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Mark J Ratain

Publications and source records attributed to Mark J Ratain.

At least 37 records · Page 2Linked to original sources
PubMed2005

Successful implementation of the randomized discontinuation trial design: an application to the study of the putative antiangiogenic agent carboxyaminoimidazole in renal cell carcinoma--CALGB 69901.

PURPOSE: To assess the disease-stabilizing activity of carboxyaminoimidazole (CAI) in patients with metastatic renal cell cancer (RCC) using a randomized discontinuation trial (RDT) design. PATIENTS AND METHODS: Recruited patients had a performance status of 0 to 2, minimal neuropathy or cerebellar dysfunction, measurable disease, and normal organ function. Treatment with 250 mg/d CAI was initiated in all patients and continued until disease progression in those with an objective response. Protocol treatment was discontinued for unacceptable toxicity or progressive disease; patients with stable disease at the 16-week evaluation point were randomly assigned in a double-blind manner to continued CAI or placebo. The primary end point was the stable disease rate in the randomized groups. RESULTS: A total of 368 patients were accrued and received therapy. Ninety percent had a performance status of 0 or 1, 80% underwent a prior nephrectomy, and 41% had received no prior systemic therapy. Serious or life-threatening toxicity was experienced by 34%, with asthenia (15%) and neuropsychiatric difficulties (7%) being most common. At the randomization point, 51% of patients had progressed, 30% withdrew, 1% experienced a partial response, and 17% had stable disease and were randomly assigned. A Bayesian futility analysis utilizing the first 49 randomly assigned patients suggested that the probability of demonstrating a higher stable disease rate in the experimental group was less than 9% even under the most optimistic a priori assumptions, and further trial accrual was halted. CONCLUSION: CAI is inactive in RCC. The RDT design should be further explored for evaluating activity of putative disease stabilizing agents.

Adult↗
PubMed2005

Modulation of irinotecan with cyclosporine: a phase II trial in advanced colorectal cancer.

INTRODUCTION: Despite the extensive clinical experience with irinotecan, significant concerns remain regarding its toxicity. In a phase I trial, we modulated irinotecan pharmacokinetics by inhibiting biliary excretion of SN-38, the active metabolite of irinotecan, using cyclosporine. The modulation appeared to decrease the gastrointestinal toxicity of irinotecan and suggested that irinotecan activity might also be retained. Hence, we conducted this phase II trial in patients with colorectal cancer (CRC) to further evaluate the toxicity and activity of irinotecan modulated with cyclosporine. PATIENTS AND METHODS: Sixteen patients with 5-fluorouracil refractory CRC were treated. Cyclosporine (5 mg/kg) was administered as a 6-h infusion and irinotecan (60 mg/m2/day, 90-min infusion) was started 3 h after initiation of the Cyclosporine. Both agents were given weekly for 4 weeks, every 6 weeks. Responses were assessed every 12 weeks, and toxicity was monitored weekly. RESULTS: Sixteen patients were evaluable for toxicity and 11 for response. There was 1 partial response (6%). Five patients had SD lasting a median of 12 weeks. Grade 3/4 diarrhea was observed in only 13% of the patients. CONCLUSION: Pharmacokinetic modulation of irinotecan using parenteral cyclosporine appears to decrease the incidence of diarrhea in CRC patients. Given the modest activity of irinotecan monotherapy, a larger study would be required to assess if the modulation improves the toxicity without compromising this activity. The available clinical data suggest that pharmacokinetic modulation of irinotecan should be evaluated further to define its optimal clinical utility.

Adult↗
PubMed2005

Global gene expression as a function of germline genetic variation.

Common, functional, germline genetic polymorphisms have been associated with clinical cancer outcomes. Little attention has been paid to the potential phenotypic consequences of germline genetic variation on downstream genes. We determined the germline status of 16 well-characterized functional polymorphisms in 126 children with newly diagnosed acute lymphoblastic leukemia (ALL). We assessed whether global gene expression profiles of diagnostic ALL blasts from the same patients differed by these germline polymorphic genotypes. Gene expression values were adjusted for ALL-subtype-specific patterns. Of the 16 loci, only the UGT1A1 promoter repeat polymorphism [A(TA)nTAA] (UGT1A1*28) and GSTM1 deletion were significant predictors of global gene expression in a supervised approach, which divided patients based on their germline genotypes [UGT1A1: 124 probe sets, false discovery rate (FDR)=13%, P< or =0.0031; GSTM1: 112 probe sets, FDR=42.5%, P< or =0.0084]. Genes whose expression distinguished the UGT1A1 (TA) 7/7 genotype from the other UGT1A1 genotypes included HDAC1, RELA and SLC2A1; those that distinguished the GSTM1 null genotype from non-null genotype included NBS1 and PRKR. In an unsupervised approach, the gene expression profiles using the entire array delineated two major clusters of patients. The only germline genotype frequency that differed between the two clusters was UGT1A1 (P=0.002; Fisher's exact test). Although their expression is limited to specific tissues, both GSTM1 and UGT1A1 are involved in the conjugation (and thus transport, excretion and lipophilicity) of a broad range of endobiotics and xenobiotics, which could plausibly have consequences for gene expression in different tissues.

