Adjudicated efficacy results were available for 132 patients and showed good or excellent hemostasis achieved on andexanet in 109 patients (83%), Dr. Connolly . The effect on hemostasis was consistent regardless of patient age, sex, bleeding site, type of anticoagulant, and dosage tested.
Thrombotic events during the 30 days following treatment occurred in 24 of 227 patients (11%) who received andexanet and were evaluable for safety. Notably, no clustering of thrombotic events occurred early, even among the 129 patients who restarted on an anticoagulant during the 30 days after treatment. Among the 129 patients who restarted on an anticoagulant, 9 (7%) had a thrombotic event during the 30-day follow-up, compared with 15 events among 98 patients (15%) who did not restart on an anticoagulant.
Dr. Connolly acknowledged that a limitation of the ANNEXA-4 study is the absence of a control group, but he added that he and his associates believed randomizing patients with a serious bleed to placebo control would not have been “practical, feasible, or ethical.”
ANNEXA-4 is sponsored by Portola Pharmaceuticals, the company developing andexanet alfa (AndexXa). Dr. Connolly has been a consultant to Portola, and also to Bayer, Boehringer-Ingelheim, Bristol-Myers Squibb, and Sanofi-Aventis. Dr. Kirtane has received research support from several device manufacturers.
SOURCE: Connolly S. ACC 2018.