By Mark D. Uehling
August 18, 2004 | Six months. That's how long Laboratory Corporation of America (LabCorp) needed for a fast-track project to develop a DNA test for the main risk factor that leads to chronic obstructive pulmonary disease (COPD).
The fact that molecular geneticists have studied a1-antitrypsin (AAT) deficiency for 25 years may inject a note of caution into too much excitement over such a rapid timetable for coming up with a genomic test.
But by whatever schedule it was born, the AAT test identifies the most common, modifiable genetic factor leading to COPD. COPD is the nation's fourth-deadliest disease, afflicting 26 million people and killing 120,000. Surprisingly, for such a common disorder, LabCorp was able to make the AAT test a noninvasive cheek swab, not a blood test, making it appealing for a variety of primary care physician offices and other screening locations where fancier equipment is rarely found.
Paul Billings, LabCorp's vice president and national director of genetics and genomics, has a longtime in interest in COPD and, as a physician, has treated patients with the disorder. "Unlike cancer and heart disease, which have been relatively flat or decreasing in terms of their public health impact, lung disease of this sort is growing," he says. "I've been interested to translate and accelerate the progress in genomics into healthcare. LabCorp is looking for areas where there are unmet medical needs, where improvement in diagnostics can lead to better outcomes and/or better use of currently available therapeutics."
Indeed, there is new competition with a variety of protein-based drugs to treat AAT deficiency. Bayer once had the market to itself with Prolastin, but in recent years Baxter's Aralast and Aventis Behring’s Zemaira entered the fray.
But other stars had also come into alignment. There were no doubts that COPD is a major public health problem: One in 12 Americans may carry an AAT deficiency gene. Existing diagnostic tests aren’t perfect. Two major professional groups (the American Thoracic Society and the European Respiratory Society) have recommended additional screening for AAT, which explains why up to 50 percent of individuals exposed to a particular irritant -- whether tobacco or a noxious chemical -- develops COPD.
The company's development of a cystic fibrosis test helped in the AAT project. LabCorp studied more than 100 alleles linked to the disorder, and selected those that could reliably and accurately show which patients had the defect. Says Billings: "We can detect around 10 disease-associated alleles. The test is very sensitive and very specific."
He notes that the medical literature shows that simply doing the AAT test -- but not taking a drug -- can improve the patient's life. "The diagnostic step leads to better outcomes even if you don't apply the therapeutic," Billings notes, leading patients to change jobs or reduce their exposure to a lung irritant. "People act on that information. You will find other people in the family with the susceptibility who are presymptomatic who will be able to arrest it or retard it at an earlier stage, which is beneficial for those individuals and for the healthcare system."
But it's not yet clear if the healthcare system will pay for the $200 test. Billings is hopeful. "The cost of managing patients with COPD is enormous. If this leads to better management of people with mild or early COPD, or better treatment of the patient who might otherwise need a lung transplant, the test itself is cheap."
In general, Billings says, it can prove as difficult to understand a test's reception among insurers as it is to work out the chemistry at the bench. But the company hopes to do more projects of this sort.
"Genomics is an absolutely top priority within LabCorp," he says. "It's one of the major focuses. In our strategic plan going forward, genomics is an absolutely essential part of our differentiation and branding. We intend to be the leader in bringing genomic technology to healthcare and having it applied appropriately to the benefit of patients."