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Biomedical subjects

F A Dorr

Publications and source records attributed to F A Dorr.

At least 19 recordsLinked to original sources
PubMed2002

Dose ranging pharmacokinetic trial of high-dose alicaforsen (intercellular adhesion molecule-1 antisense oligodeoxynucleotide) (ISIS 2302) in active Crohn's disease.

BACKGROUND AND AIMS: To evaluate the safety, pharmacokinetics and clinical efficacy of the intercellular adhesion molecule-1 antisense phosphorothioate oligonucleotide alicaforsen (ISIS 2302) at 250-350 mg in Crohn's disease. METHODS: : Patients (> 50 kg) with active Crohn's disease (Crohn's disease activity index > or = 220) were assigned by gender, randomly, to two alicaforsen treatment groups: 300 or 350 mg, infused intravenously three times a week for 4 weeks. All patients weighing 36-50 kg received 250 mg of alicaforsen. Background aminosalicylates, antibiotics, immunosuppressives and corticosteroids were permitted, but tumour necrosis factor-alphainhibitors were prohibited. The primary end-point was clinical remission (Crohn's disease activity index < or = 150). RESULTS: Twenty-two patients were enrolled with a mean baseline Crohn's disease activity index of 304. Steroids were used by 27%, 5-aminosalicylic acid by 68% and immunosuppressives by 27%; 23% had previously received infliximab. Five subjects withdrew after one to three infusions for infusion-related symptoms. Nine patients (41%) experienced clinical remission. Fifty-three per cent of the evaluable subjects receiving more than three infusions experienced remission (18% at week 8; 29% at week 12). The overall response, using a minimum decrease of 70 in the Crohn's disease activity index, was 41-47% for the evaluable group, at weeks 8 and 12. The median duration of remission was 14 weeks. Plasma pharmacokinetic results showed overlapping levels (Cmax, AUC) for the three doses. The infusion-related reaction profile consisted of fever, chills, headache, nausea, emesis or arthralgias, typically occurring 2-4 h after completion of the first infusion. Reactions were less frequent in patients receiving background corticosteroids. The 2-4-h transient post-infusion partial thromboplastin time prolongation values, a class effect of phosphorothioate oligonucleotides, were 18, 21 and 23 s for 250, 300 and 350 mg, respectively. CONCLUSIONS: Alicaforsen (ISIS 2302), at fixed doses of 300 and 350 mg, achieved the desired drug exposure and may be an effective therapy for Crohn's disease. Infusion-related reactions were observed less frequently in patients on corticosteroids, and with decreasing frequency with continued treatment.

Adolescent↗
PubMed2001

Association of c-Raf expression with survival and its targeting with antisense oligonucleotides in ovarian cancer.

c-Raf is an essential component of the extracellular related kinase (ERK) signal transduction pathway. Immunohistochemical staining indicated that c-Raf was present in 49/53 ovarian adenocarcinomas investigated and high c-Raf expression correlated significantly with poor survival (P = 0.002). c-Raf protein was detected in 15 ovarian cancer cell lines. Antisense oligodeoxynucleotides (ODNs) (ISIS 5132 and ISIS 13650) reduced c-Raf protein levels and inhibited cell proliferation in vitro. Selectivity was demonstrated by the lack of effect of ISIS 5132 on A-Raf or ERK, while a random ODN produced only minor effects on growth and did not influence c-Raf expression. ISIS 5132 produced enhanced apoptosis and cells accumulated in S and G(2)/M phases of the cell cycle. In vivo, ISIS 5132 inhibited growth of the s.c. SKOV-3 xenograft while a mismatch ODN had no effect. These data indicate that high levels of c-Raf expression may be important in ovarian cancer and use of antisense ODNs targeted to c-Raf could provide a strategy for the treatment of this disease.

Animals↗
PubMed2001

Phase I Trial of ISIS 5132, an antisense oligonucleotide inhibitor of c-raf-1, administered by 24-hour weekly infusion to patients with advanced cancer.

