Biomedical subjects

David Gandara

Publications and source records attributed to David Gandara.

15 recordsLinked to original sources

PubMed2006

A phase I study of oxaliplatin in combination with gemcitabine: correlation of clinical outcome with gene expression.

PURPOSE: Oxaliplatin has in vitro activity similar to or higher than other platinum agents. Preclinically, gemcitabine has demonstrated synergy when combined with platinum compounds. These facts formed the rationale for determining the maximum tolerated dose (MTD) of gemcitabine in combination with oxaliplatin. METHODS: Eligible patients with advanced incurable solid tumors were given oxaliplatin 130 mg/m2 as a 2-h infusion on day 1 followed by escalating doses of gemcitabine given over 30 min on day 1 and 8 of a 21-day cycle. RESULTS: A total of 43 patients were enrolled, including 30 patients at the MTD in an expanded cohort. At a gemcitabine dose of 800 mg/m2, 1/6 patients had a dose limiting toxicity (DLT) (grade 3 blurred vision and memory loss). At 1,000 mg/m2, 1/6 patients had a DLT (grade 3 increase in AST). At 1,200 mg/m2, 2/3 patients had a DLT (grade 4 thrombocytopenia and grade 3 confusion). The MTD of gemcitabine with 130 mg/m2 of oxaliplatin was therefore 1,000 mg/m2. The clearances of gemcitabine and ultrafilterable platinum are within the ranges previously reported for single agents. A patient with colon cancer had a partial response, and 21 patients had a best response of stable disease. In patients with tumor biopsies treated at the MTD, decreased ribonucleotide reductase M2 expression correlated with response. CONCLUSION: Treatment with gemcitabine and oxaliplatin was well tolerated with primarily hematologic toxicity at the MTD. Study of biochemical correlates of response remain of interest thought current results remain exploratory.

Adult↗

PubMed2006

Analysis of ribonucleotide reductase M2 mRNA levels in patient samples after GTI-2040 antisense drug treatment.

This study describes the development of a rapid and practical real-time RT-PCR method to quantify ribonucleotide reductase M2 (RRM2) mRNA in tumor and peripheral white blood cells (WBCs) from patients treated with GTI-2040, an antisense drug currently in clinical trials. In order to assess target down-regulation by GTI-2040, RRM2 mRNA expression levels were analyzed in pre- and post-treatment samples from a phase II clinical trial of GTI-2040 combined with capecitabine in patients with metastatic breast cancer. Target gene RRM2 mRNA levels were evaluated using quantitative RT-PCR method: real-time PCR (TaqMan) with fluorescein labeled probes on an ABI 7900HT instrument, with additional post-processing of the data to adjust for differences in total RNA in-put across the samples. Data are presented from a patient for whom both biopsy and PBMC samples were available, demonstrating applicability of this reproducible, highly sensitive real-time RT-PCR method for the detection and quantification of mRNAs for RRM2 in human WBC and tissue samples. By providing quantitative measurement of changes in target gene expression, this method may provide an opportunity to determine the correlation between target response to GTI-2040 antisense and clinical response in patients. Furthermore this assay may assess whether WBC samples are an appropriate surrogate tissue for approximating target down-regulation in the tumor.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2005

Integration of novel therapeutics into combined modality therapy of locally advanced non-small cell lung cancer.

Novel therapeutic agents (NTA) directed against a wide array of newly described molecular targets are now entering clinical investigation, many in the treatment of non-small cell lung cancer (NSCLC). The great majority of these clinical trials have been directed toward patients with advanced stage (metastatic) disease. More recently, study of NTAs has turned toward earlier-stage disease. Locally advanced, or stage III, NSCLC represents a large and heterogeneous group of patients and several clinically distinct substages. During the last 15 years, randomized clinical trials have shown improved survival with sequential chemoradiation compared with radiation alone and, more recently, the superiority of concurrent versus sequential chemoradiation. As NTAs have increasingly shown clinical activity against NSCLC, questions of how to incorporate them into clinical trials in stage III disease, whether they should be given together with radiotherapy, substituting for chemotherapy, or whether they should be added to current chemoradiation strategies, all remain as issues. Here, we describe conceptual issues, preclinical rationale, and ongoing or planned clinical trials incorporating NTAs into current treatment paradigms for unresectable stage III NSCLC.

