Experiences and challenges in data monitoring for clinical trials within an international tropical disease research network.

BACKGROUND: Models for the structure and procedures of data and safety monitoring boards (DSMBs) continue to evolve in response to issues of new and of old concern. Some authors have called for an open dialogue on these questions through publication of the experiences of DSMBs in addressing them. PURPOSE: The goal of this paper is to add to the current discussion about acceptable models for establishing, serving on, and reporting to monitoring committees, particularly those that oversee multiple studies in less developed countries. The paper seeks to do so by describing the establishment and subsequent operation of one such multi-trial DSMB over a five-year period. This DSMB was formed to monitor trials conducted by members of the International Centers for Tropical Disease Research (ICTDR) network of the National Institute of Allergy and Infectious Diseases (NIAID). METHODS: The operational model and experiences are summarized by the authors, who had immediate responsibilities for directing the DSMB's activities. RESULTS: The board played an active, traditional role in assuring that patient safety was maintained and that current standards for clinical research were met. In addition, both NIAID and the board members viewed education of investigators to be an important role for the board to play in this particular setting. This affected the threshold for identifying which trials would be monitored, and it impacted several procedures adopted by the board. LIMITATIONS: This report reflects the observations of those involved in managing the DSMB, including comments offered by the DSMB and by investigators, but not data gathered in a systematic way. CONCLUSIONS: The operational model described here has allowed the DSMB to fulfill its role in the oversight of the trials. We hope that the ideas we present may help others facing similar situations and may stimulate further critical thinking about DSMB structure and function.

Paromomycin: no more effective than placebo for treatment of cryptosporidiosis in patients with advanced human immunodeficiency virus infection. AIDS Clinical Trial Group.

To evaluate the efficacy of paromomycin for the treatment of symptomatic cryptosporidial enteritis in human immunodeficiency virus-infected adults, we conducted a prospective, randomized, double-blind, placebo-controlled trial before the widespread introduction of highly active antiretroviral therapy (HAART). Seven units under the auspices of the AIDS Clinical Trials Group enrolled 35 adults with CD4 cell counts of < or = 150/mm(3). Initially, 17 patients received paromomycin (500 mg 4 times daily) and 18 received matching placebo for 21 days. Then all patients received paromomycin (500 mg q.i.d.) for an additional 21 days. Clinical definitions of response were measured by an average number of bowel movements per day in association with concurrent need for antidiarrheal agents that was lower than that before study entry. There was no treatment response during the placebo-controlled phase of the study according to protocol-defined criteria (P=.88). Three paromomycin recipients (17.6%) versus 2 placebo recipients (14.3%) responded completely. Rates of combined partial and complete responses in the paromomycin arm (8 out of 17, 47.1%) and the placebo arm (5 out of 14, 35.7%) of the study were also similar (P=.72). The clinical course of cryptosporidiosis was quite variable. Paromomycin was not shown to be more effective than placebo for the treatment of symptomatic cryptosporidial enteritis. However, inadequate statistical power prevents definitive rejection of the usefulness of paromomycin as therapy for this infection.

Micronutrients and infectious diseases: thoughts on integration of mechanistic approaches into micronutrient research.

Results of field and laboratory studies provide convincing evidence that micronutrient deficiencies contribute to the mortality and morbidity of infectious diseases. Despite encouraging results in large trials, understanding the mechanisms by which micronutrients contribute to the outcome of the encounter between an individual and an infectious agent requires additional hypothesis-driven research. Presumably, such understanding should lead to translational studies with targeted nutritional therapy. Although these mechanistic studies are varied and complex, they must be done systematically and should include examination of the mechanisms by which micronutrients affect host-pathogen interactions, development of appropriate animal models and reliable methods for the assessment of micronutrient levels, and translation of the results of basic research findings into clinical studies. Moving the frontiers of micronutrient research from the laboratory to the field will be challenging. However, sound scientific research should lead toward better human health.