Child↗
PubMed2005

A functional common polymorphism in a Sp1 recognition site of the epidermal growth factor receptor gene promoter.

The epidermal growth factor receptor (EGFR) plays a prominent role in cell growth and development. Its regulation in humans is complex and incompletely understood. In this study, 12 new polymorphisms were discovered in the 5'-regulatory region of EGFR gene and 2 common single nucleotide polymorphisms (-216G/T and -191C/A) were found in the essential promoter area, one of which is located in a Sp1 recognition site (-216). Transient transfection in human cancer and primary cell lines showed significantly different promoter activity between the two most common haplotypes (-216G-191C and -216T-191C). The replacement of G by T at position -216 increases the promoter activity by 30%. A transient transfection assay in the Sp1-deficient cell line (Schneider cell line 2) showed a strong dependence of EGFR promoter activity on Sp1 and confirmed the effect of the aforementioned polymorphisms. Electrophoretic mobility shift assay also showed a significantly higher binding efficiency of nuclear protein or pure Sp1 protein to the T allele compared with the G allele. We then investigated the allelic imbalance of EGFR transcription in fibroblast cell lines with heterozygous genotype at -216G/T but C/C homozygous genotype at -191C/A. The expression of mRNA carrying T-C haplotype was significantly stronger compared with that of G-C haplotype (P < 0.02). Thus, we successfully showed that a common polymorphism in the EGFR promoter was associated with altered promoter activity and gene expression both in vitro and in vivo. Our findings have implications for cancer etiology and therapy and may also be relevant to the inherited susceptibility of other common diseases.

Base Sequence↗
PubMed2005

Phase I trial of orally administered CEP-701, a novel neurotrophin receptor-linked tyrosine kinase inhibitor.

PURPOSE: A phase I clinical trial in patients with advanced carcinomas was conducted using the orally available neurotrophin receptor-linked tyrosine kinase receptor inhibitor, CEP-701. The objectives were to determine the maximum tolerated dose (MTD), dose-limiting toxicities, and pharmacokinetic profile of this orally administered agent. PATIENTS AND METHODS: A total of 30 patients were accrued to receive escalating BID doses of CEP-701 in cycles lasting 28 days. Between 3 and 6 patients were enrolled at each dose level. Once the MTD was determined, nine de novo patients were recruited to receive that level of drug. Pharmacokinetic studies were performed after the first dose, with additional sampling to assess intraindividual variability. RESULTS: The dosages ranged from 5 mg BID to 160 mg BID. While the criteria for MTD were not met at the dose levels administered, DLTs were observed at 80 and 120 mg BID. Treatment related adverse events, especially of the gastrointestinal system, made CEP-701 poorly tolerated at dosages above 40 mg BID. While CEP-701 did not produce an objective tumor response in any patient, 7 of the 30 patients received treatment for 3 months or more, including 3 who were on study with stable disease for more than 6 months. Orally administered CEP-701 was rapidly absorbed, with a mean t(max) between 1 and 3 hours. At higher dose levels, serum drug levels showed greater than dose-proportional increases by Day 28 versus Day 1. CONCLUSION: CEP-701 40 mg BID was well tolerated by patients with advanced malignancy and is the recommended dose level for planned phase II trials. Further study is necessary to determine the clinical efficacy of this novel new chemotherapeutic agent.

Administration, Oral↗
PubMed2005

Pharmacokinetic variability of anticancer agents.

The translation of advances in cancer biology to drug discovery can be complicated by pharmacokinetic variation between individuals and within individuals, and this can result in unpredictable toxicity and variable antineoplastic effects. Previously unrecognized variables (such as genetic polymorphisms) are now known to have a significant impact on drug disposition. How can the pharmacokinetic variability of anticancer agents be reduced? This will require the understanding of correlations between pharmacokinetics and treatment outcomes, the identification of relevant patient parameters, mathematical modelling of individual and population pharmacokinetics, and the development of algorithms that will tailor doses to the individual patient.

