Phase II study of sphingosomal vincristine in patients with recurrent or refractory adult acute lymphocytic leukemia

Review on novel targeted enzyme drug delivery systems: enzymosomes

The goal of this review is to present enzymosomes as an innovative means for site-specific drug delivery. Enzymosomes make use of an enzyme's special characteristics, such as its capacity to accelerate the reaction rate and bind to a particular substrate at a regulated rate. Enzymosomes are created when an enzyme forms a covalent linkage with a liposome or lipid vesicle surface. To construct enzymosomes with specialized activities, enzymes are linked using acylation, direct conjugation, physical adsorption, and encapsulation techniques. By reducing the negative side effects of earlier treatment techniques and exhibiting efficient medication release, these cutting-edge drug delivery systems improve long-term sickness treatments. They could be a good substitute for antiplatelet medication, gout treatment, and other traditional medicines. Recently developed supramolecular vesicular delivery systems called enzymosomes have the potential to improve drug targeting, physicochemical characteristics, and ultimately bioavailability in the pharmaceutical industry. Enzymosomes have advantages over narrow-therapeutic index pharmaceuticals as focusing on their site of action enhances both their pharmacodynamic and pharmacokinetic profiles. Additionally, it reduces changes in normal enzymatic activity, which enhances the half-life of an enzyme and accomplishes enzyme activity on specific locations.

Pomegranate extract-loaded sphingosomes for the treatment of cancer: Phytochemical investigations, formulation, and antitumor activity evaluation

AIM

Formulation of Pomegranate Extracts (PE)-loaded sphingosomes as an antitumor therapy for the intravenous and passive targeted delivery to various tumor types, especially that of the breast, colon, and uterus; to increase the therapeutic activity and decrease the adverse effects profile.

METHODS

The pericarp and seeds' juice of Punica granatum were each extracted using D.W. and ethanol. Phytochemical investigation of all extracts was carried out including total phenolics, flavonoids, and anthocyanins contents, the antioxidant activity, as well as HPLC analysis of phenolics and flavonoids. The antitumor potential of all extracts was also tested utilizing three cell lines: MCF-7, HeLa, and HCT116. The candidate extract was chosen for the formulation phase and was entrapped into the sphingosomes using the thin-film hydration method and employing three different PE: lipids weight ratios. The synthesized formulations were characterized for their size, morphological features, zeta potential, entrapment efficiency, and in vitro drug release and kinetics modeling studies. The optimized formula was further analyzed by FTIR spectroscopy and electron microscopy. The antitumor activity of F2 was also investigated using the same cancer cell lines compared to the plant extract.

RESULTS

The highest phenolics, flavonoids, and anthocyanins contents were observed in the ethanolic pericarps extract (EPE), followed by the ethanolic seeds extract (ESE). Consequently, EPE showed a higher antitumor activity hence it was selected for the formulation phase. PE-loaded sphingosomes formula (F2) was selected for having the highest EE% (71.64%), and a sustained release profile with the highest in vitro release (42.5±9.44%). By employing the DDSolver, the Weibull model was found the most suitable to describe the PE release kinetics compared to other models. The release mechanism was found to follow Fickian diffusion. Simulated pharmacokinetic parameters have portrayed F2 as the candidate formula, with the highest AUC (536.095) and slowest MDT (0.642 h). In addition, F2 exhibited a significant (p>0.05) stronger and prolonged anticancer effect against MCF-7, HeLa, and HCT116 cell lines at all concentrations tested compared to the free extract.

CONCLUSION

The results proved that sphingosomes are an effective delivery system, improving pharmacological efficacy and reducing serious side effects of anticancer medications and natural products.

Anatomical Targeting of Anticancer Drugs to Solid Tumors Using Specific Administration Routes: Review

Despite remarkable recent progress in developing anti-cancer agents, outcomes of patients with solid tumors remain unsatisfactory. In general, anti-cancer drugs are systemically administered through peripheral veins and delivered throughout the body. The major problem with systemic chemotherapy is insufficient uptake of intravenous (IV) drugs by targeted tumor tissue. Although dose escalation and treatment intensification have been attempted in order to increase regional concentrations of anti-tumor drugs, these approaches have produced only marginal benefits in terms of patient outcomes, while often damaging healthy organs. To overcome this problem, local administration of anti-cancer agents can yield markedly higher drug concentrations in tumor tissue with less systemic toxicity. This strategy is most commonly used for liver and brain tumors, as well as pleural or peritoneal malignancies. Although the concept is theoretically reasonable, survival benefits are still limited. This review summarizes clinical results and problems and discusses future directions of regional cancer therapy with local administration of chemotherapeutants.

Review on Different Vesicular Drug Delivery Systems (VDDSs) and Their Applications

BACKGROUND

Colloidal dispersions, also known as vesicular drug delivery systems (VDDSs), are highly ordered assemblies composed of one or more concentric bilayers formed by the self-assembly of amphiphilic building blocks in the presence of water.

OBJECTIVE

VDDSs are important to target the entrapped drugs at specific sites inside the body, control the drug release, enhance the drug bioavailability, and reduce undesired side effects.

METHODS

There are different types of VDDSs suitable for the entrapment of both hydrophilic and lipophilic drugs. According to the patent composition, VDDSs are classified into lipid-based and nonlipid- based VDDSs.

RESULTS

There are different types of VDDSs which include liposomes, ethosomes, transferosomes, ufasomes, colloidosomes, cubosomes, niosomes, bilosomes, aquasomes, etc. Conclusion: This review article aims to address the different types of VDDSs, their advantages and disadvantages, and their therapeutic applications.

Vesicular Nanocarriers for Phytocompounds in Wound Care: Preparation and Characterization

The need to develop wound healing preparations is a pressing challenge given the limitations of the current treatment and the rising prevalence of impaired healing wounds. Although herbal extracts have been used for many years to treat skin disorders, due to their wound healing, anti-inflammatory, antimicrobial, and antioxidant effects, their efficacy can be questionable because of their poor bioavailability and stability issues. Nanotechnology offers an opportunity to revolutionize wound healing therapies by including herbal compounds in nanosystems. Particularly, vesicular nanosystems exhibit beneficial properties, such as biocompatibility, targeted and sustained delivery capacity, and increased phytocompounds’ bioavailability and protection, conferring them a great potential for future applications in wound care. This review summarizes the beneficial effects of phytocompounds in wound healing and emphasizes the advantages of their entrapment in vesicular nanosystems. Different types of lipid nanocarriers are presented (liposomes, niosomes, transferosomes, ethosomes, cubosomes, and their derivates’ systems), highlighting their applications as carriers for phytocompounds in wound care, with the presentation of the state-of-art in this field. The methods of preparation, characterization, and evaluation are also described, underlining the properties that ensure good in vitro and in vivo performance. Finally, future directions of topical systems in which vesicle-bearing herbal extracts or phytocompounds can be incorporated are pointed out, as their development is emerging as a promising strategy.

