Biomedical subjects

Robert E Martell

Publications and source records attributed to Robert E Martell.

5 recordsLinked to original sources

PubMed2005

A phase I trial of the novel farnesyl protein transferase inhibitor, BMS-214662, in combination with paclitaxel and carboplatin in patients with advanced cancer.

PURPOSE: This phase I study was conducted to determine the toxicities, pharmacokinetics, and pharmacodynamics of BMS-214662, a farnesyl transferase inhibitor, in combination with paclitaxel and carboplatin, in patients with advanced solid tumors. EXPERIMENTAL DESIGN: Patients with solid tumors received one of six escalating dose levels of BMS-214662 infused over 1 hour given following paclitaxel and carboplatin on the first day of a 21-day cycle. Toxicities were graded by the National Cancer Institute common toxicity criteria and recorded as maximum grade per patient for each treatment cycle. Inhibition of farnesyl transferase activity in peripheral blood mononuclear cells (PBMCs) was evaluated. Accumulation of unfarnesylated HDJ-2 in PBMCs of patients was evaluated as a marker of farnesyl transferase inhibition by BMS-214662. RESULTS: Thirty patients received 141 cycles of treatment through six dose levels. Dose-limiting toxicities were neutropenia, thrombocytopenia, nausea, and vomiting. There was no pharmacokinetic interaction between BMS-214662 and paclitaxel. The maximum tolerated dose was established as BMS-214662 (160 mg/m(2)), paclitaxel (225 mg/m(2)) and carboplatin (area under the curve = 6 on day 1), every 21 days. Inhibition of HDJ-2 farnesylation in PBMCs of patients was shown. One measurable partial response was observed in a patient with taxane-resistant esophageal cancer. There was partial regression of evaluable disease in two other patients (endometrial and ovarian cancer). Stable disease (> 4 cycles) occurred in eight other patients. CONCLUSIONS: The combination of BMS-214662 with paclitaxel and carboplatin was well tolerated, with broad activity in solid tumors. There was no correlation between dose level and accumulation of unfarnesylated HDJ-2 in PBMCs nor tumor response.

Adult↗

PubMed2002

Analysis of age, estimated creatinine clearance and pretreatment hematologic parameters as predictors of fludarabine toxicity in patients treated for chronic lymphocytic leukemia: a CALGB (9011) coordinated intergroup study.

PURPOSE: Fludarabine is a renally excreted agent that is an effective treatment for chronic lymphocytic leukemia (CLL), a disease predominantly of the elderly. We sought to determine whether age, renal function or pretreatment hematologic status predicted toxicity of fludarabine treatment for CLL. METHODS: We evaluated 192 patients with previously untreated B-cell CLL who were entered onto the fludarabine treatment arm (25 mg/m(2) daily for 5 days every 28 days) of CALGB study 9011, an intergroup study with participation from SWOG, CTG/NCI-C and ECOG. Patients were required to have serum creatinine within 1.5 times normal. Hematologic indices and infections were recorded during the first 28-day cycle of treatment. A time-to-toxicity endpoint was evaluated over the entire course of fludarabine treatment. Creatinine clearance (CrCl(est)) was estimated using serum creatinine, age and body mass index. RESULTS: The median age was 64 years (range 37-87 years) and median CrCl(est) was 62 ml/min (range 27-162 ml/min, interquartile range 52-79 ml/min). We found no association between age and incidence of hematologic toxicity or infection during the first cycle of treatment. There was a strong association between CrCl(est) and the time-to-toxicity endpoint. Patients with CrCl(est) below 80 ml/min had increased incidence of toxicity during their treatment course ( P<0.0001). Pretreatment anemia, thrombocytopenia and Rai stage were highly associated with the incidence of neutrophil toxicity and grade III/IV hematologic toxicities during the first cycle of treatment ( P<0.0001). CONCLUSIONS: Patient age was not an independent risk factor for fludarabine-related toxicity, but CrCl(est) was associated with time to toxicity.