Adsorption↗
PubMed2005

Haplotypes of variants in the UDP-glucuronosyltransferase1A9 and 1A1 genes.

OBJECTIVES: Nine different functional UGT1A enzymes are generated from a single UGT1A gene by alternative splicing, with each enzyme having a unique exon 1. SN-38, the active metabolite of the anticancer agent irinotecan, is metabolized by both UGT1A1 and UGT1A9. We aim to characterize the UGT1A9-UGT1A1 haplotypes in Asians and Caucasians and gain insights on their functional consequences. METHODS: Asian and Caucasian individuals were genotyped for UGT1A1 and UGT1A9 variants. RESULTS: A higher frequency of the UGT1A9 -118T10 allele was observed in Asians compared to Caucasians, while the -275T>A and -2152C>T variants were relatively uncommon in Caucasians and not found in Asians. The strongest linkage disequilibrium (LD) was observed between the UGT1A1 -53 and -3156 and between the UGT1A9 -275 and -2152 loci. Lower LD was observed between the -118 UGT1A9 variant and the UGT1A1 variants. Fourteen UGT1A9-UGT1A1 haplotypes were found in Asians, seven of them found to be shared by both populations. Common UGT1A9-UGT1A1 diplotypes were defined, and a difference was observed across the SN-38 glucuronidation rates in Caucasian livers stratified by diplotypes. CONCLUSION: This study for the first time described common UGT1A9-UGT1A1 haplotypes, highlighting important ethnic differences between Asians and Caucasians. If the functional effect of these haplotypes can be confirmed, this haplotypic information would be applicable to the correct design of prospective clinical studies of irinotecan, as well as of other drugs primarily metabolized by both UGT1A1 and UGT1A9.

Asian People↗
PubMed2004

Prospective evaluation of body surface area as a determinant of paclitaxel pharmacokinetics and pharmacodynamics in women with solid tumors: Cancer and Leukemia Group B Study 9763.

PURPOSE: To study a fixed dose (360 mg) of paclitaxel given i.v. over 3 hours to female patients, and to evaluate prospectively the relationships between the following: body surface area and toxicity; body surface area and pharmacokinetics; and pharmacokinetics and toxicity. EXPERIMENTAL DESIGN: The eligibility criteria included the following: female sex; solid tumors; no more than one prior chemotherapy regimen; no prior paclitaxel; performance status of 0 to 2; and normal organ function. Paclitaxel plasma concentrations were quantified by high-performance liquid chromatography. The area under the curve, total body clearance, and hours above 0.05 micromol/L (T > 0.05) were calculated. RESULTS: Thirty-two patients were enrolled, and 29 patients received the correct dose and regimen. For statistical analyses, 26 patients had complete follow-up blood counts, 23 patients had complete data to correlate blood counts and area under the curve, and 25 patients had data to correlate blood counts and T > 0.05. The main toxicity was neutropenia of grade 3 and 4 severity in 21% and 25% of patients, respectively, in cycle 1. The worst grade of any toxicity, nadir WBC and absolute neutrophil count, and survival fractions were assessed; no significant relationship was found between body surface area and any measure of toxicity. Body surface area correlated inversely with area under the curve (r = -0.67; P < 0.001) and correlated with total body clearance (r = 0.69; P < 0.001), but body surface area did not correlate with T > 0.05. Neither area under the curve nor total body clearance were correlated with nadir absolute neutrophil count or survival fractions, but a significant correlation was found between T > 0.05 and log(nadir absolute neutrophil count; r = -0.41; P = 0.04). CONCLUSIONS: These results suggest that fixed dosing of paclitaxel is feasible in women, which would simplify the administration of this drug.

Adult↗
PubMed2004

Dose-ranging pharmacodynamic study of tipifarnib (R115777) in patients with relapsed and refractory hematologic malignancies.

