Pegylated liposomal doxorubicin in the management of ovarian cancer

Dual-loaded liposomal carriers to combat chemotherapeutic resistance in breast cancer

INTRODUCTION

The resistance to chemotherapy is a significant hurdle in breast cancer treatment, prompting the exploration of innovative strategies. This review discusses the potential of dual-loaded liposomal carriers to combat chemoresistance and improve outcomes for breast cancer patients.

AREAS COVERED

This review discusses breast cancer chemotherapy resistance and dual-loaded liposomal carriers. Drug efflux pumps, DNA repair pathways, and signaling alterations are discussed as chemoresistance mechanisms. Liposomes can encapsulate several medicines and cargo kinds, according to the review. It examines how these carriers improve medication delivery, cancer cell targeting, and tumor microenvironment regulation. Also examined are dual-loaded liposomal carrier improvement challenges and techniques.

EXPERT OPINION

The use of dual-loaded liposomal carriers represents a promising and innovative strategy in the battle against chemotherapy resistance in breast cancer. This article has explored the various mechanisms of chemoresistance in breast cancer, emphasizing the potential of dual-loaded liposomal carriers to overcome these challenges. These carriers offer versatility, enabling the encapsulation and precise targeting of multiple drugs with different modes of action, a crucial advantage when dealing with the complexity of breast cancer treatment.

Phase I study of pegylated liposomal doxorubicin and cisplatin in patients with advanced osteosarcoma

PURPOSE

The repeated use of doxorubicin is limited due to dose-limiting cardiac toxicity. Pegylated liposomal doxorubicin (PEG-LD, Duomeisu) has a reduced cardiac toxicity. This phase I study aimed to investigate the maximum tolerated doses (MTDs) and dose-limiting toxicities (DLTs) of the PEG-LD and cisplatin combination in patients with metastatic and recurrent osteosarcoma.

METHODS

Patients were given PEG-LD at a dose of 40, 50, or 60 mg/m² on day 1 of each 21-day cycle, according to a 3 + 3 approach for dose escalation. Cisplatin was administered as a fixed dose of 100 mg/m² for every cycle. Toxicities and tumor response were observed.

RESULTS

A total of 15 patients were enrolled in this trial, and nine of the patients had received prior doxorubicin. The MTD of PEG-LD was reached at 50 mg/m² in this regimen, with neutropenic fever and stomatitis as DTLs. The main adverse event (AE) was myelosuppression. The most common non-hematological AEs were vomiting, hypoproteinemia, stomatitis and transient sinus arrhythmia. Grade 3-4 toxicity was neutropenia, leukopenia, thrombocytopenia, anemia and stomatitis in the whole cohort. All the AEs were relieved after symptomatic and supportive treatment. Totally, the overall response rate was 13.3% and disease control rate was 66.7%. For the six patients who have not received prior doxorubicin, one partial response and five stable diseases were observed.

CONCLUSION

We provide the data showing that PEG-LD 50 mg/m² combined with cisplatin 100 mg/m² demonstrated an acceptable safety profile and promising clinical activity in advanced osteosarcoma, which merits further evaluation in phase II studies.

TRIAL REGISTRATION

ChiCTR1900021550.

Pegylated liposomal doxorubicin-related palmar-plantar erythrodysesthesia: a literature review of pharmaceutical and clinical aspects

OBJECTIVES

The rate of dermal toxicity has been shown to increase in patients receiving pegylated liposomal doxorubicin (PLD), particularly palmar-plantar erythrodysesthesia (PPE). However, it is difficult to diagnose and treat PLD-related PPE due to its delayed dermal performance, unclear pathogenetic mechanism, and the lack of specific preventive measures. The aim of this study was to provide potential management strategies for PPE associated with PLD.

METHODS

The current article reviews the available data regarding the pharmacological and clinical aspects of PLD, including the formulation and pharmacokinetics of PLD, dose and schedule contribution to PPE, concomitant drugs affecting skin toxicity of PLD, the pathogenesis of PPE, and preventive measures and treatment of PLD-related PPE.

