Regulatory activities to address the needs of older patients

At the Drug Information Association (DIA) 49th annual meeting, for the first time regulators (Dr Francesca Cerreta, Dr Robert Temple and Dr Yasuko Asahina) from the three International Conference on Harmonization (ICH) co-sponsor regions came together in a forum to discuss their perspective on how the aging population impacts on drug development and on the design of clinical trials. In 2010, the ICH E7 Guideline (Studies in support of Special Populations: Geriatrics) was revised with the addition of a Questions and Answers document to take into account the rapidly changing world demographics. Regulators from the three ICH regions (Europe, USA and Japan) discuss here how they foresee the application of this guideline, and the impact that this might have on new drug development and clinical trial design. This article aims to summarize the discussions at the session for the benefit of a wider audience.

When to conduct a renal impairment study during drug development: US Food and Drug Administration perspective

To optimize drug therapy for individuals, it is critical to understand how various intrinsic (e.g., age, gender, race, genetics, organ impairment) and extrinsic factors (e.g., diet, smoking, concomitantly administered drugs) affect drug exposure and response.(1) Up to now, it has been far easier to discover effects on exposure caused by these factors, and the US Food and Drug Administration (FDA) has published several guidance documents with recommendations on how to evaluate these factors during drug development.

Drug interaction studies: study design, data analysis, and implications for dosing and labeling

One of the most effective ways in which regulatory agencies communicate with sponsors and guide drug development is through the issuance of guidances or guidelines. These can be issued domestically in a given region such as the United States by the Food and Drug Administration (FDA) or internationally through the International Conference on Harmonization. Currently, there are over 400 final or draft guidances that can be found through the FDA website. The development of guidances proceeds through a process known as Good Guidance Practices, which is intended to assure that there is an appropriate level of meaningful public participation in the development of guidance. In the past 10 years, clinical pharmacology guidances covering important areas have been issued, including pharmacokinetic data in patients with renal and hepatic impairment, dose-response studies, and drug-drug interactions.

Microarray analysis of eosinophils reveals a number of candidate survival and apoptosis genes

The increase in eosinophils at the site of antigen challenge has been used as evidence to suggest that this cell type plays a role in the pathophysiology of asthma. Aberrant production of several different cytokines, particularly interleukin (IL)-5, has been shown to result in eosinophilia. IL-5 influences the development and maturation of eosinophils in a number of different ways. Of note is the ability of IL-5 to act as a survival factor for eosinophils specifically inhibiting apoptosis. The precise mechanism by which IL-5 exerts its effect remains obscure. We used microarray technologies to investigate the changes in the messenger RNA expression profile of eosinophils after treatment with IL-5. Using the Affymetrix Hu6800 chip, a total of 80 genes were observed to be regulated by 2-fold or greater. Many of the genes previously identified as regulated by IL-5 were regulated in our microarray experiments. Of the 73 genes found to be upregulated, many were shown to play a role in adhesion, migration, activation, or survival of eosinophils or hematopoietic cells, whereas the function of others was unknown. To facilitate the identification of genes that govern the apoptosis and survivability of eosinophils, we used an alternative cellular model, TF1.8 cells, whose survival was also dependent on IL-5. Comparison of these models identified four genes, Pim-1, DSP-5 (hVH3, B23), CD24, and SLP-76, whose regulation was similarly coordinated in both systems. Identification of Pim-1 and SLP-76 as regulated by IL-5 led us to suggest a direct role for these proteins in the IL-5 signaling pathway in eosinophils. The tissue distribution of these genes demonstrated that Pim-1 and SLP-76 were relatively restricted to the eosinophil compared with their expression in brain, bone marrow, kidney, liver, and lung. By contrast, DSP-5 and CD24 were confirmed as ubiquitous in their expression by microarray.

