Cancer pharmacogenomics and pharmacoepidemiology: setting a research agenda to accelerate translation.

Recent advances in genomic research have demonstrated a substantial role for genomic factors in predicting response to cancer therapies. Researchers in the fields of cancer pharmacogenomics and pharmacoepidemiology seek to understand why individuals respond differently to drug therapy, in terms of both adverse effects and treatment efficacy. To identify research priorities as well as the resources and infrastructure needed to advance these fields, the National Cancer Institute (NCI) sponsored a workshop titled "Cancer Pharmacogenomics: Setting a Research Agenda to Accelerate Translation" on July 21, 2009, in Bethesda, MD.

Phase II trial of bryostatin-1 in combination with cisplatin in patients with recurrent or persistent epithelial ovarian cancer: a California cancer consortium study.

Background: The California Cancer Consortium has performed a Phase II trial of infusional bryostatin, a protein kinase C inhibitor isolated from the marine invertebrate bryozoan, Bugula Neritina, a member of the phylum Ectoprocta, in combination with cisplatin, in patients (pts) with recurrent platinum-sensitive or resistant ovarian cancer (OC).

Methods: Pts received bryostatin 45 mcg/m(2) as a 72 h continuous infusion followed by cisplatin 50 mg/m(2). Cycles were repeated every 3 weeks.

Development of a validated immunofluorescence assay for γH2AX as a pharmacodynamic marker of topoisomerase I inhibitor activity.

Purpose: Phosphorylated histone H2AX (γH2AX) serves as a biomarker for formation of DNA double-strand break repair complexes. A quantitative pharmacodynamic immunofluorescence assay for γH2AX was developed, validated, and tested in human tumor xenograft models with the use of clinically relevant procedures.

Experimental Design: The γH2AX immunofluorescence assay uses a novel data quantitation and image processing algorithm to determine the extent of nuclear-specific γH2AX staining in tumor needle biopsies and hair follicles collected from mice bearing topotecan-responsive A375 xenografts.

Histone gammaH2AX and poly(ADP-ribose) as clinical pharmacodynamic biomarkers.

Tumor cells are often deficient in DNA damage response (DDR) pathways, and anticancer therapies are commonly based on genotoxic treatments using radiation and/or drugs that damage DNA directly or interfere with DNA metabolism, leading to the formation of DNA double-strand breaks (DSB), and ultimately to cell death. Because DSBs induce the phosphorylation of histone H2AX (γH2AX) in the chromatin flanking the break site, an antibody directed against γH2AX can be employed to measure DNA damage levels before and after patient treatment. Poly(ADP-ribose) polymerases (PARP1 and PARP2) are also activated by DNA damage, and PARP inhibitors show promising activity in cancers with defective homologous recombination (HR) pathways for DSB repair.

AACR-FDA-NCI Cancer Biomarkers Collaborative consensus report: advancing the use of biomarkers in cancer drug development.

Recent discoveries in cancer biology have greatly increased our understanding of cancer at the molecular and cellular level, but translating this knowledge into safe and effective therapies for cancer patients has proved to be challenging. There is a growing imperative to modernize the drug development process by incorporating new techniques that can predict the safety and effectiveness of new drugs faster, with more certainty, and at lower cost. Biomarkers are central to accelerating the identification and adoption of new therapies, but currently, many barriers impede their use in drug development and clinical practice.

Adenocarcinoma of the small bowel: changes in the landscape?

Purpose Of Review: Small bowel adenocarcinoma (SBA) is a rare cancer with a poor prognosis and little information to guide its management. In recent years, improved diagnostic imaging and an increase in reported experience with use of chemotherapy may alter the way we manage SBA. This review will summarize recent advances in characterization, imaging, and treatment of SBA.

Analysis of Food and Drug Administration-approved anticancer agents in the NCI60 panel of human tumor cell lines.

Since the early 1990s the Developmental Therapeutics Program of the National Cancer Institute (NCI) has utilized a panel of 60 human tumor cell lines (NCI60) representing 9 tissue types to screen for potential new anticancer agents. To date, about 100,000 compounds and 50,000 natural product extracts have been screened. Early in this program it was discovered that the pattern of growth inhibition in these cell lines was similar for compounds of similar mechanism.

The statistics of phase 0 trials.

The PD-driven phase 0 trial is a new form, designed to be a first-in-man study, often of a new agent, conducted to assess drug effect on a molecular target, by means of a pharmacodynamic (PD) assay, in a very small number (10-15) of patients. Such a study is meant to be a proof of principle trial to determine whether the agent yields the PD effect predicted by pre-clinical studies. The dosage is meant to be pharmacologically active, but is neither toxic nor likely to yield clinical benefit.