RESULTS

The long circulation structure of polyethylene glycol liposomes may be one of the reasons for PPE. PLD has radically different pharmacokinetic characteristics, including prolonged blood circulation time, decreased body distribution volume, and slow clearance. Altering the schedules and doses of PLD or combining it with platinum compounds can optimise clinical efficacy and minimise the occurrence of PPE. Doses of 150-200 mg of pyridoxine daily have been widely used for the prevention and treatment of PPE. Regional cooling and plasma filtration have been used for PPE prophylaxis.

CONCLUSIONS

To date, the mechanism of PPE induced by PLD remains unclear, and no complete preventive medication has been established. Further research and prospective randomised studies are needed to understand the management options in PLD-related PPE.

Preclinical immunotherapy with Cytokine-Induced Killer lymphocytes against epithelial ovarian cancer

Despite improvements in surgery and medical treatments, epithelial ovarian cancer (EOC) remains the most lethal gynaecological malignancy. Aim of this study is to investigate the preclinical immunotherapy activity of cytokine-induced killer lymphocytes (CIK) against epithelial ovarian cancers, focusing on platinum-resistant settings. We generated CIK ex vivo starting from human peripheral blood samples (PBMCs) collected from EOC patients. Their antitumor activity was tested in vitro and in vivo against platinum-resistant patient-derived ovarian cancer cells (pdOVCs) and a Patient Derived Xenograft (PDX), respectively. CIK were efficiently generated (48 fold median ex vivo expansion) from EOC patients; pdOVCs lines (n = 9) were successfully generated from metastatic ascites; the expression of CIK target molecules by pdOVC confirmed pre and post treatment in vitro with carboplatin. The results indicate that patient-derived CIK effectively killed autologous pdOVCs in vitro. Such intense activity was maintained against a subset of pdOVC that survived in vitro treatment with carboplatin. Moreover, CIK antitumor activity and tumor homing was confirmed in vivo within an EOC PDX model. Our preliminary data suggest that CIK are active in platinum resistant ovarian cancer models and should be therefore further investigated as a new therapeutic option in this extremely challenging setting.

In Vivo and In Vitro Anticancer Activity of Doxorubicin-loaded DNA-AuNP Nanocarrier for the Ovarian Cancer Treatment

In this study, we have determined the anticancer activity of doxorubicin (Dox)-loaded DNA/gold nanoparticle (AuNP) nanocarrier (Dox-DNA-AuNP) for the treatment of ovarian cancer. The anticancer effect of Dox-DNA-AuNP was evaluated in vitro using the EZ-Cytox cell viability assay on three human ovarian cancer cell lines, SK-OV-3, HEY A8, and A2780. Dox-DNA-AuNP exhibited outstanding activity with good IC50 values of 4.8, 7.4, and 7.6 nM for SK-OV-3, HEY A8, and A2780, respectively. In vivo evaluation further demonstrated the superior anticancer effects of Dox-DNA-AuNP by inhibiting tumor growth compared to free Dox in an established SK-OV-3 xenograft mice model. Dox-DNA-AuNP showed about a 2.5 times higher tumor growth inhibition rate than free Dox. Furthermore, the immunohistochemical analysis of Ki67 antigen expression showed the lowest number of proliferative cells in the ovarian tumor tissue treated with Dox-DNA-AuNP. These results suggest Dox-DNA-AuNP might be a potential effective agent in ovarian cancer chemotherapy.

The use of ex vivo ovary culture for assessment of alterations in steroidogenesis following neonatal exposure to poly(ethylene glycol)-block-polylactide methyl ether or titanium dioxide nanoparticles in Wistar rats

Objectives. Rapid development and widespread application of different types of nanoparticles (NPs) may result in increased exposure of humans and animals to NPs. Recently, reproductive toxicity due to NP exposure has become a major component of risk assessment. Current data have suggested that NPs may pose adverse effects on male and female reproductive health by altering normal testis and ovarian structure, and sex hormone levels. To detect possible alterations in steroidogenesis in adult and infantile rats following neonatal exposure to polymeric poly(ethylene glycol)-block-polylactide methyl ether (PEG-b-PLA) or titanium dioxide (TiO2) NPs, whole ovary cultures were used.