Placebo-controlled trials and active-control trials in the evaluation of new treatments. Part 1: ethical and scientific issues

In recent years, several authors have argued that placebo-controlled trials are invariably unethical when known effective therapy is available for the condition being studied, regardless of the condition or the consequences of deferring treatment. Some have also disputed the value of placebo-controlled trials in such a setting, asserting that the comparison of new treatment with old treatment is sufficient to establish efficacy and is all that should be of interest. This article considers the ethical concerns about use of placebo controls and describes the limited ability of active-control equivalence (also known as noninferiority) trials to establish efficacy of new therapies in many medical contexts. The authors conclude that placebo-controlled trials are not uniformly unethical when known effective therapies are available; rather, their acceptability is determined by whether the patient will be harmed by deferral of therapy. If patients are not harmed, such trials can ethically be carried out. Furthermore, active-control trials, although valuable, informative, and appropriate in many circumstances, often cannot provide reliable evidence of the effectiveness of a new therapy.

Placebo-controlled trials and active-control trials in the evaluation of new treatments. Part 2: practical issues and specific cases

Placebo controls are commonly used in clinical trials of investigational treatments because they have important advantages. In recent years, some have criticized the use of placebo-controlled trials when effective alternative therapy exists, regardless of the expected effect of the therapy. In part 1 of this paper, ethical arguments are addressed and the interpretive problems inherent in the use of active-control equivalence trials to establish efficacy of a new treatment are clarified. However, uncertainties may complicate decisions about appropriate use of placebo controls in some situations. Part 2 discusses more fully the ethical considerations for using placebo controls in particular medical settings. The value and relevance of placebo-controlled trials of new agents in situations in which proven effective therapy is available are also explored.

Long-term follow-up of bowel management after spinal cord injury

Although neurogenic bowel is a major sequelae of spinal cord injury (SCI), little is known about long-term outcomes of bowel management. The major purposes of this study were to: 1) describe bowel management programs, 2) determine the prevalence of gastrointestinal (GI) complaints, including evacuation problems and GI symptoms, 3) describe the impact of neurogenic bowel on life activities, 4) describe satisfaction with bowel management and, 5) identify the relationship between outcomes and selected injury characteristics. A telephone survey questionnaire was administered to 171 adults with a mean SCI duration of 8.9 years (SD = 8.9) and mean age of 39.5 years (SD = 14.5). The most common bowel program reported was chemical rectal stimulant (39%). The average dietary fiber intake was 6.8 grams (SD = 4.6). The prevalence of total GI complaints was 90% and 76% during the past year and the past month, respectively. Despite the high prevalence of complaints, overall satisfaction was high. Persons with long-term SCI can benefit from continuing assessment by the rehabilitation team, dietary instruction on fiber needs, and dissemination of information on new methods or treatments. Future research needs include prospective studies to assess change over time and to test interventions to improve outcomes.

Temporal decline in filling prescriptions for terfenadine closely in time with those for either ketoconazole or erythromycin

Temporal changes in the rates of filling terfenadine prescriptions within 2 days of those for either oral erythromycin or oral ketoconazole were described with use of paid pharmacy claims data from 1988 through 1994 in state Medicaid programs from Michigan and Ohio and in a large health maintenance organization. There were rapid and significant declines in the rates of filling prescriptions for either erythromycin or ketoconazole within 2 days of prescriptions for terfenadine in all three databases that coincided with 1992 publicity about the cardiovascular risk of terfenadine. These findings suggest that the use of terfenadine with contraindicated medications has declined in response to relabeling and publicity concerning the safe use of terfenadine. Further study is necessary to estimate the absolute level of concurrent use of terfenadine with contraindicated medications.

Approval of new drugs in the United States. Comparison with the United Kingdom, Germany, and Japan

In a study reported herein, the marketing approval dates of 214 drugs newly introduced into the world market from January 1990 through December 1994 were compared in 4 countries. The analysis reveals that the United States and the United Kingdom have similar patterns of drug availability, although the United States has a number of therapies with significant public health benefits that are not yet available in the United Kingdom. The findings also show that the United States outpaces both Germany and Japan in approving important new drugs. Various strategies adopted by the Food and Drug Administration to expedite its pharmaceutical review process, including the use of industry user fees, are described.

