Richard S. Kaplan

Participation of Patients 65 Years of Age or Older in Cancer Clinical Trials

PURPOSEnAlthough 61% of new cases of cancer occur among the elderly, recent studies indicate that the elderly comprise only 25% of participants in cancer clinical trials. Further investigation into the reasons for low elderly participation is warranted. Our objective was to evaluate the participation of the elderly in clinical trials sponsored by the National Cancer Institute (NCI) and assess the impact of protocol exclusion criteria on elderly participation.nnnPATIENTS AND METHODSnWe conducted a retrospective analysis using NCI data, analyzing patient and trial characteristics for 59,300 patients enrolled onto 495 NCI-sponsored, cooperative group trials, active from 1997 through 2000. Our main outcome measure was the proportion of elderly patients enrolled onto cancer clinical trials compared with the proportion of incident cancer patients who are elderly.nnnRESULTSnOverall, 32% of participants in phase II and III clinical trials were elderly, compared with 61% of patients with incident cancers in the United States who are elderly. The degree of underrepresentation was more pronounced in trials for early-stage cancers than in trials for late-stage cancers (P <.001). Furthermore, protocol exclusion criteria on the basis of organ-system abnormalities and functional status limitations were associated with lower elderly participation. We estimate that if protocol exclusions were relaxed, elderly participation in cancer trials would be 60%.nnnCONCLUSIONnThe elderly are underrepresented in cancer clinical trials relative to their disease burden. Older patients are more likely to have medical histories that make them ineligible for clinical trials because of protocol exclusions. Insurance coverage for clinical trials is one step toward improvement of elderly access to clinical trials. Without a change in study design or requirements, this step may not be sufficient.

Phase II Trial of the Antiangiogenic Agent Thalidomide in Patients With Recurrent High-Grade Gliomas

PURPOSEnLittle progress has been made in the treatment of adult high-grade gliomas over the last two decades, thus necessitating a search for novel therapeutic strategies. Malignant gliomas are vascular or angiogenic tumors, which leads to the supposition that angiogenesis inhibition may represent a potentially promising strategy in the treatment of these tumors. We present the results of a phase II trial of thalidomide, a putative inhibitor of angiogenesis, in the treatment of adults with previously irradiated, recurrent high-grade gliomas.nnnPATIENTS AND METHODSnPatients with a histologic diagnosis of anaplastic mixed glioma, anaplastic astrocytoma, or glioblastoma multiforme who had radiographic demonstration of tumor progression after standard external-beam radiotherapy with or without chemotherapy were eligible. Patients were initially treated with thalidomide 800 mg/d with increases in dose by 200 mg/d every 2 weeks until a final daily dose of 1,200 mg was achieved. Patients were evaluated every 8 weeks for response by both clinical and radiographic criteria.nnnRESULTSnA total of 39 patients were accrued, with 36 patients being assessable for both toxicity and response. Thalidomide was well tolerated, with constipation and sedation being the major toxicities. One patient developed a grade 2 peripheral neuropathy after treatment with thalidomide for nearly a year. There were two objective radiographic partial responses (6%), two minor responses (6%), and 12 patients with stable disease (33%). Eight patients were alive more than 1 year after starting thalidomide, although almost all with tumor progression. Changes in serum levels of basic fibroblastic growth factor (bFGF) were correlated with time to tumor progression and overall survival.nnnCONCLUSIONnThalidomide is a generally well-tolerated drug that may have antitumor activity in a minority of patients with recurrent high-grade gliomas. Future studies will better define the usefulness of thalidomide in newly diagnosed patients with malignant gliomas and in combination with radiotherapy and chemotherapy. Additionally, studies will be needed to confirm the potential utility of changes in serum bFGF as a marker of antiangiogenic activity and/or glioma growth.

Phase I/II Study of Imatinib Mesylate for Recurrent Malignant Gliomas: North American Brain Tumor Consortium Study 99-08

Purpose: Phase I: To determine the maximum tolerated doses, toxicities, and pharmacokinetics of imatinib mesylate (Gleevec) in patients with malignant gliomas taking enzyme-inducing antiepileptic drugs (EIAED) or not taking EIAED. Phase II: To determine the therapeutic efficacy of imatinib. Experimental Design: Phase I component used an interpatient dose escalation scheme. End points of the phase II component were 6-month progression-free survival and response. Results: Fifty patients enrolled in the phase I component (27 EIAED and 23 non-EIAED). The maximum tolerated dose for non-EIAED patients was 800 mg/d. Dose-limiting toxicities were neutropenia, rash, and elevated alanine aminotransferase. EIAED patients received up to 1,200 mg/d imatinib without developing dose-limiting toxicity. Plasma exposure of imatinib was reduced by ∼68% in EIAED patients compared with non-EIAED patients. Fifty-five non-EIAED patients (34 glioblastoma multiforme and 21 anaplastic glioma) enrolled in the phase II component. Patients initially received 800 mg/d imatinib; 15 anaplastic glioma patients received 600 mg/d after hemorrhages were observed. There were 2 partial response and 6 stable disease among glioblastoma multiforme patients and 0 partial response and 5 stable disease among anaplastic glioma patients. Six-month progression-free survival was 3% for glioblastoma multiforme and 10% for anaplastic glioma patients. Five phase II patients developed intratumoral hemorrhages. Conclusions: Single-agent imatinib has minimal activity in malignant gliomas. CYP3A4 inducers, such as EIAEDs, substantially decreased plasma exposure of imatinib and should be avoided in patients receiving imatinib for chronic myelogenous leukemia and gastrointestinal stromal tumors. The evaluation of the activity of combination regimens incorporating imatinib is under way in phase II trials.

