Sequenom Blood Test for Down’s Syndrome Clears Higher Hurdle, Company Plots Aggressive Moves Toward Market

Sequenom CEO Harry Stylli vowed to me last fall that he is on a mission to build the “Google of Molecular Diagnostics” in San Diego. Now he has a new batch of clinical trial results in hand that has done nothing to diminish his audacious goal.

The San Diego-based company (NASDAQ: [[ticker:SQNM]]) said last night that its diagnostic method, which analyzes the RNA of a tiny sample of the mother’s blood instead of more-invasive procedures that run the risk of miscarriage, was almost 100 percent accurate at spotting Down syndrome in a developing fetus. The data was collected from blood samples of 858 pregnant women (which includes data from the first 400 reported in September), Sequenom says. Detailed results should be published in peer-reviewed journal in mid-2009, the company says.

The results from the study, which confirm earlier findings, means that the company remains on track to introduce its SEQureDx test to the U.S. market in June, Stylli says. This is potentially a “paradigm-changing breakthrough” in the words of analyst Elemer Piros of Rodman & Renshaw, because the Sequenom technique is far more accurate than traditional blood tests that fish for proteins in the blood, and it’s safer than highly- accurate but invasive procedures like amniocentesis and CVS, which carry a risk of miscarriage.

With about 4.2 million live births in the U.S. every year, and about two-thirds of fetuses already getting screened for Down syndrome, this is a big opportunity.

“This is outstanding performance,” Stylli says. “The more data we look at, statistically, the better the data gets.”

The concept driving Sequenom’s test is that as the fetus develops, small fragments of its DNA and RNA spill into the mother’s bloodstream, Stylli says. The Sequenom test fishes out those DNA and RNA fragments, which can identify with certainty whether a child has a copy of an extra chromosome, the cause of Down’s. This is a big concern for many families, because Down’s is a leading cause of mental retardation, occurring in about 1 in 1,000 births, and the risk increases as expectant mothers age.

Here’s a basic rundown of the data from the full group of 858 patients analyzed in what is called the R&D study, according to presentations Sequenom made to analysts last night. The test was 100 percent accurate at predicting when a fetus had Down’s, when it was double-checked with the gold-standard for accuracy, amniocentesis. There was, however, one case of a “false positive” result in which the test said a fetus had Down’s, when, in fact, didn’t. Statistically, that means the test is 99.9 percent accurate, almost identical to the track record of amniocentesis, Stylli says.

This data stands far above the standard protein-based tests, the standard tool for millions of pregnant women. Those tests also can generate false positive results, which alarm the family about a disease unnecessarily between 10 percent and 25 percent of the time, depending on the test.

The latest results aren’t going to be used as marketing material

Author: Luke Timmerman

Luke is an award-winning journalist specializing in life sciences. He has served as national biotechnology editor for Xconomy and national biotechnology reporter for Bloomberg News. Luke got started covering life sciences at The Seattle Times, where he was the lead reporter on an investigation of doctors who leaked confidential information about clinical trials to investors. The story won the Scripps Howard National Journalism Award and several other national prizes. Luke holds a bachelor’s degree in journalism from the University of Wisconsin-Madison, and during the 2005-2006 academic year, he was a Knight Science Journalism Fellow at MIT.