BOOTS MANOPLAX DISAPPOINTING PHASE III PRELIMINARY RESULTS
Executive Summary
BOOTS MANOPLAX DISAPPOINTING PHASE III PRELIMINARY RESULTS are leading the company to consider cancellation of future trials with the drug, the U.K. parent company, Boots PLC, said in a Sept. 22 release. Preliminary results from key congestive heart failure studies in the U.S. and U.K. "indicate that the comparative improvement in patients using Manoplax [flosequinan] in the trials is not as great as expected," Boots explained. "It is possible that a full evaluation of the results could lead Boots to decide not to proceed with the Manoplax program in certain countries [and] complete cancellation is also a possibility." Even if Boots decides to pursue an NDA in the U.S., the company commented, "further clinical trials will be required which will result in a delay in making applications to market Manoplax of at least two years." Boots had been planning mortality studies with head-to-head comparisons of flosequinan to ACE inhibitors beginning in early 1990 ("The Pink Sheet" May 8, T&G-13). Flosequinan is an oral nitroprusside with both arterial and venal dilating effects. Boots issued the release in compliance with British stock exchange rules, which require a listed company to "notify the stock exchange of any information which is likely to lead to substantial movements in the price of its shares," the company explained in a Sept. 28 letter to Manoplax clinical investigators. The letter from Boots Director of Medical Services M. Busson, MD, reported that Phase III results from the multicenter, double-blind, placebo controlled 16 week U.K. trial in patients with mild congestive heart failure showed a "trend" in improvements in exercise tolerance; however "the difference did not quite reach significance (p=.05) at 16 weeks." In an identical U.S. study, a trend in improvement was also noted, "but the variability in results is such that the improvement on flosequinan is not statistically significantly better than that on placebo." The Phase III results contradict "previous results from placebo-controlled studies in more severe grades of cardiac failure which have all shown significant improvements over four to six weeks," the letter notes. Analysis of the data is not due to be completed "for some weeks" the company said, emphasizing that no final decisions will be made until then. While "the overall results did not quite achieve conventional levels of statistical significance, the practical problems associated with undertaking these long term exercise tolerance studies in cardiac failure must be borne in mind when viewing these results," Boots told the investigators.