PTI: Rational Market Reaction to Ph1 Results

Shares of Proteostasis Therapeutics Inc. PTI, +328.84% blasted off to a four-fold gain (up 301%) on extremely heavy volume after the biopharmaceutical company announced positive results from a phase 1 trial of its cystic fibrosis treatment. Volume spiked to over 44 million shares, compared with the full-day average of 152,000 shares. The company said changes in sweat chloride concentration and in percent predicted FEV (ppFEV) were assessed, and dose-dependent improvements were observed. For ppFEV, "a maximum and statistically significant increase" from baseline was reported, and a "statistically significant" increase from placebo was also noted. "These data are the first results seen using an entirely new CF doublet, compare favorably to standard of care, and demonstrate the potential of next-generation CFTR modulators to further improve outcomes in this disease," said Carsten Schwarz, head of the Adult Cystic Fibrosis Centre at Berlin University. The stock had tumbled 67.6% year to date through Wednesday, while the S&P 500 SPX, -1.01% had gained 5.1%.

[Update: 12:54 ET, 61M  traded, pps + 6.59]