ARYx Therapeutics receives guidance in writing from FDA on tecarfarin

ARYx Therapeutics, Inc. (NASDAQ:ARYX), a biopharmaceutical company, today announced that is has received guidance in writing from the U.S. Food and Drug Administration (FDA) confirming that the existing development pathway remains acceptable to seek regulatory approval of ARYx’s novel anticoagulant agent, tecarfarin (ATI-5923). This guidance results from a series of discussions between ARYx and the FDA following the recent completion of the Phase 2/3 EmbraceAC clinical trial in which tecarfarin essentially replicated the efficacy and safety demonstrated in two previous Phase 2 clinical trials testing the compound (see press release dated July 7, 2009). ARYx sought guidance from the FDA on a number of key elements in the continued development of tecarfarin, including: whether the maintenance of a patients’ therapeutic level of anticoagulation, as measured by the International Normalized Ratio (INR), could continue to serve as a surrogate measure of outcomes; whether one successful additional clinical trial, comparing the safety and efficacy of tecarfarin to warfarin, the leading anticoagulant therapy, in a real-world setting, could establish tecarfarin’s superiority over warfarin and be sufficient for approval; and, preliminarily, the design elements of the real-world trial required for approval.

“The FDA confirmed we are on a proper course to seek regulatory approval and recognized that tecarfarin appeared to have a substantial treatment effect by maintaining patients within the target time in therapeutic range 74% of the time treated”

In its written response, the FDA confirmed that tecarfarin’s current development pathway to seek approval remains acceptable. The FDA reiterated that INR measurements could be used as a surrogate endpoint, that the superiority of tecarfarin over warfarin could be established in the additional clinical trial that compares tecarfarin to warfarin in a real-world setting, and that a successful outcome in this trial could be sufficient to seek regulatory approval to market tecarfarin. In their guidance, the FDA provided preliminary feedback on the design of this additional clinical trial so that it might provide adequate efficacy and safety data for their assessment, recognizing that the use of a surrogate endpoint should allow for a smaller clinical trial, of shorter duration, than one based upon outcomes.

"The FDA confirmed we are on a proper course to seek regulatory approval and recognized that tecarfarin appeared to have a substantial treatment effect by maintaining patients within the target time in therapeutic range 74% of the time treated," said Dr. Paul Goddard, chairman and chief executive officer of ARYx. "We are quite satisfied with the FDA’s guidance and remain confident that in a real world setting tecarfarin will demonstrate its superiority over warfarin in safely maintaining patients’ INR within the target therapeutic range. We anticipate continuing this dialogue with the FDA as we now seek their approval for the specific design of the real-world trial through a Special Protocol Assessment. With this detailed guidance in hand, we will continue to pursue a partnership with a large pharmaceutical company to execute this trial to hopefully gain tecarfarin’s marketing approval. ARYx believes that a substantial number of patients require an improved chronic oral anticoagulant therapy which can be easily monitored to ensure appropriate anticoagulation.”