The pharmacokinetics of liposomal encapsulated daunorubicin are not modified by HAART in patients with HIV-associated Kaposi's sarcoma

Application of Nanoparticles in Drug Delivery for the Treatment of Osteosarcoma: Focusing on the Liposomes

Osteosarcoma (OS) is one of the most common primary bone malignancies in children and adolescents. The toxicity to healthy tissues from conventional therapeutic strategies, including chemotherapy and radiotherapy, and drug resistance, severely affect OS patients' quality of life and cancer-specific outcomes. Many efforts have been made to develop various nanomaterial-based drug delivery systems with specific properties to overcome these limitations. Among the developed nanocarriers, liposomes are the most successful and promising candidates for providing targeted tumor therapy and enhancing the safety and therapeutic effect of encapsulated agents. Liposomes have low immunogenicity, high biocompatibility, prolonged half-life, active group protection, cell-like membrane structure, safety, and effectiveness. This review will discuss various nanomaterial-based carriers in cancer therapy and then the characteristics and design of liposomes with a particular focus on the targeting feature. We will also summarize the recent advances in the liposomal drug delivery system for OS treatment in preclinical and clinical studies.

Towards the use of localised delivery strategies to counteract cancer therapy-induced cardiotoxicities

Cancer therapies have significantly improved cancer survival; however, these therapies can often result in undesired side effects to off target organs. Cardiac disease ranging from mild hypertension to heart failure can occur as a result of cancer therapies. This can warrant the discontinuation of cancer treatment in patients which can be detrimental, especially when the treatment is effective. There is an urgent need to mitigate cardiac disease that occurs as a result of cancer therapy. Delivery strategies such as the use of nanoparticles, hydrogels, and medical devices can be used to localise the treatment to the tumour and prevent off target side effects. This review summarises the advancements in localised delivery of anti-cancer therapies to tumours. It also examines the localised delivery of cardioprotectants to the heart for patients with systemic disease such as leukaemia where localised tumour delivery might not be an option.

Lipid-based nanoparticle formulations for small molecules and RNA drugs

Introduction: Liposomes and lipid-based nanoparticles (LNPs) effectively deliver cargo molecules to specific tissues, cells, and cellular compartments. Patients benefit from these nanoparticle formulations by altered pharmacokinetic properties, higher efficacy, or reduced side effects. While liposomes are an established delivery option for small molecules, Onpattro® (Sanofi Genzyme, Cambridge, MA) is the first commercially available LNP formulation of a small interfering ribonucleic acid (siRNA). Areas covered: This review article summarizes key features of liposomal formulations for small molecule drugs and LNP formulations for RNA therapeutics. We describe liposomal formulations that are commercially available or in late-stage clinical development and the most promising LNP formulations for ASOs, siRNAs, saRNA, and mRNA therapeutics. Expert opinion: Similar to liposomes, LNPs for RNA therapeutics have matured but still possess a niche application status. RNA therapeutics, however, bear an immense hope for difficult to treat diseases and fuel the imagination for further applications of RNA drugs. LNPs face similar challenges as liposomes including limitations in biodistribution, the risk to provoke immune responses, and other toxicities. However, since properties of RNA molecules within the same group are very similar, the entire class of therapeutic molecules would benefit from improvements in a few key parameters of the delivery technology.

Mathematical modeling in cancer nanomedicine: a review

Cancer continues to be among the leading healthcare problems worldwide, and efforts continue not just to find better drugs, but also better drug delivery methods. The need for delivering cytotoxic agents selectively to cancerous cells, for improved safety and efficacy, has triggered the application of nanotechnology in medicine. This effort has provided drug delivery systems that can potentially revolutionize cancer treatment. Nanocarriers, due to their capacity for targeted drug delivery, can shift the balance of cytotoxicity from healthy to cancerous cells. The field of cancer nanomedicine has made significant progress, but challenges remain that impede its clinical translation. Several biophysical barriers to the transport of nanocarriers to the tumor exist, and a much deeper understanding of nano-bio interactions is necessary to change the status quo. Mathematical modeling has been instrumental in improving our understanding of the physicochemical and physiological underpinnings of nanomaterial behavior in biological systems. Here, we present a comprehensive review of literature on mathematical modeling works that have been and are being employed towards a better understanding of nano-bio interactions for improved tumor delivery efficacy.

