Warfarin replacements Xarelto, Pradaxa and Eliquis were not significantly different from the older drug in terms of overall safety reports, healthcare informatics company AdverseEvents said, based on an analysis of post-approval data. However, patients taking Eliquis, the oral anticoagulant being co-marketed by Pfizer and Bristol-Myers Squibb, reported a relatively lower number of serious adverse events like hospitalization or death.

Among Eliquis patients reporting side effects, 21% said they had been hospitalized, while among those on warfarin, 50% cited hospitalizations. By comparison, 43% of patients taking J&J’s Xarelto and 39% of those on Boehringer Ingelheim’s Pradaxa flagged events of a serious nature.

In response to the report, J&J’s Janssen unit issued the following statement: “The cross-treatment comparison in this report lacks scientific validity for a number of reasons. Apixaban was approved recently for one clinical use. In just over one year, it has been prescribed to far fewer patients and may not yet have an established pattern in reported adverse events. It is not valid to compare one medicine with a single use to other medicines that have several clinical uses, different durations of therapy and far more patients using the treatments.”

Janssen also pointed out that, to date, 5.4 million prescriptions have been written for Xarelto in the US across its six indications since 2011, and about 435,000 prescriptions since 2012 across its single indication. In addition, it pointed out, the FDA standard for comparing the safety of treatments requires substantial evidence, such as two adequate and well-controlled studies.