Transarterial Chemoembolization Using Sorafenib in a Rabbit VX2 Liver Tumor Model: Pharmacokinetics and Antitumor Effect

Explosomes: A new modality for DEB-TACE local delivery of sorafenib: In vivo proof of sustained release

The current medical practice in treating Hepatocellular carcinoma (HCC) using Drug Eluting Transarterial chemoembolization (DEB-TACE) technique is limited only to hydrophilic ionizable drugs, that can be attached ionically to the oppositely charged beads. This limitation has forced physicians to subscribe the more hydrophobic, first treatment option drugs, like sorafenib systemically via the oral route, thus flooding the patient system with a very powerful, non-specific, multiple-receptor tyrosine kinase inhibitor that is associated with notorious side effects. In this paper, a new modality is introduced, where highly charged, drug loaded liposomes are added to oppositely charged DEBs in a manner causing them to "explode" and the drug is eventually attached to the beads in the lipid patches covering their surfaces; therefore we call them "Explosomes". After fully describing the preparation process and in vitro characterization, this manuscript delves into an in vivo pharmacokinetic study over 50 New Zealand rabbits, where explosomal loading is challenged vs oral as well as current practice of emulsifying sorafenib in lipiodol. Over 14 days of follow up, and compared to other groups, explosomal loading of SRF on embolic beads proved to cause a slower release pattern with longer Tmax, lower Cmax and less washout to general circulation in healthy animals. This treatment modality opens a new untapped door for local sustained delivery of hydrophobic drugs in catheterized organs.

A VEGFR targeting peptide-drug conjugate (PDC) suppresses tumor angiogenesis in a TACE model for hepatocellular carcinoma therapy

Transcatheter arterial chemoembolization (TACE) has become the preferred therapy for unresectable advanced hepatocellular carcinoma (HCC). However, the embolization of tumor-feeding arteries by TACE always leads to hypoxia-related tumor angiogenesis, which limited the therapeutic effect for HCC. In this paper, we used a VEGFR targeting peptide VEGF125 − 136 (QKRKRKKSRYKS) to conjugate with a lytic peptide (KLUKLUKKLUKLUK) to form a peptide-drug conjugate (PDC). We used cell affinity assay to detect the peptide binding ability to VEGFR highly expressed cell lines, and CCK8, cell apoptosis to confirm the cellular toxicity for different cell lines. Meanwhile, we created a VX2 tumor-bearing rabbit model to assess the in vivo anti-tumor effect of the peptide conjugate in combination with TAE. HE staining was used to verify the in vivo safety of the peptide conjugate. IHC was used to assess the anti-angiogenesis and cell toxicity of the peptide conjugate in tumor tissues. The peptide conjugate could not only target VEGFR in cell surface and inhibit VEGFR function, but also have potent anti-cancer effect. We luckily found the peptide conjugate showed potent cytotoxicity for liver cancer cell Huh7 (IC50 7.3 ± 0.74 μM) and endothelial cell HUVEC (IC50 10.7 ± 0.292 μM) and induced cell apoptosis of these two cell lines. We also found the peptide conjugate inhibited cell migration of HUVEC through wound healing assay. Besides, these peptides also showed better in vivo anti-tumor effect than traditional drug DOX through TACE in VX2 rabbit tumor model, and efficiently inhibit angiogenesis in tumor tissues with good safety. In conclusion, our work may provide an alternative option for clinical HCC therapy via TACE combination.

Schematic presentation of the design of VEGFR targeting peptide conjugate (QR-KLU) and the antineoplastic efficacy of peptide QR-KLU in vitro and in vivo.

Pharmacokinetics and Early Tumor Response to Conventional Transarterial Chemoembolization with Sorafenib and Doxorubicin in a VX2 Rabbit Tumor Model

PURPOSE

To investigate the pharmacokinetics (PK) and early effects of conventional transarterial chemoembolization (c-TACE) using sorafenib and doxorubicin on tumor necrosis, hypoxia markers, and angiogenesis in a rabbit VX2 liver tumor model.

MATERIALS AND METHODS

VX2 tumor-laden New Zealand White rabbits (n=16) were divided into two groups; one group was treated with hepatic arterial administration of ethiodized oil-doxorubicin emulsion (DOX-TACE), and the other group was treated with ethiodized oil, sorafenib, and doxorubicin emulsion (SORA-DOX-TACE). Animals were sacrificed within 3 days post-procedure. Levels of sorafenib and doxorubicin were measured in blood, tumor, and adjacent liver using mass spectrometry. Tumor necrosis was determined by histopathological examination. Intra-tumoral hypoxia-inducible factor 1α (HIF-1α), vascular endothelial growth factor (VEGF), and microvessel density (MVD) were determined by immunohistochemistry.