Optimization of Tabersonine Methoxylation to Increase Vindoline Precursor Synthesis in Yeast Cell Factories

Plant specialized metabolites are widely used in the pharmaceutical industry, including the monoterpene indole alkaloids (MIAs) vinblastine and vincristine, which both display anticancer activity. Both compounds can be obtained through the chemical condensation of their precursors vindoline and catharanthine extracted from leaves of the Madagascar periwinkle. However, the extensive use of these molecules in chemotherapy increases precursor demand and results in recurrent shortages, explaining why the development of alternative production approaches, such microbial cell factories, is mandatory. In this context, the precursor-directed biosynthesis of vindoline from tabersonine in yeast-expressing heterologous biosynthetic genes is of particular interest but has not reached high production scales to date. To circumvent production bottlenecks, the metabolic flux was channeled towards the MIA of interest by modulating the copy number of the first two genes of the vindoline biosynthetic pathway, namely tabersonine 16-hydroxylase and tabersonine-16-O-methyltransferase. Increasing gene copies resulted in an optimized methoxylation of tabersonine and overcame the competition for tabersonine access with the third enzyme of the pathway, tabersonine 3-oxygenase, which exhibits a high substrate promiscuity. Through this approach, we successfully created a yeast strain that produces the fourth biosynthetic intermediate of vindoline without accumulation of other intermediates or undesired side-products. This optimization will probably pave the way towards the future development of yeast cell factories to produce vindoline at an industrial scale.

Pharmacokinetic Considerations in Amputees

PURPOSE

The purpose of this article is to review the currently available assessment tools for measuring renal function, body weight, and body surface area in the amputee population.

METHODS

PubMed and Web of Science were searched using the following key terms: amputation, dose adjustment, and estimation of body weight. Articles published in languages other than English were excluded from the search.

RESULTS

Despite the increasing prevalence of amputations, there is little literature available that discusses its impact on the patient and how these physiological changes can affect pharmacokinetics. Very little information is available to guide dose adjustment in this patient population. This article discusses several factors to consider when determining optimum dosing regimens in patients with different levels of amputations.

CONCLUSION

This article will evaluate the applicability of methods mentioned in existing literature for measuring changes in renal function, body weight, and body surface area in amputees.

In vitro effect of curcumin in combination with chemotherapy drugs in Ph+ acute lymphoblastic leukemia cells

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), is characterized by the t(9;22)(q34q11) that generates the BCR-ABL protein with uncontrolled tyrosine kinase activity. Recently, a connection between BCR-ABL signaling with NF-κB activation mediated by CK2 has been hypothesized. Approximately 95% of patients with Ph+ ALL have the BCR-ABLp190 isoform, which causes aggressive leukemia with a high rate of chemotherapy resistance. Therefore, the use of compounds that could improve the efficacy of chemotherapy drugs is of particular interest. Curcumin is an active chemical in turmeric with antineoplastic potential; it regulates protein-kinases by modulating downstream molecular pathways. The present study evaluated the effect of curcumin in combination with the chemotherapeutic drugs vincristine, imatinib and daunorubicin in the human OP-1 cell line. Several doses of the chemotherapy drugs were examined, and the effects were evaluated following 12, 24 and 48 h of exposure. The interaction between the chemotherapy drugs and curcumin was determined by the dose-effect curve, which generated a combination index (CI); these data were represented in isobolograms. In addition, the individual effect of each drug was compared with its effect in combination with curcumin on cell viability, apoptosis degree, NF-κB activation and gene expression changes. The present study observed that curcumin potentiates the efficacy of vincristine and imatinib, generating an additive/synergistic effect in a dose- and time-dependent manner. These combinations significantly increased the apoptosis degree, decreased the activation of NF-κB and the expression of its regulated genes. Conversely treatment with daunorubicin + curcumin combination produced an antagonistic/additive effect in a dose-dependent manner, and this combination significantly increased the apoptosis degree. However, this effect seems not to be associated with NF-κB activity, as no significant changes were observed in its activation or in the expression of the genes that it regulates. The results of the present study demonstrate that curcumin may be used as an adjuvant agent for chemotherapy in patients with Ph+ ALL.

Nanopharmaceuticals and nanomedicines currently on the market: challenges and opportunities

There has been a revolution in nanotechnology and nanomedicine. Since 1980, there has been a remarkable increase in approved nano-based pharmaceutical products. These novel nano-based systems can either be therapeutic agents themselves, or else act as vehicles to carry different active pharmaceutical agents into specific parts of the body. Currently marketed nanostructures include nanocrystals, liposomes and lipid nanoparticles, PEGylated polymeric nanodrugs, other polymers, protein-based nanoparticles and metal-based nanoparticles. A range of issues must be addressed in the development of these nanostructures. Ethics, market size, possibility of market failure, costs and commercial development, are some topics which are on the table to be discussed. After passing all the ethical and biological assessments, and satisfying the investors as to future profitability, only a handful of these nanoformulations, successfully obtained marketing approval. We survey the range of nanomedicines that have received regulatory approval and are marketed. We discuss ethics, costs, commercial development and possible market failure. We estimate the global nanomedicine market size and future growth. Our goal is to summarize the different approved nanoformulations on the market, and briefly cover the challenges and future outlook.

Sphingosine metabolism as a therapeutic target in cutaneous melanoma

Melanoma is by far the most aggressive type of skin cancer with a poor prognosis in its advanced stages. Understanding the mechanisms involved in melanoma pathogenesis, response, and resistance to treatment has gained a lot of attention worldwide. Recently, the role of sphingolipid metabolism has been studied in cutaneous melanoma. Sphingolipids are bioactive lipid effector molecules involved in the regulation of various cellular signaling pathways such as inflammation, cancer cell proliferation, death, senescence, and metastasis. Recent studies suggest that sphingolipid metabolism impacts melanoma pathogenesis and is a potential therapeutic target. This review focuses on defining the role of sphingolipid metabolism in melanoma carcinogenesis, discussing sphingolipid-based therapeutic approaches, and highlighting the areas that require more extensive research.

