Doxorubicin Drug-Eluting Embolic Chemoembolization of Hepatocellular Carcinoma: Study of Midterm Doxorubicin Delivery in Resected Liver Specimens

Biodegradable Microembolics with Nanografted Polyanions Enable High-Efficiency Drug Loading and Sustained Deep-Tumor Drug Penetration for Locoregional Chemoembolization Treatment

Transarterial chemoembolization (TACE), the mainstay treatment of unresectable primary liver cancer that primarily employs nondegradable drug-loaded embolic agents to achieve synergistic vascular embolization and locoregional chemotherapy effects, suffers from an inferior drug burst behavior lacking long-term drug release controllability that severely limits the TACE efficacy. Here we developed gelatin-based drug-eluting microembolics grafted with nanosized poly(acrylic acid) serving as a biodegradable ion-exchange platform that leverages a counterion condensation effect to achieve high-efficiency electrostatic drug loading with electropositive drugs such as doxorubicin (i.e., drug loading capacity >34 mg/mL, encapsulation efficiency >98%, and loading time <10 min) and an enzymatic surface-erosion degradation pattern (∼2 months) to offer sustained locoregional pharmacokinetics with long-lasting deep-tumor retention capability for TACE treatment. The microembolics demonstrated facile microcatheter deliverability in a healthy porcine liver embolization model, superior tumor-killing capacity in a rabbit VX2 liver cancer embolization model, and stabilized extravascular drug penetration depth (>3 mm for 3 months) in a rabbit ear embolization model. Importantly, the microembolics finally exhibited vessel remodeling-induced permanent embolization with minimal inflammation responses after complete degradation. Such a biodegradable ion-exchange drug carrier provides an effective and versatile strategy for enhancing long-term therapeutic responses of various local chemotherapy treatments.

A 3D Tumor-Mimicking In Vitro Drug Release Model of Locoregional Chemoembolization Using Deep Learning-Based Quantitative Analyses

Primary liver cancer, with the predominant form as hepatocellular carcinoma (HCC), remains a worldwide health problem due to its aggressive and lethal nature. Transarterial chemoembolization, the first-line treatment option of unresectable HCC that employs drug-loaded embolic agents to occlude tumor-feeding arteries and concomitantly delivers chemotherapeutic drugs into the tumor, is still under fierce debate in terms of the treatment parameters. The models that can produce in-depth knowledge of the overall intratumoral drug release behavior are lacking. This study engineers a 3D tumor-mimicking drug release model, which successfully overcomes the substantial limitations of conventional in vitro models through utilizing decellularized liver organ as a drug-testing platform that uniquely incorporates three key features, i.e., complex vasculature systems, drug-diffusible electronegative extracellular matrix, and controlled drug depletion. This drug release model combining with deep learning-based computational analyses for the first time permits quantitative evaluation of all important parameters associated with locoregional drug release, including endovascular embolization distribution, intravascular drug retention, and extravascular drug diffusion, and establishes long-term in vitro-in vivo correlations with in-human results up to 80 d. This model offers a versatile platform incorporating both tumor-specific drug diffusion and elimination settings for quantitative evaluation of spatiotemporal drug release kinetics within solid tumors.

Initial Transarterial Chemoembolization (TACE) Using HepaSpheres 20-40 µm and Subsequent Lipiodol TACE in Patients with Hepatocellular Carcinoma > 5 cm

Purpose: To investigate clinical outcomes of drug-eluting bead transarterial chemoembolization (DEB-TACE) using HepaSpheres 20–40 µm in diameter and subsequent cisplatin-based lipiodol TACE (Cis-TACE) in patients with hepatocellular carcinoma (HCC) > 5 cm. Materials and Methods: This study included 39 consecutive patients (34 men, 5 women; mean age, 63.5 years; range, 39–80 years) who underwent DEB-TACE using HepaSpheres 20–40 µm as first-line treatment for HCC > 5 cm (mean diameter, 8.2 cm; range, 5.1–13 cm) between September 2018 and August 2019. Patients with new tumors, residual tumors, or tumor growth after initial DEB-TACE underwent subsequent Cis-TACE. Results: All 39 patients underwent initial DEB-TACE successfully, with 35 (89.7%) and three (7.7%) patients experiencing minor and major complications, respectively. After initial DEB-TACE, one patient (2.6%) achieved complete response (CR), 35 (89.7%) achieved partial response (PR), and three (7.7%) experienced progressive disease (PD). During a median follow-up period of 14.4 months (range, 0.6–23 months), 23 patients underwent Cis-TACE, with 11, three, and nine achieving CR, PR, and PD, respectively. The median overall survival time was 20.9 months (95% confidence interval (CI), 18.6–23.2 months), the median time to progression was 8.8 months (95% CI, 6.5–11.1 months), and the median time to local tumor recurrence was 16 months (95% CI, 7.4–24.6 months). Conclusions: DEB-TACE using HepaSpheres 20–40 µm in diameter can be a safe and effective initial treatment method in patients with HCC > 5 cm. Subsequent Cis-TACE constitutes a good adjuvant method to enhance tumor response after initial DEB-TACE.

