Cancer drugs' side effects often identified late after FDA approval By Anthony J. Brown, MD Serious adverse drug reactions (ADRs) are often discovered and reported many years after a cancer drug has been approved by the US Food and Drug Administration, new research shows. This suggests a need for better detection and reporting of such events. "In one case, a package insert was not revised to reflect a serious reaction until 36 years after the drug was approved," senior author Dr. Charles L. Bennett, from Northwestern University in Chicago, told Reuters Health. "For many cancer drugs, it appears that dissemination of adverse event information is just not optimal," he noted. "Sometimes the package insert wasn't revised or the event wasn't reported in a Dear Doctor letter or a journal article." In the new study, Dr. Bennett's team identified 25 serious ADRs that occurred with 22 cancer drugs and were reported between 2000 and 2002. The ADRs resulted in death or severe organ failure, they report in the October 15th issue of the Journal of Clinical Oncology. About half of the serious events were reported at least 5 years after FDA approval, the authors note. The shortest and longest periods from FDA approval to event reporting were 0.5 years and 35.9 years, respectively. The most common reporting method was package insert revision followed by description in a medical journal and a Dear Doctor letter. Only five of the ADRs were reported by all three methods and 13 were reported by two of the methods. The rate of post-approval ADRs was particularly high for agents that went through accelerated drug approval. "Eighty percent of accelerated approval drugs versus 25% of standard approval drugs end up with a serious ADR," Dr. Bennett noted. Follow-up confirmatory studies are recommended for accelerated approval drugs, but in only a few cases have such studies actually been done, he added. "I think active surveillance efforts are needed in the US to better identify post-approval ADRs with cancer drugs. We need dedicated pharmacovigilance," Dr. Bennett said. The message for clinicians is to report adverse events no matter how small they seem to be, Dr. Bennett emphasized. "At least 90% of events don't get reported," he added. J Clin Oncol 2003;21:3859-3866. Thanks to Reuters Health Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.