Assessment of Irinotecan Loading and Releasing Profiles of a Novel Drug-Eluting Microsphere (CalliSpheres) In Vitro

A Comparative Study of DC Beads, Callispheres and Multimodal Imaging Nano-Assembled Microspheres Loaded with Irinotecan in Vitro

Introduction: In recent years, the development of drug-eluting embolization beads that can be imaged has become a hot research topic in regard to meeting clinical needs. In our previous study, we successfully developed nano-assembled microspheres (NAMs) for multimodal imaging purposes. NAMs can not only be visualized under CT/MR/Raman imaging but can also load clinically required doses of doxorubicin. It is important to systematically compare the pharmacokinetics of NAMs with those of commercially available DC Beads and CalliSpheres to evaluate the clinical application potential of NAMs. Methods: In our study, we compared NAMs with two types of drug-eluting beads (DEBs) in terms of irinotecan, drug-loading capacity, release profiles, microsphere diameter variation, and morphological characteristics. Results: Our results indicate that NAMs had an irinotecan loading capacity similar to those of DC Beads and CalliSpheres but exhibited better sustained release in vitro. Conclusion: NAMs have great potential for application in transcatheter arterial chemoembolization for the treatment of colorectal cancer liver metastases.

An In Vitro Comparative Study of Three Drug-Eluting Beads Loaded with Raltitrexed

Background: This study investigated the raltitrexed loading method, compatible stability with contrast agent, release profiles, and morphological properties of CalliSpheres, DC Bead, and HepaSphere. Materials and Methods: The amounts of raltitrexed added, loading medium, loading condition, and drug concentrations were investigated as factors influencing drug loading efficiency. Compatible stability with iopamidol was tested. Release profiles were accessed by a flowthrough apparatus system. Morphological properties were evaluated by a scanning electron microscope (SEM). Diameters were measured by a laser diffraction particle size analyzer. Results: With the optimized method, the amount of raltitrexed loading to a marketed drug-eluting beads (DEBs) package was 2.67 mg for CalliSpheres, 2.34 mg for DC Bead, and 3.19 mg for HepaSphere. For all three DEBs, the drug leak rate was >50% within 2 h after mixing with iopamidol, and the time to reach 75% of the release plateau was within 10 min. Diameters increased after drug loading. Drug crystals were observed on the surface of DEBs in SEM. Conclusions: The amount of drug loading could meet clinical requirements by the optimized method. All three raltitrexed-loaded DEBs showed poor compatible stability with iopamidol, as well as rapid drug release performance, which should be noticed in clinical practice.

Bevacizumab-loaded CalliSpheres beads: in vitro loading, release profiles and application in rabbit liver VX2 tumor model

Background

Bevacizumab loaded drug-eluting beads have the potential to reduce TACE related VEGF expression. The purpose of this study was to investigate the in vitro loading, and release profiles of bevacizumab (BEV) loaded on Callispheres beads (CB) and its application in rabbit liver VX2 tumor model.

Methods

CB with sizes of 100-300 um and 300-500 um were divided into 5 groups, respectively. BEV with different content was prepared for CB loading, releasing and detected in the solution at different time points. The diameters of CB in each group were measured under a light microscope to calculate the shrinkage rate. The rabbit with VX2 liver model were divided into control group, CB-TACE group, CB-TACE+BEV group, and BEV group. The data of blood test, CT image, HE and IHC staining were compared and analyzed.

Results

The shrinkage rate of the 100-300 um CB was 2.6-7.2%, while the 300-500 um CB was 0.2-7.1%. The BEV-loaded CB (BEV-CB) has a burst release during the first hour and following gradually released with time. The release profiles of 100-300 um CB reach 34% in 24 hours, while the 300-500 um CB to 25.8%. BEV-CB with sizes of 100-300 um was chosen to perform transcatheter arterial chemoembolization (TACE). The results showed that BEV-CB-TACE not only gradually increased the content of BEV in serum and organ tissue but also reduced the level of VEGF in serum. Pathological results suggested that the expression of HIF-1 was elevated while VEGF and MVD decreased when compared to the other groups.

Conclusion

In conclusion, this study confirms that Callispheres beads could efficiency loaded BEV. BEV-CB-TACE has a good safety and effectiveness, and its application could reduce the level of VEGF-A in serum in the treatment of VX2 tumors.

