Best hope or last hope: access to phase III clinical trials of HER-2/neu for advanced stage breast cancer patients

Breast cancer is a major public health problem, with a 12% incidence among women. The over-expression of the proto-oncogene HER-2/neu is associated with 30% of breast and ovarian cancers that are very aggressive and do not respond to standard therapeutic regimens. Entrance into clinical trials can represent the best hope and even the last hope for these patients. Entrance, however, is based on satisfying eligibility criteria. In examining advanced stage breast cancer patients' access to phase III clinical trials for HER-2/neu, two specific arguments regarding eligibility will be addressed. First, if research is to provide the utilitarian goal of the 'greatest good to the greatest number', delineation of the population receiving the 'good', rather than a homogeneous sub-set of this population, must be addressed, along with patients' values and goals, very relevant to determining a 'good life', how to achieve it, and whether a treatment is a part of that process. Second, the 'good' being generated should involve realistic, practical values of quality ways of living with advanced breast cancer and not just increased survival, or cure. Arguments for relaxing criteria are based on an accurate versus over-simplified interpretation of utilitarian principles and concepts of human flourishing. Only through addressing these issues can the true 'good' of clinical trials and research be given to the greatest number of people.

Radiotherapy review on national surgical adjuvant breast and bowel project (NSABP) phase III breast cancer clinical trials: is there a need for submission of portal/simulation films?

In all National Surgical Adjuvant Breast and Bowel Project (NSABP) breast cancer trials in which patients are treated with lumpectomy and postoperative breast irradiation, the quality assurance requirements dictate submission of a completed radiotherapy data form with the stated administered doses, the volumes treated, treatment prescription and daily treatment record sheets, dosimetry and calculation sheets, isodose distributions on the breast contour, photos of the patient in the treatment position, and portal or simulation films. A review of radiotherapy data on 1,982 patients who had lumpectomies accrued to seven recent NSABP breast cancer studies revealed only 2 patients who were judged to have inadequate fields. In both cases, a very small portion of the breast tissue was not included in the irradiated volume as demonstrated by the submitted films. On this basis, it was argued that submission of portal or simulation films for patients receiving postlumpectomy breast irradiation is not necessary. However, there was concern as to the incidence of patients with a possible excess amount of lung tissue included in the irradiated volume. To address this concern, the amount of irradiated lung was determined for the first 208 patients who had lumpectomies, with submitted data entered into the recent NSABP pathologic node-positive protocol B-28. Current NSABP radiation therapy guidelines suggest limiting the thickness of the irradiated lung in the portal beams to < or =3 cm. Only two patients (<1%) were found to have >3 cm of irradiated lung tissue in the treatment volume. Portal film submission is a considerable inconvenience to the individual institutions and is costly in terms of shipping, handling, and storage. These results indicate that submission of portal films is not a necessary part of quality assurance in NSABP breast cancer protocols. The NSABP has therefore eliminated the requirement for routine submission of portal films in protocols for which radiotherapy is not part of the test question.

Cardiovascular drugs: discrepancies in demographics between pre- and post-registration use

OBJECTIVES

To study discrepancies in demographic characteristics between patients participating in pre-registration phase III trials of cardiovascular drugs, registered in the Netherlands, and patient populations in daily practice representing the actual users of the drugs after registration.

METHODS

Comparison of age and sex distribution in registration files of 15 cardiovascular drugs [angiotensin-converting enzyme (ACE)inhibitors/angiotensin II receptor antagonists, calcium channel blockers, beta-adrenergic blocking agents, vasodilators, HMG-CoA reductase inhibitors and thrombolytics] with patients selected from a general practitioner (GP) registration database, who had received prescriptions for drugs from the therapeutic classes for the registered indications (hypertension, hypercholesterolaemia or angina pectoris) or were diagnosed with myocardial infarction. Moderate discrepancy was defined as more than 10% difference between the populations, large discrepancy by more than 20% difference. Clinical trials were also analysed by region of trial performance with respect to patient selection criteria, differences in male/female ratios and ethnic origin of patients.

RESULTS

Phase III clinical trials in registration files of drugs registered for hypertension, angina pectoris and myocardial infarction had a moderate to large under-representation of female patients. Patients aged more than 65 years, who accounted for more than 50% of drug use indicated for hypertension, angina pectoris and myocardial infarction, were under-represented in the clinical trials of drugs registered for all indications. Trials performed in North America included relatively fewer female patients compared with European trials, and showed different patterns in the ethnic origin between indications.

CONCLUSIONS

Clinically relevant subgroups of cardiovascular patients are under-represented in pre-registration phase III trials. These findings concern major areas of cardiovascular diseases, i.e. hypertension, hypercholesterolaemia, angina pectoris and myocardial infarction. Widely used therapeutic classes of drugs are affected and regional differences in trial performance are present.

