Understanding thalidomide-associated deep vein thrombosis/pulmonary emboli (DVT/PE): Comparison of quality and information included in adverse event reports from clinical trials, clinical practice, STEPS, and the medical literature

Abstract

3142 Background: The most common serious adverse event associated with thalidomide use for cancer patients has been DVT/PE. Methods: The Research on Adverse Drug Reactions and Reports (RADAR) project reviewed: 1) all DVT/PE cases reported to the FDA from 1998 to 2003 (n= 235 cases) and 2) medical literature reports for 2002–2003 (n= 22 studies) for incidence rates. Results: Case Report Information: In comparison with reports from clinical practice settings (n=166), clinical trial reports (n = 69) had higher rates of inclusion of information on: thalidomide administration dates (77% vs. 32%), DVT/PE onset date (62% vs. 23%), number of days from thalidomide administration to DVT/PE (52% vs. 17%), and DVT/PE treatment (76% vs. 42%) [p < .0001 for each comparison]. Both clinical trial and none clinical trial FDA adverse event reports were: 1) very complete for: patient age, gender, thalidomide dose, indication, and survival and 2) incomplete for information on tests used to document DVT/PE diagnoses and notation that the case had been reported to the System for Thalidomide Education and Prescribing Safety (STEPS) program. Incidence Rates varied according to cancer diagnosis, stage, and concomitant therapies: Conclusions: 1) Reporting of information on thalidomide-associated DVT/PE to the FDA or to STEPS is rarely complete, especially outside of the clinical trial setting and 2) rates of DVT/PE continue to be high, despite increased awareness of this complication. No significant financial relationships to disclose.