PURPOSE: Tipifarnib, an orally bioavailable inhibitor of farnesyl transferase, has activity in hematologic malignancies, but the dose required to achieve the proposed biologic end point, inhibition of farnesylation, is unknown. PATIENTS AND METHODS: The impact on post-translational farnesylation was assessed in 42 patients with refractory hematologic malignancies and bone marrow involvement. Tipifarnib was taken orally for 21 days of a 28-day cycle. For cycle 1, patients were randomly assigned to one of four dose levels: 100 mg bid, 200 mg bid, 300 mg bid, and 600 mg bid. In cycle 1, peripheral blood and bone marrow mononuclear cells were analyzed for inhibition of HDJ2 prenylation by Western blot analysis at baseline and on day 21. RESULTS: Twenty-three patients were assessable for analysis of HDJ2 prenylation before and after therapy. Inhibition of farnesylation was noted at all dose levels, although the highest level of inhibition was noted at the 300-mg-bid dose. The inhibition of farnesylation in the peripheral blood correlated with the inhibition in the bone marrow (r = 0.62). Of the 26 patients assessable for clinical activity after cycle 1, three patients had a significant decrease in total blasts count (acute myeloid leukemia in two patients, and chronic myelogenous leukemia in one patient). The inhibition of farnesylation was greater in the three responders than the nonresponders (P = .03). CONCLUSION: Farnesylation as measured by HDJ2 analysis was inhibited at all dose levels administered. Clinical activity may correlate with the degree of farnesylation inhibition, rather than dose of tipifarnib, and escalation beyond 300 mg bid might not result in additional clinical activity.

Administration, Oral↗
PubMed2004

Quality of life impact of three different doses of suramin in patients with metastatic hormone-refractory prostate carcinoma: results of Intergroup O159/Cancer and Leukemia Group B 9480.

BACKGROUND: Research has suggested that men with hormone-refractory prostate carcinoma have a lower quality of life (QOL) compared with men who have hormone-sensitive prostate carcinoma and that quality of life (QOL) steadily declines over the last year of life for men with prostate carcinoma. The primary purpose of the current study was to evaluate whether there was evidence of palliative effects associated with suramin at any of the three doses administered in the original clinical trial. METHODS: Patients with histologically confirmed advanced hormone-refractory adenocarcinoma of the prostate were randomized to receive suramin at a low dose (n = 129; median age, 69 years), an intermediate dose (n = 129; median age, 71 years), or a high dose (n = 127; median age, 70 years) as part of the Intergroup 0159/Cancer and Leukemia Group B 9480 trial. Patients completed a battery of assessment tools, including the Functional Assessment of Cancer Therapy (FACT)-Prostate, the Center for Epidemiological Studies-Depression Scale (CES-D), the Brief Pain Inventory, and an opioid medication log, at baseline, on Day 1 of the sixth week of active therapy, during the second week after treatment termination, and 3 months after administration of the final suramin dose. RESULTS: Patients who received low-dose suramin reported improvement in QOL (FACT-General: P < 0.01; FACT-Treatment Outcome Index: P < 0.01) and decreased levels of depression (CES-D: P < 0.0006) during treatment compared with patients in the intermediate- and high-dose arms. After treatment, all groups experienced equal decreases in FACT and CES-D scores. CONCLUSIONS: The pattern of results suggests that the lowest dose of suramin administered had a palliative effect in terms of improvement in QOL and decreased levels of depression and that this effect was lost once suramin was discontinued.

Adenocarcinoma↗
PubMed2004

Delivery of a liposomal c-raf-1 antisense oligonucleotide by weekly bolus dosing in patients with advanced solid tumors: a phase I study.

PURPOSE: Rapid cleavage in vivo and inefficient cellular uptake limit the clinical utility of antisense oligonucleotides (AON). Liposomal formulation may promote better intratumoral AON delivery and inhibit degradation in vivo. We conducted the first clinical evaluation of this concept using a liposomal AON complementary to the c-raf-1 proto-oncogene (LErafAON). EXPERIMENTAL DESIGN: A dose escalation study was done to determine the maximum tolerated dose and to characterize the toxicities of LErafAON given as weekly intravenous infusion for 8 weeks to adults with advanced solid tumors. Pharmacokinetic analysis and evaluation of c-raf-1 target suppression in peripheral blood mononuclear cells were included. RESULTS: Twenty-two patients received LErafAON (median 7 infusions; range 1-27) at doses of 1, 2, 4, and 6 mg/kg/week. Across all dose cohorts patients experienced infusion-related hypersensitivity reactions including flushing, dyspnea, hypoxia, rigors, back pain, and hypotension. Prolonged infusion duration and pretreatment with acetaminophen, H1- and H2-antagonists, and corticosteroids reduced the frequency and severity of these reactions. Progressive thrombocytopenia was dose-limiting at 6 mg/kg/week. No objective responses were observed. Two patients treated at the maximum tolerated dose of 4 mg/kg/week had evidence of stable disease, with dosing extended beyond 8 weeks. Pharmacokinetic analysis revealed persistence of detectable circulating rafAON at 24 hours in 7 of 10 patients in the highest 2 dose cohorts. Suppression of c-raf-1 mRNA was noted in two of five patients analyzed. CONCLUSIONS: Dose-independent hypersensitivity reactions and dose-dependent thrombocytopenia limited tolerance of LErafAON. Future clinical evaluation of this approach will depend on modification of the liposome composition.