Drug-Eluting Microsphere Versus Cisplatin-Based Transarterial Chemoembolization for the Treatment of Hepatocellular Carcinoma: Propensity Score-Matched Analysis

OBJECTIVE. The purpose of this study was to compare the safety and efficacy of transarterial chemoembolization (TACE) with 30- to 60-μm drug-eluting microspheres with those of cisplatin-based TACE in the treatment of unresectable hepatocellular carcinoma (HCC). MATERIALS AND METHODS. This retrospective single-center study included 607 patients who underwent drug-eluting microsphere (30-60 μm, loaded with doxorubicin) TACE (n = 119) or cisplatin-based TACE (n = 488) as first-line treatment of unresectable HCC between April 2017 and April 2018. With a propensity model correcting for selection bias, patients were selected from each treatment group to compare the effectiveness of drug-eluting microsphere TACE with that of cisplatin TACE. RESULTS. In the entire study population, the rates of major complications (1.7% vs 1.8%, p > 0.999), objective tumor response (80.7% vs 79.7%, p = 0.899), and time to progression (p = 0.536) were not significantly different between the drug-eluting microsphere TACE and cisplatin TACE groups. However, the drug-eluting microsphere TACE group had significantly higher objective tumor regression rates in subgroups with Barcelona Clinic Liver Cancer (BCLC) stage C disease (p = 0.033) and a maximal tumor size larger than 5 cm (p = 0.011). After adjustment by propensity score matching, the rates of major complications, objective tumor response, and time to progression remained similar between the two groups. CONCLUSION. Both TACE with 30- to 60-μm drug-eluting microspheres and cisplatin TACE were safe and effective for treating unresectable HCC. In patients with BCLC stage C disease and patients with large (> 5 cm) HCCs, TACE with 30- to 60-μm drug-eluting micro-spheres may have a better chance of obtaining an objective tumor response than conventional TACE performed with the protocol used in this study.

Porcine and Human In Vivo Simulations for Doxorubicin-Containing Formulations Used in Locoregional Hepatocellular Carcinoma Treatment

It is important to be able to simulate and predict formulation effects on the pharmacokinetics of a drug in order to optimize effectivity in clinical practice and drug development. Two formulations containing doxorubicin are used in the treatment of hepatocellular carcinoma (HCC): a Lipiodol-based emulsion (LIPDOX) and a loadable microbead system (DEBDOX). Although equally effective, the formulations are vastly different, and little is known about the parameters affecting doxorubicin release in vivo. However, mathematical modeling can be used to predict doxorubicin release properties from these formulations and its in vivo pharmacokinetic (PK) profiles. A porcine semi-physiologically based pharmacokinetic (PBPK) model was scaled to a human physiologically based biopharmaceutical (PBBP) model that was altered to include HCC. DOX in vitro and in vivo release data from LIPDOX or DEBDOX were collected from the literature and combined with these in silico models. The simulated pharmacokinetic profiles were then compared with observed porcine and human HCC patient data. DOX pharmacokinetic profiles of LIPDOX-treated HCC patients were best predicted from release data sets acquired by in vitro methods that did not use a diffusion barrier. For the DEBDOX group, the best predictions were from the in vitro release method with a low ion concentration and a reduced loading dose. The in silico modeling combined with historical release data was effective in predicting in vivo plasma exposure. This can give useful insights into the release method properties necessary for correct in vivo predictions of pharmacokinetic profiles of HCC patients dosed with LIPDOX or DEBDOX.