Liproca Depot: A New Antiandrogen Treatment for Active Surveillance Patients.

BACKGROUND: There is increasing interest in nonmorbid treatments for low- and intermediate-risk prostate cancer with fewer side effects than surgery or radiotherapy. OBJECTIVE: To investigate the tolerability, safety, and antitumor effects of the intraprostatic NanoZolid depot formulation Liproca Depot (LIDDS AB, Uppsala, Sweden) with antiandrogen 2-hydroxyflutamide (2-HOF) in men with low- or intermediate-risk localized prostate cancer managed with active surveillance. DESIGN, SETTING, AND PARTICIPANTS: This clinical phase 2b trial, LPC-004, involved 61 patients. The 2-HOF-containing formulation Liproca Depot was injected transrectally into the prostate under ultrasound guidance. A single dose of 35% or 45% of the prostate volume (study part 1) and a fixed dose of 16 or 20 ml (study part 2) of the formulation were evaluated. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES: The primary endpoints were tolerability and the reduction in serum prostate-specific antigen (PSA) 5 mo after injection. Antitumor effects were evaluated with magnetic resonance imaging (MRI) and prostate biopsies. Quality of life was assessed using a validated questionnaire (International Prostate Symptom Score). RESULTS AND LIMITATIONS: All doses were safe and well tolerated, without hormonal side effects. In part 2 of the study, the PSA reduction was greatest for the group receiving 16 ml, with an average decrease of 14%, and 95% of patients had a PSA reduction. Some 78% of patients showed a prostate volume decrease compared to baseline. Prostate MRI and biopsies confirmed stable or reduced lesion size. However, post treatment biopsies were performed at the discretion of the investigator, and not routinely. Most patients were amenable to a second injection. CONCLUSIONS: PSA and prostate volume decreased in most patients. Indications of efficacy were shown by post-treatment MRI and biopsies demonstrating stabilization or regression in the majority of cases. PATIENT SUMMARY: Liproca Depot is a safe, minimally invasive treatment that offers the potential for cancer control in patients with intermediate-risk prostate cancer. Further clinical evaluation is warranted.

Biodistribution of fluorescence-labelled EGF protein from slow release NanoZolid depots in mouse.

AIM: The study was designed to evaluate the ability of the calcium sulfate based NanoZolid® drug delivery technology to locally release the epidermal growth factor (EGF) protein while maintaining its biological activity. METHODS: NanoZolid-formulated EGF protein labelled with a near infrared dye (EGF-NIR) depots or EGF-NIR dissolved in PBS were injected subcutaneously into mice bearing EGF receptor (EGFR) positive human A549 lung cancer tumors inoculated subcutaneously. The release and biodistribution of the EGF-NIR were investigated in vivo longitudinally up to 96 h post administration, utilizing whole body fluorescence imaging. In order to confirm the in vivo findings, histological analysis of tumor cryosections was performed to investigate EGF-NIR fluorescent signal and EGFR expression level by immunofluorescence labelling. RESULTS: The in vivo fluorescence imaging showed a controlled release profile of the EGF-NIR loaded in the NanoZolid depots compared to free EGF-NIR. Histological analysis of the tumors further demonstrated a prevailing distribution of EGF-NIR in regions with high levels of EGFR expression. CONCLUSION: Calcium sulfate based depots can be used to formulate EGF while maintaining its biological activity, e.g. receptor binding capability. This may have a good clinical potential for local delivery of biomolecules to enhance treatment efficacy and minimize systemic adverse effects.

An Intraprostatic Modified Release Formulation of Antiandrogen 2-Hydroxyflutamide for Localized Prostate Cancer.

PURPOSE: We investigated the tolerability, safety and antitumor effects of a novel intraprostatic depot formulation of antiandrogen 2-hydroxyflutamide (in NanoZolid®) in men with localized prostate cancer. MATERIALS AND METHODS: Two clinical trials, LPC-002 and LPC-003, were performed in a total of 47 men. The formulation was injected transrectally into the prostate under ultrasound guidance. In LPC-002 the effects on prostate specific antigen and prostate volume were measured for 6 months in 24 patients. In LPC-003 antitumor effects were evaluated by histopathology and magnetic resonance imaging including spectroscopy during 6 or 8 weeks in 23 patients. In each study testosterone and 2-hydroxyflutamide in plasma were measured as well as quality of life parameters. RESULTS: In LPC-002 (mean dose 690 mg) a reduction was observed in prostate specific antigen and prostate volume. Average nadir prostate specific antigen and prostate volume were 24.9% and 14.0% below baseline, respectively. When increasing the dose in LPC-003 to 920 and 1,740 mg, average prostate specific antigen decreased 16% and 23% after 6 and 8 weeks, respectively. Magnetic resonance imaging and magnetic resonance spectroscopy showed morphological changes and a global reduction in metabolite concentrations following treatment, indicating an antitumor response. Injections did not result in hormone related side effects. Three serious adverse events were reported and all resolved with oral antibiotic treatment. CONCLUSIONS: Intraprostatic injections of 2-hydroxyflutamide depot formulations showed antitumor effects, and proved to be safe and tolerable. However, for better anticancer effects higher doses and better dose distribution are suggested.

Antitumoral effect and reduced systemic toxicity in mice after intra-tumoral injection of an in vivo solidifying calcium sulfate formulation with docetaxel.

