The anti-leukemic effect and molecular mechanisms of novel hydroxamate and benzamide histone deacetylase inhibitors with 5-aza-cytidine.

Histone deacetylase inhibitors (HDACi) demonstrate considerable in vitro and in vivo activity and clinical efficacy in the treatment of hematological malignancies. Pre-clinical and early phase clinical trials identify therapeutic activity using a combination of HDACi and demethylating agents which may be more efficacious than single agent treatment. Our studies aimed to determine the effects and molecular mechanisms of action of novel hydroxamate (MCT-3) and benzamide [MGCD0103 (MG)] HDACi's in the HL-60 cell line alone and in combination with the demethylating agent 5-aza-cytidine (AZA). MG, MCT-3 and AZA treatment significantly inhibited HL-60 cell growth in vitro with MG being the most potent agent. MG in combination with AZA demonstrated no significant increase in inhibition of cell growth over MG treatment alone whilst MCT-3 in combination with AZA demonstrated increased inhibition of cell growth over either agent alone although no more significant than MG alone. MG alone or MCT-3 in combination with AZA significantly increased p15 and caspase-3 expression. MG and MCT-3 significantly attenuated AZA-induced MMP-9 mRNA expression and proteolytic activity. Interestingly, MCT-3, MG and AZA alone and in combination increased expression of the novel tumour suppressor gene Nur77, important in leukemogenesis, with MG a more potent inducer as a single agent. These observations suggest the enhanced anti-leukemia activity of the combination of AZA and HDACi may only reside with certain HDACi classes and may be in-part explained by regulation of genes associated with cell cycle arrest, apoptosis and tumour suppression.

The anti-leukemic effect of a novel histone deacetylase inhibitor MCT-1 and 5-aza-cytidine involves augmentation of Nur77 and inhibition of MMP-9 expression.

A combination of demethylating agents and histone deacetylase inhibitors (HDACi) has been proposed as a novel therapy in leukemia and myelodysplasia. In HL-60 cells azacytidine (AZA) and Metacept-1 (MCT-1), a novel HDACi augmented inhibition of cell growth and increased apoptosis. In identifying a molecular mechanism responsible for these effects MCT-1 alone and in combination with AZA induced p15INK4b, p21WAF1/CIP1 and Caspase-3 whilst attenuating Bcl-XL expression. Interestingly, MCT-1 in combination with AZA significantly induced the recently identified suppressor of leukemogenesis Nur77 and attenuated AZA-induced MMP-9 expression. The combination of MCT-1 and AZA is more effective in inhibiting leukemic cell growth and induction of apoptosis. Regulation of a recently identified tumour suppressor gene together with cell cycle, apoptosis and matrix degrading proteases may underpin the molecular mechanism responsible for these effects.

Detailed analysis of a randomized phase III trial: can the tolerability of capecitabine plus docetaxel be improved without compromising its survival advantage?

BACKGROUND: In a phase III trial, 3-weekly capecitabine (1250 mg/m(2) twice daily days 1-14) plus docetaxel (75 mg/m(2) day 1) demonstrated significantly superior overall survival to 3-weekly docetaxel (100 mg/m(2) day 1). We report a retrospective analysis of the impact of capecitabine/docetaxel dose reduction on safety and efficacy. PATIENTS AND METHODS: Safety and efficacy data were analyzed retrospectively according to the actual doses of capecitabine and docetaxel administered. RESULTS: More patients receiving capecitabine/docetaxel (65%) had dose reductions for adverse events than docetaxel alone (35%). In most patients requiring dose reduction with the combination (80%), capecitabine and docetaxel were simultaneously reduced to 950 mg/m(2) and 55 mg/m(2), respectively. Subsequently, there were fewer cycles (17%) with grade 3/4 adverse events than with the full doses (34%). Time to progression and overall survival appeared to be similar in patients starting the second cycle with reduced doses of capecitabine/docetaxel and those who continued to receive full doses of capecitabine/docetaxel for at least the first four cycles. CONCLUSIONS: Capecitabine/docetaxel dosing flexibility allows management of side-effects without compromising efficacy. This retrospective analysis, as well as multiple phase II studies of taxanes with reduced-dose capecitabine, shows that reducing the starting dose of capecitabine with docetaxel is a reasonable strategy for the treatment of patients with metastatic breast cancer. In addition, reducing the dose of both agents may be appropriate.

