Progress in differentiation induction as a treatment for acute promyelocytic leukemia and beyond.

The Joint International Conference on Acute Promyelocytic Leukemia and Differentiation Therapy held from October 4-7, 2001 in Rome, Italy was part of a series of biannual conferences, which had its beginnings in Sardinia in 1985, with the goal of establishing differentiation induction and programmed cell death as cancer cell-selective therapies. As in the past, the organizers of this meeting joined basic and clinical investigators in workshops to establish collaboration and information exchange. Because only a portion of the conference is summarized, additional information can be obtained from the abstracts published in Journal of Biological Regulators and Homeostatic Agents, Volume 15, 2001. The next International Conference on Differentiation Therapy will be held in Shanghai from October 24-27, 2003.

Using best practice to create a pathway to improve management of irritable bowel syndrome: aiming for timely diagnosis, effective treatment and equitable care.

BACKGROUND: Irritable bowel syndrome (IBS) costs the National Health Service almost £12 million per annum. Despite national guidelines advising primary care management, these have failed to stem secondary care referrals of patients with likely IBS for unnecessary and costly assessment and investigation without necessarily achieving resolution of their symptoms. METHODS: In 2011, an integrated team from primary and secondary care developed a business case using baseline data to create a Somerset-wide IBS pathway using Clinical Commissioning Group funding. This provided face-to-face general practitioners (GP) education, developed a diagnostic pathway and funded faecal calprotectin (FC) testing to exclude inflammatory pathology for patients aged 16-45 years with likely IBS and no alarm symptoms. For those with FC≤50 µg/g, we provided a management algorithm and community-based dietetic treatment. Audit results measured usage and outcomes from FC testing, changes in patterns and costs of new patients reviewed in gastroenterology outpatients and dietetic IBS treatment outcomes. RESULTS: The proportion of new patient slots used reduced from 14.3% to 8.7% over 10 months while overall costs reduced by 25% for patients with no alarm symptoms and likely IBS aged 16-45 years. FC results confirmed research findings with no inflammatory pathology, if FC≤50 µg/g over 2 years. 63% of patients had satisfactory control of their IBS after specialist dietetic input with 74% reporting improved quality of life. CONCLUSIONS: The combination of GP education, providing diagnosis and management pathways, using FC to exclude inflammatory pathology and providing an effective treatment for patients with likely IBS appeared successful in our pilot. This proved cost-effective, reduced secondary care involvement and improved patient care.

Clinical Features and HLA Association of 5-Aminosalicylate (5-ASA)-induced Nephrotoxicity in Inflammatory Bowel Disease.

BACKGROUND AND AIMS: Nephrotoxicity is a rare idiosyncratic reaction to 5-aminosalicylate (5-ASA) therapies. The aims of this study were to describe the clinical features of this complication and identify clinically useful genetic markers so that these drugs can be avoided or so that monitoring can be intensified in high-risk patients. METHODS: Inflammatory bowel disease patients were recruited from 89 sites around the world. Inclusion criteria included normal renal function prior to commencing 5-ASA, ≥50% rise in creatinine any time after starting 5-ASA, and physician opinion implicating 5-ASA strong enough to justify drug withdrawal. An adjudication panel identified definite and probable cases from structured case report forms. A genome-wide association study was then undertaken with these cases and 4109 disease controls. RESULTS: After adjudication, 151 cases of 5-ASA-induced nephrotoxicity were identified. Sixty-eight percent of cases were males, with nephrotoxicity occurring at a median age of 39.4 years (range 6-79 years). The median time for development of renal injury after commencing 5-ASA was 3.0 years (95% confidence interval [CI] 2.3-3.7). Only 30% of cases recovered completely after drug withdrawal, with 15 patients requiring permanent renal replacement therapy. A genome-wide association study identified a suggestive association in the HLA region (p = 1×10(-7)) with 5-ASA-induced nephrotoxicity. A sub-group analysis of patients who had a renal biopsy demonstrating interstitial nephritis (n = 55) significantly strengthened this association (p = 4×10(-9), odds ratio 3.1). CONCLUSIONS: This is the largest and most detailed study of 5-ASA-induced nephrotoxicity to date. It highlights the morbidity associated with this condition and identifies for the first time a significant genetic predisposition to drug-induced renal injury.

