Ximelagatran and clinical trials and FDA
Objective:In clinical trials, the efficacy and safety of the oral direct thrombin inhibitor ximelagatran have been evaluated in the prevention or treatment of thromboembolic conditions known to have high morbidity and mortality. In these studies, raised aminotransferase levels were observed during long-term use (>35 days). The aim of this analysis is to review the data regarding these hepatic findings in the long-term trials of ximelagatran.
Patients and methods: The prospective analysis included 6948 patients randomised to ximelagatran and 6230 patients randomised to comparator (warfarin, low-molecular weight heparin followed by warfarin or placebo). Of these, 6931 patients received ximelagatran for a mean of 357 days and 6216 patients received comparator for a mean of 389 days. An algorithm was developed for frequent testing of hepatic enzyme levels. A panel of four hepatologists analysed all cases of potential concern with regard to causal relation to ximelagatran treatment using an established evaluation tool (Roussel Uclaf Causality Assessment Method [RUCAM]).
Results: An elevated alanine aminotransferase (ALT) level of >3 × the upper limit of normal (ULN) was found in 7.9% of patients in the ximelagatran group versus 1.2% in the comparator group. The increase in ALT level occurred 1–6 months after initiation of therapy and data were available to confirm recovery of the ALT level to 3 × ULN and total bilirubin level of >2 × ULN (within 1 month of the ALT elevation), regardless of aetiology, were infrequent, occurring in 37 patients (0.5%) treated with ximelagatran, of whom one sustained a severe hepatic illness that appeared to be resolving when the patient died from a gastrointestinal haemorrhage. No death was observed directly related to hepatic failure caused by ximelagatran.
Conclusion: Treatment with ximelagatran has been associated with mainly asymptomatic elevation of ALT levels in a mean of 7.9% of patients in the long-term clinical trial programme and nearly all of the cases occurred within the first 6 months of therapy. Rare symptomatic cases have been observed. An algorithm has been developed for testing ALT to ensure appropriate management of patients with elevated ALT levels. Regular ALT testing should allow the clinical benefits of ximelagatran to reach the widest population of patients while minimising the risk of hepatic adverse effects.
BMC Medical Research Methodology at the 35th Annual Conference of the .. — BMC Pediatrics
The conference will focus on issues such as design and analysis of clinical trials, methods in biostatistics and development of clinical prediction models.
Does the European clinical trials directive really improve clinical trial approval time?
To facilitate and improve clinical research within Europe, the European Union (EU) adopted in 2001 the Clinical Trials Directive (EUCTD). The aim of this study was to compare duration between submission of a clinical drug trial application and approval by regulatory authorities in EU countries regulated by EUCTD vs. EU countries regulated by local legislation and, second, to compare the duration of regulatory approval in Europe vs. the USA and Australia.