Clinical outcomes of vinorelbine loading CalliSpheres beads in the treatment of previously treated advanced lung cancer with progressive refractory obstructive atelectasis

Background: Drug-eluting beads bronchial arterial chemoembolization (DEB-BACE) has been used in the treatment of locally advanced lung cancer and has the potential to improve outcomes and reduce recurrence. However, DEB-BACE shows a poor therapeutic effect in advanced lung cancer after failure of multiple therapies. This study assessed the effect of DEB-BACE in the treatment of progressive lung cancer with refractory obstructive atelectasis. Methods: Progressive advanced lung cancer patients with refractory obstructive atelectasis were voluntarily enrolled in this study after failure of multiple conventional therapies. Baseline information, DEB-BACE treatment process, and changes in clinical symptoms were recorded. The primary endpoints were the objective response rate (ORR) and improvement rate of dyspnea. The secondary endpoints were time-to-progression (TTP), overall survival (OS), and rate of pulmonary re-expansion. Treatment-related adverse events and serious adverse events were analyzed to assess the safety of DEB-BACE. The Cox regression model was performed to analyze the possible factors impacting prognosis of DEB-BACE. Results: DEB-BACE was successfully performed with CalliSpheres beads loaded with vinorelbine in the 20 enrolled patients. ORR and disease control rate were 80% and 85%, respectively, at the first follow-up (43.4 ± 15.26 days). The improvement rate of dyspnea was 85% and 80% at 1 week and 1 month (p < 0.0001, p < 0.0001), respectively. TTP was 41.25 ± 14.43 days and 89.55 ± 61.7 days before and after DEB-BACE, respectively; DEB-BACE delayed the progression of advanced lung cancer (p < 0.0001). OS was 238.03 ± 33.74 days (95% confidence interval: 171.9-304.16). The rate of pulmonary re-expansion was 80% at the first follow-up. The reasons for poor prognosis were tumor necrosis, longer disease duration, and pulmonary atelectasis duration (p = 0.012, p = 0.038, p = 0.029). Massive hemoptysis was observed in two cases, and one patient died of asphyxia caused by hemoptysis. Moderate hemoptysis occurred in one case. All three adverse events were considered as the result of the tumor cavity after DEB-BACE. Conclusion: DEB-BACE loaded with vinorelbine is a feasible option for progressive advanced lung cancer with obstructive atelectasis after failure of other treatments.

Efficacy and Safety of TACE Combined with Regorafenib versus TACE in the Third-Line Treatment of Colorectal Liver Metastases

BACKGROUND

The liver is the most common site of metastasis in colorectal cancer. In patients with unresectable colorectal liver metastases, the 5-year survival rate is less than 5%. Many patients with colorectal liver metastases require effective subsequent therapy after the failure of standard first-line/second-line therapy. The purpose of this study is to investigate the efficacy and safety of TACE combined with Regorafenib versus TACE in the third-line treatment of patients with colorectal liver metastases.

METHOD

The clinical data of 132 patients with colorectal liver metastases were collected. There were two groups: TACE + Regorafenib group (N = 63); TACE group (N = 69). TACE uses CalliSpheres® drug-loaded microspheres (loaded with irinotecan). Regorafenib is administered at a dose of 120 mg once daily. If the patient is severely intolerable, the regorafenib dose is adjusted to 80 mg once daily. Primary study endpoints were (1) to evaluate the tumor response, ORR, and DCR and (2) to evaluate OS and PFS in the two groups. Secondary study endpoints were (1) to compare the performance status, CEA, CA19-9 after treatment between the two groups and (2) to compare the incidence of adverse events between the two groups.

RESULTS

There were significant differences in tumor response, ORR, DCR, OS, and PFS after treatment between the two groups. TACE combined with the Regorafenib group versus the TACE group: ORR (57.1% vs 33.3%), DCR (82.5% vs 68.1%), mOS (18.2 months vs 11.3 months), and mPFS (8.9 months vs 5.3 months). The performance status after treatment was better in the TACE + Regorafenib group than in the TACE group (P < 0.05). The CEA and CA19-9 negative rates after treatment were higher in the TACE + Regorafenib group than in the TACE group (P < 0.05).