Pharmacokinetics and Pharmacodynamics Modeling and Simulation Systems to Support the Development and Regulation of Liposomal Drugs

Liposomal formulations have been developed to improve the therapeutic index of encapsulated drugs by altering the balance of on- and off-targeted distribution. The improved therapeutic efficacy of liposomal drugs is primarily attributed to enhanced distribution at the sites of action. The targeted distribution of liposomal drugs depends not only on the physicochemical properties of the liposomes, but also on multiple components of the biological system. Pharmacokinetic⁻pharmacodynamic (PK⁻PD) modeling has recently emerged as a useful tool with which to assess the impact of formulation- and system-specific factors on the targeted disposition and therapeutic efficacy of liposomal drugs. The use of PK⁻PD modeling to facilitate the development and regulatory reviews of generic versions of liposomal drugs recently drew the attention of the U.S. Food and Drug Administration. The present review summarizes the physiological factors that affect the targeted delivery of liposomal drugs, challenges that influence the development and regulation of liposomal drugs, and the application of PK⁻PD modeling and simulation systems to address these challenges.

Liposomal Drug Delivery Systems and Anticancer Drugs

Cancer is a life-threatening disease contributing to ~3.4 million deaths worldwide. There are various causes of cancer, such as smoking, being overweight or obese, intake of processed meat, radiation, family history, stress, environmental factors, and chance. The first-line treatment of cancer is the surgical removal of solid tumours, radiation therapy, and chemotherapy. The systemic administration of the free drug is considered to be the main clinical failure of chemotherapy in cancer treatment, as limited drug concentration reaches the tumour site. Most of the active pharmaceutical ingredients (APIs) used in chemotherapy are highly cytotoxic to both cancer and normal cells. Accordingly, targeting the tumour vasculatures is essential for tumour treatment. In this context, encapsulation of anti-cancer drugs within the liposomal system offers secure platforms for the targeted delivery of anti-cancer drugs for the treatment of cancer. This, in turn, can be helpful for reducing the cytotoxic side effects of anti-cancer drugs on normal cells. This short-review focuses on the use of liposomes in anti-cancer drug delivery.

Liposomal Formulations in Clinical Use: An Updated Review

Liposomes are the first nano drug delivery systems that have been successfully translated into real-time clinical applications. These closed bilayer phospholipid vesicles have witnessed many technical advances in recent years since their first development in 1965. Delivery of therapeutics by liposomes alters their biodistribution profile, which further enhances the therapeutic index of various drugs. Extensive research is being carried out using these nano drug delivery systems in diverse areas including the delivery of anti-cancer, anti-fungal, anti-inflammatory drugs and therapeutic genes. The significant contribution of liposomes as drug delivery systems in the healthcare sector is known by many clinical products, e.g., Doxil®, Ambisome®, DepoDur™, etc. This review provides a detailed update on liposomal technologies e.g., DepoFoam™ Technology, Stealth technology, etc., the formulation aspects of clinically used products and ongoing clinical trials on liposomes.

Case Report: No Response to Liposomal Daunorubicin in a Patient with Drug-Resistant HIV-Associated Visceral Leishmaniasis

Visceral leishmaniasis (VL) in patients with HIV co-infection presents a significant therapeutic challenge due to the lessened chance of achieving long-term cure. We report a case of VL in a 60-year-old man with HIV infection who became refractory to anti-leishmania treatment due to multi-drug resistance. In the face of a worsening clinical situation, and with no other options available, he was treated with an experimental regimen of liposomal daunorubicin, which has previously been shown to have in vitro activity against Leishmania donovani and to be effective treatment of VL in animal studies. To our knowledge, he was the first patient with VL and HIV co-infection to have this treatment evaluated. We report on the lack of response to this treatment and possible causes for its failure.