Adult↗
PubMed2004

A phase I trial of gemcitabine plus cladribine in patients with advanced hematologic malignant diseases.

PURPOSE: Gemcitabine and cladribine (2CdA) are nucleoside analogues that decrease DNA synthesis via inhibition of ribonucleotide reductase; the combination could be additive or synergistic. We conducted a dose escalation study to establish the maximum tolerable doses (MTD) of gemcitabine and 2CdA when given in combination in patients with advanced hematologic malignancies and to describe the toxicity profile of this combination. PATIENTS AND METHODS: A total of 45 patients with advanced hematologic diseases were enrolled into two groups. Group A had adequate baseline hematopoiesis, defined as absolute neutrophil count (ANC) >1 x 10(9)/l and platelet count >50 x 10(9)/l. Group B did not meet these criteria. Hematologic dose-limiting toxicity (DLT) for group A was defined as grade 4 neutropenia or thrombocytopenia lasting >28 days; group B was not evaluated for hematologic toxicity. Nonhematologic DLT was defined similarly for both groups. Death occurring during the first cycle of treatment was considered a DLT event only if it was related to drug toxicity. Gemcitabine was administered as a 4-h intravenous infusion once every 28 days. 2CdA was administered over 1 h daily for the first 3 days of each 28-day cycle. RESULTS: The MTD was not reached in either group. Myelosuppression was common, but not dose-limiting. Febrile neutropenia and infections were also common, particularly in group B, and judged in most cases to be due to bone marrow failure at baseline. Nonhematologic toxicities were generally mild, and skin rash, the most frequently observed, was dose-limiting in one patient enrolled in each group. Four deaths (three during the first cycle of treatment) occurred at the highest dose level tested in group B (gemcitabine 5000 mg/m2 and 2CdA 16 mg/m2). Although only one of these deaths was dose-limiting by stated criteria, this dose level did not appear to be safely tolerated in this patient population. Several responses were observed in patients with Hodgkin's disease. CONCLUSIONS: The combination of gemcitabine and 2CdA is feasible in patients with hematologic malignancies. Phase II studies of this combination should be considered, particularly in patients with Hodgkin's disease.

Adult↗
PubMed2004

A phase I trial of pharmacokinetic modulation of carboxyamidotriazole (CAI) with ketoconazole in patients with advanced cancer.

PURPOSE: Carboxyamidotriazole (CAI) is a novel antineoplastic agent in clinical development with limited oral bioavailability. In vitro, ketoconazole has been demonstrated to inhibit CYP3A4-mediated metabolism of CAI. We performed this phase I trial to determine if ketoconazole-mediated CYP3A4 inhibition would lead to favorable alteration of CAI pharmacokinetics, and to evaluate the safety, toxicity and tolerability of the proposed combination. DESIGN: Forty-seven patients were treated using a standard three patients per cohort CAI dose-escalation scheme. In cycle 1, CAI was administered alone on day-6 followed by a single dose of ketoconazole (200 mg) on day 0. CAI and ketoconazole (200 mg/day) were subsequently coadministered on days 1 and 3-28. Plasma samples for pharmacokinetic analysis were obtained following the doses on days-6 and 1. All subsequent cycles were of 28-day duration, and consisted of daily CAI and ketoconazole coadministration. RESULTS: Pharmacokinetic analysis was performed on samples from 44 patients. In most patients administration of ketoconazole produced an increase in CAI AUC and Cmax with a decrease in CAI clearance. Seven patients experienced stable disease for up to 12 months. Gastrointestinal and constitutional toxicities were the most common toxicities. CONCLUSIONS: Coadministration of CAI with ketoconazole increased CAI exposure in most of the patients without altering the toxicity profile of CAI. The highest CAI dose administered on the trial was 300 mg/day. The clinical utility of such a modulation strategy might be explored in future clinical trials of CAI.

Adult↗