Adult↗

PubMed2002

Comprehensive assessment of the elderly cancer patient: the feasibility of self-report methodology.

PURPOSE: Comprehensive geriatric assessment (CGA) has aided the medical community greatly in understanding the quality-of-life issues and functional needs of older patients. With its professional team assessment approach, however, CGA may be time consuming and costly. The goal of the present study was to assess the ability of cancer patients to complete a self-administered CGA and then to characterize cancer patients across multiple domains and age groups. PATIENTS AND METHODS: Two hundred sixty-six male outpatient oncology patients at the Durham Veterans Affairs Medical Center were asked to fill out a survey assessing 10 domains (demographics, comorbid conditions, activities of daily living, functional status, pain, financial well being, social support, emotional state, spiritual well-being, and quality of life). RESULTS: Seventy-six percent of the patients who received their surveys and kept their appointments returned the assessment tool. Older oncology patients had significantly less education (P <.0001), income (P =.05), frequent exercise (P =.01), and chance of being disease free (P =.003) than younger patients. Other findings in older patients were a higher rate of marriage (P =.02), more difficulty in taking medications (P =.05), and less cigarette (P =.03) and alcohol (P =.03) use. Members of all age cohorts reported a sense of social support, with younger patients deriving this more from family and friends than older patients, and older patients deriving social support more from membership in religious communities than younger patients. No differences were found across age groups for number and impact of comorbid illnesses, number of medications, basic and instrumental activities of daily living, pain, overall health rating, financial adequacy, anxiety, depression, and quality of life. CONCLUSION: CGA can be conducted in an outpatient cancer community using a self-report format. Despite the fact that this population varied demographically across age groups and is limited to veterans, this study demonstrated remarkable similarities between younger and older cancer patients in terms of functional status, health states, and quality of life.

Activities of Daily Living↗

PubMed2002

Optimizing aptamer activity for gene therapy applications using expression cassette SELEX.

RNA aptamers against a variety of clinically relevant target proteins have been generated. For example, we previously isolated an RNA aptamer that inhibits the function of the E2F family of transcription factors that play a critical role in the control of cell proliferation. However, the development of this and other aptamers for gene therapy applications has been complicated by the fact that expression of RNA aptamers in the context of flanking sequences can inhibit the ability of an aptamer to fold into its functional conformation. Insertion of the E2F aptamer into a tRNA expression cassette resulted in the production of high levels of chimeric tRNA that contains a misfolded and inactive aptamer in transfected mammalian cells. To overcome this problem, we randomized the sequence flanking the aptamer and selected for chimeric tRNAs that retained high affinity binding to E2F1. This expression cassette SELEX strategy yielded RNAs that bind E2F with high affinity (IC50 of 15 nM) and which can be expressed at high levels in mammalian cells. Moreover, these chimeric tRNA-E2F aptamers are functional and can inhibit E2F-mediated transactivation by up to 80% in human 293 cells. Expression cassette SELEX should greatly facilitate the use of aptamers for a variety of gene therapy applications.

Cell Cycle Proteins↗

PubMed2002

Therapeutic enhancement of IL-2 through molecular design.

A recombinant human IL-2 analog (rIL-2, Proleukin) is currently being evaluated for clinical benefit in HIV infected patients. It is approved for therapy of patients with metastatic melanoma and renal cell carcinoma. Treatment of cancer patients with rIL-2 results in durable responses but is associated with life-threatening toxicity, which limits its use to patients in relatively good health. Antitumor efficacy associated with rIL-2 therapy are hypothesized to be mediated by distinct types of cells that express structurally different forms of the IL-2 receptor. This hypothesis suggests that it might be possible to engineer an IL-2 variant addressing the risks associated with the therapeutic use of IL-2. In this article, we review the clinical experience with IL-2 and its analogs, the evidence that different IL-2 receptors may dissociate efficacy and toxicity, and describe the generation of a novel IL-2 variant with the potential for a superior therapeutic index.

Animals↗