William P. Steward

Phase I clinical trial of oral curcumin : biomarkers of systemic activity and compliance

Curcumin, a polyphenolic antioxidant derived from a dietary spice, exhibits anticancer activity in rodents and in humans. Its efficacy appears to be related to induction of glutathione S-transferase enzymes, inhibition of prostaglandin E2 (PGE2) production, or suppression of oxidative DNA adduct (M1G) formation. We designed a dose-escalation study to explore the pharmacology of curcumin in humans. Fifteen patients with advanced colorectal cancer refractory to standard chemotherapies consumed capsules compatible with curcumin doses between 0.45 and 3.6 g daily for up to 4 months. Levels of curcumin and its metabolites in plasma, urine, and feces were analyzed by high-pressure liquid chromatography and mass spectrometry. Three biomarkers of the potential activity of curcumin were translated from preclinical models and measured in patient blood leukocytes: glutathione S-transferase activity, levels of M1G, and PGE2 production induced ex vivo. Dose-limiting toxicity was not observed. Curcumin and its glucuronide and sulfate metabolites were detected in plasma in the 10 nmol/L range and in urine. A daily dose of 3.6 g curcumin engendered 62% and 57% decreases in inducible PGE2 production in blood samples taken 1 hour after dose on days 1 and 29, respectively, of treatment compared with levels observed immediately predose (P < 0.05). A daily oral dose of 3.6 g of curcumin is advocated for Phase II evaluation in the prevention or treatment of cancers outside the gastrointestinal tract. PGE2 production in blood and target tissue may indicate biological activity. Levels of curcumin and its metabolites in the urine can be used to assess general compliance.

Guidelines for the management of gastroenteropancreatic neuroendocrine (including carcinoid) tumours (NETs)

These guidelines update previous guidance published in 2005. They have been revised by a group who are members of the UK and Ireland Neuroendocrine Tumour Society with endorsement from the clinical committees of the British Society of Gastroenterology, the Society for Endocrinology, the Association of Surgeons of Great Britain and Ireland (and its Surgical Specialty Associations), the British Society of Gastrointestinal and Abdominal Radiology and others. The authorship represents leaders of the various groups in the UK and Ireland Neuroendocrine Tumour Society, but a large amount of work has been carried out by other specialists, many of whom attended a guidelines conference in May 2009. We have attempted to represent this work in the acknowledgements section. Over the past few years, there have been advances in the management of neuroendocrine tumours, which have included clearer characterisation, more specific and therapeutically relevant diagnosis, and improved treatments. However, there remain few randomised trials in the field and the disease is uncommon, hence all evidence must be considered weak in comparison with other more common cancers.

Phase III Randomized Comparison of Gemcitabine Versus Gemcitabine Plus Capecitabine in Patients With Advanced Pancreatic Cancer

PURPOSE Both gemcitabine (GEM) and fluoropyrimidines are valuable treatment for advanced pancreatic cancer. This open-label study was designed to compare the overall survival (OS) of patients randomly assigned to GEM alone or GEM plus capecitabine (GEM-CAP). PATIENTS AND METHODS Patients with previously untreated histologically or cytologically proven locally advanced or metastatic carcinoma of the pancreas with a performance status <or= 2 were recruited. Patients were randomly assigned to GEM or GEM-CAP. The primary outcome measure was survival. Meta-analysis of published studies was also conducted. RESULTS Between May 2002 and January 2005, 533 patients were randomly assigned to GEM (n = 266) and GEM-CAP (n = 267) arms. GEM-CAP significantly improved objective response rate (19.1% v 12.4%; P = .034) and progression-free survival (hazard ratio [HR], 0.78; 95% CI, 0.66 to 0.93; P = .004) and was associated with a trend toward improved OS (HR, 0.86; 95% CI, 0.72 to 1.02; P = .08) compared with GEM alone. This trend for OS benefit for GEM-CAP was consistent across different prognostic subgroups according to baseline stratification factors (stage and performance status) and remained after adjusting for these stratification factors (P = .077). Moreover, the meta-analysis of two additional studies involving 935 patients showed a significant survival benefit in favor of GEM-CAP (HR, 0.86; 95% CI, 0.75 to 0.98; P = .02) with no intertrial heterogeneity. CONCLUSION On the basis of our trial and the meta-analysis, GEM-CAP should be considered as one of the standard first-line options in locally advanced and metastatic pancreatic cancer.

