = 6.83, degrees of freedom [df] = 3; p<0.08; I(2) = 56%). Complications in both groups were assessed and no significant difference was observed (χ(2) = 6.34, degrees of freedom [df]  = 4; p<0.18; I(2)= 37%). Severe complications were also assessed and no significant difference was observed (χ(2) = 6.47, degrees of freedom [df]  = 4; p<0.17; I(2)= 38%). No publication bias relating to the above outcomes was detected by funnel plot. DEB-TACE benefited disease control without an increase in complications and severe complications.

What Is the Most Effective Drug Delivery System for Cisplatin during the Treatment of Hepatic Tumors with Single-Session Transcatheter Chemotherapy? A Pilot Study

Background/Aims

The aim of this study was to determine the pharmacodynamics of cisplatin following three different treatment procedures for intrahepatic arterial infusion therapy for hepatocellular carcinoma (HCC).

Methods

We divided 13 HCC patients into the following three groups: group A, lone injection of cisplatin (n=3); group B, combined injection of cisplatin and lipiodol, with embolization using small gelatin cubes (GCs) (n=5); and group C, injection of suspended lipiodol with cisplatin powder, with embolization using small GCs (n=5). In each group, the free cisplatin concentration in the hepatic vein was measured at 0, 5, 10, and 30 minutes.

Results

The mean free cisplatin concentrations were as follows. For group A, the mean was 48.58 µg/mL at 0 minute, 7.31 µg/mL at 5 minutes, 5.70 µg/mL at 10 minutes, and 7.15 µg/mL at 30 minutes. For the same time points, for group B, the concentrations were 8.66, 4.23, 3.22, and 1.65 µg/mL, respectively, and for group C, the concentrations were 4.81, 2.61, 2.52, and 1.75 µg/mL, respectively. The mean area under the curve (AUC)_0-infinity for the free cisplatin concentration was 7.80 in group A, 2.48 in group B, and 2.27 in group C. The AUC_0-infinity for the free cisplatin concentration gradually decreased, from group A to group C.

Conclusions

These results indicate that the combination of lipiodol and small GCs may be useful for delaying cisplatin drainage from the liver.

Transcatheter arterial chemoembolization using cisplatin powder mixed with degradable starch microspheres for colorectal liver metastases after FOLFOX failure: results of a phase I/II study

PURPOSE

To report the results of a phase I/II study of a transcatheter arterial chemoembolization protocol using cisplatin powder and degradable starch microspheres (DSM) for unresectable colorectal liver metastases after failure of FOLFOX (5-flourouracil, leucovorin plus oxaliplatin) chemotherapy conducted to determine the recommended dose of cisplatin powder and to assess the efficacy and safety of the protocol.

MATERIALS AND METHODS

A fine-powder formulation of cisplatin was mixed with DSM and administered via the hepatic artery every 4 weeks. In phase I, three cohorts of patients received escalating doses of cisplatin powder: 50 mg/m(2), 65 mg/m(2), and 80 mg/m(2). In phase II, tumor response, toxicity, and survival times were assessed.

RESULTS

The study enrolled 24 patients. Previously, FOLFOX had been administered to all patients, an irinotecan-containing regimen had been administered to 12 patients, and bevacizumab or cetuximab or both had been administered to 14 patients. In phase I, dose-limiting toxicity did not appear at any level, and the recommended dose of cisplatin powder was determined to be 80 mg/m(2). In phase II, a tumor response rate of 61.1% was achieved. The median hepatic progression-free survival and overall survival were 8.8 months (95% confidence interval [CI], 4.06-13.5 mo) and 21.1 months (95% CI, 8.37-33.8 mo). The following grade 3 toxicities were observed: thrombocytopenia (12.5%), aspartate transaminase elevation (33.3%), alanine transaminase elevation (12.5%), hyponatremia (8.3%), and cholecystitis (4.2%).

CONCLUSIONS

This study shows that transcatheter arterial chemoembolization with cisplatin powder at a dose of 80 mg/m(2) mixed with DSM is well tolerated and can produce a high response rate with a long survival time for patients with unresectable colorectal liver metastases after failure of FOLFOX.