Liposome Formulations of Hydrophobic Drugs

Here we report methods of preparation for liposome formulations containing lipophilic drugs. In contrast to the encapsulation of water soluble compounds into the entrapped aqueous volume of a liposome, drugs with lipophilic properties are incorporated into the phospholipid bilayer membrane. Water-soluble molecules, for example cytotoxic or antiviral nucleosides can be transformed into lipophilic compounds by attachment of long alkyl chains, allowing their stable incorporation into liposome membranes and taking advantage of the high loading capacity lipid bilayers provide for lipophilic molecules. We created a new class of cytotoxic drugs by chemical transformation of the hydrophilic drugs cytosine-arabinoside (ara-C), 5-fluoro-deoxyuridine (5-FdU), and ethinylcytidine (ETC) into lipophilic compounds and their formulation in liposomes.The concept of chemical modification of water-soluble molecules by attachment of long alkyl chains and their stable incorporation into liposome bilayer membranes represent a very promising method for the development of new drugs not only for the treatment of tumors or infections but also for many other diseases.

Treating adults with acute lymphocytic leukemia: new pharmacotherapy options

INTRODUCTION

Advances in acute lymphocytic leukemia (ALL) therapy has led to long-term survival rates in children. However, only 30%-40% of adults achieve long-term disease-free survival. After relapse, the outcome of salvage chemotherapy is very disappointing with less than 10% of long survival. Novel agents are therefore desperately required to improve response rates and survival, but also the quality of life of patients. Areas covered: The following review is a comprehensive summary of various novel options reported over the past few years in the therapeutic area of adult ALL. Expert opinion: Identifying key components involved in disease pathogenesis may lead to new approaches. In a near future, the incorporation of monoclonal antibodies and T-cell directed approaches including blinatumomab and chimeric antigen receptor T cells may increase the cure rates and may reduce the need for intensive therapy.

Lipid-Based Drug Delivery Systems in Cancer Therapy: What Is Available and What Is Yet to Come

Cancer is a leading cause of death in many countries around the world. However, the efficacy of current standard treatments for a variety of cancers is suboptimal. First, most cancer treatments lack specificity, meaning that these treatments affect both cancer cells and their normal counterparts. Second, many anticancer agents are highly toxic, and thus, limit their use in treatment. Third, a number of cytotoxic chemotherapeutics are highly hydrophobic, which limits their utility in cancer therapy. Finally, many chemotherapeutic agents exhibit short half-lives that curtail their efficacy. As a result of these deficiencies, many current treatments lead to side effects, noncompliance, and patient inconvenience due to difficulties in administration. However, the application of nanotechnology has led to the development of effective nanosized drug delivery systems known commonly as nanoparticles. Among these delivery systems, lipid-based nanoparticles, particularly liposomes, have shown to be quite effective at exhibiting the ability to: 1) improve the selectivity of cancer chemotherapeutic agents; 2) lower the cytotoxicity of anticancer drugs to normal tissues, and thus, reduce their toxic side effects; 3) increase the solubility of hydrophobic drugs; and 4) offer a prolonged and controlled release of agents. This review will discuss the current state of lipid-based nanoparticle research, including the development of liposomes for cancer therapy, different strategies for tumor targeting, liposomal formulation of various anticancer drugs that are commercially available, recent progress in liposome technology for the treatment of cancer, and the next generation of lipid-based nanoparticles.

Drug delivery systems and combination therapy by using vinca alkaloids

Developing new methods for chemotherapy drug delivery has become a topic of great concern. Vinca alkaloids are among the most widely used chemotherapy reagents for tumor therapy; however, their side effects are particularly problematic for many medical doctors. To reduce the toxicity and enhance the therapeutic efficiency of vinca alkaloids, many researchers have developed strategies such as using liposome-entrapped drugs, chemical- or peptide-modified drugs, polymeric packaging drugs, and chemotherapy drug combinations. This review mainly focuses on the development of a vinca alkaloid drug delivery system and the combination therapy. Five vinca alkaloids (eg, vincristine, vinblastine, vinorelbine, vindesine, and vinflunine) are reviewed.

Structure, development, preclinical and clinical efficacy of blinatumomab in acute lymphoblastic leukemia

ABSTRACT 

The treatment of acute lymphoblastic leukemia (ALL) in adults remains challenging and novel therapies are needed. The antigen, CD19, is expressed by >90% of pre-B ALLs and represents an attractive therapeutic target. The bispecific T-cell-engaging antibody, blinatumomab, targets CD19 and has demonstrated encouraging results in minimal residual disease positive and relapsed/refractory pre-B ALL. In this review, we discuss in detail the mechanism of action and key pharmacologic aspects of blinatumomab. In addition, the preclinical studies, clinical studies and toxicities are summarized.

Are PEGylated liposomes better than conventional liposomes? A special case for vincristine

Cancer poses a significant threat to human health worldwide, and many therapies have been used for its palliative and curative treatments. Vincristine has been extensively used in chemotherapy. However, there are two major challenges concerning its applications in various tumors: (1) Vincristine's antitumor mechanism is cell-cycle-specific, and the duration of its exposure to tumor cells can significantly affect its antitumor activity and (2) Vincristine is widely bio-distributed and can be rapidly eliminated. One solution to these challenges is the encapsulation of vincristine into liposomes. Vincristine can be loaded into conventional liposomes, but it quickly leak out owing to its high membrane permeability. Numerous approaches have been attempted to overcome this problem. Vincristine has been loaded into PEGylated liposomes to prolong circulation time and improve tumor accumulation. These liposomes indeed prolong circulation time, but the payout characteristic of vincristine is severer, resulting in a compromised outcome rather than a better efficacy compared to conventional sphingomyelin (SM)/cholesterol (Chol) liposomes. In 2012, the USA Food and Drug Administration (FDA) approved SM/Chol liposomal vincristine (Marqibo®) for commercial use. In this review, we mainly focus on the drug's rapid leakage problem and the potentially relevant solutions that can be applied during the development of liposomal vincristine and the reason for conventional liposomal vincristine rather than PEGylated liposomes has access to the market.