In areas where leishmaniasis is endemic, visceral leishmaniasis (VL) is a potentially incurable AIDS illness in HIV infected people. Co-infection with HIV and any of the Leishmania species that cause VL can result in failure of the CD4 lymphocyte count to rise above 200 cells/mm³ despite sustained, effective suppression of HIV infection, and this failure of CD4 recovery then commonly prevents immune mediated eradication of VL despite aggressive, prolonged anti-Leishmania treatment. The situation is made more challenging by the limited number of agents active against VL and their high rate of adverse effects. We report the first evaluation of liposomal daunorubicin used to treat VL in a patient with HIV and L. infantum co-infection. We selected this drug on the basis of the proven activity of anthracyclines against Leishmania species both in vitro and in animal models and the well tolerated use of daunorubicin in HIV infected patients with Kaposi’s sarcoma. This treatment proved unsuccessful in our patient, probably because resistance of L. infantum to liposomal daunorubicin had been induced by previous treatment with another anti-leishmania drug, miltefosine.

Pilot study evaluating the interaction between paclitaxel and protease inhibitors in patients with human immunodeficiency virus-associated Kaposi's sarcoma: an Eastern Cooperative Oncology Group (ECOG) and AIDS Malignancy Consortium (AMC) trial

PURPOSE

Paclitaxel, a cytotoxic agent metabolized by cytochrome P450 hepatic enzymes, is active for the treatment of human immunodeficiency (HIV) associated Kaposi's sarcoma. Protease inhibitors are commonly used to treat HIV infection and are known to inhibit cytochrome P450. We sought to determine whether protease inhibitors alter the pharmacokinetics of paclitaxel.

METHODS

Patients with advanced HIV-associated KS received paclitaxel (100 mg/m(2)) by intravenous infusion over 3 h, and plasma samples were collected to measure paclitaxel concentration. The area under the curve (AUC) was calculated using a combination of the log and linear trapezoidal rule, and clearance was calculated as the dose/AUC. Pharmacokinetics were compared with respect to antiretroviral therapy and toxicity,

RESULTS

Thirty-four patients received paclitaxel, of whom 20 had no prior paclitaxel therapy and were assessable for response. Twenty-seven had pharmacokinetic studies performed. Paclitaxel exposure was higher in patients taking protease inhibitors compared to those who were not taking protease inhibitors. The increased exposure did not correlate with efficacy or toxicity. Of the 20 patients assessable for response, 6 (30%) had an objective response and median progression-free survival was 7.8 months (95% confidence interval, 5.6, 21.0 months).

CONCLUSION

Despite higher exposure to paclitaxel, patients on protease inhibitors did not experience enhanced toxicity or efficacy.

Ongoing change in the treatment of HIV-associated malignancies in the HAART era

Implementation of highly active antiretroviral therapy (HAART) has changed the epidemiology, clinical outcome and therapeutic approach of HIV-associated malignancies. Whereas Kaposi sarcoma and primary CNS non-Hodgkin lymphoma have decreased dramatically, systemic non-Hodgkin lymphoma incidence seems unchanged, perhaps increasing as with other tumor incidence. Owing to HAART-induced immune function preservation, response rates to chemotherapy and survival times in patients with HIV-associated malignancies have neared those observed in their HIV-negative counterparts. Hence, intensive regimens have been more and more extensively used with promising results. This may also apply to other therapeutic options, such as biotherapy, and procedures, such as stem cell rescue following high-dose chemotherapy or heterologous stem cell transplant, which have so far been precluded to HIV-infected subjects as a matter of fact. A trend toward a full assimilation of HIV-infected people with cancer and the general population with the same pathology is ongoing.

AIDS-related malignancies: state of the art and therapeutic challenges

Despite the impact of combination antiretroviral therapy (cART) on HIV-related mortality, malignancy remains an important cause of death in the current era. Although the advent of cART has resulted in reductions in the incidence of Kaposi's sarcoma and non-Hodgkin's lymphoma, non-AIDS-defining malignancies present an increased risk for HIV-infected patients, characterized by some common clinical features, generally with a more aggressive behavior and a more advanced disease at diagnosis, which is responsible for poorer patient outcomes. Specific therapeutic recommendations are lacking for these new nonopportunistic malignancies, such as Hodgkin's lymphoma, anal cancer, lung cancer, hepatocarcinoma, and many others. Antiretroviral agents have a propensity for causing drug interactions as a result of their ability to either inhibit or induce the cytochrome P450 (CYP) enzyme system. Because many antineoplastic drugs are also metabolized by the CYP system, coadministration with cART could result in either drug accumulation with increased toxicity, or decreased efficacy of one or both classes of drugs. Further research delineating the combined safety and pharmacokinetics of antiretrovirals and antineoplastic therapy is necessary. Special considerations of these AIDS-related and non-AIDS-related malignancies and their clinical and therapeutic aspects constitute the subject of this review.

