Simon Joel

A randomized trial to evaluate the effect of schedule on the activity of etoposide in small-cell lung cancer.

Etoposide is an increasingly used and well-tolerated drug in cancer medicine. Its cytotoxic action is phase-specific and it has demonstrated schedule dependency in both in vitro and animal studies, but clinical evidence of the importance of drug scheduling is uncertain. The two administration schedules of etoposide that have been compared in this randomized study of 39 patients with previously untreated extensive small-cell lung cancer treated with single-agent etoposide were 500 mg/m2 as a continuous intravenous (IV) infusion over 24 hours or five consecutive daily 2-hour infusions each of 100 mg/m2. Both regimens were repeated every 3 weeks, for a maximum of six cycles. Patients received combination chemotherapy with vincristine, doxorubicin, and cyclophosphamide (VAC) or radiotherapy on failure to respond or at relapse, depending on their Karnofsky performance status. The same therapy was used in both arms of the study. All patients are evaluable for response to etoposide. In the 24-hour arm, two patients achieved a partial remission, resulting in an overall response rate of 10%. In the 5-day schedule, 16 patients had a partial response and one had a complete remission, producing an overall response rate of 89%, which was significantly superior to that in the 24-hour arm (P less than .001). The median duration of remission to etoposide in the 5-day arm was 4.5 months. Bone marrow toxicity was similar in both schedules. Etoposide pharmacokinetics were measured in all patients, and total areas under the concentration versus time curves (AUCs) were equivalent in both regimens. This study has clearly demonstrated the importance of etoposide scheduling in humans, and the superiority of five daily infusions over a 24-hour continuous infusion. The response rate to single-agent etoposide using an efficacious schedule in extensive small-cell lung cancer has been determined to be in excess of 80%.

Morphine and metabolite behavior after different routes of morphine administration: demonstration of the importance of the active metabolite morphine-6-glucuronide.

The pharmacokinetic parameters of morphine, morphine‐6‐glucuronide, and morphine‐3‐glucuronide were studied after single‐dose morphine administration by five different routes. The quantitative significance of the active metabolite morphine‐6‐glucuronide was assessed, and the effects of novel dosing forms on morphine metabolism and distribution were examined. After administration of intravenous morphine the morphine‐6‐glucuronide plasma AUC exceeded that of morphine. After administration of oral morphine very low morphine levels were observed—the morphine‐6‐glucuronide plasma AUC exceeded that of morphine by a factor of 9:1. Sublingual, buccal, and sustained‐release buccal morphine tablet administration resulted in delayed absorption, with attenuation and delay of peak morphine and metabolite levels. Morphine bioavailability and morphine glucuronide production were not altered.

Measuring cytokine levels in blood: Importance of anticoagulants, processing, and storage conditions

The stability and recovery of six human recombinant cytokines (tumour necrosis factor (TNF), interferon-alpha (IFN-alpha), IFN-gamma, interleukin-1 alpha (IL-1 alpha), IL-1 beta, and IL-6) from whole blood was investigated with a view to optimizing blood collection and storage procedures prior to performing immunoassays. Blood from healthy volunteers was subjected to various processing and storage procedures. Blood samples were treated with either: ethylenediamine tetraacetic acid (EDTA) (1.5 mg/ml blood) (E); EDTA/Trasylol (1.5 mg and 1000 KIU/ml blood) (ET); heparin (30 IU/ml) (H) or allowed to clot (serum). The bloods were spiked with individual cytokines, split into aliquots and kept at 4 degrees C or RT. In the first instance spiked bloods from healthy volunteers (n = 5 per cytokine) were processed using sterile and non-pyrogenic materials and procedures. At regular time intervals, samples were cold spun, separated, flash frozen and assayed for the appropriate cytokine using RIA/IRMA methods. In a further study, timed separation was repeated with spiked blood from healthy volunteers (n = 5 per cytokine) using normal commercially available blood collection materials and procedures. In a third study, spiked blood from healthy volunteers (n = 3 per cytokine) was processed under sterile and non-pyrogenic conditions, and the blood samples separated, aliquoted and flash frozen within half hour of collection. These were then subjected to repeated cycles of freeze thawing at 4 degrees C or RT before assaying. In general, the stability of cytokines in whole blood was improved by storage at 4 degrees C and/or rapid separation. There was no significant difference between samples handled under sterile, non-pyrogenic conditions and those collected using normal blood collection procedures. The blood collection procedures described in this paper did not induce any of the six cytokines in the unspiked blood. Overall, EDTA-treated samples performed most consistently. The addition of trasylol did not significantly affect the results. Most of the cytokines appeared unaffected by up to three freeze thaw cycles. The stability and recovery of the spiked cytokines varied from least stable to most stable spiked cytokine as follows; TNF-alpha less than IL-6 less than IFN-gamma less than IL-1 alpha less than IFN-alpha less than IL-1 beta. The recovery of spiked IFN-gamma from heparinized plasma samples was considerably higher than any other plasma or serum samples. The recovery of spiked TNF-alpha and IL-6 from serum samples was consistently lower than amounts recovered from plasma samples (anticoagulant treated).(ABSTRACT TRUNCATED AT 400 WORDS)