The clinical application of targeting cancer through histone acetylation and hypomethylation.

Methods of gene inactivation include genetic events such as mutations or deletions. Epigenetic changes, heritable traits that are mediated by changes in DNA other than nucleotide sequences, play an important role in gene expression. Two epigenetic events that have been associated with transcriptional silencing include methylation of CpG islands located in gene promoter regions of cancer cells and changes in chromatin conformation involving histone acetylation. Recent evidence demonstrates that these processes form layers of epigenetic silencing. Reversal of these epigenetic processes and up-regulation of genes important to prevent or reverse the malignant phenotype has therefore become a new therapeutic target in cancer treatment.

Quantification of 5-azacytidine in plasma by electrospray tandem mass spectrometry coupled with high-performance liquid chromatography.

5-Azacytidine (5AC), a nucleoside analogue and hypomethylating agent, has anticancer properties and has been utilized in the treatment of various malignancies. 5AC is unstable and rapidly hydrolyzed to several by-products, including 5-azacytosine and 5-azauracil. A sensitive, reliable method was developed to quantitate 5AC using LC/MS/MS to perform pharmacokinetic and pharmacodynamic studies on 5AC combination therapy trials. Blood samples were collected in a heparinized tube and immediately processed for storage. To increase the stability of 5AC in plasma, 25 ng/mL tetrahydrouridine was added to the plasma and snap frozen. Plasma samples were extracted using acetonitrile then cleaned up by Oasis MCX ion exchange solid-phase extraction cartridges. 5AC was separated on an YMC Jsphr M80 C(18) column with gradient elution of ammonium acetate (2 mM) with 0.1% formic acid and methanol mobile phase. 5AC elutes at 5.0 +/- 0.2 min with a total run time of 30 min. Identification was through positive-ion mode and multiple reaction monitoring mode at m/z+ 244.9-->113.0 for 5AC and m/z+ 242.0-->126.0 for 5-methyl-2'-deoxycytidine, the internal standard. The lower limit of quantitation of 5AC was 5 ng/mL in human plasma, and linearity was observed from 5 to 500 ng/mL fitted by linear regression with 1/x weight. This method is 50 times more sensitive than previously published assays and successfully allows studies to characterize the pharmacokinetics and pharmacodynamics of 5AC.

A phase I dose-finding study of 5-azacytidine in combination with sodium phenylbutyrate in patients with refractory solid tumors.

PURPOSE: This was a phase I trial to determine the minimal effective dose and optimal dose schedule for 5-azacytidine (5-AC) in combination with sodium phenylbutyrate in patients with refractory solid tumors. The pharmacokinetics, pharmacodynamics, and antineoplastic effects were also studied. EXPERIMENTAL DESIGN: Three dosing regimens were studied in 27 patients with advanced solid tumors, and toxicity was recorded. The pharmacokinetics of the combination of drugs was evaluated. Repeat tumor biopsies and peripheral blood mononuclear cells (PBMC) were analyzed to evaluate epigenetic changes in response to therapy. EBV titers were evaluated as a surrogate measure for gene re-expression of epigenetic modulation in PBMC. RESULTS: The three dose regimens of 5-AC and phenylbutyrate were generally well tolerated and safe. A total of 48 cycles was administrated to 27 patients. The most common toxicities were bone marrow suppression-related neutropenia and anemia, which were minor. The clinical response rate was disappointing for the combination of agents. One patient showed stable disease for 5 months whereas 26 patients showed progressive disease as the best tumor response. The administration of phenylbutyrate and 5-AC did not seem to alter the pharmacokinetics of either drug. Although there were individual cases of targeted DNA methyltransferase activity and histone H3/4 acetylation changes from paired biopsy or PBMC, no conclusive statement can be made based on these limited correlative studies. CONCLUSION: The combination of 5-AC and phenylbutyrate across three dose schedules was generally well tolerated and safe, yet lacked any real evidence for clinical benefit.