Methods. Newborn female Wistar rats were intraperitoneally (i.p.) injected daily with two different doses of PEG-b-PLA NPs (20 and 40 mg/kg body weight, b.w.) or TiO2 NPs (1% LD50 TiO2=59.2 µg/kg b.w. and 10% LD50 TiO2=592 µg/kg b.w.) from postnatal day 4 (PND 4) to PND 7. The ovaries were collected on PND73 and PND15 of PEG-b-PLA- and TiO2 NP-treated rats, respectively, and their corresponding control animals. Minced ovaries were cultured in vitro in the absence (basal conditions) or presence of gonadotropins (follicle-stimulating hormone, FSH and luteinizing hormone, LH) and insulin-like growth factor-1 (IGF-1) (stimulated conditions) for 6 days. At indicated time intervals, culture media were collected for steroid hormone (progesterone, estradiol) analysis by specific radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) kits.

Results. Basal progesterone and estradiol secretion by ovaries from adult rats (PND73) were significantly decreased (p<0.01) in both PEG-b-PLA-treated groups after 3 days and 1 day of ex vivo ovary culture, respectively, compared with control group. With the presence of FSH/LH and IGF-1 in the culture medium, progesterone and estradiol production significantly increased (p<0.001) compared to basal levels. Stimulated progesterone production was significantly decreased (p<0.05) in PEG-b-PLA40-treated group after 3 days of culture compared with controls. After ex vivo culture of rat ovaries collected on PND15, basal progesterone and estradiol levels measured in the culture media did not differ between control and both TiO2 NP-treated groups. The ovaries from rats neonatally exposed to both doses of TiO2 NPs failed to respond to FSH/IGF stimulation in progesterone secretion at all time intervals.

Conclusions. The obtained results indicate that neonatal exposure to NPs in female rats may alter ovarian steroidogenic output (steroid hormone secretion) and thereby might subsequently induce perturbation of mammalian reproductive functions. Possible mechanisms (induction of oxidative stress, inflammation) of adverse effects of NPs on ovarian function should be further elucidated.

Drug eruptions associated with tumor therapy: Great imitators

Many studies have investigated cutaneous reactions to antitumor drugs and found them to be quite numerous. We describe drug eruptions that may be associated with different therapies by class: antimetabolite chemotherapeutics, genotoxic agents, spindle inhibitors, signal transduction inhibitors, and immunotherapies. Methotrexate is most often associated with mucocutaneous reactions, alkylating antimetabolite agents with hyperpigmentation, and platinum antimetabolite agents with type I IgE-mediated hypersensitivity reactions. Anthracycline derivatives can induce the hand-foot syndrome in patients, and bleomycin is associated with a bleomycin-induced flagellate erythema. Taxane spindle inhibitors can result in acneiform eruptions, which may also be seen with use of epidermal growth factor receptor inhibitors. Imatinib and its derivatives can cause a truncal maculopapular eruption, whereas multikinase inhibitors can produce a hand-foot-skin reaction. Vemurafenib can result in squamous cell carcinomas and photosensitivity. First-generation mammalian target of rapamycin inhibitors may cause a maculopapular eruption initially involving the face and neck. Programmed death (PD)-1-ligand and receptor inhibitors are associated with bullous pemphigoid. Ipilimumab, targeting Cytotoxic -T- Lymphocyte- associated (CTLA-4) receptors, can cause a morbilliform reaction, whereas Interleukin -2 (IL-2) analogs can create the capillary leak syndrome. Chemotherapeutic drug eruptions classically can manifest in the aforementioned ways; however, it is important to understand that they are associated with myriad cutaneous adverse effects, which may be mistaken for organic skin disease. Oncologists prescribing these medications should be familiar with the cutaneous side effects of these medications, and so they may counsel patients to be on the lookout for them.

68Ga-Galmydar: A PET imaging tracer for noninvasive detection of Doxorubicin-induced cardiotoxicity

Background

Cancer patients undergoing Doxorubicin (DOX) treatment are susceptible to acute and chronic cardiac anomalies, including aberrant arrhythmias, ventricular dysfunction, and heart failure. To stratify patients at high risk for DOX -related heart failure (CHF), diagnostic techniques have been sought. While echocardiography is used for monitoring LVEF and LV volumes due to its wide-availability and cost-efficiency, it may not identify early stages of the initiation of DOX-induced systolic heart failure. To address these limitations, PET tracers could also provide noninvasive assessment of early and reversible metabolic changes of the myocardium.