Antineoplastic Agents↗

PubMed2005

Vinorelbine plus cisplatin vs. observation in resected non-small-cell lung cancer.

BACKGROUND: We undertook to determine whether adjuvant vinorelbine plus cisplatin prolongs overall survival among patients with completely resected early-stage non-small-cell lung cancer. METHODS: We randomly assigned patients with completely resected stage IB or stage II non-small-cell lung cancer to vinorelbine plus cisplatin or to observation. The primary end point was overall survival; principal secondary end points were recurrence-free survival and the toxicity and safety of the regimen. RESULTS: A total of 482 patients underwent randomization to vinorelbine plus cisplatin (242 patients) or observation (240); 45 percent of the patients had pathological stage IB disease and 55 percent had stage II, and all had an Eastern Cooperative Oncology Group performance status score of 0 or 1. In both groups, the median age was 61 years, 65 percent were men, and 53 percent had adenocarcinomas. Chemotherapy caused neutropenia in 88 percent of patients (including grade 3 febrile neutropenia in 7 percent) and death from toxic effects in two patients (0.8 percent). Nonhematologic toxic effects of chemotherapy were fatigue (81 percent of patients), nausea (80 percent), anorexia (55 percent), vomiting (48 percent), neuropathy (48 percent), and constipation (47 percent), but severe (grade 3 or greater) toxic effects were uncommon (<10 percent). Overall survival was significantly prolonged in the chemotherapy group as compared with the observation group (94 vs. 73 months; hazard ratio for death, 0.69; P=0.04), as was relapse-free survival (not reached vs. 46.7 months; hazard ratio for recurrence, 0.60; P<0.001). Five-year survival rates were 69 percent and 54 percent, respectively (P=0.03). CONCLUSIONS: Adjuvant vinorelbine plus cisplatin has an acceptable level of toxicity and prolongs disease-free and overall survival among patients with completely resected early-stage non-small-cell lung cancer.

Adult↗

PubMed2005

Southwest Oncology Group: two decades of experience in non-small cell lung cancer.

Over the past two decades, studies of the Southwest Oncology Group have consistently reported stable esophagitis rates despite changing scales with concurrent chest radiotherapy and cisplatin/etoposide regimens. Patient selection has perhaps contributed to increased survival over this period. The Southwest Oncology Group has incorporated surgical questions and advanced the field with a steady use of consistent therapies (ie, cisplatin/etoposide plus radiotherapy of 45 Gy [induction therapy] and cisplatin/etoposide plus at least 61 Gy) in potentially operable or unresectable disease. Further studies examining the addition of either docetaxel or novel agents to such regimens are underway.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2005

Computer-assisted image analysis of bronchioloalveolar carcinoma.

In clinical trials, response rate is an important endpoint for assessing the efficacy of an anticancer drug. The Response Evaluation Criteria for Solid Tumors (RECIST) has been widely used as a standard method to assess response. The RECIST requires only 1-dimensional measurement of tumor size. However, bronchioloalveolar carcinoma (BAC), which commonly presents as infiltrative or micronodular lesions, is not always readily assessable by RECIST. During the past 2 years, we have been developing computer-based programs to more accurately measure tumor size on chest computed tomography (CT) scans. In a first-generation computer-assisted image analysis (CAIA) system, we were able to capture and quantify lesions on CT scans by linking the software programs of eFilm, HyperSnap, and Scion. We have applied this CAIA approach to measuring BAC response to gefitinib in the Southwest Oncology Group (S0126) trial. However, this first-generation CAIA system involves multiple manual steps and is therefore labor intensive. We are now developing a fully automated CAIA program based on a versatile software platform, ImageJ, created at the National Institutes of Health. Taking theoretical and physical considerations into account, Java plug-in programs for ImageJ are created to automatically analyze CT scans in the Digital Imaging and Communications in Medicine format. We have demonstrated the feasibility of an ImageJ-based automated CAIA program for measuring BAC bidimensionally on CT scans. This automated CAIA system will be applied in a prospective clinical trial of the GVAX vaccine in patients with BAC.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed2004

Phase II trial of carboplatin and infusional cyclosporine in platinum-resistant recurrent ovarian cancer.