BACKGROUND: Docetaxel is a cytostatic agent approved for treatment of non-small cell lung cancer as well as other cancers. Although docetaxel is an effective cytostatic agent, its effectiveness in clinical practice is associated with a variety of acute and long term side-effects. To overcome systemic side-effects, a slow release formulation based on calcium sulfate with docetaxel for intra-tumoral administration was developed. METHODS: Two formulations with the calcium sulfate NanoZolid technology were generated with a twofold difference in docetaxel drug load. The formulations were injected intra-tumorally as a paste which solidified within the tumor. The effects of the two intra-tumoral injection formulations were tested in female mice (n=60) inoculated with subcutaneous Lewis lung carcinoma cells. The two formulations were compared to systemic intraperitoneal injection of docetaxel and a placebo formulation without docetaxel. Tumor volumes were measured and systemic side-effects were evaluated using body weight and cell counts from whole blood as well as plasma concentrations. RESULTS: Both docetaxel formulations showed a significantly higher antitumor efficacy compared to placebo, which was comparable to that of systemic administration of docetaxel. Moreover, the intra-tumoral formulations with docetaxel showed reduced systemic toxicity compared to systemic treatment, including less weight loss and no decrease in blood cell counts. CONCLUSIONS: The results suggest that intra-tumoral slow release calcium sulfate based formulations with docetaxel can be an alternative strategy as an efficient local antitumoral treatment with reduced systemic toxicity.

Pharmacokinetics of an injectable modified-release 2-hydroxyflutamide formulation in the human prostate gland using a semiphysiologically based biopharmaceutical model.

The local distribution of 2-hydroxyflutamide (2-HOF) in prostate tissue after a single intraprostatic injection of a novel parenteral modified-release (MR) formulation in patients with localized prostate cancer was estimated using a semiphysiologically based biopharmaceutical model. Plasma concentration-time profiles for 2-HOF were acquired from a phase II study in 24 patients and the dissolution of the MR formulation was investigated in vitro. Human physiological values and the specific physicochemical properties of 2-HOF were obtained from the literature or calculated via established algorithms. A compartmental modeling approach was adopted for tissue and blood in the prostate gland, where the compartments were modeled as a series of concentric spherical shells contouring the centrally positioned depot formulation. Discrete fluid connections between the blood compartments were described by the representative flow of blood, whereas the mass transport of drug from tissue to tissue and tissue to blood was described by a one-dimensional diffusion approximation. An empirical dissolution approach was adopted for the release of 2-HOF from the formulation. The model adequately described the plasma concentration-time profiles of 2-HOF. Predictive simulations indicated that the local tissue concentration of 2-HOF within a distance of 5 mm from the depot formulation was approximately 40 times higher than that of unbound 2-HOF in plasma. The simulations also indicated that spreading the formulation throughout the prostate gland would expose more of the gland and increase the overall release rate of 2-HOF from the given dose. The increased release rate would initially increase the tissue and plasma concentrations but would also reduce the terminal half-life of 2-HOF in plasma. Finally, an in vitro-in vivo correlation of the release of 2-HOF from the parenteral MR formulation was established. This study shows that intraprostatic 2-HOF concentrations are significantly higher than systemic plasma concentrations and that increased distribution of 2-HOF throughout the gland, using strategic imaging-guided administration, is possible. This novel parenteral MR formulation, thus, facilitates good pharmacological effect while minimizing the risk of side effects.

Treatment of intermediate stage hepatocellular carcinoma: a review of intrahepatic doxorubicin drug-delivery systems.

The biopharmaceutical properties of doxorubicin delivered via two drug-delivery systems (DDSs) for the palliative treatment of unresectable hepatocellular carcinoma were reviewed with relation to the associated liver and tumor (patho)physiology. These two DDSs, doxorubicin emulsified with Lipiodol(®) and doxorubicin loaded into DC Bead(®) are different regarding tumor delivery, release rate, local bioavailability, if and how they can be given repeatedly, biodegradability, length of embolization and safety profile. There have been few direct head-to-head comparisons of these DDSs, and in-depth investigations into their in vitro and in vivo performance is warranted.

Investigation of hepatobiliary disposition of doxorubicin following intrahepatic delivery of different dosage forms.

Unresectable, intermediate stage hepatocellular carcinoma (HCC) is often treated palliatively in humans by doxorubicin (DOX). The drug is administered either as a drug-emulsified-in-Lipiodol (DLIP) or as drug loaded into drug eluting beads (DEB), and both formulations are administered intrahepatically. However, several aspects of their in vivo performance in the liver are still not well-understood. In this study, DLIP and DEB were investigated regarding the local and systemic pharmacokinetics (PK) of DOX and its primary metabolite doxorubicinol (DOXol). An advanced PK-multisampling site acute in vivo pig model was used for simultaneous sampling in the portal, hepatic, and femoral veins and the bile duct. The study had a randomized, parallel design with four treatment groups (TI-TIV). TI (n = 4) was used as control and received an intravenous (i.v.) infusion of DOX as a solution. TII and TIII were given a local injection in the hepatic artery with DLIP (n = 4) or DEB (n = 4), respectively. TIV (n = 2) received local injections of DLIP in the hepatic artery and bile duct simultaneously. All samples were analyzed for concentrations of DOX and DOXol with UPLC-MS/MS. Compared to DLIP, the systemic exposure for DOX with DEB was reduced (p < 0.05), in agreement with a slower in vivo release. The approximated intracellular bioavailability of DOX during 6 h appeared to be lower for DEB than DLIP. Following i.v. infusion (55 min), DOX had a liver extraction of 41 (28-53)%, and the fraction of the dose eliminated in bile of DOX and DOXol was 20 (15-22)% and 4.2 (3.2-5.2)%, respectively. The AUCbile/AUCVP for DOX and DOXol was 640 (580-660) and 5000 (3900-5400), respectively. In conclusion, DLIP might initially deliver a higher hepatocellular concentration of DOX than DEB as a consequence of its higher in vivo release rate. Thus, DLIP delivery results in higher intracellular peak concentrations that might correlate with better anticancer effects, but also higher systemic drug exposure and safety issues.