Lopinavir–Ritonavir Dramatically Affects the Pharmacokinetics of Irinotecan in HIV Patients With Kaposi’s Sarcoma

The coadministration of protease inhibitors with anticancer drugs in the management of human immunodeficiency virus-related malignancies can cause potential drug-drug interactions. The effect of lopinavir/ritonavir (LPV/RTV) on the pharmacokinetics of irinotecan (CPT11) has been investigated in seven patients with Kaposi's sarcoma. Coadministration of LPV/RTV reduces the clearance of CPT11 by 47% (11.3+/-3.5 vs 21.3+/-6.3 l/h/m(2), P=0.0008). This effect was associated with an 81% reduction (P=0.02) of the AUC (area under the curve) of the oxidized metabolite APC (7-ethyl-10-[4-N-(5-aminopentanoic-acid)-1-piperidino]-carbonyloxycamptothecin). The LPV/RTV treatment also inhibited the formation of SN38 glucuronide (SN38G), as shown by the 36% decrease in the SN38G/SN38 AUCs ratio (5.9+/-1.6 vs 9.2+/-2.6, P=0.002) consistent with UGT1A1 inhibition by LPV/RTV. This dual effect resulted in increased availability of CPT11 for SN38 conversion and reduced inactivation on SN38, leading to a 204% increase (P=0.0001) in SN38 AUC in the presence of LPV/RTV. The clinical consequences of these substantial pharmacokinetic changes should be investigated.

Oncologic Complications of Human Immunodeficiency Virus Infection: Changing Epidemiology, Treatments, and Special Considerations in the Era of Highly Active Antiretroviral Therapy

Although highly active antiretroviral therapy (HAART) has revolutionized the treatment of human immunodeficiency virus (HIV)-positive patients, malignancies in the setting of HIV infection remain an appreciable problem. We evaluated the changing epidemiology of HIV-related malignancies, optimal neoplastics and their effect on viral dynamics, and evidence regarding drug interactions between chemotherapy and antiretrovirals. A MEDLINE search (January 1966-June 2006) was performed to identify clinical trials, review articles, and meta-analyses; abstracts from HIV conferences were also searched. Survival of patients with HIV-related malignancies has substantially improved since the advent of HAART. Chemotherapy for malignancies in the HIV-positive population generally resembles that for the HIV-negative population, with trials revealing an elevated frequency of toxicities in HIV-positive patients. Studies of antineoplastics have shown no long-term adverse effects on viral dynamics in terms of immunologic or virologic HIV markers. Limited pharmacokinetic data with antineoplastics and antiretrovirals suggest possible changes in some pharmacokinetic parameters, but these results should be interpreted cautiously because of the small numbers of patients enrolled in the trials. Researchers also report an increased frequency of chemotherapy-related toxicities when HAART was coadministered with antineoplastics. This increase was likely due to impairment of cytochrome P450 metabolism of antineoplastics by protease inhibitors. Because of the survival benefits of HAART, the integration of antiretrovirals with chemotherapy is now preferred for patients with HIV-related malignancies. However, because the metabolic pathways of many of these agents are similar, the effectiveness of antineoplastic therapy and its related toxicities should be vigilantly monitored in this patient population.