Phase I Dose Escalation Pharmacokinetic Study in Healthy Volunteers of Resveratrol, a Potential Cancer Chemopreventive Agent

The red grape constituent resveratrol possesses cancer chemopreventive properties in rodents. The hypothesis was tested that, in healthy humans, p.o. administration of resveratrol is safe and results in measurable plasma levels of resveratrol. A phase I study of oral resveratrol (single doses of 0.5, 1, 2.5, or 5 g) was conducted in 10 healthy volunteers per dose level. Resveratrol and its metabolites were identified in plasma and urine by high-performance liquid chromatography-tandem mass spectrometry and quantitated by high-performance liquid chromatography-UV. Consumption of resveratrol did not cause serious adverse events. Resveratrol and six metabolites were recovered from plasma and urine. Peak plasma levels of resveratrol at the highest dose were 539 ± 384 ng/mL (2.4 μmol/L, mean ± SD; n = 10), which occurred 1.5 h post-dose. Peak levels of two monoglucuronides and resveratrol-3-sulfate were 3- to 8-fold higher. The area under the plasma concentration curve (AUC) values for resveratrol-3-sulfate and resveratrol monoglucuronides were up to 23 times greater than those of resveratrol. Urinary excretion of resveratrol and its metabolites was rapid, with 77% of all urinary agent-derived species excreted within 4 h after the lowest dose. Cancer chemopreventive effects of resveratrol in cells in vitro require levels of at least 5 μmol/L. The results presented here intimate that consumption of high-dose resveratrol might be insufficient to elicit systemic levels commensurate with cancer chemopreventive efficacy. However, the high systemic levels of resveratrol conjugate metabolites suggest that their cancer chemopreventive properties warrant investigation. (Cancer Epidemiol Biomarkers Prev 2007;16(6):1246–52)

Doxorubicin versus CYVADIC versus doxorubicin plus ifosfamide in first-line treatment of advanced soft tissue sarcomas: a randomized study of the European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group.

PURPOSE The aim of this trial was to compare the activity and toxicity of single-agent doxorubicin with that of two multidrug regimens in the treatment of patients with adult advanced soft tissue sarcomas. PATIENTS AND METHODS This was a prospective randomized phase III trial performed by 35 cancer centers within the Soft Tissue and Bone Sarcoma Group of the European Organization for Research and Treatment of Cancer (EORTC). Six hundred sixty-three eligible patients were randomly allocated to receive either doxorubicin 75 mg/m2 (arm A), cyclophosphamide, vincristine, doxorubicin, and dacarbazine (CYVADIC) (arm B), or ifosfamide 5 g/m2 plus doxorubicin 50 mg/m2 (arm C). RESULTS The overall response rate was 24% (95% confidence interval, 20.7% to 27.3%) among eligible patients and 26% among assessable patients. No statistically significant difference was detected among the three study arms in terms of response rate (arm A, 23.3%; arm B, 28.4%; and arm C, 28.1%), remission duration (median, 46 weeks on arm A, 48 weeks on arm B, and 44 weeks on arm C), or overall survival (median, 52 weeks on arm A, 51 weeks on arm B, and 55 weeks on arm C). The degree of myelosuppression was significantly greater for the combination of ifosfamide and doxorubicin than for the other two regimens. Cardiotoxicity was also more frequent in this arm, but other toxicities were similar. CONCLUSION In advanced soft tissue sarcomas of adults, single-agent doxorubicin is still the standard chemotherapy against which more intensive or new drug treatments should be compared. Combination chemotherapy cannot be recommended outside a controlled clinical trial with the exclusion of some subsets of sarcoma patients for whom significant tumor volume reduction may be an important end point of a chemotherapy regimen.

Detection of curcumin and its metabolites in hepatic tissue and portal blood of patients following oral administration

Studies in vitro and in animal models of colorectal and hepatocellular cancers suggest that curcumin is an effective chemopreventive agent. In this pilot trial, we investigated whether oral administration of curcumin results in concentrations of the agent in normal and malignant human liver tissue, which are sufficient to elicit pharmacological activity. In total, 12 patients with hepatic metastases from colorectal cancer received 450–3600 mg of curcumin daily, for 1 week prior to surgery. Levels of curcumin and its metabolites were measured by HPLC in portal and peripheral blood, bile and liver tissue. Curcumin was poorly available, following oral administration, with low nanomolar levels of the parent compound and its glucuronide and sulphate conjugates found in the peripheral or portal circulation. While curcumin was not found in liver tissue, trace levels of products of its metabolic reduction were detected. In patients who had received curcumin, levels of malondialdehyde-DNA (M1G) adduct, which reflect oxidative DNA changes, were not decreased in post-treatment normal and malignant liver tissue when compared to pretreatment samples. The results suggest that doses of curcumin required to furnish hepatic levels sufficient to exert pharmacological activity are probably not feasible in humans.

Dietary polyphenolic phytochemicals--promising cancer chemopreventive agents in humans? A review of their clinical properties.

