Biomedical subjects

John L Marshall

Publications and source records attributed to John L Marshall.

At least 19 recordsLinked to original sources

PubMed2024

Tumor specimen cold ischemia time impacts molecular cancer drug target discovery.

Tumor tissue collections are used to uncover pathways associated with disease outcomes that can also serve as targets for cancer treatment, ideally by comparing the molecular properties of cancer tissues to matching normal tissues. The quality of such collections determines the value of the data and information generated from their analyses including expression and modifications of nucleic acids and proteins. These biomolecules are dysregulated upon ischemia and decompose once the living cells start to decay into inanimate matter. Therefore, ischemia time before final tissue preservation is the most important determinant of the quality of a tissue collection. Here we show the impact of ischemia time on tumor and matching adjacent normal tissue samples for mRNAs in 1664, proteins in 1818, and phosphosites in 1800 cases (tumor and matching normal samples) of four solid tumor types (CRC, HCC, LUAD, and LUSC NSCLC subtypes). In CRC, ischemia times exceeding 15 min impacted 12.5% (mRNA), 25% (protein), and 50% (phosphosites) of differentially expressed molecules in tumor versus normal tissues. This hypoxia- and decay-induced dysregulation increased with longer ischemia times and was observed across tumor types. Interestingly, the proteomics analysis revealed that specimen ischemia time above 15 min is mostly associated with a dysregulation of proteins in the immune-response pathway and less so with metabolic processes. We conclude that ischemia time is a crucial quality parameter for tissue collections used for target discovery and validation in cancer research.

Humans↗

PubMed2006

Costimulatory molecules as adjuvants for immunotherapy.

Tumor-associated antigens (TAAs) are by definition either weakly immunogenic or functionally nonimmunogenic. Therefore, efforts have concentrated on the development of vaccine strategies in which the presentation of TAAs to the immune system results in far greater activation of T cells than that occurring naturally in the host. Several strategies are being explored in our laboratory and others to enhance the immunogenicity of TAAs. These are: (a) placing the gene coding for the tumor antigen, as a transgene, into poxvirus vectors. (b) The use of diversified prime and boost vaccine strategies employing two different types of poxvirus vectors. (c) The use of T-cell costimulation; accomplished by placing transgenes for different T-cell costimulation molecules into viral vectors along with the transgenes for the TAA. (d) Altering the amino acid sequence of the TAA to enhance the host immune response. (e) The use of cytokines, and in particular GM-CSF, as a biologic adjuvant. This review will focus on the current state of the use of costimulatory molecules as adjuvants for immunotherapy, and in particular, as immunomodulators for cancer vaccines.

Adjuvants, Immunologic↗

PubMed2006

Clinical experiences with G17DT in gastrointestinal malignancies.

The development of new agents for the treatment of gastrointestinal malignancies is increasing in pace and importance. The discovery of novel targets, namely the epidermal growth factor receptor and vascular endothelial growth factor, have sparked an explosion of new agents being tested in gastrointestinal malignancies. Clearly, novel agents and approaches are required. G17DT is a novel immunoconjugate designed to elicit a humoral response against the N-terminal end of G17 gastrin. In this overview, the authors summarize the clinical research focused on gastrointestinal tract cancers to date. In total, there is a clear signal of efficacy with this compound, although further testing is required in order for this efficacy to be demonstrated in a manner that will support regulatory approval.

Animals↗

PubMed2006

Targeted therapy for colorectal cancer.

There has been a revolution in the treatment of colorectal cancer over the last decade. Part of this revolution has been the discovery of agents that target particular aspects of cancer, namely vascular endothelial growth factor and epidermal growth factor receptor. Novel targeted agents have been evaluated in clinical trials and have demonstrated significant anticancer activity. Furthermore, a number of these compounds have been approved for clinical use. Data supporting the use of targeted agents in the treatment of colorectal cancer are reviewed, and the "future for potential novel agents and pathways are discussed.

Animals↗

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

Immunologic therapies for gastrointestinal cancers.