The continuing increase in the incidence of primary central nervous system non-Hodgkin lymphoma: A surveillance, epidemiology, and end results analysis

Primary central nervous system lymphoma (PCNSL) is an extranodal form of non‐Hodgkin lymphoma arising in the craniospinal axis. The incidence of PCNSL appears to be increasing.

GNOSIS: Guidelines for neuro-oncology: Standards for investigational studies—reporting of phase 1 and phase 2 clinical trials

We present guidelines to standardize the reporting of phase 1 and phase 2 neuro-oncology trials. The guidelines are also intended to assist with accurate interpretation of results from these trials, to facilitate the peer-review process, and to expedite the publication of important and accurate manuscripts. Our guidelines are summarized in a checklist format that can be used as a framework from which to construct a phase 1 or 2 clinical trial.

Cancer Molecular Analysis Project: Weaving a rich cancer research tapestry

The Cancer Molecular Analysis Project (CMAP) of the NCI is integrating diverse cancer research data to elucidate fundamental etiologic processes, enable development of novel therapeutic approaches, and facilitate the bridging of basic and clinical science.

Diaziquone, 2,5‐diaziridinyl‐3,6‐biscarboethoxyamino‐1,4‐benzoquinone, plasma and cerebrospinal fluid kinetics

Plasma and cerebrospinal fluid (CSF) kinetics of diaziquone, 2,5‐diaziridinyl‐3,6‐biscarboethoxyamino‐1,4‐benzoquinone (AZQ), were evaluated after intravenous injection in patients with implanted Ommaya reservoirs. After a 30‐min infusion plasma disappearance was very rapid, with a disposition half‐life of 2 to 6 min and an elimination half‐life of 25 to 35 min. Area under the concentration‐time curve for CSF was 22% to 42% of the corresponding plasma area. Based upon total plasma AZQ concentration, volume of distribution for AZQ was 2.0 to 10.0 l/m2. Plasma binding of AZQ was 79% in one normal subject. When the effect of plasma binding is considered, distribution volumes are more plausible and it appears that free plasma AZQ is completely available to the CSF.

National Cancer Institute Clinical Trials Program in Colorectal Cancer.

Colorectal cancer will be diagnosed in approximately 150,000 patients in the USA this year. Chemotherapy has recently been shown to improve survival when given as adjuvant therapy to surgery in patients with stage III colorectal cancer. Demonstration of this benefit required large, randomized controlled trials. Either 5-fluorouracil (5-FU) and leucovorin for 6 months or 5-FU and levamisole for 12 months are currently considered standard adjuvant treatment for stage III colorectal cancer. However, current adjuvant trials are comparing continuous infusion and intravenous bolus 5-FU regimens and oral uracil/Ftorafur with intravenous 5-FU and leucovorin, as well as studying the timing of chemotherapy in the adjuvant setting. Subsequent adjuvant trials will examine newer regimens with activity in advanced colorectal cancer, as well as the efficacy of monoclonal antibodies. Other trials will study which type of surgery is optimal and whether adjuvant therapy is helpful in stage II colon cancer. Trials in metastatic disease will focus on combinations of newer agents which may improve survival in this patient group. Studies in rectal cancer will focus on determining which agents are optimal in combination with radiation therapy in the adjuvant setting. Molecular characteristics of tumor cells are being defined, which may guide therapy in the future. Careful, logically designed clinical trials will hopefully provide more efficacious therapy for this common cancer.

Issues in regulatory guidelines for data monitoring committees.

As clinical trials have emerged as the major research method for evaluating new interventions, the process for monitoring intervention safety and benefit has also evolved. The Data Monitoring Committee (DMC) has become the standard approach to implement this responsibility for many Phase III trials. Recent draft guidelines on the operation of DMCs by the Food and Drug Administration (FDA) have raised issues that need further clarification or discussion, especially for industry sponsored trials. These include, the time when DMCs are needed, the role of the independent statistician to support the DMC, and sponsor participation at DMC meetings. This paper provides an overview of these issues, based on the discussions at the January, 2003 workshop sponsored by Duke Clinical Research Institute.