Current status of embolic agents for liver tumor embolization

Gelatin sponge and polyvinyl alcohol particles have been the most popular particulate embolic agents for transarterial chemoembolization (TACE) of liver tumors. Over the last decade, calibrated microspheres have been introduced and increasingly used in liver tumor embolization in Western countries. In addition, drug-eluting beads (DEB) have been introduced for sustained local drug release. Such long-awaited spherical embolic agents will be introduced in Japan in the near future. The advantages of these microspheres are that particles are uniform in size and shape, and easy to inject through a microcatheter. They can travel distally to vessels corresponding to the particle size; in other words, the occlusion level can be predicted according to the particle size chosen. Thus, new bland microspheres and DEB may bring a significant advancement to embolization for primary liver tumors as well as hepatic metastases from various cancers. However, at this point, the published data suggests that both conventional TACE and DEB-TACE are equally effective for treatment of unresectable hepatocellular carcinoma, when patients are carefully selected. Therefore, indication, patient selection, and embolization techniques will be essential in order to individually adapt newer embolic agents based on oncological, anatomical and technical considerations.

Switching the loaded agent from epirubicin to cisplatin: salvage transcatheter arterial chemoembolization with drug-eluting microspheres for unresectable hepatocellular carcinoma

PURPOSE

There is no consensus on switching anticancer agents loaded onto drug carriers in transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC). This study aimed to evaluate the safety and clinical outcomes of TACE with cisplatin-loaded microspheres (CLM-TACE) in HCC patients refractory to TACE with epirubicin-loaded microspheres (ELM-TACE).

METHODS

Between February 2008 and June 2010, 85 patients with unresectable HCC refractory to ELM-TACE were enrolled to undergo CLM-TACE. The number of ELM-TACE sessions until judgment of resistance ranged from 1 to 4 (median, 2.1). CLM-TACE was performed using 50-100-μm superabsorbent polymer microspheres loaded with 1 mg cisplatin/1 mg microspheres together with hepatic arterial infusion of 25 mg cisplatin and 500 mg 5-fluorouracil per patient. Tumor responses were evaluated by computed tomography according to the European Association for the Study of the Liver criteria.

RESULTS

The median number of CLM-TACE treatment sessions was 1.8 (range, 1-5), and the mean total dose of cisplatin per session was 42.8 mg (range, 30.0-59.0). After 6 months, 3 (3.5%) patients achieved complete response, 31 (36.5%) had partial response, 15 (17.6%) had stable disease, and 36 (42.4%) had progressive disease. The median overall survival and time to treatment failure after initial CLM-TACE were 13.3 and 7.2 months, respectively. Overall, 9.4% of patients experienced grade 3/4 adverse events.

CONCLUSION

Switching the loaded agent from epirubicin to cisplatin is a safe, well-tolerated, and efficacious treatment strategy for salvage TACE with drug-eluting microspheres in HCC patients refractory to ELM-TACE.

Transarterial chemoembolization with cisplatin as second-line treatment for hepatocellular carcinoma unresponsive to chemoembolization with epirubicin-Lipiodol emulsion

PURPOSE

The purpose of this retrospective study was to investigate the efficacy of transarterial chemoembolization (TACE) using cisplatin as a second-line treatment for advanced hepatocellular carcinoma (HCC) unresponsive to TACE using epirubicin-Lipiodol emulsion at our institution.

MATERIALS AND METHODS

Between January 2006 and March 2009, 51 patients with unresectable HCC underwent TACE using cisplatin. All patients had shown persistent viable tumor or tumor progression after at least 2 sessions of TACE using epirubicin-Lipiodol emulsion. TACE procedures consisted of arterial injection of a mixture of Lipiodol and cisplatin (30-100 mg [mean 57 ± 21]) (n = 29) or arterial infusion of cisplatin (30-100 mg [mean 87 ± 19]) solution (n = 22) followed by injection of 1-mm porous gelatin particles. Early tumor response was assessed by contrast-enhanced computed tomography (CT) according to Response Evaluation Criteria in Solid Tumors (RECIST) and European Association for the Study of the Liver (EASL) criteria. Overall survival and progression-free survival was calculated using the Kaplan-Meier method. Toxicity was assessed according to NCI-CTCAE version 3 criteria.

RESULTS

Response rates were 11.8 and 27.5% by RECIST and EASL criteria, respectively. Overall survival rates were 61.9, 48.2, and 28.9% at 1, 2, and 3 years, respectively, and the median survival time was 15.4 months. Progression-free survival rate was 35.2% at 1 year, and median progression-free survival time was 3.1 months. No major complications were observed, and the occurrence of postembolization syndrome was minimal. Grade 3 to 4 toxicities included thrombocytopenia (5.8%), increased aspartate aminotransferase (AST) level (35.3%), and increased alanine aminotransferase (ALT) level (23.5%).

CONCLUSION

Switching the TACE anticancer drug from epirubicin to cisplatin might be the feasible option for advanced HCC, even when considered resistant to the initial form of TACE.