Objective

Herein, we report a preliminary investigation of ⁶⁸Ga-Galmydar potential to monitor Dox-induced cardiomyopathy in vivo, ex vivo, and in cellulo employing both nuclear- and optical imaging.

Methods and results

To assess ⁶⁸Ga-Galmydar ability for monitoring DOX-induced cardiomyopathy, microPET imaging was performed 5 d post treatment of rats either with a single dose of DOX (15 mg/kg) or vehicle as a control (saline) and images were co-registered for anatomical reference using CT. Following tail-vein injection of the radiotracer in rats at 60 min, micro-PET/CT static scan (10 min acquisition), ⁶⁸Ga-Galmydar demonstrated 1.91-fold lower uptake in hearts of DOX-treated (standard uptake value; SUV: 0.92, n = 3) rats compared with their vehicle treated (SUV: 1.76, n = 3) control counterparts. For correlation of PET imaging data, post-imaging quantitative biodistribution studies were also performed, wherein excised organs were counted for γ activity, and normalized to injected dose. The post imaging pharmacokinetic data also demonstrated heart uptake values of 2.0 fold lower for DOX treated rats(%ID/g; DOX: 0.44 ± 0.1, n = 3) compared to their vehicle-treated controls (%ID/g; Control: 0.89 ± 0.03, n = 3, p = 0.04). Employing the fluorescent traits of Galmydar, live cell fluorescence imaging indicated a gradual decrease in uptake and retention of Galmydar within mitochondria of H9c2 cells following DOX-treatment, while indicating dose-dependent and time-dependent uptake profiles. Following depolarization of electronegative transmembrane gradients at the mitochondrial membrane, the uptake of the probe was decreased in H9c2 cells, and the uptake profiles were found to be identical, using both fluorescence and radiotracer bioassays. Finally, the decreased uptake of the metalloprobe in H9c2 cells also correlated with caspase-3 expression resulting from DOX-induced cardiotoxicity and cell death.

Conclusions

⁶⁸Ga-Galmydar could provide a noninvasive assessment of DOX-related and likely reversible metabolic changes at earliest stages. Further studies with other chemotherapeutics (potentially capable of inducing cardiomyopathy) are underway.

Adverse eff ects of polymeric nanoparticle poly(ethylene glycol)- block-polylactide methyl ether (PEG-b-PLA) on steroid hormone secretion by porcine granulosa cells

Objectives. Development of nanoparticles (NPs) for biomedical applications, including medical imaging and drug delivery, is currently undergoing a dramatic expansion. Diverse effects of different type NPs relating to mammalian reproductive tissues have been demonstrated. Th e objective of this study was to explore the in vitro effects of polymeric nanoparticle poly(ethylene glycol)-blockpolylactide methyl ether (PEG-b-PLA NPs) on functional state and viability of ovarian granulosa cells (GCs), which play an important role in maintaining ovarian function and female fertility.

Methods. The GCs isolated from porcine ovarian follicles were incubated with the different concentrations of PEG-b-PLA NPs (PEG average Mn=350 g/mol and PLA average Mn=1000 g/mol; 0.2-100 μg/ml) or poly(ethylene glycol) with an average molecular weight of 300 (PEG-300; 0.2- 40 mg/ml) in the presence or absence of stimulators, follicle-stimulating hormone (FSH; 1 μg/ml), androstenedione (100 nM), forskolin (10 μM) or 8Br-cAMP (100 μM), for different time periods (24, 48, 72 h). At the end of the incubation, progesterone and estradiol levels produced by GCs were measured in the culture media by radioimmunoassay. Th e viability of GCs was determined by the method using a colorimetric assay with MTT.

Results. Treatment of GCs with PEG-b-PLA NPs induced a significant decrease in basal as well as FSH-stimulated progesterone secretion above the concentration of 20 and 4 μg/ml, respectively. Moreover, PEG-b-PLA NPs reduced forskolin-stimulated, but not cAMP-stimulated progesterone production by GCs. A dose-dependent inhibition of androstenedione-stimulated estradiol release by GCs was found by the action of PEG-b-PLA NPs. Incubation of GCs with PEG-300 significantly inhibited basal as well as FSH-stimulated progesterone secretion above the concentration of 40 mg/ml. PEG-b-PLA NPs and PEG-300 significantly reduced the viability of GCs at the highest tested concentrations (100 μg/ml and 40 mg/ml, respectively).