Liposomal vincristine for relapsed or refractory Ph-negative acute lymphoblastic leukemia: a review of literature

Acute lymphoblastic leukemia (ALL) is a heterogeneous group of hematologic malignancies that arise from clonal proliferation of immature lymphoid cells in the bone marrow, peripheral blood and other organs. There are approximately 3000 new adult cases diagnosed every year in the United States with a 5-year overall survival ranging from 22% to 50%. Most adult patients with ALL who achieve a complete response will ultimately relapse and for this subset of patients the only hope of curative therapy is successful re-induction to achieve a complete response followed by allogeneic transplant. Conventional vincristine has been used in all phases of ALL therapy but its efficacy is limited by cumulative toxicity, typically neuropathic in nature. Historically, the dose of conventional vincristine has been capped at 2 mg to avoid severe neurotoxicity. Liposomal vincristine [as vincristine sulfate liposomal injection (VSLI)] constitutes encapsulating vincristine in a sphingomyelin/cholesterol envelope. This process is thought to enhance drug delivery to the target tissues, decrease neurotoxicity by reducing the percentage of free drug in the plasma and therefore results in increased efficacy with acceptable toxicity. Results from recent trials using VSLI in the setting of relapsed/refractory Ph-negative ALL have been encouraging. VSLI as salvage monotherapy has been successful in inducing complete responses in a minority of adults with relapsed/refractory ALL so that they can be bridged to stem-cell transplantation. Rigorous post-approval testing needs to be conducted to clarify its utility in the clinic.

Bridging cancer biology and the patients' needs with nanotechnology-based approaches

Cancer remains as stressful condition and a leading cause of death in the western world. Actual cornerstone treatments of cancer disease rest as an elusive alternative, offering limited efficacy with extensive secondary effects as a result of severe cytotoxic effects in healthy tissues. The advent of nanotechnology brought the promise to revolutionize many fields including oncology, proposing advanced systems for cancer treatment. Drug delivery systems rest among the most successful examples of nanotechnology. Throughout time they have been able to evolve as a function of an increased understanding from cancer biology and the tumor microenvironment. Marketing of Doxil® unleashed a remarkable impulse in the development of drug delivery systems. Since then, several nanocarriers have been introduced, with aspirations to overrule previous technologies, demonstrating increased therapeutic efficacy besides decreased toxicity. Spatial and temporal targeting to cancer cells has been explored, as well as the use of drug combinations co-encapsulated in the same particle as a mean to take advantage of synergistic interactions in vivo. Importantly, targeted delivery of siRNA for gene silencing therapy has made its way to the clinic for a "first in man" trial using lipid-polymeric-based particles. Focusing in state-of-the-art technology, this review will provide an insightful vision on nanotechnology-based strategies for cancer treatment, approaching them from a tumor biology-driven perspective, since their early EPR-based dawn to the ones that have truly the potential to address unmet medical needs in the field of oncology, upon targeting key cell subpopulations from the tumor microenvironment.

Acute lymphoblastic leukemia in adults: encouraging developments on the way to higher cure rates

Conventional cytotoxic chemotherapy for adult acute lymphoblastic leukemia (ALL) is not adequate to cure most patients of the disease. Complete remission is achieved in the majority of patients, but responses are often not durable. Allogeneic stem cell transplant is used for patients with high risk features, including those who are positive for minimal residual disease after induction and consolidation therapy. Nevertheless, transplant is a toxic intervention, and does not guarantee long-term disease-free survival. Monoclonal antibodies target surface antigens present on leukemic blasts, with the aim of minimizing off-target toxicity. Rituximab, an antibody directed against CD20, prolongs the survival of younger adults with ALL when added to chemotherapy in the frontline setting. Novel agents, such as the cytotoxin-antibody conjugate inotuzumab, and the bispecific T-cell engaging compound blinatumomab, have exhibited marked antileukemic activity in the relapsed setting. As these agents continue in clinical development, it will be important to eventually incorporate them in the frontline treatment approach. We review current strategies for treating adult ALL, with a focus on novel and targeted therapies that are under development.

High-dose vincristine sulfate liposome injection (Marqibo) Is not associated with clinically meaningful hematologic toxicity

BACKGROUND

Vincristine sulfate liposome injection (VSLI) facilitates vincristine dose intensification and densification, is active in untreated and relapsed lymphoma, and has been approved in the United States for relapsed and refractory acute lymphoblastic leukemia. Cancer- and concomitant chemotherapy-related anemia, neutropenia, and thrombocytopenia in patients with hematologic malignancy have complicated the evaluation of hematologic toxicity related to new drugs.

PATIENTS AND METHODS

We assessed the hematologic toxicity of VSLI 2.25 mg/m(2) administered every 14 (cohort 1) or 7 (cohort 2) days in 54 patients with metastatic uveal melanoma, a cancer not known to involve the bone marrow.

RESULTS

Cohort 2 received a greater median number of VSLI doses (6 vs. 4) within a shorter median period (5.7 vs. 8.7 weeks), resulting in a larger median cumulative exposure (22.6 vs. 17.7 mg) and near doubling of the median dose density (2.2 vs. 4.0 mg/wk) compared with cohort 1. Despite greater VSLI exposure and dose density, cohort 2 had a lower median decrease from baseline in the neutrophil count and a greater increase from baseline in the platelet count compared with cohort 1. Hematologic adverse events (AEs) were uncommon and mostly grade 1 or 2 in severity. No grade 4 hematologic AEs developed.

CONCLUSION

VSLI at its approved dose resulted in a low incidence of clinically meaningful hematologic toxicity. A near doubling of the median dose density did not have an identifiable effect on the reported incidence and severity of hematologic AEs. VSLI could be well suited for use combined with myelosuppresive drugs and for patients unable to tolerate peripheral blood cytopenia.