PURPOSE: To determine the response rate to 26-h continuous infusion cyclosporine A (CSA) combined with a fixed dose level of carboplatin (CBDCA) in patients with recurrent ovarian cancer, and to determine the effect of CSA on the pharmacokinetics of CBDCA. EXPERIMENTAL DESIGN: To examine the effect of duration of CSA exposure on reversal of CBDCA resistance, clonogenic assays were performed in vitro in platinum-resistant A2780 cells. CBDCA (AUC 4) with CSA repeated every 3 weeks was then administered to patients on this phase II study. Pharmacokinetics of CSA and CBDCA were determined in a subset of patients. RESULTS: Preincubation of platinum-resistant A2780 cells with CSA reversed CBDCA resistance in a concentration-dependent and time-dependent manner. A group of 23 patients received 58 courses of CBDCA/CSA therapy. One partial response was observed. Eight patients achieved disease stabilization. Toxicity was similar to that observed in our previous phase I study and consisted of myelosuppression, nausea, vomiting, and headache. The mean +/- SD end-of-infusion CSA level (HPLC assay) was 1253 +/- 400 microg/ml. The pharmacokinetic studies suggest that CSA does not increase CBDCA AUC. CONCLUSIONS: Steady-state levels of >1 microg/ml CSA (HPLC assay) are achievable in vivo. Modest partial reversal of platinum resistance (in one patient with an objective response and in eight patients with stable disease noted) is achievable in vivo in patients pretreated with CSA. This phenomenon is not explained by alterations in CBDCA pharmacokinetics.

Adult↗

PubMed2004

Enhancement of radiotherapy with DNA topoisomerase I-targeted drugs.

Since its discovery more than a century ago, ionizing radiation has become a mainstay therapy for patients suffering from cancers. Currently, radiotherapy provides cure or palliative care for approximately one half of the cancer population. The anticancer efficacy of radiotherapy is, however, largely limited by its lack of tumor specificity and, consequently, normal tissue toxicity. There is an urgent need to develop systemic adjuncts that can enhance the efficacy and the selectivity of radiotherapy toward tumor cells. DNA topoisomerase I (TOP1)-targeted drugs such as camptothecin derivatives represent a novel class of chemotherapeutic agents that have recently been shown to be excellent radiation sensitizers. Combined modality therapy with TOP1-targeted drugs and radiotherapy represents a new promising cancer therapy. The mechanism of enhancement of radiotherapy by TOP1-targeted drugs is under intense investigation. Clinical trials using combinations of radiation and camptothecin derivatives are also currently ongoing in various solid tumors including brain, head and neck, and lung cancers. A better understanding of the radiosensitization (RS) mechanism of TOP1-targeted drugs is pivotal to their clinical application, as well as in guiding the development of better radiation sensitizers.

Animals↗

PubMed2004

Is inhibition of cancer angiogenesis and growth by paclitaxel schedule dependent?

It has been speculated that weekly paclitaxel enhances antiangiogenesis and, hence, results in a greater inhibition of cancer growth than the 3-week schedule. We compared the weekly and 3-week schedules of paclitaxel in inhibiting angiogenesis, tumor growth and bone marrow hematopoiesis in a lung cancer model. Vehicle or paclitaxel was administered i.p. to three groups of nude mice bearing a human lung cancer. The vehicle was given weekly for six doses or every 3 weeks for two doses (Group A). Paclitaxel was administered at 20 mg/kg/week for six doses (Group B) or 60 mg/kg/3 weeks for two doses (Group C). The tumor growth rate was reduced by 50% equally in both the paclitaxel-treated groups. Intratumoral microvasculature was reduced by 70% in each paclitaxel-treated group. However, white blood cell count was significantly reduced in Group C in comparison with that of Group A or B. We conclude that in this model, angiogenesis and tumor growth were inhibited to the same extent when paclitaxel was administered on a weekly or 3-week schedule. Inhibition of tumor growth by paclitaxel was associated with suppression of angiogenesis. Weekly administration of paclitaxel resulted in a lower degree of leukopenia than with the 3-week schedule, mimicking the clinical setting.