Pharmacoeconomic analysis of adjuvant oral capecitabine vs intravenous 5-FU/LV in Dukes' C colon cancer: the X-ACT trial.

Oral capecitabine (Xeloda) is an effective drug with favourable safety in adjuvant and metastatic colorectal cancer. Oxaliplatin-based therapy is becoming standard for Dukes' C colon cancer in patients suitable for combination therapy, but is not yet approved by the UK National Institute for Health and Clinical Excellence (NICE) in the adjuvant setting. Adjuvant capecitabine is at least as effective as 5-fluorouracil/leucovorin (5-FU/LV), with significant superiority in relapse-free survival and a trend towards improved disease-free and overall survival. We assessed the cost-effectiveness of adjuvant capecitabine from payer (UK National Health Service (NHS)) and societal perspectives. We used clinical trial data and published sources to estimate incremental direct and societal costs and gains in quality-adjusted life months (QALMs). Acquisition costs were higher for capecitabine than 5-FU/LV, but higher 5-FU/LV administration costs resulted in 57% lower chemotherapy costs for capecitabine. Capecitabine vs 5-FU/LV-associated adverse events required fewer medications and hospitalisations (cost savings pound3653). Societal costs, including patient travel/time costs, were reduced by >75% with capecitabine vs 5-FU/LV (cost savings pound1318), with lifetime gain in QALMs of 9 months. Medical resource utilisation is significantly decreased with capecitabine vs 5-FU/LV, with cost savings to the NHS and society. Capecitabine is also projected to increase life expectancy vs 5-FU/LV. Cost savings and better outcomes make capecitabine a preferred adjuvant therapy for Dukes' C colon cancer. This pharmacoeconomic analysis strongly supports replacing 5-FU/LV with capecitabine in the adjuvant treatment of colon cancer in the UK.

Brain as sanctuary site of relapse in germ cell cancer patients previously treated with chemotherapy.

BACKGROUND: Post chemotherapy isolated relapse to the brain of germ cell cancer is potentially curable. PATIENTS AND METHODS: We reviewed the experience of germ cell cancer with cerebral metastases at the CRC Wessex Medical Oncology Unit in Southampton. Patients were classified according to their presentation (initial diagnosis, solitary relapse or widespread). Treatment and outcome of these patients is presented and compared with previous series. RESULTS: Of 1049 patients treated for metastatic germ cell cancer, 15 were diagnosed with cerebral metastases. Six patients had cerebral sanctuary site relapse, and underwent resection and cranial irradiation. Four of these are continuously disease free after treatment at 2, 67, 96, and 145 months from therapy, another is receiving chemotherapy for limited systemic relapse and the sixth has relapsed and died. Three further patients relapsed with cerebral disease in the presence of active disease elsewhere and each progressed and died. The final six patients had cerebral disease at presentation of whom five have progressed and died. CONCLUSIONS: Isolated cerebral metastases occurring after successful systemic chemotherapy for germ cell cancer are curable. An aggressive salvage approach with surgery followed by radiotherapy is indicated.

A phase I and pharmacokinetic study of subcutaneously-administered recombinant human interleukin-4 (rhuIL-4) in patients with advanced cancer.

PURPOSE: To investigate the pharmacokinetics and tolerability of recombinant human interleukin-4 (rhuIL-4), administered by daily subcutaneous injection, in patients with advanced cancer. PATIENTS AND METHODS: Fourteen patients with advanced cancer treated with rhuIL-4 at escalating dose levels of 0.25, 1.0 and 5.0 microg/kg/day, on days 1, 8-17, and 28-57. The primary endpoints of the study were toxicity of rhuIL-4 and the determination of the pharmacokinetics of rhuIL-4 when given by subcutaneous injection. Secondary endpoints included effects on blood counts, hematopoietic cell precursors, and various immunologic parameters. RESULTS: rhuIL-4 was well tolerated at all three dose levels. Detectable serum levels of IL-4 were found in patients at the 1.0 and 5.0 microg/kg/day dose levels. Peak serum IL-4 levels were achieved about 2 h after injection and IL-4 was still detectable 8 h after injection. No grade 4 toxicities were observed and grade 3 toxicities were confined to fever, headache and raised hepatic alkaline phosphatase. No consistent hematological or immunologic effects were observed. Although therapeutic efficacy was not an endpoint, one complete response (Hodgkin's disease) was observed. One patient with chronic lymphocytic leukemia progressed on therapy. CONCLUSION: rhuIL-4 up to 5.0 microg/kg/day is well tolerated when given by subcutaneous injection. Biologically relevant serum IL-4 levels can be achieved and sustained for at least 8 h after a single injection.

