NEW YORK (GenomeWeb News) – Shares of Sequenom fell around 10 percent in Wednesday trade, a day after the firm released additional data from a study on its prenatal screening technology for Down syndrome.
The San Diego-based firm said that in the study of 459 samples the test correctly identified all 22 T21 positive samples and 14 second-trimester Down syndrome samples. However, there was one false positive and no false negatives, which was confirmed by chorionic villus sampling and amniocentesis. The firm said that its DNA-based method correctly detected the one homozygous sample that the RNA-based method did not resolve.
Last week, Sequenom had reported its RNA-based test had detected all eight first trimester Down syndrome samples with no false positives or negatives, as well as 14 of 15 second trimester Down syndrome samples.
Thus far, Sequenom has released data on its SEQureDx test from a total of 858 samples. It said that the positive predictive value is 96.6 percent, versus the 100 percent it had previously stated last week, and the negative predictive value is 100 percent.
In a research note published Tuesday, Lazard Capital Markets analyst Sean Lavin said that the revised numbers "do not change the data at all and will make no difference in adoption, but hurt credibility, as shown by the share price."
Following the release of the study results on Wednesday evening last week, Sequenom's shares closed up 1 percent on Thursday at $22.73. But, since releasing the revised data on Tuesday morning, its shares have dropped nearly 24 percent. Sequenom's shares closed today at $16.93, down 10.4 percent.
Sequenom expects to launch in June the SEQureDx test for assessing fetal aneuploidy in maternal blood.