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Biomedical subjects

John Leighton

Publications and source records attributed to John Leighton.

8 recordsLinked to original sources
PubMed2005

Approval summary for erlotinib for treatment of patients with locally advanced or metastatic non-small cell lung cancer after failure of at least one prior chemotherapy regimen.

PURPOSE: To describe the Food and Drug Administration (FDA) review and approval of erlotinib (Tarceva, OSI Pharmaceuticals, Melville, NY) for treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) after failure of at least one prior chemotherapy regimen. EXPERIMENTAL DESIGN: The FDA reviewed raw data in electronic format from a randomized controlled clinical trial comparing erlotinib with placebo in patients with locally advanced or metastatic NSCLC after failure of at least one prior chemotherapy regimen. RESULTS: Patients were randomized in a 2:1 ratio (erlotinib, n = 488 and placebo, n = 243). Erlotinib was superior to placebo for survival, progression-free survival, and tumor response rate. Exploratory analyses indicate that epidermal growth factor receptor status may be an important predictor of the erlotinib survival effect. Rash (75% versus 17%) and diarrhea (54% versus 18%) in the erlotnib and placebo group respectively were the most common adverse events. Severe rash occurred in 9% and severe diarrhea in 6% of erlotinib-treated patients and each resulted in study discontinuation in 1% of patients. Dose reductions were required for 10% of patients with rash and 4% of patients with diarrhea. CONCLUSIONS: On November 18, 2004, the FDA granted erlotinib regular approval for treatment of patients with locally advanced or metastatic NSCLC after failure of at least one prior chemotherapy regimen. The applicant has committed to conduct post-marketing clinical trials to assess further the effect of epidermal growth factor receptor expression, measured with immunohistochemical staining, on erlotinib treatment effect.

Adolescent↗
PubMed2003

Pharmacogenetics and pharmacogenomics in drug development and regulatory decision making: report of the first FDA-PWG-PhRMA-DruSafe Workshop.

The use of pharmacogenetics and pharmacogenomics in the drug development process, and in the assessment of such data submitted to regulatory agencies by industry, has generated significant enthusiasm as well as important reservations within the scientific and medical communities. This situation has arisen because of the increasing number of exploratory and confirmatory investigations into variations in RNA expression patterns and DNA sequences being conducted in the preclinical and clinical phases of drug development, and the uncertainty surrounding the acceptance of these data by regulatory agencies. This report summarizes the outcome of a workshop cosponsored by the Food and Drug Administration (FDA), the Pharmacogenetics Working Group (PWG), the Pharmaceutical Research and Manufacturers of America (PhRMA), and the PhRMA Preclinical Safety Committee (DruSafe). The specific aim of the workshop was to identify key issues associated with the application of pharmacogenetics and pharmacogenomics, including the feasibility of a regulatory "safe harbor" for exploratory genome-based data, and to provide a forum for industry-regulatory agency dialogue on these important issues.

Clinical Trials as Topic↗
PubMed2003

Approval summary for zoledronic acid for treatment of multiple myeloma and cancer bone metastases.

PURPOSE: This article summarizes data submitted to the United States Food and Drug Administration for marketing approval of zoledronic acid (Zol; Novartis Pharmaceuticals, East Hanover, NJ), a bisphosphonate drug for treating patients with bone metastases. EXPERIMENTAL DESIGN: We review the chemistry, toxicology, pharmacology, and clinical study results submitted to support the supplemental New Drug Application for Zol for treatment of patients with bone metastases. Four- and 8-mg Zol doses were selected for Phase III trials based on bone resorption markers and clinical efficacy parameters. Patients with bone metastases were randomized in three Phase III studies (prostate cancer, solid tumors, and multiple myeloma or breast cancer) to receive 4 or 8 mg of Zol or to a control arm. The control was a placebo in the prostate cancer study and the other solid tumor study and was 90 mg of pamidronate (Pam) in the study of breast cancer and multiple myeloma. Studies were amended twice because of renal toxicity, initially to increase Zol infusion time from 5 to 15 min and later to decrease the dose in the Zol 8-mg arm to 4 mg. The efficacy end point was skeletal-related events (SREs), a composite end point consisting of pathologic fracture, radiation therapy to bone, changes in antineoplastic therapy for bone pain (prostate cancer only), surgery to bone, or spinal cord compression. This end point was analyzed either as the proportion of patients with SRE or time to first SRE. The breast cancer and myeloma study used a noninferiority statistical analysis methods to determine efficacy. RESULTS: In prostate cancer, both the proportions analysis and time-to-SRE analysis showed significantly less bone morbidity on Zol (4 mg) than placebo, but no significant difference between Zol (8 mg) and placebo in either analysis. In the solid tumor study, the time to SRE analysis but not the proportions analysis showed significantly less skeletal morbidity on Zol (4 mg) than placebo, and Zol (8 mg) was significantly better than placebo in both analyses. The breast cancer and myeloma study demonstrated noninferiority of Zol compared with Pam, with Zol retaining at least 49.3% of the Pam treatment effect previously demonstrated in placebo-controlled trials. Zol was approved on February 22, 2002, by the United States Food and Drug Administration for the "treatment of patients with multiple myeloma and documented bone metastases from solid tumors, in conjunction with standard antineoplastic therapy. Prostate cancer should have progressed after treatment with at least one hormonal therapy." The recommended dose and schedule is 4 mg of Zol infused over 15 min every 3-4 weeks. Increased Zol doses and shorter infusions are not recommended because of potential renal toxicity.