The results of efforts to improve compliance with supportive periodontal treatment in a private practice

Patients who receive routine supportive periodontal treatment (SPT) tend to keep their teeth longer and enjoy greater periodontal health than those individual who do not receive this therapy. Previous studies have found less than optimal compliance to suggested SPT. The study reported in this paper covered 5 years of patient data and measured the effects of efforts to improve compliance in a private periodontal practice. These efforts included attempts at simplifying compliance, maintaining records of compliance, informing patients of the consequences of noncompliance, and attempting to identify noncompliers before active periodontal therapy was initiated. The results were measured against a similar group studied in previous work within the same office published in 1984. The main finding of the present study was an increase in complete compliance from 16% in 1984 to 32% in 1991. This increase came largely at the expense of the noncompliant group. The reason for the increase in compliance is likely due to efforts to increase compliance carried out in the office. However, other factors such as change in the hygiene practice law, increased public awareness of dental needs, and economic depression may also have affected compliance. This information suggests that noncompliance can be reduced if the problem is recognized and efforts are made to increase compliance.

Commentary concerning demonstration of safety and efficacy of investigational anticancer agents in clinical trials

Expeditious clinical development and approval of new drugs that are beneficial to patients are matters of high priority. There has been a great deal of discussion within the oncology community about what should constitute evidence of effectiveness of new anticancer agents for purposes of drug approval. This commentary is intended to illustrate a variety of end points that can lead to approval of new anticancer agents for specific clinical situations. Although the ultimate hope of antineoplastic therapy is prolongation of life, there are other effects of anticancer drugs that constitute clear clinical benefit and represent evidence of effectiveness. The guiding principle is that the beneficial effects obtained from a new drug should sufficiently outweigh the adverse effects such that the potential risk:benefit ratio achieved by an individual patient is favorable. The assessment of a new drug should flexibly evaluate safety and efficacy in the context of the specific clinical condition being treated. Early discussions with the Food and Drug Administration (FDA) and the National Cancer Institute (NCI) are recommended to identify prospectively the end points and trial designs needed to demonstrate effectiveness of a new drug. The general principles discussed will likely apply to the drug approval process for other medical disciplines as well.

Problems in the use of large data sets to assess effectiveness

Large data sets are an attractive source of information for outcome assessment, but their use involves certain problems and risks. Data base evaluations are retrospective and unblinded; they often represent the result of multiple analyses of multiple endpoints, and it is difficult to identify the procedures used and analytic choices made because critical details are often omitted. While data bases can suggest problems and offer answers, they cannot prove them; data base analyses must be followed by trials.

Government viewpoint of clinical trials of cardiovascular drugs

The design of clinical trials affects their usefulness in evaluating the effectiveness and safety of drugs. Problems associated with active control studies are described and methods are given for effective dose-finding. The importance of dose-finding and dose-interval determination is emphasized.

The importance of adverse reaction reporting by physicians. Suprofen and the flank pain syndrome

The role of spontaneous reporting in detecting the suprofen-associated flank pain syndrome was examined, including the specific effect of the "Dear Doctor" letter in accelerating the information-gathering process once the initial signal was generated. We believe this to be a noteworthy example of the ability of spontaneous reporting to produce a timely and unequivocal signal of drug-related risk. It also serves to demonstrate the need for vigilant postmarketing surveillance for all newly marketed drugs in the United States, even though considerable premarketing and postmarketing drug experience may exist from use in countries outside of the United States.

Food and Drug Administration requirements for approval of new anticancer drugs

For approval of new drugs, the law requires a minimum of two independent well-controlled studies for each indication. The preferred study design is prospective, randomized, and comparative. The use of historical controls, while sometimes acceptable, must be justified. A favorable effect on survival and/or quality of life is generally required for approval. The study of cancer drugs in combination presents problems which are discussed. Drug firms are strongly urged to discuss the protocols with the Food and Drug Administration prior to initiating phase III comparative studies to be used for approval of the drug.

Stimulation of steroid secretion in adrenal tumor cells by choleragen

Choleragen, the pure protein from cholera toxin, stimulates steroid secretion by Y-1 adrenal tumor cells in culture. The secreted steroids are the same as seen after addition of adrenocorticotropic hormone. Half-maximal stimulation occurs at 15 pM; stimulation is essentially irreversible by washing and partially reversible (for about 1 hr) by antibody, and there is a latent period of about 60 min before stimulation is seen. Stimulation of adenylate cyclase occurs at about 30-fold higher choleragen concentrations. Gangliosides inhibit choleragen stimulation when added before but not after the toxin. Lipopolysaccharides from Escherichia coli, Salmonella typhosa, and Serratia marcescens also stimulate steroid secretion, but are less potent than choleragen.