The pharmacokinetics of morphine and morphine glucuronides in kidney failure

The pharmacokinetics of morphine and its glucuronide metabolites were investigated in three groups of patients with kidney failure (nondialyzed, receiving dialysis, and transplantation) and compared with a group of normal healthy volunteers. Patients in all three renal groups were undergoing surgical procedures (nondialyzed group undergoing arteriovenous fistula formation, dialysis group undergoing placement of a peritoneal dialysis catheter, and the transplant group undergoing live donor kidney transplant). A sensitive, specific high‐performance liquid chromatographic assay was used to quantitate morphine, morphine‐3‐glucuronide, and morphine‐6‐glucuronide. Patients with kidney failure had a significantly increased morphine area under the curve (AUC) compared with control subjects. There was also an increase in the metabolites morphine‐3‐glucuronide and morphine‐6‐glucuronide that was severalfold greater than the increase in morphine AUC. This metabolite accumulation was reversed by kidney transplantation, providing an elegant confirmation on the role of the kidney in morphine pharmacology.

Bortezomib Therapy in Patients With Relapsed or Refractory Lymphoma: Potential Correlation of In Vitro Sensitivity and Tumor Necrosis Factor Alpha Response With Clinical Activity

PURPOSE To determine the efficacy of bortezomib in patients with lymphoid malignancy, correlating clinical response with effect on plasma cytokines and in vitro activity in primary cultures. PATIENTS AND METHODS Patients received bortezomib (1.3 mg/m2) on days 1, 4, 8, and 11 of a 3-week cycle. Plasma tumor necrosis factor alpha (TNF-alpha) and interleukin-6 were measured before each treatment, and bortezomib activity was examined in patient samples grown in primary culture. RESULTS Fifty-one patients received a total of 193 cycles of treatment. Twenty-four patients had mantle cell lymphoma (MCL), 13 had follicular lymphoma (FL), six had lymphoplasmacytic lymphoma, six had Hodgkins disease (HD), and one each had diffuse large B-cell lymphoma and adult T-cell leukemia/lymphoma. Patients were heavily pretreated with a median of four previous therapies. Significant grade 3 to 4 toxicities were thrombocytopenia (n = 22), fatigue (n = 10), and peripheral neuropathy (n = 3). Seven patients with MCL responded to treatment (one complete response, six partial responses [PRs]; overall response rate, 29%). Two patients with FL achieved a late PR 3 months after discontinuing therapy. Two patients with Waldenströms macroglobulinemia and one patient with HD achieved a PR. MCL primary cultures demonstrated greater sensitivity to bortezomib than FL (median 50% effective concentration for viability, 209 nmol/L v 1,311 nmol/L, respectively; P = .07), which correlated with clinical response. A median reduction in plasma TNF-alpha of 98% was observed in six patients with MCL who responded to bortezomib compared with a reduction of 38% in six nonresponders (P = .07). CONCLUSION Bortezomib demonstrates encouraging efficacy in MCL in heavily pretreated individuals. Response was associated with a reduction in plasma TNF-alpha and in vitro sensitivity in a small number of patients.