Vincristine sulfate liposomal injection for acute lymphoblastic leukemia

Vincristine (VCR) is one of the most extensively used cytotoxic compounds in hemato-oncology. VCR is particularly important for the treatment of acute lymphoblastic leukemia (ALL), a disease that accounts for approximately one-third of all childhood cancer diagnoses. VCR's full therapeutic potential has been limited by dose-limiting neurotoxicity, classically resulting in autonomic and peripheral sensory-motor neuropathy. In the last decade, however, the discovery that liposomal encapsulation of chemotherapeutics can modulate the pharmacokinetic characteristics of a compound has stimulated much interest in liposomal VCR (vincristine sulfate liposomal injection [VSLI]) formulations for the treatment of ALL and other hematological malignancies. Promising data from recent clinical trials investigating VSLI in adults with ALL resulted in US Food and Drug Administration approval for use in patients with Philadelphia chromosome (t[9;22]/BCR-ABL1) (Ph)-negative (Ph-) disease. Additional clinical trials of VSLI in adults and children with both Ph-positive (Ph+) and Ph- ALL are ongoing. Here we review the preclinical and clinical experience to date with VSLI for ALL.

Treating relapsed or refractory Philadelphia chromosome-negative acute lymphoblastic leukemia: liposome-encapsulated vincristine

Acute lymphoblastic leukemia (ALL) remains a disease with poor outcomes in adults. While induction chemotherapy achieves a complete remission in almost 90% of patients, the majority will relapse and die of their disease. Relapsed ALL is associated with a high reinduction mortality and chemotherapy resistance, with allogeneic hematopoietic stem cell transplantation offering the only therapy with curative potential. However, there is no efficacious and well tolerated standard regimen accepted as a “bridge” to allogeneic stem cell transplantation or as definitive treatment for patients who are not transplant candidates. Vincristine is an active drug in patients with ALL, but its dose intensity is limited by neurotoxicity, and its full potential as an anticancer drug is thus not realized. Encapsulation of vincristine into sphingomyelin and cholesterol nanoparticle liposomes facilitates dose-intensification and densification to enhanced target tissues with reduced potential for toxicity. Vincristine sulfate liposome injection (VSLI) is associated with significant responses in clinically advanced ALL, and has recently been approved by the US Food and Drug Administration for treatment of relapsed and clinically advanced Philadelphia chromosome-negative ALL. This review provides an overview of the preclinical and clinical studies leading to the approval of VSLI for the treatment of relapsed and refractory ALL, and suggests potential areas of future clinical development.

The protective role of parsley extract against vincristine mutagenicity in Drosophila melanogaster

In this study, Drosophila melanogaster males were treated with parsley plant extract and the anticancer drug vincristine (VCR) singly and in combined treatments (pre, co and post-treatments) to detect the mutagenic effects by using sex-linked recessive lethal test (SLRL) and estimation of cholinesterase enzyme (ChE) activities in order to compare the sensitivity of the two test systems. A wild type strain Oregon-R (Or-R) male flies of D. melanogaster were reared on a medium containing one concentration of each of VCR and parsley (4 ml/100 ml medium) in each single and combined treatment. Also the activity of ChE was estimated in some insects of the two generations: F1 females, F2 bar eye females (heterozygous) and F2 wild types males. The results indicate that both of parsley and vincristine did not cause significant increases of SLRL test in either the single or combined treatments. In contrast, estimation of ChE activities showed significant increase in all the broods within single and combination treatments, except female of the second generation of spermatid brood which treated with parsley and VCR at the same time. It is concluded that enzyme estimation is more sensitive than SLRL test for detection the mutagenic effect for parsley's extract and vincristine.

Vincristine sulfate liposome injection: a guide to its use in refractory or relapsed acute lymphoblastic leukemia

Adult patients with acute lymphoblastic leukemia frequently relapse or are refractory to conventional treatments. The vincristine sulfate liposome injection (Marqibo(®)) encapsulates the drug in a liposome composed of sphingomyelin and cholesterol to improve tumor drug exposure. At a dose of 2.25 mg/m(2) once weekly, this formulation was associated with an overall response rate of 35 % in adults with Philadelphia chromosome-negative relapsed or refractory disease. There were no new or unexpected toxicities.

Diverse functions of ceramide in cancer cell death and proliferation

Ceramide, a bioactive sphingolipid, is now at the forefront of cancer research. Classically, ceramide is thought to induce death, growth inhibition, and senescence in cancer cells. However, it is now clear that this simple picture of ceramide no longer holds true. Recent studies suggest that there are diverse functions of endogenously generated ceramides, which seem to be context dependent, regulated by subcellular/membrane localization and presence/absence of direct targets of these lipid molecules. For example, different fatty-acid chain lengths of ceramide, such as C(16)-ceramide that can be generated by ceramide synthase 6 (CerS6), have been implicated in cancer cell proliferation, whereas CerS1-generated C(18)-ceramide mediates cell death. The dichotomy of ceramides' function in cancer cells makes some of the metabolic enzymes of ceramide synthesis potential drug targets (such as Cers6) to prevent cancer growth in breast and head and neck cancers. Conversely, activation of CerS1 could be a new therapeutic option for the development of novel strategies against lung and head and neck cancers. This chapter focuses on recent discoveries about the mechanistic details of mainly de novo-generated ceramides and their signaling functions in cancer pathogenesis, and about how these mechanistic information can be translated into clinically relevant therapeutic options for the treatment of cancer.

Drug Monographs: Ziv-aflibercept and Vincristine Sulfate Liposome

The complexity of cancer chemotherapy requires pharmacists be familiar with the complicated regimens and highly toxic agents used. This column reviews various issues related to preparation, dispensing, and administration of antineoplastic therapy, and the agents, both commercially available and investigational, used to treat malignant diseases.

Relapsed or refractory pediatric acute lymphoblastic leukemia: current and emerging treatments

Relapsed acute lymphoblastic leukemia (ALL) represents a major cause of morbidity and mortality in pediatrics. With contemporary chemotherapy, >85% of patients with newly diagnosed ALL survive. Unfortunately, 20% of these patients will relapse and for these children, outcomes remain poor despite our best known chemotherapy protocols. Most of these children will achieve a second complete remission, but maintaining this remission remains difficult. Because relapsed ALL is such a significant cause of morbidity and mortality, it is the focus of much research interest. Efforts have been made and continue to focus on understanding the underlying biology that drives relapse. The role of hematopoietic stem cell transplantation in relapsed ALL remains unclear, but many clinicians still favor this for high-risk patients given the poor prognosis with current chemotherapy alone. It is important to use new drugs with little cross-resistance in the treatment of relapsed ALL. New classes of agents are currently being studied. We also discuss prognostic factors and the biology of relapsed ALL.