Conclusions. The obtained results indicate that polymeric NPs PEG-b-PLA might induce alterations in steroid hormone production by ovarian GCs and thereby could modify reproductive functions.

Real-World Management of Trabectedin/Pegylated Liposomal Doxorubicin in Platinum-Sensitive Recurrent Ovarian Cancer Patients: A National Survey

BACKGROUND

Trabectedin (T) plus pegylated liposomal doxorubicin (PLD) is approved for treatment of platinum-sensitive recurrent ovarian cancer (ROC). Despite the recommendations and guidelines, variations in managing T/PLD administration in routine clinical practice cannot be excluded. We aimed at setting up an Italian survey collecting data about management of T/PLD administration in ROC patients.

METHODS

We carried out the development of a questionnaire-based survey on routine clinical practice in the management of ROC patients administered T/PLD. The survey registered the physicians' approach to modification/discontinuation of treatment, type of modifications, reasons why, and so on. The survey was transmitted to medical oncologists and gynecologic oncologists practicing in national centers/institutions.

RESULTS

Fifty-eight Italian centers/institutions returned the compiled questionnaire; participants practiced at community cancer centers or hospitals (56.9%), academic institutions (36.2%), and other settings (private clinics, etc) (6.9%). There was no statistically significant difference in the distribution of practice setting according to geographic areas. Most responders were medical oncologists (84.5%) and were members (82.8%) of at least 1 scientific society or cooperative group. Almost 31.5% of responders reported interruption of the whole treatment, mostly because of toxicity (41.2%), followed by patients' choice (29.4%), or achievement of clinical benefit (23.5%). Dose reduction was referred by 47.4% of responders. Reduction of dose for both drugs was referred by 88.5% of responders, and the extent of dose reduction ranged between 10% and 30%.

CONCLUSIONS

This survey highlights the gaps in transposing evidence-based or consensus guidelines in the real-world management of T/PLD administration; these findings could be useful in order to focus the attention on specific knowledge and/or experience gaps and plan pertinent educational programs.

Anticancer Properties and Pharmaceutical Applications of Plumbagin: A Review

It has been shown that plumbagin, a bioactive naphthoquinone isolated from three major plant families viz. Plumbaginaceae, Ebenceae and Droseraceae, definitively exhibits anticancer potential in diverse cancer cells both in vitro and in vivo. Plumbagin shows antineoplastic effects via multi-channel molecular mechanisms, including the induction of apoptosis and autophagy, the disruption of the cell cycle, the inhibition of invasion and metastasis, and anti-angiogenesis. Plumbagin inhibits the growth of cancer cells mainly through the modulation of the signals of PI3K/Akt/mTOR, AMPK, Ras, and so on. The pharmaceutical applications of plumbagin combined with nanocarriers to achieve better therapeutic efficiency are discussed in this review Among them, liposomes, nanoparticles, microspheres, micelles, and nisosomes are used in cancer treatment. The anticancer study of plumbagin in vivo is also summarized in this review. On the whole, we aim to review the research progress of plumbagin both in pharmacological and pharmaceutical filed, which may provide some reference for further research of plumbagin.

Cost–effectiveness of gemcitabine versus PEGylated liposomal doxorubicin for recurrent or progressive ovarian cancer: comparing chemotherapy with nanotherapy

This article examines the cost–effectiveness of chemotherapy (gemcitabine) versus nanotherapy (PEGylated liposomal doxorubicin) in the treatment of ovarian cancer. Significant differences in costs were mainly due to the initial drug costs, which were €1285.28 in favor of chemotherapy. These costs were more than offset by hospitalization costs, which were €2670.21 in favor of the nanotherapy. The cost per quality-adjusted life week (QALW) for the nanotherapy was estimated to be €220.92/QALW for the base case and ranged from €170–318/QALW based on model assumptions. The clinical benefit associated with nanotherapy was achieved, yielding not only positive cost–effectiveness results, but also, surprisingly, financial savings. Although more studies are necessary, this first comprehensive analysis supports the further use of nanotherapy for ovarian cancer.