Exon array analyses across the NCI-60 reveal potential regulation of TOP1 by transcription pausing at guanosine quartets in the first intron.

Because topoisomerase 1 (TOP1) is critical for the relaxation of DNA supercoils and because it is the target for the anticancer activity of camptothecins, we assessed TOP1 transcript levels in the 60 cell line panel (the NCI-60) of the National Cancer Institute's anticancer drug screen. TOP1 expression levels varied over a 5.7-fold range across the NCI-60.

Phase I trial of fixed-dose rate gemcitabine in combination with bortezomib in advanced solid tumors.

Background: Bortezomib demonstrates synergism with gemcitabine via a fixed-dose rate (FDR). The aim of this phase I trial in solid tumors was to establish the maximum tolerated dose (MTD) and safety data for this combination.

Patients And Methods: Twenty-nine patients with a median age of 63 (range 36-84) years and median Karnofsky Performance Status of 90 (range 60-100) were enrolled and treated with bortezomib (1.

Plasma and cerebrospinal fluid pharmacokinetics of topotecan in a phase I trial of topotecan, tamoxifen, and carboplatin, in the treatment of recurrent or refractory brain or spinal cord tumors.

Purpose: This study was designed to ascertain the dose-limiting toxicities (DLT) and maximally tolerated doses of the combination of fixed-dose tamoxifen and carboplatin, with escalating doses of topotecan, and to determine the pharmacokinetics of topotecan in the plasma and cerebrospinal fluid.

Methods: Tamoxifen 100 mg po bid, topotecan 0.25, 0.

Monitoring drug-induced gammaH2AX as a pharmacodynamic biomarker in individual circulating tumor cells.

Purpose: Circulating tumor cells (CTC) in peripheral blood of patients potentially represent a fraction of solid tumor cells available for more frequent pharmacodynamic assessment of drug action than is possible using tumor biopsy. However, currently available CTC assays are limited to cell membrane antigens. Here, we describe an assay that directly examines changes in levels of the nuclear DNA damage marker gammaH2AX in individual CTCs of patients treated with chemotherapeutic agents.

Phase I trial of 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), a heat shock protein inhibitor, administered twice weekly in patients with advanced malignancies.

Purpose: Phase I dose-escalation study to determine the toxicity and maximum tolerated dose (MTD) of 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), a heat shock protein 90 (Hsp90) inhibitor, administered on a twice weekly schedule in patients with advanced cancer.

Experimental Design: 17-DMAG was administered as a 1- to 2-h infusion twice weekly in 4-week cycles. An accelerated titration design was followed until toxicity was observed, at which point standard dose-escalation proceeded.

A phase I trial of UCN-01 and prednisone in patients with refractory solid tumors and lymphomas.

Purpose: UCN-01 potently inhibits protein kinase C, phosphatidylinositide-dependent kinase-1, and checkpoint kinase 1, which are involved in regulating cell cycle progression. We designed a phase I study to determine the maximum tolerated dose (MTD) of UCN-01 with prednisone in patients with advanced malignancies.

Methods: UCN-01 was administered as a continuous intravenous infusion over 72 h in cycle 1 and 36 h in subsequent cycles.

Role of Phase 0 trials in drug development.

Phase 0 trials can provide proof of concept that an agent modulates its intended target without exposing patients to the drug-tolerability testing that precedes efficacy evaluation. Drugs that do not modulate their targets can be discarded, focusing development resources on the most clinically promising agents. However, wider uptake of Phase 0 trials may be hindered by ethical concerns over their lack of therapeutic intent, the substantial resources required to develop and validate target assays or skepticism that such trials save development time.

Immunohistochemical detection of poly(ADP-ribose) polymerase inhibition by ABT-888 in patients with refractory solid tumors and lymphomas.

Purpose: Targeting the poly (ADP-ribose) polymerase (PARP) pathway for cancer treatment has been an active area of pre-clinical and clinical research. We aimed to determine whether the PARP inhibitor ABT-888 hits its therapeutic target in tumors by immunohistochemistry during a Phase 0 trial conducted at the National Cancer Institute.

Experimental Design: The expression of poly (ADP-ribose) (PAR) and full size PARP-1 were quantitatively examined by immunohistochemistry in paraffin-embedded tumor biopsies at baseline and 3-24 h after a single oral dose (25 or 50 mg) of ABT-888.