Angiogenesis Inhibitors↗

PubMed2003

Quantification of chemotherapeutic target gene mRNA expression in human breast cancer biopsies: comparison of real-time reverse transcription-PCR vs. relative quantification reverse transcription-PCR utilizing DNA sequencer analysis of PCR products.

The solid tumor mRNA expression of genes related to the mechanism of action of certain antineoplastic agents is often predictive of clinical efficacy. We report here on the development of a rapid and practical real-time RT-PCR method to quantify genetic expression in solid tumors. The genes examined are related to the intracellular pharmacology of gemcitabine and cisplatin, two drugs that are used in the treatment of several types of advanced cancer. We evaluated target gene mRNA levels from breast tumor samples using two quantitative RT-PCR methods: 1) an improved relative RT-PCR method using fluorescence-labeled primers, automated PCR set up, and GeneScan analysis software; and 2) real-time RT-PCR with redesigned primers using an ABI 7900HT instrument, with additional postprocessing of the data to adjust for efficiency differences across the target genes. Using these methods, we quantified mRNA expression levels of deoxycytidine kinase (dCK), deoxycytidylate deaminase (dCDA), the M1 and M2 subunits of ribonucleotide reductase (RRM1, RRM2), and excision cross complementation group 1 (ERCC1) in 35 human "fresh" frozen breast cancer biopsies. While both assay methods were substantially more rapid than traditional RT-PCR, real-time RT-PCR appeared to be superior to the amplification end-point measurement in terms of precision and high throughput, even when a DNA sequencer was used to assess fluorescence-labeled PCR products. This reproducible, highly sensitive real-time RT-PCR method for the detection and quantification of the mRNAs for dCK, dCDA, RRM1, RRM2, and ERCC1 in human breast cancer biopsies appears to be more informative and less time-consuming than either classical radioisotope-dependent RT-PCR or the technique utilizing GeneScan analysis described herein. By allowing the measurement of intratumoral target gene expression, these new methods may prove useful in predicting the clinical utility of gemcitabine- and platinum-containing chemotherapy programs in patients with solid tumors.

Algorithms↗

PubMed2003

Pharmacology of oxaliplatin in solid tumor patients with hepatic dysfunction: a preliminary report of the National Cancer Institute Organ Dysfunction Working Group.

Oxaliplatin, which was recently approved by the US Food and Drug Administration for the treatment of advanced colorectal cancer, is often administered to patients with altered liver function caused by hepatic metastases. Because of the absence of data on the clearance of oxaliplatin in patients with liver dysfunction, and to develop dosing recommendations for the safe use of oxaliplatin in this clinical setting, the Organ Dysfunction Working Group of the National Cancer Institute performed a phase I and pharmacokinetic trial of this drug in patients displaying a wide range of liver function abnormalities. Sixty patients grouped into five classes of liver function were enrolled in this study, including a 12-patient control group with normal liver function, 15 patients with "mild," 16 patients with "moderate," and 16 with "severe" liver dysfunction, as well as one patient who had undergone liver transplantation. The patients had a median age of 62 years and a Eastern Cooperative Oncology Group performance status of 0. All patients had received prior systemic chemotherapy, and 70% had a diagnosis of a gastrointestinal malignancy. The control patients were treated with 130 mg/m(2) oxaliplatin intravenously every 21 days; the starting doses for patients with mild, moderate, or severe liver dysfunction or post-liver transplantation were 105, 80, or 60 mg/m(2), respectively. Cohorts of three or more patients were escalated from these starting doses to 130 mg/m(2) if dose-limiting toxicities were not observed, and pharmacokinetic evaluations were performed at each dose level for every category of liver dysfunction. We found that oxaliplatin was well tolerated at its recommended dose and schedule of 130 mg/m(2) every 21 days in patients with all levels of liver dysfunction, and that there was no apparent alteration in the clearance of either total or ultrafilterable platinum species from plasma, even in patients with severe hepatic functional abnormalities.