RESULTS

The median intra-tumoral concentration of sorafenib in the SORA-DOX-TACE group was 17.7 μg/mL [Interquartile range (IQR), 7.42-33.5] and its maximal plasma concentration (C_max) was 0.164 μg/mL (IQR, 0.0798-0.528). The intra-tumoral concentration and C_max of doxorubicin were similar between the groups; 4.08 μg/mL (IQR, 3.18-4.79) and 0.677 μg/mL (IQR, 0.315-1.23) in DOX-TACE, and 1.68 (IQR, 0.795-4.08) and 0.298 μg/mL (IQR, 0.241-0.64) in SORA-DOX-TACE, respectively. HIF-1α expression was increased in SORA-DOX-TACE group compared to DOX-TACE group. Tumor volume, tumor necrosis, VEGF expression, and MVD were similar between the two groups.

CONCLUSIONS

Addition of sorafenib to DOX-TACE emulsion delivered to VX2 liver tumors resulted in high intra-tumoral and low systemic concentrations of sorafenib without altering the PK of doxorubicin.

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.

Transcatheter Arterial Embolization Containing Donafenib Induces Anti-Angiogenesis and Tumoricidal CD8+ T-Cell Infiltration in Rabbit VX2 Liver Tumor

Purpose

To evaluate the effect and immune response of transcatheter arterial embolization (TAE) combined with donafenib in rabbit VX2 liver tumor model.

Materials and Methods

Thirty-six New Zealand white rabbits with VX2 liver tumor were randomly divided into three groups. The LD group was treated with the emulsion of 0.5 mL lipiodol and 4 mg donafenib via hepatic arterial administration. The LE group was treated with the emulsion of 0.5 mL lipiodol and 4 mg epirubicin. The control group was treated with the equal volume of saline. Four rabbits were euthanized in each group on day 1, 3 and 7 after treatment. The tumor growth, histological markers associated with angiogenesis and immune response were assessed by imaging and histopathology. In addition, immune modulatory cytokines included interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and biochemical hepatorenal function were measured.

Results

Compared to other groups, LD group achieved lower tumor growth rate, fewer metastatic lesions, and higher tumor necrosis rate on day 7 after treatment. The percentage of CD31-positive area in the LD group was significantly lower than that in the LE group on day 3 and 7 after treatment. In addition, CD8⁺ lymphocytes infiltration was more pronounced in LD group than in LE group on day 7 after treatment, regardless of in the tumor or adjacent liver tissue. Serum cytokines including IL-6, TNF-α and IFN-γ were strongly upregulated in the LD group on day 1 after treatment. And there was no significant difference in the hepatorenal function between LD group and LE group after treatment.

Conclusion

The combination of TAE and angiogenesis inhibitor donafenib resulted in a potentiated tumoricidal effect, anti-angiogenesis and antitumour T cell response in rabbit VX2 liver tumor model. This may provide a potential basis for exploring the immune-related mechanisms of embolization in liver cancer.

Transarterial Embolization of Liver Cancer in a Transgenic Pig Model

PURPOSE

To develop and characterize a porcine model of liver cancer that could be used to test new locoregional therapies.

MATERIALS AND METHODS

Liver tumors were induced in 18 Oncopigs (transgenic pigs with Cre-inducible TP53^R167H and KRAS^G12D mutations) by using an adenoviral vector encoding the Cre-recombinase gene. The resulting 60 tumors were characterized on multiphase contrast-enhanced CT, angiography, perfusion, micro-CT, and necropsy. Transarterial embolization was performed using 40-120 μm (4 pigs) or 100-300 μm (4 pigs) Embosphere microspheres. Response to embolization was evaluated on imaging. Complications were determined based on daily clinical evaluation, laboratory results, imaging, and necropsy.

RESULTS

Liver tumors developed at 60/70 (86%) inoculated sites. Mean tumor size was 2.1 cm (range, 0.3-4 cm) at 1 week. Microscopically, all animals developed poorly differentiated to undifferentiated carcinomas accompanied by a major inflammatory component, which resembled undifferentiated carcinomas of the human pancreatobiliary tract. Cytokeratin and vimentin expression confirmed epithelioid and mesenchymal differentiation, respectively. Lymph node, lung, and peritoneal metastases were seen in some cases. On multiphase CT, all tumors had a hypovascular center, and 17/60 (28%) had a hypervascular rim. After transarterial embolization, noncontrast CT showed retained contrast medium in the tumors. Follow-up contrast-enhanced scan showed reduced size of tumors after embolization using either 40-120 μm or 100-300 μm Embosphere microspheres, while untreated tumors showed continued growth.