Interactions Between Antiretrovirals and Antineoplastic Drug Therapy

Despite the established impact of highly active antiretroviral therapy (HAART) in reducing HIV-related morbidity and mortality, malignancy remains an important cause of death. Patients who receive the combination of cancer chemotherapy and HAART may achieve better response rates and higher rates of survival than patients who receive antineoplastic therapy alone. However, the likelihood of drug interactions with combined therapy is high, since protease inhibitors (PIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) are substrates and potent inhibitors or inducers of the cytochrome P450 (CYP) system. Since many antineoplastic drugs are also metabolised by the CYP system, coadministration with HAART could result in either drug accumulation and possible toxicity, or decreased efficacy of one or both classes of drugs. Although formal, prospective pharmacokinetic interaction studies are not available in most instances, it is possible to infer the nature of drug interactions based on the metabolic fates of these agents. Paclitaxel and docetaxel are both metabolised by the CYP system, although differences exist in the nature of the isoenzymes involved. Case reports describing adverse consequences of concomitant taxane-antiretroviral therapy exist. Although other confounding factors may have been present, these cases serve as reminders of the vigilant monitoring necessary when taxanes and HAART are coadministered. Similarly, vinca alkaloids are substrates of CYP3A4 and are, thus, vulnerable to PI- or NNRTI-mediated changes in their pharmacokinetics. Interactions with the alkylating agents cyclophosphamide and ifosfamide are complicated as a result of the involvement of the CYP3A4 and CYP2B6 isoenzymes in both the metabolic activation of these drugs and the generation of potentially neurotoxic metabolites. Existing data regarding the metabolic fate of the anthracyclines doxorubicin and daunorubicin suggest that clinically detrimental interactions would not be expected with coadministered HAART. Commonly used endocrine therapies are largely substrates of the CYP system and may, therefore, be amenable to modulation by concomitant HAART. In addition, tamoxifen itself has been associated with reduced concentrations of both anastrozole and letrozole, raising the concern that similar inducing properties may adversely affect the outcome of PI- or NNRTI-based therapy. Similarly, dexamethasone is both a substrate and concentration-dependent inducer of CYP3A4; enhanced corticosteroid pharmacodynamics may result with CYP3A4 inhibitors, while the efficacy of concomitant HAART may be compromised with prolonged dexamethasone coadministration. Since PIs and NNRTIs may also induce or inhibit the expression of P-glycoprotein, the potential for additional interactions to arise via modulation of this transporter also exists. Further research delineating the combined safety and pharmacokinetics of antiretrovirals and antineoplastic therapy is necessary.

Effect of highly active antiretroviral therapy (HAART) on pharmacokinetics and pharmacodynamics of doxorubicin in patients with HIV-associated non-Hodgkin's lymphoma

BACKGROUND

We demonstrated that highly active antiretroviral therapy (HAART) increases the toxic effect of cyclophosphamide, vincristine, doxorubicin (DOX) and prednisone (CHOP) in HIV-patients with non-Hodgkin's lymphoma (NHL). To ascertain the cause of increased toxicity, we investigated the pharmacokinetics of DOX in HIV-patients with NHL treated with CHOP with and without HAART.

METHODS

Complete pharmacokinetics and pharmacodynamic analysis was determined in 19 patients during 38 cycles of chemotherapy: 19 cycles with CHOP and 19 CHOP + HAART in a crossover-designed study. HAART included protease inhibitors indinavir (IDV) in nine patients, saquinavir (SQV) hard gel in six patients and nelfinavir (NFV) in four patients.

RESULTS

No significant effects of HAART on pharmacokinetics parameters of DOX were observed. Similarly, no differential effect on DOX pharmacokinetics among IDV, SQV, and NFV was evidenced. Significant associations (P=0.012) were observed between DOX AUC0-infinity (area under the concentration curve) and G3-G4 WHO haematologic toxicity, in patients treated with CHOP alone, but not in those treated with CHOP + HAART (P = not significant).

CONCLUSION

We demonstrated that HAART therapy has no significant effect on DOX pharmacokinetics. DOX AUC appears to be a predictor of toxicity only in patients treated with CHOP alone. Other factors beside DOX plasma levels are detrimental for toxicity after CHOP + HAART. Therefore, pharmacodynamic interactions between HAART and DOX should be considered.

Population pharmacokinetics of liposomal daunorubicin in children

AIMS

To investigate the population pharmacokinetics of daunorubicin in children after administration of liposomal daunorubicin (Daunoxome).

METHODS

Plasma samples from 19 children with relapsed acute myeloic leukaemia and five children with other malignancies were collected. Daunoxome was administered as a 1- to 2.5 h infusion with doses ranging from 30 to 60 mg m(-2). Overall, 214 samples were analysed for daunorubicin using capillary electrophoresis, and population pharmacokinetic modelling was performed using NONMEM.