Antineoplastic Agents↗

PubMed2002

Phase I pharmacodynamic study of time and sequence dependency of hydroxyurea in combination with gemcitabine: a California Cancer Consortium Trial.

Preclinical studies in our laboratory have demonstrated that prior exposure to hydroxyurea increases the percentage of cells in S phase, enhancing the cytotoxicity of subsequent gemcitabine treatment in human oropharyngeal KB cells. To evaluate the clinical implications of this time- and sequence-dependent potentiation, we performed a phase I trial of hydroxyurea given over 24 h followed by a 30-min infusion of gemcitabine in weeks 1 and 2 of a 3-week cycle. The dose of hydroxyurea was fixed at 500 mg orally every 6 h for four doses starting 24 h before each dose of gemcitabine. The initial dose level of gemcitabine was 250 mg/m(2) on days 2 and 9, and this was escalated stepwise to 1000 mg/m(2) on days 2 and 9. Gemcitabine pharmacokinetics were determined on days 2 and 9 of the first cycle. Of 27 patients enrolled (12 female, 15 male), 24 were evaluable for response and 23 were evaluable for toxicity. Their median age was 56 years (range 27-76 years). Tumor types included lung, head and neck, pancreas, breast, colon, prostate, stomach, ovary, esophagus, germ cell, thyroid, gallbladder, and unknown primary. A total of 80 cycles of treatment were completed. One patient (unknown primary) had an objective partial response lasting 21 months, and 12 patients had stable disease. All observed dose-limiting toxicities were related to myelosuppression. The gemcitabine maximum tolerated dose was established at 750 mg/m(2) on days 2 and 9. Hydroxyurea had no effect on the plasma pharmacokinetics of gemcitabine. These results suggest that hydroxyurea followed by gemcitabine can be safely administered and has activity on this schedule. We are presently developing a phase II trial of this regimen for patients with platinum-resistant head and neck cancer.

Adult↗

PubMed2002

Adjuvant and neoadjuvant treatments for NSCLC.

In stage III non-small cell lung cancer (NSCLC), the use of induction chemotherapy prior to radiotherapy produces a significant increase in median survival of three to four months (from 11 to 14 months), a benefit which appears to be achieved through improved systemic control of the disease. Hyperfractionated radiotherapy, although it enhances local control, seems not to improve survival. Concurrent chemoradiotherapy has emerged as the most successful strategy. It led to increased locoregional control and to a 3-4 month improvement of median survival when compared with induction chemotherapy prior to radiotherapy. Docetaxel is a radiosensitizing agent and has been extensively investigated in phase I/II settings of concurrent chemoradiotherapy. Use of the other cytotoxics such as paclitaxel, or irinotecan in concurrent chemoradiotherapy strategies is also feasible. Of particular interest are the results of SWOG 9504, a phase II study in which cisplatin/etoposide concurrent chemoradiotherapy was followed by three cycles of docetaxel consolidation. Median survival is 26 months, 1-year survival 76% and 3-year survival 40%. These survival data, achieved in pathologically staged IIIB patients, are highly encouraging and support further evaluation of this approach. Among stage III patients eligible for radical treatment with surgery or radiotherapy, the addition of neoadjuvant docetaxel at 100 mg/m(2) for three cycles is tolerable and appears to be associated with a trend towards increased survival.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

Premedication strategy for weekly paclitaxel.