A randomized trial of two etoposide schedules in small-cell lung cancer: the influence of pharmacokinetics on efficacy and toxicity

PURPOSE Etoposide is a schedule-dependent drug, as demonstrated by the superiority of 5 consecutive daily infusions over a continuous 24-hour infusion in patients with small-cell lung cancer. A randomized trial has therefore been conducted to compare an extended 8-day regimen with the 5-day schedule. PATIENTS AND METHODS Ninety-four patients with small-cell lung cancer (35 limited disease, 59 extensive disease) were randomized to receive single-agent etoposide 500 mg/m2, either as 5 daily 2-hour infusions of 100 mg/m2 or as 8 daily 75-minute infusions of 62.5 mg/m2, both repeated every 3 weeks for six cycles. Single-agent carboplatin was administered at relapse in both arms of the study. Patients were stratified at randomization according to extent of disease and Karnofsky performance status (KPS). RESULTS The overall response rate was 81% in the 5-day arm and 87% in the 8-day arm, with median survival durations of 7.1 and 9.4 months, respectively (no significant differences). The time over which plasma etoposide exceeded low plasma concentrations was significantly longer in patients who responded compared with patients who did not respond. This was most significant for time at concentrations greater than 1, 1.5, and 2 micrograms/mL. Hematologic toxicity was significantly worse in the 5-day arm of the study (cycle no. 1 nadir neutrophil count, 0.8 x 10(9)/L v 1.7 x 10(9)/L). Stepwise regression analysis found duration of exposure to plasma etoposide greater than 3 micrograms/mL to be predictive of nadir neutrophil count and duration of exposure to plasma etoposide greater than 2 micrograms/mL to be predictive of nadir WBC count. CONCLUSION The 5-day and 8-day regimens had equivalent activity in small-cell lung cancer. A pharmacokinetic association between concentrations of etoposide and response and toxicity was found. Antitumor activity was associated with the maintenance of lower levels of etoposide than found to be associated with hematologic toxicity. This supports the hypothesis that the schedule of etoposide administration may affect efficacy and toxicity, and that prolonged exposure to low concentrations of etoposide may improve the therapeutic ratio for this drug.

Randomized placebo‐controlled trial of the activity of the morphine glucuronides

Morphine‐6‐glucuronide (M6G) is an active metabolite of morphine with potent analgesic activity. Morphine‐3‐glucuronide (M3G), the most prevalent metabolite, has minimal affinity for opioid receptors. It has been suggested from animal model data and by examination of metabolite ratios in humans that M3G may functionally antagonize the respiratory depressant and analgesic actions of morphine and M6G.

A 'modified de Gramont' regimen of fluorouracil, alone and with oxaliplatin, for advanced colorectal cancer.