Lipid-based nanoparticle delivery of Pre-miR-107 inhibits the tumorigenicity of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer worldwide with about 600,000 new cases diagnosed in the last year. Our laboratory showed that miR-107 expression is reduced and functions as a tumor suppressor gene in HNSCC suggesting the potential application of miR-107 as a novel anticancer therapeutic. In this study, we determined the efficiency and efficacy of cationic lipid nanoparticles to deliver pre-miR-107 (NP/pre-miR-107) in HNSCC cells in vitro and in vivo. NP/pre-miR-107 increased delivery of miR-107 into HNSCC cells by greater than 80,000-fold compared to free pre-miR-107. Levels of known miR-107 targets, protein kinase Cε (PKCε), cyclin-dependent kinase 6 (CDK6), and hypoxia-inducible factor 1-β (HIF1-β), decreased following NP/pre-miR-107 treatment. Clonogenic survival, cell invasion, and cell migration of HNSCC cells was inhibited with NP/pre-miR-107. Moreover, NP/pre-miR-107 reduced the cancer-initiating cell (CIC) population and dampened the expression of the core embryonic stem cell transcription factors, Nanog, Oct3/4, and Sox2. In a preclinical mouse model of HNSCC, systemic administration of NP/pre-miR-107 significantly retarded tumor growth by 45.2% compared to NP/pre-miR-control (P < 0.005, n = 7). Kaplan-Meier analysis showed a survival advantage for the NP/pre-miR-107 treatment group (P = 0.017). Our results demonstrate that cationic lipid nanoparticles are an effective carrier approach to deliver therapeutic miRs to HNSCC.

Pharmacotherapeutic advances in the treatment of acute lymphoblastic leukaemia in adults

Acute lymphoblastic leukaemia (ALL) in adults is a challenging malignancy in that many patients will show evidence of initial chemotherapy responsiveness but will subsequently relapse. The disease is heterogeneous and outcomes vary dramatically depending on the prognostic factors present in an individual patient. An important determinant of outcome is the age of the patient. The stunning success of therapy in paediatric ALL has led to the use of intensive paediatric regimens in adolescents and young adults with what appear to be improved outcomes. For patients who relapse or have high-risk features, blood and marrow transplantation (BMT) continues to play an important role in the therapeutic armamentarium. The use of reduced-intensity conditioning regimens for allogeneic BMT suggests that outcomes may be improved by this approach. Monoclonal antibodies are showing benefit as single agents in the relapsed setting or in combination with chemotherapy in newly diagnosed patients. In recent years, several new chemotherapeutic agents have shown promise as single agents and are being incorporated into multi-agent chemotherapy. The development of tyrosine kinase inhibitors for Philadelphia chromosome-positive leukaemias has significantly improved outcomes. The molecular revolution has led to the identification of new aberrant molecular pathways in the pathogenesis of ALL, and drugs targeting these aberrancies are in various stages of development preclinically and clinically. These developments bring the hope that therapeutic outcomes in adult ALL can begin to approach those seen in the paediatric setting.

Liposomes functionalized with acidic lipids rescue Aβ-induced toxicity in murine neuroblastoma cells

The loss of synapses and neurons in Alzheimer's disease (AD) is thought to be at least partly induced by toxic species formed by the amyloid beta (Aβ) peptide; therefore, therapeutics aimed at reducing Aβ toxicity could be of clinical use for treatment of AD. Liposomes are suitable vehicles for therapeutic agents and imaging probes, and a promising way of targeting the various Aβ forms. We tested liposomes functionalized with phosphatidic acid, cardiolipin, or GM1 ganglioside, previously shown to have high Aβ-binding capacity. Mimicking Aβ-induced toxicity in mouse neuroblastoma cell lines, combined with administration of cell viability-modulating agents, we observed that functionalized liposomes rescued cell viability to different extents. We also detected rescue of the imbalance of GSK-3β and PP2A activity, and reduction in tau phosphorylation. Thus, these liposomes appear particularly suitable for implementing further therapeutic strategies for AD.

Anthracycline dose intensification in adult acute lymphoblastic leukemia: lack of benefit in the context of the fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone regimen

BACKGROUND

In previous studies of frontline therapy for adult acute lymphoblastic leukemia (ALL), early treatment with higher doses of anthracyclines has been reported to improve outcome. The current study was conducted to evaluate whether addition of anthracycline-based consolidation chemotherapy (Course 2) with liposomal daunorubicin (150 mg/m2 intravenously [IV] on Days 1 and 2) and cytarabine (1.5 g/m2 IV on Days 1 and 2) to the standard hyper-CVAD regimen (fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with high dose methotrexate and cytarabine) would improve outcome.

METHODS

Sixty-eight consecutive adults with de novo ALL or lymphoblastic lymphoma were treated with this modified hyper-CVAD regimen inclusive of rituximab for CD20 expression≥20%.

RESULTS

Sixty-three (93%) patients achieved complete response (CR). With a median follow-up of 90 months, the 5-year CR duration (CRD) and overall survival (OS) rates were 46% and 44%, respectively. Compared with 208 patients treated with standard hyper-CVAD (rates of 45% and 47%, respectively; P=not significant), outcome with the modified hyper-CVAD regimen was not improved overall. Outcome was improved by the addition of rituximab for the CD20-positive subset (rates of CRD and OS of 50% and 53%, respectively), whereas anthracycline intensification worsened outcome for the CD20-negative subset (rates of CRD and OS of 41% and 35%, respectively; P=.01) compared with standard hyper-CVAD. A high mortality rate related to infections in CR was noted among patients aged 60 years or older.

CONCLUSIONS

In the context of the hyper-CVAD regimen, early anthracycline intensification did not improve outcome for adults with de novo ALL or lymphoblastic lymphoma.

