Genocea tanks as pneumococcal vaccine development temporarily suspended

US vaccine discovery and development company Genocea Biosciences (Nasdaq: GNCA) saw its shares plunge 29.6% to $5.08 in early trading this morning, on disappointing developments for its universal vaccine candidate against pneumococcus.

The company today announced that top-line results from a Phase IIa clinical trial for GEN-004 showed consistent reductions versus placebo in the pre-specified endpoints of the rate and density of colonization, but that neither of the endpoints achieved statistical significance. GEN-004 was safe and well tolerated by subjects.

"We are currently working with our advisors to better understand these results and to determine a next step for this program. While we did not hit statistical significance in this study, the consistent apparent effect gives us confidence in the vaccine concept and in the potential for GEN-004. At this time, we believe it is possible that future trials would require a change in some combination of dose, adjuvant or trial population to confirm any effect," said Chip Clark, president and chief executive of Genocea.