Analysts: Weak PhIII cancer data hurts BioCryst's chances at FDA

Shares of BioCryst Pharmaceuticals slipped after the Birmingham, ALA-based developer reported that only 11 percent of the patients treated with its experimental cancer therapy in a late-stage study demonstrated a partial response. Some analysts quickly raised the prospect that the data wouldn't warrant an approval at the FDA, pushing down the value of its shares by about four percent.

Tracking the skin lesions in patients suffering from T-cell lymphoma, a rare cancer of the immune system, researchers reported that the disease remained stable in more than half of the patients receiving forodesine. There were no complete responses recorded. In a separate, smaller mid-stage study of chronic lymphocytic leukemia, researchers tracked a response in three out of 25 patients.

"Heavily pretreated CTCL patients are in need of additional treatment options," said Dr. William Sheridan, BioCryst's CMO. "Two-thirds of the late-stage CTCL patients experienced stable disease or better, and forodesine was generally safe and well-tolerated at the dose evaluated in this study. The 11 percent response rate observed in this study population may reflect the impact of heavy pretreatment with multiple prior lines of therapy."

"In our opinion, 11 percent is on the low side of what the FDA would require for approval," Ren Benjamin, an analyst with Rodman & Renshaw, told Reuters. BioCryst, though, remained relatively optimistic. "We do believe it does have a chance of getting approved," said Sheridan.

BioCryst's fortunes, though, rest on the influenza drug peramivir, which gained an emergency authorization during the recent swine flu pandemic. Earlier today the developer also announced positive data from its mid-stage study of BCX4208 in gout.

- here's the release on the forodesine data
- read the release on BCX4208
- and see the Reuters report