CONCLUSIONS

Liver tumors can be induced in a transgenic pig and can be successfully treated using bland embolization.

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-loaded poly (lactide-co-glycolide) microspheres designed to improve transarterial chemoembolization therapy for hepatocellular carcinoma

Transarterial chemoembolization (TACE) has been widely introduced to treat hepatocellular carcinoma (HCC) especially for unresectable patients for decades. However, TACE evokes an angiogenic response due to the secretion of vascular endothelial growth factor (VEGF), resulting in the formation of new blood vessels and eventually tumor recurrence. Thus, we aimed to develop regorafenib (REGO)-loaded poly (lactide-co-glycolide) (PLGA) microspheres that enabled localized and sustained drug delivery to limit proangiogenic responses following TACE in HCC treatment. REGO-loaded PLGA microspheres were prepared using the emulsion-solvent evaporation/extraction method, in which DMF was selected as an organic phase co-solvent. Accordingly, we optimized the proportion of DMF, which the optimal ratio to DCM was 1:9 (v/v). After preparation, the microspheres provided high drug loading capacity of 28.6%, high loading efficiency of 91.5%, and the average particle size of 149 µm for TACE. IR spectra and XRD were applied to confirming sufficient REGO entrapment. The in vitro release profiles demonstrated sustained drug release of microspheres for more than 30 d To confirm the role of REGO-loaded microspheres in TACE, the cell cytotoxic activity on HepG2 cells and anti-angiogenic effects in HUVECs Tube-formation assay were studied in combination with miriplatin. Moreover, the microspheres indicated the potential of antagonizing miriplatin resistance of HepG2 cells in vitro. Pharmacokinetics preliminary studies exhibited that REGO could be sustainably released from microspheres for more than 30 d after TACE in vivo. In vivo anti-tumor efficacy was further determined in HepG2 xenograft tumor mouse model, demonstrating that REGO microspheres could improve the antitumor efficacy of miriplatin remarkably compared with miriplatin monotherapy. In conclusion, the obtained REGO microspheres demonstrated promising therapeutic effects against HCC when combined with TACE.

Mechanism of Action, Pharmacokinetics, Efficacy, and Safety of Transarterial Therapies Using Ethiodized Oil: Preclinical Review in Liver Cancer Models

PURPOSE

To systematically review mechanism of action, pharmacokinetics (PKs), efficacy, and safety of ethiodized oil-based locoregional therapy (LRT) for liver cancer in preclinical models.

MATERIALS AND METHODS

A MEDLINE search was performed from 1988 to 2016. Search terms included hepatocellular carcinoma (HCC), HCC, liver-cell carcinoma, liver, hepatic, hepatocarcinoma, transarterial or chemoembolization, TACE, animal, Lipiodol, Ethiodol, iodized oil, and/or poppy-seed oil. Inclusion criteria were: publication in a peer-reviewed journal, an accepted animal model, and PK/safety/efficacy data reported. Exclusion criteria were: inadequate PK, safety, or efficacy data; anticancer drug name/dose not available; and article not in English. Outcomes included intratumoral anticancer drug uptake, PKs, tolerance, tumor response, and survival.

RESULTS

Of 102 identified articles, 49 (49%) met the inclusion criteria. Seventeen, 35, and 2 articles used rat, rabbit, and pig models. Mechanism of action was investigated in 11 articles. Eleven articles reported drug uptake, PK, and tolerance data, showing 0.5%-9.5% of injected chemotherapy dose in tumor. Tumor-to-liver drug distribution ratios were 2-157. Toxicology data across 6 articles showed transient liver laboratory level elevations 1 day after LRT. There was no noteworthy liver or extrahepatic histologic damage. Nine articles reported tumor response, with 0%-30% viable tumor and -10% to -38% tumor growth at 7 days after LRT. Two articles reported survival, showing significantly longer survival after LRT vs untreated controls (56/60 d vs 33/28 d). Several articles described ethiodized oil mixed with radiopharmaceutical (n = 7), antiangiogenic (n = 6), gene (n = 6), nanoembolic (n = 5), immune (n = 2), or other novel (n = 1) agents.

CONCLUSIONS

Animal studies show preferential tumor uptake of anticancer agent, good hepatic/systemic tolerance, high tumor response, and enhanced survival after ethiodized oil-based LRT.