Bayer has responded swiftly to claims made in a study published today in a leading medical journal that Trasylol, which prevents or reduces blood loss, may increase the risk of death during the five-year period after surgery when the drug has been used.
The claim that Trasylol (aprotinin) may increase the risk of mortality during the five-year period following coronary artery bypass graft surgery is made in a study in the Journal of American Medical Association. Researchers assessed survival at six weeks, six months and on an annual basis for five years in 3,876 patients following CABG surgery and the data showed that of the 1072 patients who received treatment with Trasylol following surgery, 20.8% or 223 patients died, compared to 12.7% in the control group.
Lead study author, Dennis Mangano, concludes that use of Trasylol in this patient population “does not appear prudent because safer and less expensive alternatives are available.”
Bayer responded by noting that the data published in JAMA is a follow-on to a previous study published in January 2006 on which Dr Mangano was also the lead author and says it believes that “the methodological and analytical approaches used in the earlier study were not reliable and do not support the authors’ reported conclusions.” The Leverkusen-based group adds that “this newest paper reports on a subset of the same patient population and uses methodology and analytical approaches similar to those used in the earlier publication.
Bayer continues that “one of the limitations of both of these studies is that doctors chose whether to administer aprotinin or another treatment based on the patient’s condition. Generally, sicker patients who were already at greater risk for mortality were treated with aprotinin.” The firm also quotes the editorial by Dr Bruce Ferguson which says that “aprotinin use in cardiac surgery has never been uniformly standardised, but generally has been reserved for patients in whom the surgical team anticipated a higher risk for intraoperative blood loss. Bayer claims that “the statistical methodologies as applied by Mangano et al in the JAMA paper did not adequately address this bias.”
Trasylol has been at the centre of much publicity of late. The US Food and Drug Administration recently said that Trasylol, which is the only drug approved by the agency to reduce blood loss during coronary artery bypass surgery, needs a new label which states that it should only be used on patients who are at an increased risk for blood loss and blood transfusion during the surgical procedure.
The agency also said the drug will come with a stronger warning about possibly anaphylactoid reactions, and added that patients should not receive Trasylol if they have already been given the drug within the past year. It also said that additional warnings may need to be added in the future.
FDA began reassessing the safety of the drug earlier this year, when two separate studies suggested links to heart attack, stroke and kidney problems. In September, Bayer submitted new data to the FDA about risks of Trasylol but crucially this came days after an advisory panel meeting was held to review the drug's labelling and found it to be safe and effective.