Avalanche tumbles on AMD data

Avalanche Biotechnologies Inc. (NASDAQ:AAVL) fell $15.99 (41%) to $22.89 in after-hours trading Monday after it released top-line data from a Phase IIa study of its AVA-101 gene therapy to treat wet age-related macular degeneration.

During a conference call after market close, investors questioned company executives on multiple aspects of the study, including the control arm's unusually poor performance in best corrected visual acuity (BCVA), and an unexplained and undesirable increase in retinal thickness in the treatment group. Investors also asked whether a reduction in the number of rescue injections of Lucentis ranibizumab from the Genentech Inc. unit of Roche (SIX:ROG; OTCQX:RHHBY) would be sufficient as a clinical endpoint. ...