Topline data from a second Phase III study with Inspire Pharmaceuticals’ denufosol tetrasodium in cystic fibrosis patients failed to show any benefit of the drug in terms of the primary endpoint of improving FEV1 at 48 weeks, or any of its secondary endpoints. The Tiger-2 study results are in sharp contrast to those from the first Phase III study, Tiger-1, which were first reported in 2008 and showed denufosol tetrasodium therapy significantly improved patients’ FEV1 at 24 weeks. The Tiger-1 results were published in full in December 2010, in the American Journal of Respiratory and Critical Care Medicine, in a paper titled, Denufosol Tetrasodium in Patients with Cystic Fibrosis and Normal to Mildly Impaired Lung Function.
Tiger-2 data has likely scuppered Inspire’s original plans for denufosol commercialization in the U.S. Just last month the firm projected a potential U.S. commercial launch for denufosol in 2012. However, this timeline assumed that the Tiger-2 results were positive, that an NDA for denufosol was filed with FDA in the second half of 2011, and that FDA approved the NDA under a priority review timeline.
“These Tiger-2 results were disappointing and unexpected given the treatment effect observed in the Tiger-1 trial,” admits Adrian Adams, Inspire’s president and CEO. “We will conduct a thorough analysis of the data to fully understand the results from this trial and the impact on any future development of denufosol and on the company going forward.” The firm expects to provide a detailed corporate update by mid-February, but says it intends to focus on its ophthalmology business.
Tiger-2 patients who subsequently enrolled in the three-year open-label denufosol trial, known as Defy, will also be informed that Inspire is recommending they discontinue treatment with the drug.