The standard de Gramont (dG) regimen of fortnightly leucovorin, bolus fluorouracil and 22-h infusion of fluorouracil, d1+2, and the same regimen plus oxaliplatin, are effective but also cumbersome. We therefore present simplified ‘Modified de Gramont’ (MdG) regimens. Forty-six advanced gastrointestinal cancer patients entered a dose-exploring study of MdG, including an expanded cohort of colorectal cancer patients at optimum dose. Treatment (fortnightly) comprised: 2-h i.v.i. leucovorin (350 mg d,l-LV or 175 mg l-LV, not adjusted for patient surface area); bolus fluorouracil (400 mg m−2), then ambulatory 46-h fluorouracil infusion (2000–3600 mg m−2, cohort escalation). Subsequently, 62 colorectal patients (25 unpretreated; 37 fluorouracil-resistant) received MdG plus oxaliplatin (OxMdG) 85 mg m−2. Fluorouracil pharmacokinetics during MdG were compared with dG. The optimum fluorouracil doses for MdG alone were determined as 400 mg m−2 bolus + 2800 mg m−2 46-h infusion. A lower dose of 400 mg m−2 bolus + 2400 mg m−2 infusion which, like dG produces minimal toxicity, was chosen for the OxMdG combination. Fluorouracil exposure (AUC0–48 h) at this lower dose is equivalent to dG. With OxMdG, grade 3–4 toxicity was rare (neutropenia 2.8% cycles; vomiting or diarrhoea <1% cycles), but despite this there were two infection-associated deaths. Oxaliplatin was omitted for cumulative neurotoxicity in 17 out of 62 patients. Objective responses in colorectal cancer patients were: 1st-line MdG (22 assessable): PR=36%, NC=32%, PD=32%. 1st-line OxMdG (24 assessable): CR/PR=72%; NC=20%; PD=8%; 2nd line OxMdG (34 assessable): PR=12%; NC=38%; PD=50%. MdG and OxMdG are convenient and well-tolerated. OxMdG was particularly active as 1st-line treatment of advanced colorectal cancer. Both regimens are being further evaluated in the current UK MRC phase III trial.

Histone acetylation-mediated regulation of genes in leukaemic cells

Histone deacetylase (HDAC) and histone acetyltransferase (HAT) functions are associated with various cancers, and the inhibition of HDAC has been found to arrest disease progression. Here, we have investigated the gene expression profiles of leukaemic cells in response to the HDAC inhibitor trichostatin A (TSA) using oligonucleotide microarrays. Nucleosomal histone acetylation was monitored in parallel and the expression profiles of selected genes were confirmed by quantitative polymerase chain reaction (PCR). A large number of genes (9% of the genome) were found to be similarly regulated in CCRF-CEM and HL-60 cells in response to TSA, and genes showing primary and secondary responses could be distinguished by temporal analysis of gene expression. A small fraction of genes were highly sensitive to histone hyper-acetylation, including XRCC1, HOXB6, CDK10, MYC, MYB, NMI and CBFA2T3 and many were trans-acting factors relevant to cancer. The most rapidly repressed gene was MKRN3, an imprinted gene involved in the Prader-Willi syndrome.

The proteasome inhibitor bortezomib acts independently of p53 and induces cell death via apoptosis and mitotic catastrophe in B-cell lymphoma cell lines.

Bortezomib is a proteasome inhibitor with proven efficacy in multiple myeloma and non-Hodgkins lymphoma. This study reports the effects of bortezomib in B-cell lymphoma cell lines with differing sensitivity to bortezomib to investigate factors that influence sensitivity. Bortezomib induced a time- and concentration-dependent reduction in cell viability in five lymphoma cell lines, with EC(50) values ranging from 6 nmol/L (DHL-7 cells) to 25 nmol/L (DHL-4 cells) after 72 h. Bortezomib cytotoxicity was independent of p53 function, as all cell lines exhibited mutations by sequence analysis. The difference in sensitivity was not explained by proteasome or nuclear factor-kappaB (NF-kappaB) inhibition as these were similar in the most and least sensitive cells. NF-kappaB inhibition was less marked than that of a specific NF-kappaB inhibitor, Bay 11-7082. Cell cycle analysis showed a marked G(2)-arrested population in the least sensitive DHL-4 line only, an effect that was not present with Bay 11-7082 treatment. Conversely, in DHL-7 cells, bortezomib treatment resulted in cells moving into an aberrant mitosis, indicative of mitotic catastrophe that may contribute to increased sensitivity to bortezomib. These studies show that although bortezomib treatment had similar effects on apoptotic and NF-kappaB signaling pathways in these cell lines, different cell cycle effects were observed and induction of a further mechanism of cell death, mitotic catastrophe, was observed in the more sensitive cell line, which may provide some pointers to the difference in sensitivity between cell lines. An improved understanding of how DHL-7 cells abrogate the G(2)-M cell cycle checkpoint may help identify targets to increase the efficacy of bortezomib.