PURPOSE: Dexamethasone and histamine antagonists have been employed commonly as premedications for prophylaxis of hypersensitivity reactions (HSRs) to paclitaxel. Frequent premedications for weekly administration of paclitaxel are associated with added side-effects and extra cost. We analyzed our experience of HSRs to paclitaxel administered every 3-4 weeks, and designed a treatment algorithm to eliminate premedications in a majority of patients receiving weekly paclitaxel. PATIENTS AND METHODS: The incidence of HSRs was analyzed retrospectively in patients who received 3-hr infusions of paclitaxel (135-225 mg/m2) every 3-4 weeks in our institution over a period of 5 years. On the basis of the results of this analysis, we designed a premedication schema for patients receiving weekly paclitaxel, 50-90 mg/m2/week, as follows: Thirty minutes prior to the first weekly dose of paclitaxel, patients received intravenously (i.v.) dexamethasone (10 mg), diphenhydramine (25 mg), and cimetidine (300 mg). If no HSRs occurred, all premedications were deleted for subsequent weekly paclitaxel doses. For patients who experienced HSRs, 20 mg of dexamethasone was given orally 12 and 6 hr prior to re-challenge with paclitaxel in addition to diphenhydramine and cimetidine. RESULTS: Over a period of 5 years, 358 patients received 1608 3-hr infusions of paclitaxel (135-225 mg/m2). Hypersensitivity reactions, which occurred exclusively during the first cycle of paclitaxel administration, were observed in 14 patients. Of these 14 patients, 11 were successfully retreated with paclitaxel without HSRs, two had recurrent HSRs upon paclitaxel re-challenge, and one refused further treatment. These observations indicate that HSRs to paclitaxel occurred in 4% of patients upon first exposure, that most of these patients can be retreated successfully with paclitaxel without recurrent HSRs, and that if no HSRs occur during the first cycle, HSRs are unlikely to occur with subsequent paclitaxel administration. The premedication schema was applied to 30 patients receiving 205 one-hr infusions of weekly paclitaxel. Using this premedication strategy, no HSRs have been observed during the initial or subsequent administration of paclitaxel. CONCLUSION: We conclude that this premedication strategy is feasible and worthy of further study for patients receiving weekly paclitaxel.

Administration, Oral↗

PubMed2002

Low ERCC1 expression correlates with prolonged survival after cisplatin plus gemcitabine chemotherapy in non-small cell lung cancer.

PURPOSE: Overexpression of the excision repair cross-complementing 1 (ERCC1) gene, which is crucial in the repair of cisplatin (CDDP)-DNA adducts, is reported to negatively influence the effectiveness of CDDP-based therapy for gastric and ovarian cancers. Recent evidence indicates that Gemcitabine (Gem) may modulate ERCC1 nucleotide excision repair activity, and down-regulation of DNA repair activity by ERCC1 antisense RNA reportedly inhibits synergism of CDDP/Gem. We investigated whether ERCC1 mRNA expression levels were associated with clinical outcomes after treatment with a combination Gem/CDDP regimen for patients with advanced stage non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: Response and survival were correlated with the level of ERCC1 expression in 56 patients with advanced (stage IIIb or IV) NSCLC treated as part of a multicenter randomized trial with Gem 1250 mg/m(2) days 1 and 8 plus CDDP 100 mg/m(2) on day 1 every 3 weeks. mRNA was isolated from paraffin-embedded pretreatment primary tumor specimens, and relative expression levels of ERCC1/beta-actin were measured using a quantitative reverse transcription-PCR (Taqman) system. RESULTS: ERCC1 expression was detectable in all tumors. There were no significant differences in ERCC1 levels by gender, age, performance status, weight loss, or tumor stage. The overall response rate was 44.7%. There were no significant associations between ERCC1 expression and response. Median overall survival was significantly longer in patients with low ERCC1 expression tumors (61.6 weeks; 95% confidence interval, 42.4-80.7 weeks) compared to patients with high expression tumors (20.4 weeks, 95% confidence interval, 6.9-33.9 weeks). ERCC1 expression, Eastern Cooperative Oncology Group performance status, and presence of weight loss were significant prognostic factors for survival in a Cox proportional hazards multivariable analysis. CONCLUSIONS: These data suggest that ERCC1 expression is a predictive factor for survival after CDDP/Gem therapy in advanced NSCLC. Although there was a trend toward decreased response with high ERCC1 mRNA levels, this difference failed to reach statistical significance. This result may reflect the impact of Gem and the requirement for ERCC1 expression for CDDP/Gem synergism or may be attributable to the relatively small patient sample size in this study. Prospective studies of ERCC1 as a predictive marker for activity of CDDP-based regimens in NSCLC are warranted.

Adult↗