Pharmacokinetics and safety of Marqibo (vincristine sulfate liposomes injection) in cancer patients with impaired liver function

Marqibo (vincristine sulfate liposome injection, VSLI) is a novel liposomal formulation of vincristine sulfate (VCR) being developed for the systemic treatment of cancer. This study evaluated the pharmacokinetics (PK) of Marqibo in subjects with melanoma and impaired hepatic function. Calculated PK parameters were similar in subjects with impaired liver function compared with those in subjects with adequate liver function. Subjects with impaired liver function universally had a monoexponential total plasma VCR concentration versus time decline, whereas two thirds of subjects with adequate liver function had a biexponential decline profile. Because one third of subjects with normal hepatic function demonstrated monoexponential disposition, lack of biexponential disposition in the hepatically impaired subjects cannot be clearly attributed to liver impairment. VSLI was generally well tolerated in all subjects.

Novel therapies for relapsed acute lymphoblastic leukemia

The outcome of salvage therapy for relapsed acute lymphoblastic leukemia (ALL) remains poor. Salvage therapy mimics regimens with activity in newly diagnosed ALL. Novel strategies under investigation as monotherapy or in combination with chemotherapy improve the treatment of relapsed disease. For some ALL subsets, specific therapies are indicated. The addition of targeted therapy in Philadelphia chromo some-positive ALL has improved responses in relapsed patients without resistance to available tyrosine kinase inhibitors. Nelarabine demonstrates activity as monotherapy in T-cell ALL and is approved by the US Food and Drug Administration. Clofarabine, a second-generation purine analogue approved in pediatric leukemia, has shown activity in adult acute leukemias including ALL and acute myeloid leukemia. The role of pegaspargase in adult ALL requires further investigation. The benefit of matched related-donor allogeneic stem cell transplantation is significant for standard-risk ALL but not for high-risk ALL. Development of new drugs and agents tailored to subset-specific cytogenetic-molecular characteristics remains vital to success in treating adult ALL.

Emerging therapy for the treatment of acute lymphoblastic leukemia

IMPORTANCE OF THE FIELD

Over the last few decades, advances in acute lymphoblastic leukemia (ALL) therapy have led to long-term survival rates of > 80% in children; however, comparable rates have yet to be achieved in adults, and a large majority of patients relapse from their disease.

AREAS COVERED IN THIS REVIEW

The review describes historical therapy and advancements in ALL treatment over the past few decades, while providing a concise review of the future direction of ALL therapy. Literature was collected through peer reviewed journals and the Pharmaprojects drug profile for ALL.

WHAT THE READER WILL GAIN

Current information regarding prognostic factors for relapse, salvage therapy options and emerging drugs are provided in the review.

TAKE HOME MESSAGE

Development of new drugs with novel mechanisms, unique formulations of existing medications, as well as manipulation of current combinations of drugs remain vital to the success in adult ALL.

Liposome formulations of hydrophobic drugs

Here, we report methods of preparation for liposome formulations containing lipophilic drugs. In contrast to the encapsulation of water-soluble compounds into the entrapped aqueous volume of a liposome, drugs with lipophilic properties are incorporated into the phospholipid bilayer membrane. Water-soluble molecules, for example, cytotoxic or antiviral nucleosides can be transformed into lipophilic compounds by attachment of long alkyl chains, allowing their stable incorporation into liposome membranes and taking advantage of the high loading capacity lipid bilayers provide for lipophilic molecules. We created a new class of cytotoxic drugs by chemical transformation of the hydrophilic drugs cytosine-arabinoside (ara-C), 5-fluoro-deoxyuridine (5-FdU) and ethinylcytidine (ETC) into lipophilic compounds and their formulation in liposomes. The concept of chemical modification of water-soluble molecules by attachment of long alkyl chains and their stable incorporation into liposome bilayer membranes represent a very promising method for the development of new drugs not only for the treatment of tumors or infections, but also for many other diseases.

Phase 1 multicenter study of vincristine sulfate liposomes injection and dexamethasone in adults with relapsed or refractory acute lymphoblastic leukemia

BACKGROUND

Dose intensification of chemotherapy has improved outcome for younger adults with de novo acute lymphoblastic leukemia (ALL). Novel formulations of standard chemotherapy agents may further reduce the incidence of disease recurrence after frontline chemotherapy. Vincristine (VCR) sulfate liposomes injection (VSLI) is a sphingomyelin/cholesterol nanoparticle encapsulated VCR formulation that improves the pharmacokinetic profile of VCR without augmenting neurotoxicity.

METHODS

A phase 1 trial of weekly, intravenous VSLI at 1.5 mg/m(2), 1.825 mg/m(2), 2.0 mg/m(2), 2.25 mg/m(2), or 2.4 mg/m(2) was conducted to determine the maximum tolerated dose (MTD) using a standard, 3 + 3 dose-escalation design. Dexamethasone (40 mg) was given on Days 1 through 4 and on Days 11 through 14 of each 4-week cycle.

RESULTS

Thirty-six adults with relapsed/refractory ALL, all previously treated with conventional VCR, received at least 1 dose of VSLI. The MTD of VSLI was 2.25 mg/m(2) based on dose-limiting toxicities of grade 3 motor neuropathy, grade 4 seizure, and grade 4 hepatotoxicity in 1 patient each at the 2.4 mg/m(2) dose level. The most common toxicities attributed to VSLI included peripheral neuropathy (55%) and constipation (53%). A complete response (CR) was achieved in 7 of 36 patients (19%) based on an intent-to-treat analysis; the CR rate was 29% for the 14 patients who underwent therapy as their first salvage attempt. Four of 7 patients who achieved a CR underwent subsequent allogeneic stem cell transplantation in remission.

CONCLUSIONS

In this study, VSLI plus dexamethasone appeared to be an effective salvage therapy option for relapsed/refractory ALL. A phase 2, international, multicenter clinical trial assessing the efficacy of single-agent VSLI as second salvage therapy for patients with previously treated ALL is underway.

New therapeutic strategies in acute lymphoblastic leukemia

While cure rates of over 80% are achieved in contemporary pediatric acute lymphoblastic leukemia (ALL) protocols, most adults with ALL succumb to their disease, and little progress has been made in the treatment of refractory and relapsed ALL. Moreover, the burden of therapy is high in a significant number of newly diagnosed patients, and in all those with relapse. Early response to therapy measured by minimal residual disease evaluation has proven the single most important prognostic factor and is increasingly used in risk stratification. However, as the benefit from intensification of frontline therapy becomes limiting, it becomes increasingly challenging to rescue patients who fail on contemporary risk-adapted protocols. New therapeutic strategies are needed, not only in salvage regimens but also in frontline protocols for patients who are at high risk of relapse. Current novel approaches include new formulations of existing chemotherapeutic agents, new antimetabolites and nucleoside analogs, monoclonal antibodies against leukemic-associated antigens, cellular immunotherapy, and molecular therapeutics. Some have already been adopted into standard regimens, while others remain in early stages of development. This review summarizes the current status of these novel therapies as they get integrated into ALL regimens.