RESULTS

The data were best described by a one compartment model. Inclusion of interoccasion variability in the model (16.7% for clearance) improved strongly the precision of the estimates. The inclusion of body surface area or height as a covariate decreased interindividual variability. However, the best fit was obtained using the absolute dose, and when weight was included as a covariate for clearance (CL) and volume of distribution (V ). The final parameter estimates were: CL 6.41 ml h(-1) kg(-1) +/- 0.5 51% and V 65.4 ml kg(-1) +/- 0.5 27% (population mean +/- 0.5 interindividual variability). The area under the curve at a dose of 60 mg m(-2) was 231 mg l (-1)h.

CONCLUSIONS

In comparison with free daunorubicin, Daunoxome shows a low volume of distribution, a lower clearance and a lower interindividual variability in these parameters. This might be advantageous in reducing the variability in exposure to the drug.

Clinical presentations and standard therapy of AIDS-associated Kaposi's sarcoma

The treatment plan for a patient with AIDS-related KS should be based on tumor characteristics, control of HIV infection, comorbidities, and patient treatment goals (see Table 1). Institution of optimal antiretroviral therapy is an essential component of KS therapy. When available, enrollment in a clinical trial should be considered, except for patients who are naive to chemotherapy with symptomatic or life-threatening KS. For a patient with minimal, indolent cutaneous disease, after optimal control of HIV replication, local treatment, investigational treatment, or interferon are reasonable considerations. For the patient with rapidly progressive, cutaneous disease, tumor-related symptoms, or visceral disease, cytotoxic chemotherapy in combination with antiretroviral therapy is the first consideration. Future advances undoubtedly will include pathogenesis-based agents, either alone or in combination with currently available cytotoxic therapy.

Determination of free and liposome-associated daunorubicin and daunorubicinol in plasma by capillary electrophoresis

Liposomal daunorubicin (DaunoXome) is a formulation of the anticancer drug daunorubicin encapsulated into vesicles of about 45 nm diameter. To understand the pharmacodynamic relationships associated with the toxicity and efficacy of liposome-encapsulated daunorubicin in vivo and in vitro, it is essential to have a rapid method of separating the free and liposomal forms of the drug. We have developed and validated a method to quantify drug concentrations of liposomal daunorubicin, free daunorubicin and its main metabolite daunorubicinol that requires only 50 microl of plasma to conduct studies in children. The method involves the use of solid-phase extraction followed by capillary electrophoresis with laser-induced fluorescence (LIF) detection. With LIF detection a limit of quantification of 1 microg/l is obtained for the free form and the metabolite. Precision and accuracy are in accordance with the generally accepted criteria for bioanalytical methods. The method is rapid and allows for multiple samples to be processed simultaneously.

Phase IV study of liposomal daunorubicin (DaunoXome) in AIDS-related Kaposi sarcoma

The purpose of this article was to study the efficacy and tolerance of liposomal daunorubicin (DaunoXome) in the treatment of AIDS-associated Kaposi sarcoma (KS) as prescribed in France between September 1996 and September 1997. All patients with a positive HIV serology, histologically proven KS, and having received at least one daunorubicin treatment cycle during the study period were eligible for entry. Ninety-four patient files from 13 university hospital departments were retrospectively studied. Of 94 patients, 80% received cytostatic treatment before the first daunorubicin treatment cycle. Initial mean CD4 lymphocyte count was 114/microl. Ninety percent of the patients received highly active antiretroviral treatment (HAART) during daunorubicin treatment. Daunorubicin was administered as single chemotherapy to 70% of the patients. The total number of treatment cycles was 1,422, with a mean number of 16.1 treatment cycles (1-68) per patient and a mean cumulative daunorubicin dose of 674 mg/m2 (40-2,749). According to the AIDS Clinical Trial Group criteria, partial and complete response rates were 26.5% and 11.5%, respectively. A hematopoietic growth factor was prescribed in 29% of the treatment cycles. At the final evaluation, 71% of the patients were alive. No severe cardiotoxic event was observed despite high cumulative drug doses and prolonged follow-up. Since the introduction of HAART, this study constitutes the only evaluation of daunorubicin in a wide population. Our study confirms that daunorubicin is effective in patients with advanced KS. Daunorubicin is well tolerated over the long term in association with HAART.