Raf-1 is a serine/threonine kinase that functions as a critical effector of Ras-mediated signal transduction via the mitogen-activated protein kinase pathway. Constitutive activation of this pathway directly contributes to malignant transformation in many human tumors. A 20-base phosphorothioate oligonucleotide complementary to c-raf-1 mRNA (ISIS 5132; CGP 69846A) has been shown to specifically suppress Raf-1 expression both in vitro and in vivo. This Phase I trial, involving 22 patients with advanced cancer, was designed to evaluate the safety, feasibility, and maximum tolerated dose of ISIS 5132 administration as a weekly 24-h i.v. infusion. Pharmacokinetic analysis was performed, and c-raf-1 mRNA levels in peripheral blood mononuclear cells were assessed using quantitative reverse transcription-PCR. This trial defined a maximum tolerated dose of 24 mg/kg/week on this schedule. Two of four patients treated at 30 mg/kg/week had serious adverse events after the first dose of ISIS 5132, including acute hemolytic anemia and acute renal failure and anasarca. There were no major responses documented. Dose-dependent complement activation was demonstrated on this schedule, but not on previously evaluated schedules, of ISIS 5132 administration. In contrast to other trials of ISIS 5132, there appeared to be no consistent suppression of peripheral blood mononuclear cell c-raf-1 mRNA level on this schedule at any of the dose levels analyzed. These data suggest that the efficacy and toxicity profiles of antisense oligonucleotides may be highly dependent on the schedule of administration and support the analysis of the putative molecular target in the evaluation of novel therapeutics.

Adult↗
PubMed1999

A phase I evaluation of multitargeted antifolate (MTA, LY231514), administered every 21 days, utilizing the modified continual reassessment method for dose escalation.

PURPOSE: To determine toxicities, maximally tolerated dose (MTD), pharmacokinetic profile, and potential antitumor activity of MTA, a novel antifolate compound which inhibits the enzymes thymidylate synthase (TS), glycinamide ribonucleotide formyltransferase (GARFT), and dihydrofolate reductase (DHFR). METHODS: Patients with advanced solid tumors were given MTA intravenously over 10 min every 21 days. Dose escalation was based on the modified continual reassessment method (MCRM), with one patient treated at each minimally toxic dose level. Pharmacokinetic studies were performed in all patients. RESULTS: A total of 37 patients (27 males, 10 females, median age 59 years, median performance status 90%) were treated with 132 courses at nine dose levels, ranging from 50 to 700 mg/m(2). The MTD of MTA was 600 mg/m(2), with neutropenia and thrombocytopenia, and cumulative fatigue as the dose-limiting toxicities. Hematologic toxicity correlated with renal function and mild reversible renal dysfunction was observed in multiple patients. Other nonhematologic toxicities observed included mild to moderate fatigue, anorexia, nausea, diarrhea, mucositis, rash, and reversible hepatic transaminase elevations. Three patients expired due to drug-related complications. Pharmacokinetic analysis during the first course of treatment at the 600 mg/m(2) dose level demonstrated a mean harmonic half-life, maximum plasma concentration (Cpmax), clearance (CL), area under the curve (AUC), and apparent volume of distribution at steady state (Vdss) of 3.08 h, 137 microg/ml, 40.0 ml/min per m(2), 266 microg. h/ml, and 7.0 l/m(2), respectively. An average of 78% of the compound was excreted unchanged in the urine. Partial responses were achieved in two patients with advanced pancreatic cancer and in two patients with advanced colorectal cancer. Minor responses were obtained in six patients with advanced colorectal cancer. CONCLUSIONS: The MTD and dose for phase II clinical trials of MTA when administered intravenously over 10 min every 21 days was 600 mg/m(2). MTA is a promising new anticancer agent.

Adult↗
PubMed1999

Tamoxifen and fenretinide in women with metastatic breast cancer.

BACKGROUND: Tamoxifen and fenretinide combination therapy has been shown to be an active treatment regimen in metastatic breast cancer patients. This pilot study sought to determine whether the addition of fenretinide to tamoxifen would be associated with antitumor activity in metastatic breast cancer patients who had been previously treated with tamoxifen or who had hormone receptor negative disease. The effect of this therapy on circulating plasma transforming growth factor-beta (TGF-beta) levels and serum lipids was also examined. PATIENTS AND METHODS: Thirty-one patients were treated with tamoxifen (20 mg p.o. daily), and fenretinide (400 mg p.o. daily with a 3-day drug holiday each month). Plasma TGF-beta testing was performed using isoform specific sandwich ELISA. RESULTS: Twenty four of the 31 patients were evaluable for an antitumor response including 14 estrogen receptor (ER) positive patients who had failed prior tamoxifen therapy, seven ER-negative patients, and three hormone therapy naive ER-positive patients. There were no objective antitumor responses; three patients had stable disease for 8, 8, and 24 months. Five patients (16%) discontinued therapy for toxicity (one for grade 3 skin rash and four for abnormal dark adaptation). There was a statistically significant decrease in total cholesterol (median change per patient of -13.5 mg/dl; p = 0.049, a 6.5% decrease), and an increase in HDL levels (median change per patient of +18 mg/dl, p = 0.0001, a 35% increase) with tamoxifen and fenretinide therapy. TGF-beta1 plasma levels were normal in 26 of 28 patients, and no changes in these levels post-treatment were demonstrated. CONCLUSIONS: Tamoxifen and fenretinide therapy is not an active combination in ER negative metastatic breast cancer or in patients whose disease has progressed on tamoxifen. This combination had a beneficial effect on total serum cholesterol and HDL levels with no associated rise in serum triglyceride levels. The 400 mg dose of fenretinide was associated with symptomatic nyctalopia in one-third of patients making it an unsuitable dose for use in breast cancer prevention studies.