Lean body mass, body surface area and epirubicin kinetics.

For a number of cytotoxics, a relationship between efficacy and plasma concentrations has recently been demonstrated. Lean body mass has been demonstrated to be a useful parameter for predicting drug clearance for a number of non-cytotoxic drugs. However, the role of lean body mass in predicting drug clearance for any cytotoxic drug has not been previously reported. Our purpose was to investigate lean body mass as a predictor of epirubicin clearance. Pharmacokinetic studies were performed in 10 patients receiving single agent epirubicin. Although preliminary, this study suggests that lean body should be further evaluated and tested in dose optimization studies.

Assessment of proliferative responses to granulocyte-macrophage colony-stimulating factor (GM-CSF) in acute myeloid leukaemia using a fluorescent ligand for the nucleoside transporter.

Nucleoside transporter expression has been linked to proliferation in a variety of haemopoietic cell types. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was given for 72 h before commencing chemotherapy in 15 patients with relapsed or refractory acute myeloid leukaemia (AML) and in 11 patients serial bone marrows were taken for measurement of [3H]thymidine labelling index, Ki-67 positivity and maximal binding of 5-(SAENTA-x8)-fluorescein, a flow cytometry ligand which enumerates nucleoside transporter sites. GM-CSF caused proliferation of marrow myeloblasts in eight of 11 patients, while in three patients there was no change in proliferative indices. The expression of nucleoside transporters increased up to 4-fold in the myeloblasts from the patients showing a proliferative response to GM-CSF but there was no increase in transporters on the myeloblasts from the three non-responding patients. A close correlation was found between the fold increase in nucleoside transporter expression and the fold increase in labelling index of marrow myeloblasts (r = 0.86, n = 9, p < 0.01). In one patient with acute megakaryoblastic leukemia, GM-CSF caused parallel increases in labelling index, Ki-67 positivity and numbers of nucleoside transporters on peripheral blood blast cells. Thus induction of proliferation by cytokine increases the expression of nucleoside transporters on leukaemic myeloblasts studied in serial samples from the same source (bone marrow or blood). The suitability of 5-(SAENTA-x8)-fluorescein for two colour flow cytometric analysis allows the rapid enumeration of nucleoside transporters in the myeloblast compartment of heterogeneous marrow samples.

Prednisolone, cytosine arabinoside, lomustine (CCNU), etoposide and thioguanine (PACET) combination chemotherapy for relapsed or refractory non-Hodgkin lymphoma.

27 patients with relapsed/refractory non-Hodgkin lymphoma (NHL) received combination chemotherapy with prednisolone, cytosine arabinoside, lomustine (CCNU), etoposide and thioguanine (PACET). 25 patients are evaluable for response. 7 (26%) obtained a complete response and one (4%) a partial response. The median survival for the entire group was 6 months. 2 patients are currently alive without disease, 1 of whom has received further therapy. The regimen was intensely myelosuppressive, but was well tolerated. The complete response rate and median survival figures are comparable to previous studies of salvage therapy confirming the poor prognosis for relapsed NHL and emphasising the need for prospective randomised studies.

All-trans retinoic acid in the treatment of acute promyelocytic leukaemia.

All-trans-retinoic acid (ATRA) is known to induce differentiation of promyelocytes in vitro and also to induce remission of acute promyelocytic leukaemia in vivo. We treated 11 patients with poor prognosis acute promyelocytic leukaemia (APL) with ATRA and obtained seven complete and one partial remission. Remissions took one to three months to achieve and were associated with adverse effects including dry skin and bone pain. In eight patients the white cell count rose above 20 x 10(9)/L within the first ten days of retinoic acid treatment and this was associated with the development of pulmonary leukostasis in three patients which was fatal in one. Another two patients died of intracranial haemorrhage also within the first ten days. ATRA is a promising new agent in the induction therapy of this particular category of acute leukaemia.

