How Encysive Botched the FDA Game

With some irony, after the FDA this month issued a third call for further clinical data to prove Thelin's effectiveness, Encysive complained that the agency had adopted a new formula that "resulted in the moving of goal posts" when measuring the Stride II results.

Larger drugmaker ICOS, which had joined forces with Encysive to help develop Thelin, seemed to smell trouble even before that trial started. ICOS, now owned by Eli Lilly (LLY Quote), agreed to sell its own Thelin rights to Encysive after seeing the original Stride results.

Meanwhile, Encysive, under the leadership of new CEO Bruce Given at the time, moved forward with its plan to establish six-minute-walk improvement as the true measure of Thelin's success. In fairness, rival Gilead (GILD Quote) recently obtained FDA approval of its own PAH drug based on that same metric.

Thus, Encysive felt downright cheated in the end.

"You will all remember that Stride I missed its primary endpoint although performing well in the key secondary endpoints, most notably six-minute walk," Given stressed after the company's latest FDA setback for Thelin earlier this month. "To obtain the FDA's approval on the basis of one pivotal trial with six-minute-walk distance as the primary efficacy endpoint, we took the considerable time and effort to document a special protocol assessment, better known as SPA, with the FDA. ... We believed then -- and remain convinced now -- that Stride II had met the regulatory requirements."