Epidemiological and preclinical evidence suggests that polyphenolic phytochemicals exemplified by epigallocatechin gallate from tea, curcumin from curry and soya isoflavones possess cancer chemopreventive properties. Whilst such naturally occurring polyphenols have been the subject of numerous mechanistic studies in cells, information on their clinical properties, which might help assess their promise as human cancer chemopreventive agents, is scarce. Therefore, we present a review of pilot studies and trials with a cancer chemoprevention‐related rationale, in which either healthy individuals or patients with premalignant conditions or cancer received polyphenolic phytochemicals. The review identifies trial design elements specifically applicable to polyphenolic phytochemicals. The available evidence for tea polyphenols tentatively supports their advancement into phase III clinical intervention trials aimed at the prevention of progression of prostate intraepithelial neoplasia, leukoplakia or premalignant cervical disease. In the case of curcumin and soya isoflavones more studies in premalignacies seem appropriate to optimise the nature and design of suitable phase III trials. The abundance of flavonoids and related polyphenols in the plant kingdom makes it possible that several hitherto uncharacterised agents with chemopreventive efficacy are still to be identified, which may constitute attractive alternatives to currently used chemopreventive drugs.

Clinical trials of resveratrol.

An expanding body of preclinical evidence suggests resveratrol has the potential to impact a variety of human diseases. To translate encouraging experimental findings into human benefits, information is first needed on the safety, pharmacokinetics, pharmacodynamics, and, ultimately, clinical efficacy of resveratrol. Published clinical trials have largely focused on characterizing the pharmacokinetics and metabolism of resveratrol. Recent studies have also evaluated safety and potential mechanisms of activity following multiple dosing, and have found resveratrol to be safe and reasonably well‐tolerated at doses of up to 5 g/day. However, the occurrence of mild to moderate side effects is likely to limit the doses employed in future trials to significantly less than this amount. This review describes the available clinical data, outlines how it supports the continuing development of resveratrol, and suggests what additional information is needed to increase the chances of success in future clinical trials.

Radioembolization of Liver Metastases From Colorectal Cancer Using Yttrium-90 Microspheres With Concomitant Systemic Oxaliplatin, Fluorouracil, and Leucovorin Chemotherapy

PURPOSE Liver metastases represent the principal cause of death in patients with advanced colorectal cancer (CRC). Injection of resin microspheres (SIR Spheres)--containing the beta-emitter, yttrium-90--into the arterial supply of the liver can cause radioembolization of metastases. This treatment has not been tested with the radiosensitizing chemotherapy, oxaliplatin, which appears synergistic in the treatment of CRC when combined with fluorouracil and leucovorin (FOLFOX). PATIENTS AND METHODS A phase I study of SIR-Spheres therapy with modified FOLFOX4 systemic chemotherapy was conducted in patients with inoperable liver metastases from CRC who had not previously received chemotherapy for metastatic disease. Oxaliplatin (30 to 85 mg/m2) was administered for the first three cycles with full FOLFOX4 doses from cycle 4 until cycle 12. The primary end point was toxicity. RESULTS Twenty patients were enrolled onto the study. Five patients experienced National Cancer Institute (NCI; Bethesda, MD) grade 3 abdominal pain, two of whom had microsphere-induced gastric ulcers. The dose-limiting toxicity was grade 3 or 4 neutropenia, which was recorded in 12 patients. One episode of transient grade 3 hepatotoxicity was recorded. Mean splenic volume increased by 92% following 6 months of protocol therapy. Partial responses were demonstrated in 18 patients and stable disease in two patients. Two patients underwent partial hepatic resection following protocol therapy. Median progression-free survival was 9.3 months, and median time to progression in the liver was 12.3 months. CONCLUSION The maximum-tolerated dose was 60 mg/m2 of oxaliplatin for the first three cycles, with full FOLFOX4 doses thereafter. This chemoradiation regime merits evaluation in phase II-III trials.

PHARMACOKINETICS AND PHARMACODYNAMICS OF CURCUMIN

Curcuma spp. contain turmerin, essential oils, and curcuminoids, including curcumin. Curcumin [1,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione] is regarded as the most biologically active constituent of the spice turmeric and it comprises 2-8% of most turmeric preparations. Preclinical data from animal models and phase I clinical studies performed with human volunteers and patients with cancer have demonstrated low systemic bioavailability following oral dosing. Efficient first-pass metabolism and some degree of intestinal metabolism, particularly glucuronidation and sulfation of curcumin, might explain its poor systemic availability when administered via the oral route. A daily oral dose of 3.6 g of curcumin is compatible with detectable levels of the parent compound in colorectal tissue from patients with cancer. The levels demonstrated might be sufficient to exert pharmacological activity. There appears to be negligible distribution of the parent drug to hepatic tissue or other tissues beyond the gastrointestinal tract. Curcumin possesses wide-ranging anti-inflammatory and anticancer properties. Many of these biological activities can be attributed to its potent antioxidant capacity at neutral and acidic pH, its inhibition of cell signaling pathways at multiple levels, its diverse effects on cellular enzymes, and its effects on cell adhesion and angiogenesis. In particular, curcumins ability to alter gene transcription and induce apoptosis in preclinical models advocates its potential utility in cancer chemoprevention and chemotherapy. With regard to considerable public and scientific interest in the use of phytochemicals derived from dietary components to combat or prevent human diseases, curcumin is currently a leading agent.