The treatment of solid tumors has shown a dramatic change in recent years. This revolution has come from an improved understanding of the mechanisms of tumor growth and the relationship of cancers to their microenvironments. As part of this revolution, we have had a dramatic increase in our understanding of the immune system and the role it could play in the management of cancers. This article reviews the current data supporting the use of cancer immunologic therapies for gastrointestinal tract cancers. The scope is focused on the variety of approaches that have been used, citing the clinical data that have been obtained and reviewing future trials.

Antibodies, Monoclonal↗

PubMed2005

Novel vaccines for the treatment of gastrointestinal cancers.

Continuing advances in immunology and molecular biology during the past several decades have provided optimism that immunomodulatory strategies may be clinically useful in patients with cancer. Key advances have included: (1) recognition of the critical role of the antigen-presenting cell and greatly improved understanding of antigen processing and presentation, including the molecular interactions between HLA molecules and antigenic epitopes on the antigen-processing cell and the receptors on T cells, and (2) the roles of costimulatory molecules such as B7.1, ICAM-1, and LFA-3 in the induction and maintenance of an immune response. In addition, new techniques have allowed us to identify immunogenic antigenic determinants, alter their binding affinities, and evaluate the overall success of the intervention through both in vivo and in vitro assays. Carcinoembryonic antigen (CEA) is overexpressed in a large number of gastrointestinal, lung, and breast cancers. Clinical trials have established treatment protocols using viral vectors to immunize patients to CEA without producing deleterious autoimmune phenomena. By combining various vectors to include MUC-1 and/or CEA plus costimulatory molecules in a prime-and-boost regimen, we are beginning to see signs that this intervention can not only produce changes in immune function but also potentially improve clinical outcomes. Phase III studies to test these hypotheses are under way.

Animals↗

PubMed2005

The impact of targeted therapy on the treatment of colorectal cancer.

In the past several years, the impact of the new biologic therapies on colorectal cancer has been dramatic. The focus of this article is to summarize some of the key advances of incorporating biologically targeted therapies into the routine management of patients with colorectal cancer. We will review important data presented at the 2005 American Society of Clinical Oncology annual meeting and discuss the incorporation of these data into the most optimal management of our patients, including how best to manage side effects and keep quality of life as high as possible.

Antineoplastic Agents↗

PubMed2004

Phase I study of sequential vaccinations with fowlpox-CEA(6D)-TRICOM alone and sequentially with vaccinia-CEA(6D)-TRICOM, with and without granulocyte-macrophage colony-stimulating factor, in patients with carcinoembryonic antigen-expressing carcinomas.

PURPOSE: Our previous clinical experience with vaccinia and replication-defective avipox recombinant carcinoembryonic antigen (CEA) vaccines has demonstrated safety and clinical activity with a correlation between CEA-specific immune response and survival. Preclinical evidence demonstrated that the addition of the transgenes for three T-cell costimulatory molecules (B7-1, ICAM-1, LFA-3, designated TRICOM) results in a significant improvement in antigen-specific T-cell responses and antitumor activity. We describe here the first trial in humans of the CEA-TRICOM vaccines (also including an enhancer agonist epitope within the CEA gene). PATIENTS AND METHODS: Fifty-eight patients with advanced CEA-expressing cancers were accrued to eight cohorts that involved vaccinations with the following: replication-defective fowlpox recombinant (rF)-CEA(6D)-TRICOM; primary vaccination with recombinant vaccinia (rV)-CEA(6D)-TRICOM plus rF-CEA(6D)-TRICOM booster vaccinations; and rV-CEA(6D)-TRICOM and then rF-CEA(6D)-TRICOM, plus granulocyte-macrophage colony-stimulating factor (GM-CSF) with vaccines, or with divided doses of vaccine with GM-CSF. Vaccines were administered every 28 days for six doses and then once every 3 months. Reverting to treatments every 28 days was allowed if patients progressed on the 3-month schedule. RESULTS: In this phase I study, no significant toxicity was observed. Twenty-three patients (40%) had stable disease for at least 4 months, with 14 of these patients having prolonged stable disease (> 6 months). Eleven patients had decreasing or stable serum CEA, and one patient had a pathologic complete response. Enhanced CEA-specific T-cell responses were observed in the majority of patients tested. CONCLUSION: We demonstrated that the CEA-TRICOM vaccines are safe and can generate significant CEA-specific immune responses, and they seem to have clinical benefit in some patients with advanced cancer.