Simulation studies of phase III clinical trials to test the efficacy of a candidate HIV-1 vaccine

One question of particular importance in phase III HIV vaccine trials is the choice of efficacy measure (EM) to validly and precisely estimate the true vaccinal efficacy. Traditional EMs, based on hazard rate ratio (HRR) or cumulative incidence ratio (CIR) are time-sensitive to mode of vaccine action and population heterogeneities. Through Monte-Carlo simulation, the performance of HRR and CIR based EMs are examined across different trial designs and vaccine and population characteristics. A new EM based on log-spline hazard regression (HARE) is proposed. Given that vaccinal properties (mode of action, time-lag, waning) are unknown a priori, appropriate selection of EM is problematic, and HRR and CIR can be unreliable to estimate the true maximum efficacy of candidate products. Non-random sexual mixing can exacerbate biases in HRR and CIR. HARE can offer valid estimation across different modes of vaccine action and in presence of frailty effects, contrary to its traditional counterparts. Our simulation studies highlight the weaknesses of widely used EMs while offering guidelines for trial design and suggesting new avenues for statistical analysis.

[Surrogate endpoints]

The main endpoint of a phase III trial in oncology must be relevant clinically. In practice, this endpoint is either the disease-free or the overall survival, which requires both long term follow-up and a large number of patients. In phase II trials, it is essential to proceed rapidly, and one therefore uses a surrogate endpoint. Surrogate endpoints are adequate for phase II trials. Their use for phase III trials should be restricted to the rare situations where their validity has been established for the therapeutic and a under study. This surrogate endpoint must be faster to obtain than the clinical endpoint it replaces. Ideally, it should capture all of the treatment effect on the main endpoint, i.e. there should be no effect of the treatment on survival, once the value of the surrogate endpoint is known.

Sample size estimation in phase III cancer clinical trials

This paper deals with the basic principles involved in sample size calculation of phase III cancer clinical trials. It illustrates the concepts and factors determining the sample size. Various examples of phase III cancer clinical trials are provided and the sample size is calculated taking into account the assumptions made. The examples provided include sample sizes for comparing proportions and sample sizes for comparing survival times. Several special topics are also discussed including choice of endpoint, number of treatment groups, factorial designs and equivalence trials.

Impact of therapeutic research on informed consent and the ethics of clinical trials: a medical oncology perspective

PURPOSE

To create a more meaningful understanding of the informed consent process as it has come to be practiced and regulated in clinical trials, this discussion uses the experience gained from the conduct of therapeutic research that involves cancer patients.

DESIGN

After an introduction of the ethical tenets of the consent process in clinical research that involves potentially vulnerable patients as research subjects, background that details the use of written consent documents and of the term "informed consent" is provided. Studies from the cancer setting that examine the inadequacies of written consent documents, and the outcome of the consent process itself, are reviewed. Two ethically challenging areas of cancer clinical research, the phase I trial and the randomized controlled trial, are discussed briefly as a means of highlighting many dilemmas present in clinical trials. Before concluding, areas for future research are discussed.

RESULTS

Through an exclusive cancer research perspective, many current deficiencies in the informed consent process for therapeutic clinical trials can be critically examined. Also, new directions for improvements and areas of further research can be outlined and discussed objectively. The goals of such improvements and research should be prevention of further misguided or ineffective efforts to regulate the informed consent process.

CONCLUSION

To ignore this rich and interesting perspective potentially contributes to continued misunderstanding and apathy toward fulfilling the regulatory and ethically obligatory requirements involved in an essential communication process between a clinician-investigator and a potentially vulnerable patient who is considering clinical trial participation.

Statistical shortcomings in licensing applications

This paper concerns the statistical work carried out with respect to clinical trials conducted for regulatory purposes. Although the general quality of such work has improved markedly over recent years and is now generally high, a number of shortcomings remain. A few of these arise from failure to follow well established statistical practice. Rather more arise from a poor understanding of areas of known statistical disagreement and from the unsatisfactory use of newer and more advanced techniques. Inadequacies in reporting statistical work are commonplace. Examples of all these shortcomings are provided and emphasis is placed on the value of a statistical contribution to overall summaries such as the clinical expert report.

Clinical trials of antibacterial agents: a practical guide to design and analysis. Statisticians in the Pharmaceutical Industry Working Party

Guidelines on the conduct of clinical trials of antibacterial agents produced by the US Food and Drug Administration, the British Society for Antimicrobial Chemotherapy, the Infectious Diseases Society of America and a European Working Party have been reviewed. Although very informative, these guidelines provide limited practical guidance on the design and statistical aspects of phase III studies of antimicrobial agents. This paper describes the differences between antibacterial trials and clinical studies in other therapeutic areas with regard to subjective endpoints, dual clinical and bacteriological endpoints, frequent protocol violations and difficulty of using placebo controls. The importance of a detailed protocol and planned analysis strategy is emphasized. The choice of comparator agents, practical issues with the blinding of trial materials and the documentation of patients excluded from study entry are discussed. The use of different patient groups and different endpoints in analyses are described. The principles of equivalence and their application to trials of antibacterial agents are discussed, together with an approach to calculating sample size. A variety of statistical analyses of results are compared for different situations indicating some of the problems that can arise. Different methods of presentation of study data are included with emphasis on regulatory submissions rather than scientific publications. Some graphical presentations are recommended and issues regarding data across different studies are discussed.