Pegylated liposomal doxorubicin in the management of ovarian cancer: a systematic review and metaanalysis of randomized trials

Ovarian cancer is the leading cause of death among gynecological tumors. Carboplatin/paclitaxel represents the cornerstone of front-line treatment. Instead, there is no consensus for management of recurrent/progressive disease, in which pegylated liposomal doxorubicin (PLD) ± carboplatin is widely used. We performed a systematic review and metaanalysis to evaluate impact of PLD-based compared with no-PLD-based regimens in the ovarian cancer treatment. Data were extracted from randomized trials comparing PLD-based treatment to any other regimens in the January 2000-January 2013 time-frame. Study end-points were overall survival (OS), progression free survival (PFS), response rate (RR), CA125 response, and toxicity. Hazard ratios (HRs) of OS and PFS, with 95% CI, odds ratios (ORs) of RR and risk ratios of CA125 response and grade 3-4 toxicity, were extracted. Data were pooled using fixed and random effect models for selected endpoints. Fourteen randomized trials for a total of 5760 patients were selected and included for the final analysis, which showed no OS differences for PLD-based compared with other regimens (pooled HR: 0.94; 95% CI: 0.88-1.02; P = 0.132) and a significant PFS benefit of PLD-based schedule (HR: 0.91; 95% CI: 0.86-0.96; P = 0.001), particularly in second-line (HR: 0.85; 95% CI: 0.75-0.91) and in platinum-sensitive (HR: 0.83; 95% CI: 0.74-0.94) subgroups. This work confirmed the peculiar tolerability profile of this drug, moreover no difference was observed for common hematological toxicities and for RR, CA125 response. PLD-containing regimens do not improve OS when compared with any other schedule in all phases of disease. A marginal PFS advantage is observed only in platinum-sensitive setting and second-line treatment.

Therapeutic efficacy of combining pegylated liposomal doxorubicin and radiofrequency (RF) ablation: comparison between slow-drug-releasing, non-thermosensitive and fast-drug-releasing, thermosensitive nano-liposomes

AIMS

To determine how the accumulation of drug in mice bearing an extra-hepatic tumor and its therapeutic efficacy are affected by the type of PEGylated liposomal doxorubicin used, treatment modality, and rate of drug release from the liposomes, when combined with radiofrequency (RF) ablation.

MATERIALS AND METHODS

Two nano-drugs, both long-circulating PEGylated doxorubicin liposomes, were formulated: (1) PEGylated doxorubicin in thermosensitive liposomes (PLDTS), having a burst-type fast drug release above the liposomes' solid ordered to liquid disordered phase transition (at 42°C), and (2) non-thermosensitive PEGylated doxorubicin liposomes (PLDs), having a slow and continuous drug release. Both were administered intravenously at 8 mg/kg doxorubicin dose to tumor-bearing mice. Animals were divided into 6 groups: no treatment, PLD, RF, RF+PLD, PLDTS, and PLDTS+RF, for intra-tumor doxorubicin deposition at 1, 24, and 72 h post-injection (in total 41, mice), and 31 mice were used for randomized survival studies.

RESULTS

Non-thermosensitive PLD combined with RF had the least tumor growth and the best end-point survival, better than PLDTS+RF (p<0.005) or all individual therapies (p<0.001). Although at 1 h post-treatment the greatest amount of intra-tumoral doxorubicin was seen following PLDTS+RF (p<0.05), by 24 and 72 h the greatest doxorubicin amount was seen for PLD+RF (p<0.05); in this group the tumor also has the longest exposure to doxorubicin.

CONCLUSION

Optimizing therapeutic efficacy of PLD requires a better understanding of the relationship between the effect of RF on tumor microenvironment and liposome drug release profile. If drug release is too fast, the benefit of changing the microenvironment by RF on tumor drug localization and therapeutic efficacy may be much smaller than for PLDs having slow and temperature-independent drug release. Thus the much longer circulation time of doxorubicin from PLD than from PLDTS may be beneficial in many therapeutic instances, especially in extra-hepatic tumors.