Adult↗

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

Treatment of advanced colorectal carcinoma with oxaliplatin and capecitabine: a phase II trial.

BACKGROUND: The current study was designed to evaluate the antitumor activity and toxicity of capecitabine and oxaliplatin in previously untreated patients with advanced colorectal carcinoma. The primary endpoint of the study was to determine the objective response rate, and a secondary endpoint was to measure the time to disease progression. METHODS: A 2-stage trial was planned with an accrual goal of 35 patients. The treatment included oxaliplatin given at a dose of 130 mg/m2 on Day 1 of each 3-week cycle. Initially, capecitabine at a dose of 2000 mg/m2/day in 2 divided doses was given on Days 1-14 of each cycle, but this was reduced to a dose of 1500 mg/m2/day because of toxicity. Patients were followed by computed tomography scans every two cycles to evaluate treatment response, and toxicity was monitored. RESULTS: The first 13 patients on the trial received the higher dose of capecitabine. Although 5 responses (38.5%) were noted, 5 patients were hospitalized with diarrhea and dehydration. This toxicity led to a decrease in the dose of capecitabine to 1500 mg/m2/day and an additional 35 patients were treated. At the lower dose, the partial response rate was 37.1% (95% confidence interval [95% CI], 21.5-55.1%). The estimated median progression-free survival was 6.9 months (95% CI, 4.4-8.2 months). At the lower dose, four patients were hospitalized with diarrhea/dehydration (with one death reported), one with febrile neutropenia, and one with ventricular fibrillation. Overall, Grade (according to version 2.0 of the National Cancer Institute Common Toxicity Criteria) 3-4 diarrhea was reported to develop in 20% of those patients treated at the capecitabine dose of 1500 mg/m2/day compared with 62% of patients treated at the dose of 2000 mg/m2/day. CONCLUSIONS: The combination of oxaliplatin and capecitabine is an active and convenient regimen for the treatment of patients with advanced colorectal carcinoma and should be compared with other front-line regimens as therapy for disease.

Adult↗

PubMed2004

A phase II trial of ISIS 3521 in patients with metastatic colorectal cancer.

This phase II study was designed to characterize the clinical activity of ISIS 3521 in patients with metastatic colorectal cancer (CRC). Sixteen patients with pretreated or refractory CRC were treated with ISIS 3521. Eleven patients were given a dose of 2.0 mg/kg per day, and 5 patients received 3.0 mg/kg per day given over 21 days followed by a 7-day rest period. Patients continued with study until evidence of disease progression or unacceptable toxicity was detected. Patients underwent baseline tumor biopsies followed by a second biopsy during the last week of the first 21-day infusion. All 16 patients underwent baseline tumor biopsies, and 12 of the 16 patients underwent on-study tumor biopsies. No evidence of tumor response was observed. One patient had stable disease after 2 cycles and remained on for 1 additional cycle only to demonstrate progression of disease at that time. No dose-limiting or other significant toxicities were observed at both dosages, which could not be explained by progression of disease. Fatigue was common in all patients treated but was not dose limiting, and there was no evidence of coagulopathy. Analysis of the tumor biopsies obtained from the 11 evaluable samples showed marked uptake of ISIS 3521 in the normal liver parenchyma. However, there was minimal uptake within the tumor cells. In addition, no evidence of any alteration in protein kinase C-a within the tumors or any downstream effects leading to apoptosis were observed. ISIS 3521 demonstrated no clinical activity or target modulation in refractory metastatic CRC.

Adult↗

PubMed2003

The correlation between patient characteristics and expectations of benefit from Phase I clinical trials.

