Preclinical development of a C6-ceramide NanoLiposome, a novel sphingolipid therapeutic.

Despite the therapeutic potential of sphingolipids, the ability to develop this class of compounds as active pharmaceutical ingredients has been hampered by issues of solubility and delivery. Beyond these technical hurdles, significant challenges in completing the necessary preclinical studies to support regulatory review are necessary for commercialization. This review seeks to identify the obstacles and potential solutions in the translation of a novel liposomal technology from the academic bench to investigational new drug (IND) stage by discussing the preclinical development of the Ceramide NanoLiposome (CNL), which is currently being developed as an anticancer drug for the initial indication of hepatocellular carcinoma (HCC).

A phase I study of the ceramide nanoliposome in patients with advanced solid tumors.

PURPOSE: Ceramide is a sphingolipid metabolite that deactivates multiple oncogenic signaling pathways and promotes cell death. In-vivo data demonstrate single-agent anti-cancer activity and enhanced efficacy with combination strategies. This phase I dose-escalation trial evaluated Ceramide nanoLiposomes (CNL) in patients with advanced solid tumors and no standard treatment option. METHODS: The primary objective was to establish the maximum tolerated dose. Secondary objectives included determining the recommended phase II dose, the safety and tolerability, the pharmacokinetic profile and preliminary anti-tumor efficacy. RESULTS: 15 patients with heavily pretreated metastatic disease enrolled. Safety data were analyzed for all patients, while pharmacokinetic data were available for 14 patients. There were no grade 3 or higher treatment-related adverse events. The maximum tolerated dose was not reached and there were no dose-limiting toxicities. The most common grade 1 or 2 treatment-related adverse events included headache, fatigue, constipation, nausea and transaminitis. The maximum concentration and area under the curve increased with dose. Clearance was consistent between doses and was observed mainly through the liver without significant hepatotoxicity. The half-life ranged from 20 to 30 h and the volume of distribution was consistent with a lipophilic drug. CONCLUSIONS: CNL exhibited an encouraging safety profile and pharmacokinetic parameters, with some signals of efficacy including prolonged stable disease in 1 patient with refractory pancreatic cancer. Pre-clinical data indicate potential synergy between CNL and multiple systemic therapies including chemotherapy, targeted therapy, and immunotherapy. Future studies are planned investigating CNL in combination strategies. TRIAL REGISTRATION: This study is registered under ClinicalTrials.gov ID: NCT02834611.

Replacement of adenylate cyclase toxin in a lineage of Bordetella bronchiseptica.

Bordetella bronchiseptica is a gram-negative respiratory pathogen that infects a wide range of hosts and causes a diverse spectrum of disease. This diversity is likely affected by multiple factors, such as host immune status, polymicrobial infection, and strain diversity. In a murine model of infection, we found that the virulence of B. bronchiseptica strains, as measured by the mean lethal dose, varied widely. Strain 253 was less virulent than the typically studied strain, RB50. Transcriptome analysis showed that cyaA, the gene encoding adenylate cyclase toxin (CyaA), was the most downregulated transcript identified in strain 253 compared to that in strain RB50. Comparative genomic hybridization and genome sequencing of strain 253 revealed that the cya locus, which encodes, activates, and secretes CyaA, was replaced by an operon (ptp) predicted to encode peptide transport proteins. Other B. bronchiseptica strains from the same phylogenetic lineage as that of strain 253 also lacked the cya locus, contained the ptp genes, and were less virulent than strain RB50. Although the loss of CyaA would be expected to be counterselected since it is conserved among the classical bordetellae and believed to be important to their success, our data indicate that the loss of this toxin and the gain of the ptp genes occurred in an ancestral strain that then expanded into a lineage. This suggests that there may be ecological niches in which CyaA is not critical for the success of B. bronchiseptica.

Nanoparticulate alternatives for drug delivery.

The ability to apply nanomaterials as targeted delivery agents for drugs and other therapeutics holds promise for a wide variety of diseases, including many types of cancer. A nanodelivery vehicle must demonstrate in vivo efficacy, diminished or no toxicity, stability, improved pharmacokinetics, and controlled-release kinetics. In this issue, Lee et al. construct polymer nanobins that fulfill these requirements and demonstrate effective delivery of doxorubicin in vivo to breast cancer cells. This Perspective explores the outlook for these nanobins as well as other technologies in this field and the challenges that lie ahead.

Calcium phosphate nanocomposite particles for in vitro imaging and encapsulated chemotherapeutic drug delivery to cancer cells.

Paradigm-shifting modalities to more efficiently deliver drugs to cancerous lesions require the following attributes: nanoscale-size, targetability, and stability under physiological conditions. Often, these nanoscale drug delivery vehicles are limited due to agglomeration, poor solubility, or cytotoxicity. Thus, we have designed a methodology to encapsulate hydrophobic antineoplastic chemotherapeutics within a 20-30 nm diameter, pH-responsive, nonagglomerating, nontoxic calcium phosphate nanoparticle matrix. In the present study, we report on calcium phosphate nanocomposite particles (CPNPs) that encapsulate both fluorophores and chemotherapeutics, are colloidally stable in physiological solution for an extended time at 37 degrees C and can efficaciously deliver hydrophobic antineoplastic agents, such as ceramide, in several cell model systems.