Influence of a sampling review process for radiation oncology quality assurance in cooperative group clinical trials--results of the Radiation Therapy Oncology Group (RTOG) analysis

The Radiation Therapy Oncology Group (RTOG) designed a random sampling process and observed its influence upon radiotherapy review mechanisms in cooperative group clinical trials. The method of sampling cases for review was modeled from sampling techniques commonly used in pharmaceutical quality assurance programs, and applied to the initial (on-study) review of protocol cases. 'In control' (IC) status is defined for a given facility as the ability to meet minimum compliance standards. Upon achieving IC status, activation of the sampling process was linked to the rate of continued patient accrual for each participating institution in a given protocol. The sampling design specified that > or = 30% cases not in compliance would be detected with 80% power. A total of 458 cases was analyzed for initial review findings in four RTOG Phase III protocols. Initial review findings were compared with retrospective (final) review results. Of the 458 cases analyzed, 370 underwent initial review at on-study, while 88 did not require review as they were enrolled from institutions that had demonstrated protocol compliance. In the group that had both initial and final review, 345/370 (93%) were found to have followed the protocol or had a minor variation. Of the exempted cases, 79/88 (90%) were found to be per protocol or a minor variant. The sampling process proved itself to be cost-effective and resulted in a noticeable reduction in the workload, thus providing an improved approach to resource allocation for the group. Continued evaluation of the sampling mechanism is appropriate as study designs and participants vary over time, and as more data become available to study.(ABSTRACT TRUNCATED AT 250 WORDS)

OMERACT II: the biologics perspective

The development of biologic agents for the treatment of rheumatic diseases will necessitate inclusion of pharmacoeconomic analyses in the phase III trials. These products are expensive to manufacture, administer, and monitor. Typically, they require parenteral administration and regular monitoring. Often the duration of benefit is brief; although they may effectively serve as "induction therapy." For example, we have a "wonderful new biologic agent," judged effective by the ACR preliminary index for improvement, which after 2 treatment courses at +1500 (US) each, offers a year of "clinically meaningful" improvement with an acceptable safety profile in most patients. How will we convince our regulatory authorities and health services agencies that it should be approved and added to our formularies? It will be necessary to prospectively collect information about its costs (both direct and indirect) and the costs of alternative treatments. In the multicenter clinical trials for approval, patients' opinions about their health status, quality of life, and the treatment itself must be sought. In addition to a disease specific measure of function/disability, a generic measure of health status/quality of life should be included. Use of a health utilities instrument will allow comparison of different therapeutic interventions. The promise of specifically targeting disregulated immune responses without altering underlying normal immune function makes biologic agents uniquely attractive for use in an early disease population. It will therefore be important to identify those indirect costs saved or gained by maintaining function and work capacity, as well as the direct (and indirect) costs incurred by treatment associated toxicities.(ABSTRACT TRUNCATED AT 250 WORDS)

An overview of pharmacoepidemiology

Pharmacoepidemiology is the application of epidemiological principles and methods to the study of drug effects in human populations. The goal of this discipline is to characterize, control and predict the effects and uses of pharmacological treatment modalities. Pharmacoepidemiology is also concerned with the economic impact and health benefits of unintended drug effects. The increasing importance of pharmacoepidemiology has been created by the need to develop a more accurate portrait of how drugs are used in the general population. Sophisticated and potent drug therapies require surveillance beyond the scope of the carefully controlled clinical trials of Phases I, II and III. Case-control and cohort studies, which allow scientists to evaluate the effects of patient variables on clinical outcomes, provide a wealth of information regarding the study of unexpected drug effects, drug utilization, treatment costs and the individualization of therapy.

Early stopping rules and long-term follow-up in phase III trials

The main advantage of interim analyses is that a randomized trial can be concluded in advance. As a consequence, the cost is reduced and the protection of the individual is increased from an ethical point of view. Formal statistical methods are, however, necessary to control the overall significance level and the power of the trial. Group sequential analysis and triangular test properties are compared in the setting of randomized trials with a long-term follow-up. Potential biases secondary to the conduct of the first analyses on a small number of events are discussed. Conservative methods which employ stringent criteria for the first analyses should be used to avoid loss of power in subsequent comparisons of long-term survival when early stopping occurs. Early stopping leads to less precision in the estimation of the treatment effect as the size of the sample is reduced. Furthermore, the observed effect could be biased upwards when trials are stopped early because the effect is larger than expected and biased downwards because the effect is lower than expected. Finally, as the ultimate goal of a trial is to alter therapeutic strategies, data should always be consistent so that the medical community can be convinced that treatment management should be modified.