FDA told Amylin that an entirely new tQT study of Bydureon would have to be conducted. If the study demonstrated a clean heart-safety profile for Bydureon, Amylin could resubmit the drug again for review.
Amylin's stock price was cut in half the day Bydureon's second FDA rejection was announced. Investors were widely expecting the diabetes drug to be approved and were shocked, even angry, that FDA had thrown a new heart-safety roadblock in front of Bydureon's approval without prior warning. In the months leading up to Bydureon's resubmission and during the review process, Amylin executives had insisted to investors that FDA was satisfied the drug was heart safe.
Amylin CEO Dan Bradbury spoke to investors and analysts on an Oct. 19, 2010 conference call, held right after the company announced FDA's decision to reject Bydureon. According to a transcript of the conference call, Bradbury continued to insist that FDA's raising of a Bydureon heart safety concern came as a surprise.
"I would just be clear that it was only on receipt of the complete response letter that we were truly aware that this was an approvability issue for the agency," said Bradbury, responding to analyst questions. "The agency did request the tQT study that was done for Byetta during the timing of the review. This study was completed back in 2009. So, they certainly were reviewing it. However, we were not aware that this was an approvability issue until we received the complete response letter last night."Bradbury, in his response, fails to mention that Amylin didn't inform FDA about the Byetta tQT study when it was conducted and that FDA regulators only found out about it after being contacted by their Canadian counterparts. Bradbury also fails to say the Byetta tQT study raised safety concerns related to Bydureon of which Amylin was aware due to the action of Canadian regulators, according to the FDA's version of events. Later in the conference call, an analyst asks, "… And then was the thorough QT study required for Byetta or is this Bydureon a unique request?"