BACKGROUND: Patients in Phase I clinical trials sometimes report high expectations regarding the benefit of treatment. The authors examined a range of patient characteristics to determine which factors were associated with greater expectations of benefit from Phase I trials. METHODS: Participants were adult patients with cancer who had been offered participation in Phase I studies and had decided to participate. Patients completed interviewer-administered surveys before initiation of treatment. Physicians assessed Eastern Cooperative Oncology Group performance status for each patient. Statistical analyses (Pearson product moment correlation and t tests) used multiple imputation to account for missing data. RESULTS: Overall, 593 patients who were offered participation in Phase I trials were contacted, and 328 patients agreed to participate in a study of decision making by cancer patients. Of these, 260 patients (79%) enrolled in a Phase I trial. Patients' expectations regarding the chance that their disease would be controlled with experimental therapy were unrelated to age, gender, living situation, education level, or functional status. Expectations were correlated positively with beliefs about the benefit of standard therapy and the maximum benefit patients may experience from experimental therapy. Greater expectations of benefit were associated with better health-related quality of life, stronger religious faith, optimism, relative health stock, monetary risk seeking, and poorer numeracy. CONCLUSIONS: Expectations expressed as beliefs in personal outcomes may be related more to quality of life and personality variables than to patients' knowledge or functional status. Whether such expectations are accurate reflections of knowledge has important implications for evaluating the informed consent process.

Adult↗

PubMed2003

Superiority of oxaliplatin and fluorouracil-leucovorin compared with either therapy alone in patients with progressive colorectal cancer after irinotecan and fluorouracil-leucovorin: interim results of a phase III trial.

PURPOSE: In North America, no effective therapy has been available for patients with progressive metastatic colorectal cancer after front-line treatment with irinotecan, bolus fluorouracil (FU), and leucovorin (IFL). PATIENTS AND METHODS: Patients with metastatic colorectal cancer who progressed after IFL therapy were randomly assigned to bolus and infusional FU and leucovorin (LV5FU2), single-agent oxaliplatin, or the combination (FOLFOX4). This planned interim analysis evaluated objective response rate (RR), time to tumor progression (TTP), and alleviation of tumor-related symptoms (TRS) in an initial cohort of patients. RESULTS: Between November 2000 and September 2001, 463 patients from 120 sites in North America were randomly assigned to treatment. FOLFOX4 proved superior to LV5FU2 in all measures of clinical efficacy. Objective RRs determined by an independent radiology panel were 9.9% for FOLFOX4 versus 0% for LV5FU2 (Fisher's exact test, P <.0001). Median TTP was 4.6 months for FOLFOX4 versus 2.7 months for LV5FU2 (two-sided, stratified log-rank test, P <.0001). Relief of TRS occurred in 33% of patients treated with FOLFOX4 versus 12% of patients treated with LVFU2 (chi2 test, P <.001). Single-agent oxaliplatin was not superior to LV5FU2 in any measure of efficacy. Patients treated with FOLFOX4 experienced a higher incidence of clinically significant toxicities than patients treated with LV5FU2, but these toxicities were predictable and did not result in a higher rate of treatment discontinuation or 60-day mortality rate. CONCLUSION: For patients with metastatic colorectal cancer, second-line treatment with FOLFOX4 is superior to treatment with LVFU2 in terms of RR, TTP, and relief of TRS.

Adult↗

PubMed2003

Combined inhibition of topoisomerases: a phase I. Study of irinotecan and epirubicin.

Preclinical data suggest that the combination of inhibitors of topoisomerases I and II may be synergistic when administered together. The optimal sequence of such combinations is uncertain, but initial administration of a topoisomerase I inhibitor upregulates topoisomerase II. Several combinations of these inhibitors have been evaluated, but have not clearly demonstrated synergy. Thus, we have started a phase I study of the combination of irinotecan (CPT-11, Camptosar) and epirubicin (Ellence). Typical eligibility criteria for phase I studies were employed. Patients with a history of congestive heart failure, > 240 mg/m2 of prior doxorubicin, or > 10% weight loss in the prior 4 weeks were excluded. Irinotecan and epirubicin were administered on days 1 and 8, every 28 days. Initially, patients were treated with irinotecan at 100 mg/m2 and epirubicin at 40 mg/m2 (dose level 1). After substantial toxicity at this level, the doses to be evaluated were changed to irinotecan: 50-->75-->100 mg/m2, and epirubicin: 20-->25-->30 mg/m2. Dose-limiting toxicities were noted in 2/4 patients (2 neutropenic fever, 1 thrombocytopenia) on dose level 1; 0/3 on dose level 1A; 1/8 (neutropenia) on dose level 2A; and 1/3 (neutropenia) on dose level 3A. This is the first combination of irinotecan and epirubicin to be evaluated in humans. The toxicity, primarily myelosuppression, noted to date has exceeded the expected toxicity for the doses of the irinotecan and epirubicin alone, suggesting the possibility of a synergistic interaction of the agents on this schedule, at least in the bone marrow. Other toxicities were acceptable and non-dose-limiting. Accrual of patients continues, at level 3A (irinotecan at 75 mg/m2, epirubicin at 25 mg/m2).

