Encysive Pharmaceuticals Files Request for Formal Dispute Resolution With FDA

Encysive Pharmaceuticals announced that it has filed with the FDA a request for formal dispute resolution to contest the third approvable letter that the company received for its new drug application (NDA) for Thelin.

Encysive said it originally submitted an NDA for Thelin to treat pulmonary arterial hypertension in 2005.

The company added it received a third approvable letter from the FDA June 15, which stated that Encysive’s clinical development program for Thelin did not demonstrate the evidence of efficacy needed for approval.

According to the company, the disagreement with the FDA involves the imputation of values for STRIDE-2 patients with clinical worsening and patients who left the trial for various reasons, some of whom had six-minute walk tests performed after discontinuing Thelin treatment.

The company said its analytical approach was to include a walk value if one existed, but to exclude values that were obtained beyond a reasonable amount of time after discontinuation from the trial and therapy.

The company added that it believes that this approach was reasonable, as it was established prior to unblinding and treats active drug and placebo patients the same.