Adult↗
PubMed1999

Phase I clinical/pharmacokinetic and pharmacodynamic trial of the c-raf-1 antisense oligonucleotide ISIS 5132 (CGP 69846A).

PURPOSE: Raf-1 is a protein kinase that plays a broad role in oncogenic signaling and acts as a downstream effector of Ras in the mitogen-activated protein kinase pathway. The present study was designed to determine the maximum-tolerated dose (MTD), toxicity profile, pharmacokinetics, and antitumor activity of the c-raf-1 antisense oligodeoxynucleotide ISIS 5132 (CGP 69846A; ISIS Pharmaceuticals Inc, Carlsbad, CA). The effect of ISIS 5132 on c-raf-1 gene expression in peripheral-blood mononuclear cells (PBMCs) of treated patients was studied using a reverse transcriptase polymerase chain reaction assay. PATIENTS AND METHODS: Patients with refractory malignancies received ISIS 5132 as a 2-hour intravenous infusion three times weekly for 3 consecutive weeks. Pharmacokinetic sampling was performed during the first cycle in all patients; PBMCs for c-raf-1 mRNA analysis were collected at baseline and on days 3, 5, 8, and 15 of cycle 1 and on day 1 of each cycle thereafter. RESULTS: Thirty-one patients received ISIS 5132 at one of nine dose levels ranging from 0.5 mg/kg to 6.0 mg/kg. Clinical toxicities included fever and fatigue, but these were not dose limiting. A clinically defined MTD was not reached. The harmonic mean half-life of ISIS 5132 was 59.8 minutes (range, 35.5 to 107.3 minutes). The area under the concentration-time curve increased linearly with dose, and mean plasma clearance was 1.86 mL/kg/min (range, 1.21 to 2.41 mL/kg/min). Two patients experienced prolonged stable disease lasting more than 7 months, which was associated with persistent reduction in c-raf-1 expression in PBMCs. Significant decreases in c-raf-1 expression were identified at time points after the baseline value (P <.05) at doses >/= 2.5 mg/kg. CONCLUSION: ISIS 5132 is well tolerated at doses up to 6.0 mg/kg when administered as a thrice weekly 2-hour infusion for 3 consecutive weeks. The pharmacokinetic behavior of the drug is reproducible, and suppression of target gene expression is observed in circulating PBMCs.

Adult↗
PubMed1999

c-raf-1 depletion and tumor responses in patients treated with the c-raf-1 antisense oligodeoxynucleotide ISIS 5132 (CGP 69846A).

Abnormally regulated signaling through proliferative signal transduction pathways characterizes many of the common solid tumors. The best described of these involves potentially oncogenic proteins of the Ras family, which activate Raf proteins in the early steps of the mitogen-activated protein kinase cascade. ISIS 5132, a phosphorothioate antisense oligodexoynucleotide directed to the 3' untranslated region of the c-raf-1 mRNA, inhibits the growth of human tumor cell lines in vitro and in vivo in association with specific down-regulation of target message expression. Using a semiquantitative reverse transcription-PCR assay, we analyzed changes in c-raf-1 mRNA expression in peripheral blood mononuclear cells collected from patients with advanced cancers treated with ISIS 5132 as part of a clinical trial. Specimens were collected for analysis pretreatment and on days 3, 5, 8, and 15 of the first cycle and on day 1 of each subsequent cycle. We observed significant reductions of c-raf-1 expression from baseline by day 3 in 13 of 14 patients (P = 0.002). The time course and depletion of c-raf-1 message in peripheral blood mononuclear cells paralleled the clinical benefit in two patients. These findings demonstrate that ISIS 5132 specifically reduces target gene expression in treated patients and that peripheral blood mononuclear cells are suitable tissues for biomarker studies in future trials.

Aged↗
PubMed1999

Toward antisense oligonucleotide therapy for cancer: ISIS compounds in clinical development.

Antisense oligonucleotides offer the promise of therapeutic effect with few toxic effects, by virtue of their high selectivity. Preclinical studies have provided evidence of antisense effects in vitro and in vivo, and phase I clinical trials have demonstrated safety, feasibility and activity of antisense oligonucleotides for the treatment of cancer. This review summarizes the status of development of three anticancer antisense oligonucleotides from ISIS Pharmaceuticals.