Adult↗

PubMed2003

Improving the toxicity of irinotecan/5-FU/leucovorin: a 21-day schedule.

Irinotecan (CPT-11, Camptosar) is one of the new generation of chemotherapeutic agents that has activity in advanced colorectal cancer. It has antitumor efficacy as a single agent, and also has been combined with fluorouracil (5-FU) and leucovorin (IFL) to treat these patients. Randomized studies have confirmed the superiority of IFL to 5-FU and leucovorin alone with regard to patient survival, time to progression, and tumor response rate. The optimal schedule for combining these agents remains uncertain, but in the United States, the schedule of IFL weekly for 4 consecutive weeks repeated every 6 weeks, according to the schedule reported by Saltz et al, has been widely used, although with some toxicity (especially myelosuppression and diarrhea). In an attempt to improve the tolerability of IFL, some have advocated modifying the schedule of IFL to weekly for 2 weeks, with repeated cycles every 21 days. Twenty-three patients with advanced colorectal cancer have been treated on this schedule at a single institution. Therapy was well tolerated, with 35% of patients experiencing grade 3/4 neutropenia, two of whom had episodes of febrile neutropenia, and 9% with grade 3/4 diarrhea. The median relative dose intensity of irinotecan administered in the first 18 patients treated with this regimen was 94%. These data support the hypothesis that modifying the schedule of administration of IFL improves the tolerability and ability to deliver the regimen, but must be confirmed by randomized prospective studies, which may also attempt to evaluate the role of bolus 5-FU in the treatment of advanced colorectal cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

Initial clinical trial of oral TAC-101, a novel retinoic acid receptor-alpha selective retinoid, in patients with advanced cancer.

PURPOSE: The goals of this study were to determine the safety, toxicity, and pharmacokinetics of TAC-101, a novel synthetic retinoic acid receptor-alpha (RAR-alpha) selective retinoid, in patients with advanced cancer. PATIENTS AND METHODS: Twenty-nine patients at two centers received oral TAC-101 at doses ranging from 12 to 34 mg/m(2)/d. Pharmacokinetic sampling was performed on days 1 and 28. RESULTS: The most frequent toxicities were myalgia/arthralgia, fatigue, and triglyceridemia. No dose-limiting toxicities were observed within the first 28 days up to 28 mg/m(2). However, seven of 21 patients experienced venous thromboembolic events (VTEs) during TAC-101 treatment. Eight additional patients who received 34 mg/m(2) were treated after a hypercoagulable work-up to exclude potential risk factors for VTE, and two of eight patients subsequently experienced VTEs. The maximum tolerated dose was exceeded at 34 mg/m(2)/d within the first 28 days, with one grade 3 hypertriglyceridemia, two grade 3 myalgia/arthralgia, and one grade 3 fatigue. One patient with advanced non-small-cell lung cancer had a complete response. No other responses were observed. No autoinduction of metabolism was observed with dosing over 28 days. CONCLUSION: This is the first human clinical study with TAC-101, a RAR-alpha selective retinoid. Musculoskeletal toxicity and hypertriglyceridemia were observed characteristics of previously studied retinoids. The recommended phase II dose is 24 mg/m(2) with this treatment schedule. Alternative treatment schedules and prospective evaluation of thrombotic risk will be investigated in subsequent studies.

Adult↗

PubMed2002

A silver-free, single-sheet imaging medium based on acid amplification.

We describe a photographic medium that uses acid-amplified imaging (AAI) rather than silver halide development to amplify a latent image. The latent image is captured when small amounts of superacid are generated by the photolysis of iodonium salts sensitized by cationic dyes. During thermal processing, the quantity of acid is multiplied in a process catalyzed by strong acid, resulting in a much larger amount of a weaker acid. Acid-sensitive indicator dyes that diffuse into regions where acid has been produced form a colored image. The AAI system is not sufficiently sensitive for direct use in cameras but is suitable for many printing applications.

Journal Article↗