CONCLUSION

For the third-line treatment of colorectal liver metastases, the combination of TACE + Regorafenib had better tumor response, OS, and PFS than TACE TACE + Regorafenib combination could be considered as salvage therapy for colorectal liver metastases who failed the first- and second-line standard therapy.

Callispheres drug-eluting bead transhepatic artery chemoembolization with oral delivery of sorafenib for the treatment of unresectable liver cancer

Objective

Liver cancer is a significant contributor to global burden of cancer. Transcatheter arterial chemoembolization (TACE) is the standard of care for patients with unresectable liver cancer, and CalliSpheres, as novel drug-eluting bead (DEB) microspheres, have been found to be associated with a high tumor response rate. However, the outcomes after DEB-TACE treatment are not always satisfactory with tumor recurrence. Herein, we attempt to compare the clinical efficacy and safety of DEB-TACE with sorafenib and conventional TACE in treating advanced liver cancer.

Methods

The study retrospectively reviewed clinical records of 96 patients with liver cancer, among which there were 48 cases receiving DEB-TACE with sorafenib and 48 cases receiving conventional TACE. The physical properties of Callispheres were evaluated in HepG2 cells and a B6/J mouse model.

Results

DEB-TACE with Callispheres were demonstrated to effectively maintain stability and prolong the half-life of epirubicin. Compared with the patients receiving conventional TACE, those receiving DEB-TACE with sorafenib exhibited better patient outcomes with increased survival rate, reduced tumor volume, and declined levels of tumor markers. Additionally, DEB-TACE with Callispheres could effectively protect liver function, as well as reduce the toxic effects of loaded epirubicin, and its combination with sorafenib would not increase the incidence of adverse reactions.

Conclusion

DEB-TACE using CalliSpheres combined with sorafenib could prevent the progression of liver cancer and bring a better prognosis.

Treatment of unresectable intrahepatic cholangiocarcinoma using transarterial chemoembolisation with irinotecan-eluting beads: analysis of efficacy and safety

PURPOSE

This retrospective study evaluated the efficacy, safety, and factors affecting the prognosis of transarterial chemoembolisation with irinotecan-eluting beads with CalliSpheres (DEB-TACE) for intrahepatic cholangiocarcinoma (ICC).

MATERIALS AND METHODS

We retrospectively collected data on 39 patients with unresectable ICC who received DEB-TACE therapy. We assessed the indicators of tumour response, progression-free survival (PFS), overall survival (OS), and the incidence of adverse events. PFS and OS were analysed using Kaplan-Meier curves, while Cox analysis was used to identify factors affecting the prognosis.

RESULTS

The 3-month objective response rate (ORR) and disease control rate (DCR) of the 39 patients with unresectable ICC were 35.9% and 56.4%, respectively, while the 6-month ORR and DCR were 23.0% and 40.9%, respectively. The median OS and PFS were 11.0 months and 8.0 months, respectively. Cox analysis demonstrated that combined therapy (adjuvant sorafenib after DEB-TACE) and a low cancer antigen (CA) 125 level (≤ 35 U/ml) were independent favourable prognostic factors. Transient elevation of the aminotransferase level, nausea, vomiting, abdominal pain, fever, and hyper-bilirubinaemia were common adverse events in patients with unresectable ICC treated with DEB-TACE with CalliSphere beads (CBs). Hepatic abscess was the most serious complication, observed in one patient.

CONCLUSIONS

DEB-TACE with CBs is a safe and well-tolerated therapy in patients with unresectable ICC with a low incidence of adverse events and relatively prolonged survival. Combined therapy and low CA125 are prognostic factors associated with longer survival.

Donafenib-Loaded Callispheres Beads Embolization in a VX2 Liver Tumor: Investigating Efficacy, Safety, and Improvement of Tumor Angiogenesis After Embolization

Objective

To investigate the efficiency and safety of callispheres beads loaded with donafenib (DCBs) for embolization in a VX2 liver tumor, as well as the improvement of tumor angiogenesis following embolization.

Methods

Forty New Zealand white rabbit VX2 liver tumors were treated with four different drugs via the hepatic artery: NS (normal saline), CB (blank callispheres beads), ACB (adriamycin-loaded callispheres beads) and DCB (DCBs). Hematoxylin-eosin staining was performed to assess tumor necrosis, while MRI was employed to detect the changes in tumor size. The safety was evaluated by the liver and kidney function parameters, and the immunofluorescence and immunohistochemical staining were performed to reflect the tumor hypoxia and tumor angiogenesis following embolization.