A novel PEGylated liposome-encapsulated SANT75 suppresses tumor growth through inhibiting hedgehog signaling pathway

The Hedgehog (Hh) pathway inhibitors have shown great promise in cancer therapeutics. SANT75, a novel compound we previously designed to specially inhibit the Smoothened (SMO) protein in the Hh pathway, has greater inhibitory potency than many of commonly used Hh inhibitors. However, preclinical studies of SANT75 revealed water insolubility and acute toxicity. To overcome these limitations, we developed a liposomal formulation of SANT75 and investigated its antitumor efficacy in vitro and in vivo. We encapsulated SANT75 into PEGylated liposome and the mean particle size distribution and zeta-potential (ZP) of liposomes were optimized. Using the Shh-light2 cell and Gli-GFP or Flk-GFP transgenic reporter zebrafish, we confirmed that liposome-encapsulated SANT75 inhibited Hh activity with similar potency as the original SANT75. SANT75 encapsulated into liposome exerted strong tumor growth-inhibiting effects in vitro and in vivo. In addition, the liposomal SANT75 therapy efficiently improved the survival time of tumor-bearing mice without obvious systemic toxicity. The pathological morphology and immunohistochemistry staining revealed that liposomal SANT75 induced tumor cell apoptosis, inhibited tumor angiogenesis as assessed by CD31 and down-regulated the expression of Hh target protein Gli-1 in tumor tissues. Our findings suggest that liposomal formulated SANT75 has improved solubility and bioavailability and should be further developed as a drug candidate for treating tumors with abnormally high Hh activity.

Lipid-functionalized dextran nanosystems to overcome multidrug resistance in cancer: a pilot study

BACKGROUND

The toxicity of anticancer agents and the difficulty in delivering drugs selectively to tumor cells pose a challenge in overcoming multidrug resistance (MDR). Recently, nanotechnology has emerged as a powerful tool in addressing some of the barriers to drug delivery, including MDR in cancer, by utilizing alternate routes of cellular entry and targeted delivery of drugs and genes. However, it is unclear whether doxorubicin (Dox) can be delivered by nanotechnologic approaches.

QUESTIONS/PURPOSES

We asked whether (1) Dox-loaded lipid-functionalized dextran-based biocompatible nanoparticles (Dox/NP) can reverse MDR, (2) Dox/NP has more potent cytotoxic effect on MDR tumors than poly(ethylene glycol)-modified liposomal Dox (PLD), and (3) multidrug resistance protein 1 (MDR1) small interfering RNA loaded in these nanoparticles (siMDR1/NP) can modulate MDR.

METHODS

To create stable Dox/NP and siMDR1/NP, we used two different lipid-modified dextran derivatives. The effect of Dox or Dox/NP was tested on drug-sensitive osteosarcoma (KHOS) and ovarian cancer (SKOV-3) cell cultures in triplicate and their respective MDR counterparts KHOS(R2) and SKOV-3(TR) in triplicate. We determined the effects on drug retention, transfection efficacy of siMDR1/NP, and P-glycoprotein expression and the antiproliferative effect between Dox/NP and PLD in MDR tumor cells.

RESULTS

Fluorescence microscopy revealed efficient uptake of the Dox/NP and fluorescently tagged siMDR1/NP. Dox/NP showed five- to 10-fold higher antiproliferative activity at the 50% inhibitory concentration than free Dox in tumor cells. Dox/NP showed twofold higher activity than PLD in MDR tumor cells. siMDR1/NP (100 nM) suppressed P-glycoprotein expression in KHOS(R2).

CONCLUSIONS

Dextran-lipid nanoparticles are a promising platform for delivering Dox and siRNAs.

CLINICAL RELEVANCE

Biocompatible dextran-based nanoparticles that are directly translatable to clinical medicine may lead to new potential therapeutics for reversing MDR in patients with cancer.

