9 January 2012 - BioCryst Pharmaceuticals Inc (NASDAQ:BCRX) today unveiled positive results from 24-week, blinded safety extension of its randomised Phase IIb trial of its enzyme inhibitor BCX4208 added to allopurinol in patients with gout who had not reached the serum uric acid (sUA) therapeutic goal of <6 mg/dL on allopurinol alone.

The data from the extension phase confirms that BCX4208 was generally safe and well-tolerated and sustained sUA control over time.

Patients showed healthy immune responses to a vaccine challenge at 16 or 20 weeks of BCX4208 therapy. After the successful results of this 24-week analysis, the company anticipates to finalise Phase II regulatory discussions in the next months.

In the initial 12-week trial, 279 patients were randomised and 160 patients entered the extension phase. Patients continued their blinded, randomised therapy of BCX4208 at doses of 5 mg, 10 mg, 20 mg, 40 mg and placebo once-daily. Once-daily dose of allopurinol 300 mg was administered in all study arms.

This longer-term safety profile of BCX4208 is similar to the 12-week primary analysis results reported in October 2011. The types and rates of adverse events through 24 weeks were consistent in patients receiving BCX4208 and those on placebo. No opportunistic or unusual infections were recorded.

After 24 weeks of treatment, BCX4208 once-daily doses of 5 mg, 10 mg, 20 mg and 40 mg showed response rates of 40%, 50%, 46% and 55% respectively, compared to 25% for placebo. These results are comparable with the previously reported positive data at the 12-week primary efficacy time point.

There was a low incidence of gout flares in the trial. Gout flares over 24 weeks occurred in 5% of placebo-treated patients against 7-16% of BCX4208-treated patients.

Based on the study results, the company has selected the 5, 10 and 20 mg doses of BCX4208 for further assessment.