Animals↗
PubMed1997

Metastatic bladder cancer: advances in treatment.

At present, a combination of cisplatin, methotrexate, vinblastine and doxorubicin is the most widely used chemotherapy for metastatic bladder cancer. However, long-term follow-up shows that this combination may have little effect on survival. In addition, this regimen is toxic. New agents are needed which combine efficacy with good safety profiles. Agents which have been investigated include gallium nitrate, interferon-alpha and paclitaxel both as single agents and in combination with established cytotoxic drugs. A number of studies have been conducted in bladder cancer with the novel nucleoside analogue, gemcitabine. Response rates of up to 33% have been recorded in two phase II studies. Gemcitabine was well tolerated in both studies with few of the side-effects normally associated with cytotoxic drugs. A third study is ongoing.

Adult↗
PubMed1997

Phase II study of single-agent gemcitabine in previously untreated patients with metastatic urothelial cancer.

PURPOSE: To determine the activity of single-agent gemcitabine in previously untreated patients with metastatic transitional cell cancer. METHODS: Forty patients with measurable disease and a Karnofsky performance status > or = 60% were enrolled at five institutions between March 1994 and October 1995. Treatment consisted of gemcitabine (1,200 mg/m2) administered weekly times three on a 4-week cycle. One patient was ineligible for response evaluation because pathology review showed a metastatic melanoma. Responses were confirmed by all investigators and an independent radiologist and were maintained for at least 4 weeks. RESULTS: There were four complete and seven partial responses, for an overall response rate of 28%. Responses were seen at all sites, including liver. Median progression-free and overall survival times were 20 and 54 weeks, respectively. Toxicity was mild, with only two grade 4 toxicities. Twenty-five percent of patients experienced grade 3 neutropenia or thrombocytopenia that was rapidly reversible. CONCLUSION: Gemcitabine exhibits significant activity in metastatic transitional cell cancer with minimal toxicity, but survival remains short. Trials of gemcitabine in combination with other active agents are thus suggested.

Adult↗
PubMed1997

Improvements in survival and clinical benefit with gemcitabine as first-line therapy for patients with advanced pancreas cancer: a randomized trial.

PURPOSE: Most patients with advanced pancreas cancer experience pain and must limit their daily activities because of tumor-related symptoms. To date, no treatment has had a significant impact on the disease. In early studies with gemcitabine, patients with pancreas cancer experienced an improvement in disease-related symptoms. Based on those findings, a definitive trial was performed to assess the effectiveness of gemcitabine in patients with newly diagnosed advanced pancreas cancer. PATIENTS AND METHODS: One hundred twenty-six patients with advanced symptomatic pancreas cancer completed a lead-in period to characterize and stabilize pain and were randomized to receive either gemcitabine 1,000 mg/m2 weekly x 7 followed by 1 week of rest, then weekly x 3 every 4 weeks thereafter (63 patients), or to fluorouracil (5-FU) 600 mg/m2 once weekly (63 patients). The primary efficacy measure was clinical benefit response, which was a composite of measurements of pain (analgesic consumption and pain intensity), Karnofsky performance status, and weight. Clinical benefit required a sustained (> or = 4 weeks) improvement in at least one parameter without worsening in any others. Other measures of efficacy included response rate, time to progressive disease, and survival. RESULTS: Clinical benefit response was experienced by 23.8% of gemcitabine-treated patients compared with 4.8% of 5-FU-treated patients (P = .0022). The median survival durations were 5.65 and 4.41 months for gemcitabine-treated and 5-FU-treated patients, respectively (P = .0025). The survival rate at 12 months was 18% for gemcitabine patients and 2% for 5-FU patients. Treatment was well tolerated. CONCLUSION: This study demonstrates that gemcitabine is more effective than 5-FU in alleviation of some disease-related symptoms in patients with advanced, symptomatic pancreas cancer. Gemcitabine also confers a modest survival advantage over treatment with 5-FU.

Adult↗
PubMed1996

Economic value of gemcitabine compared to cisplatin and etoposide in non-small cell lung cancer.

