Troubled BioCryst dumps HCV preclinical program

Troubled BioCryst Pharmaceuticals ($BCRX) has ditched its preclinical hepatitis C virus program of BCX5191 and its backup compounds after results of a low-dose chimpanzee study, according to a company report filed with the Securities and Exchange Commission.

Late last year, regulators raised preclinical toxicity concerns, so BioCryst put its plans to carry out early-stage clinical trials on hold and set up an additional preclinical study. This was designed to see if nontoxic doses of BCX5191 (20 mg/day) would still have an anti-viral effect over 7 days in chimpanzees chronically infected with hep C. Now that BioCryst has completed an analysis of the results, it has revealed that this dose of BCX5191 did not reduce the viral load enough to justify continuing the development of the program.

Nearly a year ago--in February 2012--BioCryst's shares spiked 17% on positive preclinical news on BCX5191. The company's shares have dropped more than 50% since then in light of several pieces of bad news. On top of concerns from regulators about BCX5191, BioCryst in November also scrapped its flu drug peramivir in late-stage trials when monitors said that it would be futile to continue the study based on the interim results. Also late last year, the FDA put the BCX4161 program for hereditary angioedema on clinical hold, stating that it was applying GMP manufacturing standards to the process of compounding BCX4161. BioCryst predicted that this would delay the clinical program about three months.

2012 culminated in the failure of the $101 million merger between BioCryst and Presidio Pharmaceuticals and BioCryst's decision to ax half its staff in December. At the time, BioCryst said it was going to focus on BCX5191, BCX4161 and BCX4430, a broad-spectrum anti-viral. Without BCX5191, it's hard to see the company's next step.

- read the 8-K