Nonseminomatous germ cell tumor with very high serum human chorionic gonadotropin.

Most patients with disseminated nonseminomatous germ cell tumor (NSGCT) have an excellent prognosis with modern chemotherapy, although certain subgroups with a worse prognosis have been described. One such subgroup includes patients with high serum levels of the tumor marker, human chorionic gonadotropin (HCG). Sixteen patients of 104 treated for NSGCT at the CRC Wessex Medical Oncology Unit (Southampton, UK) presented with serum HCG greater than 25,000. Most of these patients exhibited features of the "choriocarcinoma syndrome" with bulky, rapidly progressive disease; frequent pulmonary, hepatic, and central nervous system complications; and a generally poorer response to standard NSGCT chemotherapy. Histologic identification of trophoblastic tumor was not made in all patients and is not essential for the diagnosis of the syndrome; indeed, closed biopsy may be contradicted in some circumstances because of the risk of hemorrhage. The NSGCT patients with poor prognosis, including patients with the choriocarcinoma syndrome, must be clearly identified in order to improve management and, eventually, cure rates.

High dose intensity combination chemotherapy for advanced epithelial ovarian carcinoma: results of a pilot study.

Retrospective studies have recently demonstrated a significant correlation between dose intensity of chemotherapy and response rates and survival in various diseases including epithelial ovarian carcinoma. As part of a proposed randomised trial to assess the effect of dose intensity on outcome in ovarian carcinoma, a pilot study has been undertaken to determine the toxicity and efficacy of the high intensity therapy. Nineteen patients with advanced ovarian carcinoma received initial treatment with cisplatin 120 mg m-2 i.v. day 1, and cyclophosphamide 1,000 mg-2 i.v. day 1, given at 21-day intervals for six cycles. The average relative dose intensity of this therapy is 1.14 when compared with the CHAP regimen. Severe toxicity was experienced by most patients. The median received average relative dose intensity was 0.90, with only one patient receiving treatment to the proposed intensity. Randomised studies of the effect of dose intensity in ovarian carcinoma are essential, but an initial step must be to assess whether the proposed high dose treatment can be delivered.

Involvement of the ileocaecal region by non-Hodgkin's lymphoma in adults: clinical features and results of treatment.

Between January 1977 and January 1988, 19 patients with non-Hodgkin's lymphoma (NHL) involving the ileocaecal region were cared for by the CRC Wessex Medical Oncology Unit. Fifteen of these patients had primary ileocaecal NHL (stages IE or IIE) and four had secondary involvement of this region (stage IV). The commonest clinical presentation was with abdominal pain and a palpable mass in the right iliac fossa. Bulky (greater than 10 cm) disease was a particularly common feature, and complete surgical removal was possible in only seven patients. All patients had intermediate (18) or high grade (one) NHL using the Working Formulation. The commonest histological subtype was diffuse large cell. Seventeen patients received postoperative therapy, comprising local radiotherapy in one and combination chemotherapy in the remaining 16. Eleven of the 19 patients remain disease-free 6-60 months from diagnosis. Because of the high incidence of bulky disease at this site, postoperative therapy may be indicated, even for patients with apparently completely excised stage I disease.

ChlVPP chemotherapy in advanced Hodgkin's disease.

Between March 1978 and January 1987 54 patients with advanced Hodgkin's disease (HD) or relapse following radiotherapy (RT) for Hodgkin's disease have been treated with combination chemotherapy consisting of chlorambucil, vinblastine, procarbazine and prednisolone (ChlVPP). A subgroup of five patients with bulky mediastinal disease received mantle RT in addition to ChlVPP chemotherapy. Forty-two patients (77.8%) entered complete remission with 33 (61.0%) remaining in unmaintained remission and 44 (81.5%) alive at a median follow up of 51 months (range: 22-103). The treatment was generally well tolerated with minimal toxicity. ChlVPP is effective first-line treatment for Hodgkin's disease with results which may be comparable to those achieved for MOPP but with significantly less toxicity.