Repligen shares tank after depression drug flunks a Ph2b

Shares of Repligen ($RGEN) dived 28 percent yesterday after the Waltham, MA-based biotech said the Phase IIb study of RG2417--an oral formulation of uridine--failed to reflect a statistically significant distance between the bipolar depression drug and a placebo. But they weren't ready to write off the program.

Investigators flagged a curious anomaly, noting patients who had been recruited at academic centers did better on the drug than the patients enrolled at commercial sites. And they hinted that the difference in response could open the door to a way forward for the therapy.

"While we are disappointed with the top-line results of the study, we plan to conduct further evaluation of the data including the observation of differences between the patients treated in academic and commercial sites to determine if there is a path forward with RG2417," said Repligen CEO Walter Herlihy. Going forward, he added, Repligen will concentrate much of its attention on a late-stage study of RG1068, a pancreatic imaging agent scheduled to produce Phase III data later in the month.

The biotech is also planning to advance programs for Friedreich's ataxia and for spinal muscular atrophy into the clinic.

- check out the Repligen release
- read the Boston Business Journal story