Characterization of highly stable liposomal and immunoliposomal formulations of vincristine and vinblastine

Purpose

Liposome and immunoliposome formulations of two vinca alkaloids, vincristine and vinblastine, were prepared using intraliposomal triethylammonium sucroseoctasulfate and examined for their ability to stabilize the drug for targeted drug delivery in vivo.

Methods

The pharmacokinetics of both the encapsulated drug (vincristine or vinblastine) and liposomal carrier were examined in Sprague Dawley rats, and the in vivo drug release rates determined. Anti-HER2 immunoliposomal vincristine was prepared from a human anti-HER2/neu scFv and studied for targeted cytotoxic activity in cell culture, and antitumor efficacy in vivo.

Results

Nanoliposome formulations of vincristine and vinblastine demonstrated similar pharmacokinetic profiles for the liposomal carrier, but increased clearance for liposome encapsulated vinblastine (t_1/2 = 9.7 h) relative to vincristine (t_1/2 = 18.5 h). Immunoliposome formulations of vincristine targeted to HER2 using an anti-HER2 scFv antibody fragment displayed a marked enhancement in cytotoxicity when compared to non-targeted liposomal vincristine control; 63- or 253-fold for BT474 and SKBR3 breast cancer cells, respectively. Target-specific activity was also demonstrated in HER2-overexpressing human tumor xenografts, where the HER2-targeted formulation was significantly more efficacious than either free vincristine or non-targeted liposomal vincristine.

Conclusions

These results demonstrate that active targeting of solid tumors with liposomal formulations of vincristine is possible when the resulting immunoliposomes are sufficiently stabilized.

Lipid-based nanoparticles as pharmaceutical drug carriers: from concepts to clinic

In recent years, various nanotechnology platforms in the area of medical biology, including both diagnostics and therapy, have gained remarkable attention. Moreover, research and development of engineered multifunctional nanoparticles as pharmaceutical drug carriers have spurred exponential growth in applications to medicine in the last decade. Design principles of these nanoparticles, including nanoemulsions, dendrimers, nano-gold, liposomes, drug-carrier conjugates, antibody-drug complexes, and magnetic nanoparticles, are primarily based on unique assemblies of synthetic, natural, or biological components, including but not limited to synthetic polymers, metal ions, oils, and lipids as their building blocks. However, the potential success of these particles in the clinic relies on consideration of important parameters such as nanoparticle fabrication strategies, their physical properties, drug loading efficiencies, drug release potential, and, most importantly, minimum toxicity of the carrier itself. Among these, lipid-based nanoparticles bear the advantage of being the least toxic for in vivo applications, and significant progress has been made in the area of DNA/RNA and drug delivery using lipid-based nanoassemblies. In this review, we will primarily focus on the recent advances and updates on lipid-based nanoparticles for their projected applications in drug delivery. We begin with a review of current activities in the field of liposomes (the so-called honorary nanoparticles), and challenging issues of targeting and triggering will be discussed in detail. We will further describe nanoparticles derived from a novel class of amphipathic lipids called bolaamphiphiles with unique lipid assembly features that have been recently examined as drug/DNA delivery vehicles. Finally, an overview of an emerging novel class of particles (based on lipid components other than phospholipids), solid lipid nanoparticles and nanostructured lipid carriers will be presented. We conclude with a few examples of clinically successful formulations of currently available lipid-based nanoparticles.

Roles of bioactive sphingolipids in cancer biology and therapeutics

In this chapter, roles of bioactive sphingolipids in the regulation of cancer pathogenesis and therapy will be reviewed. Sphingolipids have emerged as bioeffector molecules, which control various aspects of cell growth, proliferation, and anti-cancer therapeutics. Ceramide, the central molecule of sphingolipid metabolism, generally mediates anti-proliferative responses such as inhibition of cell growth, induction of apoptosis, and/or modulation of senescence. On the other hand, sphingosine 1-phosphate (S1P) plays opposing roles, and induces transformation, cancer cell growth, or angiogenesis. A network of metabolic enzymes regulates the generation of ceramide and S1P, and these enzymes serve as transducers of sphingolipid-mediated responses that are coupled to various exogenous or endogenous cellular signals. Consistent with their key roles in the regulation of cancer growth and therapy, attenuation of ceramide generation and/or increased S1P levels are implicated in the development of resistance to drug-induced apoptosis, and escape from cell death. These data strongly suggest that advances in the molecular and biochemical understanding of sphingolipid metabolism and function will lead to the development of novel therapeutic strategies against human cancers, which may also help overcome drug resistance.

Enhanced therapeutic effects on the multi-drug resistant human leukemia cells in vitro and xenograft in mice using the stealthy liposomal vincristine plus quinacrine

The multi-drug resistance (MDR) could be caused by the over-expression of adenosine triphosphate binding cassette transporters such as p-glycoprotein, thereby resulting in the efflux of anti-cancer drugs from the cells. An anti-resistant stealthy liposomal vincristine plus quinacrine was defined in this study. Human chronic myelogenous leukemia K562 and MDR K562 cells were included for comparisons. Anti-tumor activity studies were performed on female BALB/c nude mice with MDR K562 cell xenografts. Results showed that quinacrine was effective in reversing the resistance in the MDR K562 cells, and enhanced the anti-tumor effect of vincristine in K562 cells. The caspase-9 and -3 activities in the MDR K562 and K562 cells were increased with the dose rise of quinacrine. In the MDR K562 cell xenografts in mice, the anti-resistant tumor effect of the stealthy liposomal vincristine plus quinacrine was evidently observed. The enhanced anti-tumor effects of vincristine by quinacrine in the resistant/non-resistant K562 cells could be because of the direct injury and the potentiating apoptotic effect of vincristine via activating the initiator caspase-9 and subsequently the effector caspase-3, and the long circulatory effect of stealthy liposomes. The stealthy liposomal encapsulation of vincristine plus quinacrine could be a potential therapeutic approach for resistant human leukemia.