ChemGenex shares dive on FDA's leukemia drug critique

With the FDA's oncology experts preparing to gather to consider the fate of ChemGenex Pharmaceuticals' experimental leukemia drug Omapro, FDA staffers are questioning the clinical significance of the therapy. And their skeptical stance triggered a steep dive in the Australian developer's share price.

Staffers noted that data from only 66 of the 100 patients with the T315I mutation who planned to enroll in the study were submitted, with 15 percent responding to therapy. The average benefit was 7.7 months, according to Bloomberg, and the company didn't detail how it determined if patients had the genetic mutation that spurs resistance to Gleevec.

"The company is aware of the questions posed by the FDA and we are confident in our ability to answer these questions during the ODAC meeting," ChemGenex notes in a statement. But Shane Storey, an analyst with Wilson HTM Investment Group, wasn't so sure.

Storey told investors that the staffers' objections were "disconcerting" but added that they were hardly the final word on the drug. ChemGenex shares plunged 20 percent, sliding to 68 Australian cents.

- here's the story from Bloomberg