Topoisomerase I levels in the NCI-60 cancer cell line panel determined by validated ELISA and microarray analysis and correlation with indenoisoquinoline sensitivity.

Topoisomerase I (Top1) is a proven target for cancer therapeutics, and the level of Top1 in tumors has been used as a biomarker for chemotherapeutic efficacy. In this study, we report the development and validation of a two-site enzyme chemiluminescent immunoassay for Top1, which we used to measure Top1 levels in the NCI-60 cancer cell line panel. Top1 levels ranged from 0.

Expression of NADPH oxidase homologues and accessory genes in human cancer cell lines, tumours and adjacent normal tissues.

The family of NADPH oxidase (NOX) genes produces reactive oxygen species (ROS) pivotal for both cell signalling and host defense. To investigate whether NOX and NOX accessory gene expression might be a factor common to specific human tumour types, this study measured the expression levels of NOX genes 1-5, dual oxidase 1 and 2, as well as those of NOX accessory genes NoxO1, NoxA1, p47(phox), p67(phox) and p22(phox) in human cancer cell lines and in tumour and adjacent normal tissue pairs by quantitative, real-time RT-PCR. The results demonstrate tumour-specific patterns of NOX gene expression that will inform further studies of the role of NOX activity in tumour cell invasion, growth factor response and proliferative potential.

Phase 0 clinical trial of the poly (ADP-ribose) polymerase inhibitor ABT-888 in patients with advanced malignancies.

Purpose: We conducted the first phase 0 clinical trial in oncology of a therapeutic agent under the Exploratory Investigational New Drug Guidance of the US Food and Drug Administration. It was a first-in-human study of the poly (ADP-ribose) polymerase (PARP) inhibitor ABT-888 in patients with advanced malignancies.

Patients And Methods: ABT-888 was administered as a single oral dose of 10, 25, or 50 mg to determine the dose range and time course over which ABT-888 inhibits PARP activity in tumor samples and peripheral blood mononuclear cells, and to evaluate ABT-888 pharmacokinetics.

Phase I trial of GTI-2040, oxaliplatin, and capecitabine in the treatment of advanced metastatic solid tumors: a California Cancer Consortium Study.

Background: GTI-2040 is a 20-mer antisense oligonucleotide targeting the mRNA of ribonucleotide reductase M2. It was combined with oxaliplatin and capecitabine in a phase I trial in patients with advance solid tumors based on previous studies demonstrating potentiation of chemotherapy with ribonucleotide reductase inhibitors.

Methods: Patients at least 18 years of age with advanced incurable solid tumors and normal organ function as well as a Karnofsky performance status of > or =60% were eligible.

Phase II studies of gemcitabine and cisplatin in heavily and minimally pretreated metastatic breast cancer.

Purpose: Cisplatin and gemcitabine have single-agent activity in metastatic breast cancer, and preclinical data support synergy of the combination. Two parallel, phase II trials were conducted to evaluate the response rate, response duration, and toxicities of the combination. Genetic polymorphisms were analyzed for correlation with outcomes.

Five strategies for accelerating the war on cancer in an era of budget deficits.

In recent years, the National Institutes of Health's largest institute, the National Cancer Institute (NCI), has adapted to difficult economic conditions by leveraging its robust infrastructure -- which includes risk factor surveillance and population monitoring, research centers (focused on basic, translation, clinical, and behavioral sciences), clinical trials and health care research networks, and rigorously validated statistical models -- to maximize the impact of scientific progress on the public health. To continue advancement and realize the opportunity of significant, population-level changes in cancer mortality, the NCI recommends that five national-level actions be taken: (1) significantly increase enrollment of Medicare patients into cancer clinical trials through adequate physician reimbursement, (2) increase NCI/Centers for Medicare and Medicaid Services collaboration on clinical trials research to evaluate the therapeutic efficacy of anticancer drugs, (3) establish a national outcomes research demonstration project to test strategies for measuring and improving health care quality and provide an evidence base for public policy, (4) leverage existing tobacco-control collaborations and possible new authorities at the U.S.

Phase 0 clinical trials: recommendations from the Task Force on Methodology for the Development of Innovative Cancer Therapies.

The Methodology for the Development of Innovative Cancer Therapies (MDICT) task force has been established as an expert forum to develop practical guidance on the development of innovative anticancer agents, in particular targeted agents. The task force recently addressed the utility, design and application of Phase 0 clinical trials in anticancer drug development. It was concluded that the role of non-therapeutic Phase 0 trials is controversial for several reasons, including the lack of clinical benefit for participating patients.