Results

The DCB group had the smallest tumor growth rate, but the tumor necrosis rate was the highest of the four groups. Compared to the CB and ACB groups, the DCB group did not aggravate the liver damage and had no influence on kidney function. The staining results showed that, although the tumor hypoxia deteriorated after DCBs embolization, the expression of VEGF (vascular endothelial growth factor) reduced, thus inhibiting tumor angiogenesis.

Conclusion

DCB administration via hepatic artery is an effective and safe treatment for a preclinical liver cancer model, with the unique benefit of suppressing tumor angiogenesis following embolization.

Assessment of efficacy and safety by CalliSpheres versus HepaSpheres for drug-eluting bead transarterial chemoembolization in unresectable large hepatocellular carcinoma patients

This study aimed to compare efficacy and safety of HepaSpheres and CalliSpheres in unresectable large hepatocellular carcinoma (HCC) patients. One hundred and twenty-seven unresectable large HCC patients receiving drug-eluting bead transarterial chemoembolization (DEB-TACE) treatment with CalliSpheres or HepaSpheres microspheres were analyzed. Treatment response, Karnofsky performance status (KPS) score, adverse events, main liver function indexes, time to progression (TTP), and overall survival (OS) were analyzed. Objective response rate (82.7% vs. 63.8%, p=.030) and disease control rate (100.0% vs. 91.5%, p=.030) were increased in CalliSpheres group compared to HepaSpheres group at 1 month after treatment, while no difference was found between the two groups regarding treatment response at 3 or 6 months post treatment (all p>.05). The KPS score at 1, 3, and 6 months was similar between the two groups (all p>.05). As for the liver function, the ALT, AST, ALB, and TBIL levels at 7 and 30 days were of no difference between the two groups (all p>.05). In addition, the adverse events including nausea/vomiting, pain, fever, myelosuppression, biloma, and abscess were of no difference between the two groups, either (all p>.05). In terms of survival profile, there was no difference regarding TTP (6.3 months (95%CI: 5.9-6.6 months) vs. 6.0 months (95%CI: 5.6-6.4 months), p=.082) or OS (23.0 months (95%CI: 20.1-25.9 months) vs. 22.0 months (95%CI: 20.2-23.8 months), p=.571) between the two groups. In conclusion, CalliSpheres seems to be superior in short-term efficacy and equal in long-term efficacy as well as safety compared to HepaSpheres for DEB-TACE treatment in unresectable large HCC patients.

Optimized Loading of Idarubicin in CalliSpheres® Drug-Eluting Beads and Characterization of Release Profiles and Morphological Properties

This study aimed to investigate the idarubicin loading method, compatible stability with contrast agent, release profiles, and morphological properties of 50-150, 100-300, and 300-500 μm CalliSpheres^®. The amounts of idarubicin added, loading medium, loading condition, and drug concentration were investigated as factors influencing drug loading efficiency. The drug loading rate was negatively correlated with the amount drug added and diameter of CalliSpheres^® and positively correlated with the drug concentration. Compared to loading in purified water and incubation at room temperature, 5% glucose, heating, and ultrasound could accelerate drug loading. The idarubicin loading efficiency was above 95% after 10 min for all three CalliSpheres^® with the optimized method of adding 20 mg of idarubicin at a concentration of 2 mg/mL and incubating at room temperature. The drug leak rate was under 1% within 8 h after mixing with iopamidol. Drug release tests indicated the sustained-release performance of CalliSpheres^®, and the time to reach 75% of the release plateau level was 8, 26, and 51 min for 50-150, 100-300, and 300-500 μm CalliSpheres^®, respectively. After idarubicin loading, the diameters increased by 12%, 36%, and 38% for 50-150, 100-300, and 300-500 μm CalliSpheres^®, respectively, and the surface of CalliSpheres^® was observed to become smoother than that before drug loading. All three CalliSpheres^® presented satisfactory loading efficiency with the optimized method, as well as proper compatible stability and sustained release performance. Among them, 100-300 μm CalliSpheres^® are recommended.