Cohort studies safety assessments

Irl C, Hasford J. Assessing the safety of drugs in pregnancy the role of prospective cohort studies. Drug Saf 2000 22(3) 169-77. 

Although randomized, controlled trials form the basis for some of the most reliable assessments of drug safety, pregnant women usually are not eligible for participation in clinical trials. Other types of data often are used to estimate the risk associated with medication use during pregnancy, such as animal studies, case reports, case-control studies, prospective cohort studies, historical cohort studies, and voluntary reporting systems. 

No inhibitors to FVIII have been detected in patients included in the interim analysis. A follow-up safety assessment across all rAHF-PFM studies provided additional data on inhibitor risk for 50 patients who had accumulated at least 50 exposure days to rAHF-PFM. No inhibitors were detected in this expanded cohort from the PTP Continuation study. 

Table XI lists several current epidemiologic studies which improve upon earlier design limitations such as statistical power and exposure assessment. Researchers at the National Institute for Occupational Safety and Health (NIOSH) are nearing completion of a large cohort mortality study of 7,000 U.S. chemical workers from 14 companies which produced trichlorophenol, 2,4,5-T and pentachloro-phenol. A particular asset of this study is the availability of good information on type and duration of exposure of the workers.

From 1995 through 2002, we participated in four international randomized studies and one collaborative study with the University of Vermont in which pharmacological thrombolysis was employed with alteplase [tissue-type plasminogen activator (t-PA)] or tenecteplase [TNK-t-PA (TNK)]. In this chapter we summarize our experience with the cohorts of patients in all of these studies who were studied in the United Arab Emirates (UAE). The first of the studies was the Continuous Infusion versus Double Bolus of Alteplase (COBALT) study. The other three were Assessment of the Safety and Efficacy of a New Thrombolytic (ASSENT I, II, III) studies and a substudy in ASSENT II with the University of Vermont (4-8). The last study, a collaborative one with the University of Vermont, was the Enhanced Rapidity of RECanah-zation with Tenecteplase compared with Alteplase (ERRECTA) study, results of which have not yet been published. All of the patients participating in ERRECTA were patients in the UAE. 

The next level of investigation of a new cancer drug is the phase II study. Phase II trials are primarily designed to assess the efficacy of a new agent and to further evaluate its safety in larger cohorts of patients. The study design of phase II trials builds upon results from preclinical investigations and the MTD... 

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