Activity and safety of pegylated liposomal doxorubicin, 5-fluorouracil and folinic acid in inoperable hepatocellular carcinoma: A phase II study

Optimized 5-Fluorouridine Prodrug for Co-Loading with Doxorubicin in Clinically Relevant Liposomes

Liposome-based drug delivery systems have allowed for better drug tolerability and longer circulation times but are often optimized for a single agent due to the inherent difficulty of co-encapsulating two drugs with differing chemical profiles. Here, we design and test a prodrug based on a ribosylated nucleoside form of 5-fluorouracil, 5-fluorouridine (5FUR), with the final purpose of co-encapsulation with doxorubicin (DOX) in liposomes. To improve the loading of 5FUR, we developed two 5FUR prodrugs that involved the conjugation of either one or three moieties of tryptophan (W) known respectively as, 5FUR−W and 5FUR−W₃. 5FUR−W demonstrated greater chemical stability than 5FUR−W3 and allowed for improved loading with fewer possible byproducts from tryptophan hydrolysis. Varied drug ratios of 5FUR−W: DOX were encapsulated for in vivo testing in the highly aggressive 4T1 murine breast cancer model. A liposomal molar ratio of 2.5 5FUR−W: DOX achieved a 62.6% reduction in tumor size compared to the untreated control group and a 33% reduction compared to clinical doxorubicin liposomes in a proof-of-concept study to demonstrate the viability of the co-encapsulated liposomes. We believe that the new prodrug 5FUR−W demonstrates a prodrug design with clinical translatability by reducing the number of byproducts produced by the hydrolysis of tryptophan, while also allowing for loading flexibility.

On the Bayesian Derivation of a Treatment-based Cancer Ontology

Traditional cancer classifications are primarily based on anatomical locations. As knowledge is heavily compartmentalized in the oncological specialties, discovering new targets for existing drugs (drug inference) can take years. Furthermore, our lack of understanding of the mechanisms underlying drug efficacy sometimes undercuts the effectiveness of genetic approaches to drug inference. This study tackles the twin problems of cancer reclassification and drug inference by constructing a global cancer ontology inductively from treatment regimens. A topological abstraction algorithm was performed on the bipartite graph of drugs and cancers to highlight important edges, and a Bayesian algorithm was then applied to determine a new treatment-based classification of cancer, producing 6 highly significant clusters (p < 0.05), confirmed by Fisher's exact test and enrichment analyses. Edge probabilities derived from its drug inference routine matched real edge frequencies (R2 ≈ 0.96). Drug inference results were reinforced by the identification of relevant published Phase II and III clinical trials, and the drug inference routine differentiated between high- and low-likelihood targets (p < 0.05). This novel treatment-based ontology has the potential to reorganize cancer research and provide powerful tools for drug inference using global patterns of drug efficacy.

A phase II study of pemetrexed in patients with advanced hepatocellular carcinoma

Pemetrexed has demonstrated activity in hepatocellular carcinoma (HCC) cell lines, and has a manageable toxicity profile in clinical trials, suggesting its potential as a treatment for HCC patients. A multicenter, Phase II community-based study was conducted to assess the response rate and toxicity profile of single-agent pemetrexed in first-line patients with advanced or metastatic HCC. Patients premedicated with folic acid, vitamin B(12), and dexamethasone were administered pemetrexed 600 mg/m(2) IV on day 1 of each 21-day cycle until disease progression. This nonrandomized study employed Simon's 2-stage design, enrolling 21 eligible patients in the first stage, stopping accrual if < or =2 responders were observed. Responses were four stable disease, 14 progressive disease, and three not evaluable: two had early toxicities (renal/liver failure, sepsis) and one was noncompliant. The most common grade 3 hematological toxicities were neutropenia 6 of 21 (29%) and thrombocytopenia 3 of 21 (14%); with no grade 4 toxicities. Thirteen patients died on-study: 12 PD and one liver failure; none were drug-related. The median survival was 5.2 months (range, <1-12.2). The planned second stage was cancelled, and the trial was closed owing to lack of response. While pemetrexed was tolerated in this patient population, it was not active.