Antineoplastic Agents↗
PubMed2002

Approval summary for imatinib mesylate capsules in the treatment of chronic myelogenous leukemia.

PURPOSE: Chronic myelogenous leukemia (CML) results from the breakpoint cluster region-Abl fusion gene product, a tyrosine kinase involved in cell division and apoptosis. Imatinib, an orally administered inhibitor of the breakpoint cluster region-Abl tyrosine kinase, is capable of blocking proliferation and inducing apoptosis in CML cell lines. In this report, we describe the preclinical profile of imatinib and the data submitted in the New Drug Application that led to its marketing approval. EXPERIMENTAL DESIGN: Chemistry manufacturing and controls, animal toxicology, and biopharmaceutical data are described. Results of Phase I and Phase II clinical studies in patients with CML in blast crisis (CML-BC), in accelerated phase (CML-AP), and in chronic phase disease-resistant or intolerant to IFN-alpha (CML-CP) are summarized. The basis for marketing approval and postmarketing commitments by the pharmaceutical company are discussed. RESULTS: Toxicology studies in the rat, dog, and monkey show the hematological, renal, and hepatobiliary toxicity of imatinib. Pharmacokinetic studies in patients with CML demonstrate 98% imatinib bioavailability. The elimination half-lives of the parent drug and the major active metabolite, CGP74588, from plasma are approximately 18 and 40 h, respectively. Approximately 81% of the drug is eliminated in 7 days, 68% in the feces and 13% in the urine. Cytochrome P-450 3A4 is the main enzyme responsible for imatinib metabolism. Phase I and II clinical studies were conducted. The Phase I study, in 83 CML patients, evaluated oral imatinib doses from 25 to 1000 mg/day. Dose-limiting toxicity was not observed. The three Phase II studies, in CML-CP, CML-AP, and CML-BC, enrolled 1027 patients. CML-CP patients received 400 mg/day imatinib, whereas CML-AP and CML-BC patients generally received 600 mg/day imatinib. Primary study endpoints were cytogenetic response rate (CML-CP) and hematological response rate (CML-AP and CML-BC). The cytogenetic response rate for CML-CP patients was 49%. The hematological response rate of CML-AP and CML-BC patients was 63 and 26%, respectively. The most common imatinib adverse events were nausea, vomiting, myalgia, edema, and diarrhea. Elevated liver enzymes and/or bilirubin were reported in 27 patients (2.6%). CONCLUSIONS: On May 10, 2001, imatinib mesylate (Gleevec, formerly known as STI-571 and Glivec), manufactured and distributed by Novartis Pharmaceuticals, East Hanover, NJ, was approved by the United States Food and Drug Administration for the treatment of CML in three clinical settings: CML-BC, CML-AP, and CML-CP. This report summarizes the Food and Drug Administration's review of the New Drug Application.

Antineoplastic Agents↗
PubMedDate not supplied

Phase I/II study of weekly docetaxel and vinblastine in the treatment of metastatic hormone-refractory prostate carcinoma.

BACKGROUND: Phase II trials have shown that taxanes have clinical activity as single agents as well as in combination with microtubule inhibitors in the treatment of hormone-refractory prostate cancer. Recent phase III trials with docetaxel have reported a survival benefit. Most trials also report significant toxicity, including thromboembolic disease. We conducted a phase I/II study to evaluate the maximum-tolerated dose, response rate, and effects on quality of life of the combination of docetaxel and vinblastine. METHODS: Twenty men with hormone-refractory prostate cancer were treated after experiencing hormonal failure. Patients were enrolled in cohorts of three and treated with three weekly doses of docetaxel (20, 25, 30, 35, or 40 mg/m2) administered as 30-minute infusion and vinblastine (3 mg/m2) bolus. Treatment cycles were repeated every 28 days. Follow-up assessments included prostate-specific antigen level determinations, computed tomographic scans, bone scans, Brief Pain Inventory, and Functional Assessment of Cancer Therapy-Prostate Instrument (FACT-P). Toxicity was graded by National Cancer Institute common toxicity criteria. RESULTS: The maximum tolerated dose of docetaxel was 35 mg/m2. Twelve of the 19 patients (63%; 95% CI 38%-84%) evaluable patients achieved a 50% reduction in prostate-specific antigen level that persisted for 24-80 weeks. Four of eight patients with measurable soft tissue disease had a partial response. Median time to disease progression was 50 weeks. Sixteen patients completed the Brief Pain Inventory at least three times. Twelve patients reported moderate-to-severe pain scores (>or=4) at baseline. Of these 12 patients, 11 reported that their worst pain score improved by at least two levels, and five of the 12 reported decreased opioid requirements. Seventeen patients completed the FACT-P at baseline and on at least two additional visits. Nine of these 17 (53%) reported improvement in Trial Outcome Index (sum of physical, functional, prostate subscales) by >or=6 points. Anemia was common; 12/20 patients required epoetin, and two required transfusions. Venous thrombosis developed in four patients during treatment. Only two patients discontinued treatment because of toxicity. CONCLUSIONS: This combination of weekly docetaxel and vinblastine is effective, well tolerated, and associated with improved quality of life in most of the patients treated. Although estramustine was not given, the risk of thromboembolic disease remains significant.

Adenocarcinoma↗