Although chemotherapy costs have not been highlighted traditionally, there is increasing pressure to demonstrate the value of new treatments within the health care budget. Pharmaceutical companies are assessing the economic value of their products before launch. Gemcitabine is a nucleoside analogue developed for use in solid tumours. The purpose of this model was to investigate the clinical outcomes and potential cost savings for gemcitabine used as monotherapy compared to cisplatin and etoposide combination therapy in late stage non-small cell lung cancer (NSCLC), in a palliative (as opposed to aggressive) chemotherapy setting. Gemcitabine treatment data were taken from a large NSCLC study and data from retrospective chart reviews identified through the National Oncology Data Base. The model population and effectiveness of the two regimens were judged to be similar, except for baseline performance status. If drug costs were not included, the probability distribution resulting from the simulation showed median cost savings per cycle ranging from $US 1504 to $US 7425, with a medium value of $US 2154. The model suggested that gemcitabine would result in cost savings per cycle more than 90% of the time. Outpatient versus inpatient drug administrations accounted for the majority of potential cost savings. Most of the remaining cost savings were attributable to the difference in febrile neutropenia and antiemetic use. This economic model showed susbstantial savings if gemcitabine was used instead of cisplatin and etoposide combination therapy in the United States' community care setting. Some savings would be realized even if the location of treatment for both regimens was mostly outpatient. Assessment of the product's economic value before launch has assisted in our understanding of the potential areas of cost savings for gemcitabine and has guided us in the design of prospective randomized studies which included pharmacoeconomic endpoints.

Antimetabolites, Antineoplastic↗
PubMed1995

Initial phase I evaluation of the novel thymidylate synthase inhibitor, LY231514, using the modified continual reassessment method for dose escalation.

PURPOSE: To determine the toxicities, maximal-tolerated dose (MTD), pharmacokinetic profile, and potential antitumor activity of LY231514, a novel thymidylate synthase (TS) inhibitor. PATIENTS AND METHODS: Patients with advanced solid tumors were administered LY231514 intravenously over 10 minutes, weekly for 4 weeks, every 42 days. Dose escalation was based on the modified continual reassessment method (MCRM), with one patient treated at each minimally toxic dose level. Pharmacokinetic studies were performed in all patients. RESULTS: Twenty-five patients were administered 58 courses of LY231514 at doses that ranged from 10 to 40 mg/m2/wk. Reversible neutropenia was the dose-limiting toxicity. Inability to maintain the weekly treatment schedule due to neutropenia limited dose escalation on this schedule. Nonhematologic toxicities observed included mild fatigue, anorexia, and nausea. At the 40-mg/m2/wk dose level, the mean harmonic half-life, maximum plasma concentration, clearance, and apparent volume of distribution at steady-state were 2.02 hours, 11.20 micrograms/mL, 52.3 mL/min/m2, and 6.64 L/m2, respectively. No major antitumor responses were observed; however, minor responses were achieved in two patients with advanced colorectal cancer. CONCLUSION: The dose-limiting toxicity, MTD, and recommended phase II dose of LY231514 when administered weekly for 4 weeks every 42 days are neutropenia, 40 mg/m2, and 30 mg/m2, respectively.

Adult↗
PubMed1993

Prognostic factors observed in current clinical trials.

Adjuvant therapy of breast cancer has evolved over the past 15 years from an interesting clinical experiment to the standard of care for many patients. The toxicities of different treatments vary from those with minimal side effects, such as tamoxifen, to those with potentially life-threatening side effects. Current clinical trials are evaluating increasingly higher risk treatments, such as high-dose chemotherapy autologous bone marrow rescue. Chemotherapy is being used in groups that have previously been treated only with hormonal interventions or who have received no adjuvant therapy. The delineation of risk, such that the risks of treatment can be closely tied to the risk of recurrence is thus a desirable goal for clinical-laboratory research. Prognostic factors identified in treated patients, however, may be measures of treatment resistance versus treatment sensitivity rather than some underlying biologic characteristic defining a tumor's malignant potential.

Breast Neoplasms↗
PubMed1992

Controversies in the treatment of metastatic prostate cancer.

BACKGROUND: Prostate cancer is the most common cancer in American men today. Unfortunately, at the time of diagnosis, most men will have either regional or distant metastatic disease. METHODS: Six hundred three patients with advanced prostate cancer who could be examined were randomized in a double-blind, placebo-controlled trial to receive the luteinizing hormone-releasing hormone (LHRH) agonist leuprolide with either flutamide or placebo. RESULTS: Patients receiving the combined therapy arm of leuprolide and flutamide had an increased progression-free survival time of 16.9 versus 13.8 months and a survival advantage of 35.1 versus 20.3 months. A more striking difference was found in the subset of patients receiving combination therapy who had good performance and minimal disease. CONCLUSIONS: There appears to be a definite advantage of combination therapy over leuprolide alone, especially in patients with minimal disease and good performance. Another larger intergroup study using orchiectomy and flutamide versus orchiectomy and placebo is currently underway.

Double-Blind Method↗