Pegylated liposomal doxorubicin for platinum-resistant or refractory Müllerian carcinoma (epithelial ovarian carcinoma, primary carcinoma of Fallopian tube and peritoneal carcinoma): A single-institutional experience

The aim of the present study was to evaluate the efficacy and safety of pegylated liposomal doxorubicin (PLD) in patients with Müllerian carcinoma treated at our hospital. Nineteen patients with platinum-resistant Müllerian carcinoma were treated with intravenous PLD 50 mg/m(2) every 4 weeks. Tumor response was assessed by MRI following every 2-3 cycles of treatment. The severity of adverse events was assessed according to the Common Terminology Criteria for Adverse Events (v3.0). The best overall responses in the 19 patients were identified as 5 partial responses (PR), 6 stable diseases (SD) and 8 progressive diseases (PD). Response rate was 26.3%. The proportion of patients with CR, PR or SD was 57.9%. The median time to progression was 188.0 days. The median survival time was 381.0 days. Toxicity grades were identified as one grade III hand-foot syndrome, two grade III neutropenia, one grade IV hand-foot syndrome, one grade IV stomatitis and one grade IV neutropenia. The present study confirmed that PLD is an effective drug when administered as a salvage therapy for the treatment of Müllerian carcinoma and is associated with a reduced toxicity profile compared with current therapeutic options.

Accelerated blood clearance of PEGylated liposomes containing doxorubicin upon repeated administration to dogs

The accelerated blood clearance phenomenon involving anti-PEG IgM production has been recognized as an important issue for the design and development of PEGylated liposomes. Here, we show that empty PEGylated liposomes and Doxil, PEGylated liposomes containing doxorubicin, both caused anti-PEG IgM production and thereby a rapid clearance of the second and/or third dose of Doxil in Beagle dogs in a lipid-dose, inverse-dependent manner. It appears that the pharmacokinetic profile of the second and third administration of Doxil reflected the presence of anti-PEG IgM circulating in the blood. Doxil plus an excess amount of empty PEGylated liposomes rather enhanced the production of anti-PEG IgM compared to Doxil of the same doxorubicin dose. During sequential administration, increasing the lipid dose of Doxil in each dose by the addition of empty PEGylated liposomes strongly attenuated the magnitude of the ABC phenomenon during the effectuation phase of a second and third dose of Doxil. Our results suggest that the pre-clinical study of anti-cancer drug-containing PEGylated liposomes with dogs must be carefully designed and performed with monitoring of the anti-PEG IgM and liposomal drugs circulating in the blood.

The treatment of breast cancer using liposome technology

Liposome-based chemotherapeutics used in the treatment of breast cancer can in principle enhance the therapeutic index of otherwise unencapsulated anticancer drugs. This is partially attributed to the fact that encapsulation of cytotoxic agents within liposomes allows for increased concentrations of the drug to be delivered to the tumor site. In addition, the presence of the phospholipid bilayer prevents the encapsulated active form of the drug from being broken down in the body prior to reaching tumor tissue and also serves to minimize exposure of the drug to healthy sensitive tissue. While clinically approved liposome-based chemotherapeutics such as Doxil have proven to be quite effective in the treatment of breast cancer, significant challenges remain involving poor drug transfer between the liposome and cancerous cells. In this review, we discuss the recent advancements made in the development of liposome-based chemotherapeutics with respect to improved drug transfer for use in breast cancer therapy.

Pharmacokinetic and toxicity considerations for the use of anthracyclines in ovarian cancer treatment

INTRODUCTION

Safe and effective treatments are needed for ovarian cancer. While there are many drugs currently available, there has recently been a renewed novel interest in the use of anthracyclines.

AREAS COVERED

This review summarizes the available evidence on pharmacokinetic (PK) and toxicology implications of anthracyclines and pegylated liposomal doxorubicin (PLD) in the clinical management of women with epithelial ovarian cancer. This article consists of material obtained via Medline, PubMed and EMBASE literature searches, up to September 2010.

EXPERT OPINION

PLD is a liposomal formulation of doxorubicin (DXR), with a distinct pharmacokinetic profile, characterized by extended circulation time and a reduced clearance and volume of distribution with respect to the free drug. PLD is effective and well tolerated in relapsed ovarian cancer. The toxicity profile of PLD is characterized by dose-limiting mucosal and cutaneous toxicities, mild myelosuppression and decreased cardiotoxicity compared to free DXR. The good response rate, toxicity profile and pharmacokinetic profile of PLD suggest that PLD could be an option in first-line and second-line treatment in ovarian cancer; especially in those who had experienced taxane-induced toxicity or had a poor performance status.