Bristol-Myers Squibb and Pfizer have announced results at the European Society of Cardiology (ESC) Congress 2015 (29 August–2 September, London, UK) from five US real-world data retrospective analyses in patients with non-valvular atrial fibrillation (NVAF).
The studies compared the risk of different bleeding related outcomes, including major bleeding and/or any bleeding, hospitalisation and bleeding-related 30-day readmissions in routine clinical practice setting for apixaban versus warfarin, rivaroxaban and dabigatran. Results have been adjusted in order to address differences in baseline demographic and clinical characteristics.
In the three analyses that evaluated major bleeding, apixaban therapy was associated with a significantly lower risk of major bleeding compared to treatment with warfarin or rivaroxaban (specific to the different patient cohorts, definitions of major bleeding and studies’ timeframes). No significant differences in the risk of a major bleeding event were found between apixaban and dabigatran in these studies.
Two analyses evaluated all-cause hospitalisation and bleeding-related 30-day readmissions respectively among NVAF patients newly initiated on anticoagulation therapy. In these analyses, treatment with apixaban was associated with a lower risk of all-cause hospitalisation as compared to treatment with rivaroxaban and dabigatran. Patients treated with apixaban were also less likely to experience a bleeding-related 30-day readmission compared to treatment with rivaroxaban. No significant difference was observed between NVAF patients initiated on apixaban and patients initiated on dabigatran in 30-day readmissions.
“The Bristol-Myers Squibb and Pfizer Alliance is pleased to share these real-world data at one of the world’s largest and most influential cardiovascular meetings,” said Douglas Manion, head of specialty development, Bristol-Myers Squibb. “These results provide important information about the use of apixaban in real-world routine medical practice and demonstrate the importance of such data in addition to randomised clinical trials.”
“The Alliance is committed to scientific research and exchange of medical findings,” said Rory O’Connor, senior vice president and head of Global Medical Affairs, Global Innovative Pharmaceuticals Business, Pfizer. “The results of these analyses evaluating real-world data of NVAF patients provide additional information about the apixaban safety profile in a real-world clinical setting. Real-world data have the potential to supplement randomised clinical trial data by providing additional information on how a medicine performs for an approved indication in routine medical practice”.
Limitations of the real-world data analyses
There are no head-to-head trials comparing efficacy and safety between any of the novel oral anticoagulants. The results from these five analyses are limited by potential selection bias as patients were not randomised and treatment groups show differences in baseline characteristics. Hazard ratios and odds ratios were adjusted for patient demographic and clinical characteristics. Any study using a claims database is subject to potential coding errors and missing data. The interpretations of the results are based on statistical associations not causality.
