Study Confirms Effectiveness of Drug for Persistent Asthma
Analysis of 7 prior studies finds Xolair works with other drugs to reduce number of emergency medical visits
SUNDAY, March 20, 2005 (HealthDay News) -- Adding the drug Xolair to an asthma patient's medication regimen helps cut emergency medical visits, new research confirms.
The research, a pooled analysis of seven prior studies, was presented Sunday at the annual meeting of the American Academy of Allergy, Asthma and Immunology in San Antonio.
The fact that the pool analysis contained more than 4,300 patients, about half of whom were on Xolair, does give these conclusions more credibility than any single study, said study co-author Dr. Phillip Korenblat, a professor of clinical medicine at Washington University School of Medicine in St. Louis.
"That's one reason to use pooled data. It gives you a large number of people over a longer period of time. The study has more validity," Korenblat said.
The study was funded by the pharmaceutical companies Novartis and Genentech, which co-market the drug.
There are essentially two types of asthma: persistent and intermittent, explained Dr. Clifford Bassett, a clinical assistant professor of medicine at the State University of New York.
Xolair is used for the persistent asthma, which carries with it a high risk of exacerbations and resultant medical treatment. The drug interrupts the process that causes persistent asthma.
"About 5-to-10 percent of asthma is severe asthma, so it's an important group of people," Korenblat said. "If it's not controlled, it's an issue. What do you do next?"
Bassett, however, pointed out that treatment with Xolair was often a hard sell because it's an injection that needs to be taken about once a month for the rest of your life.
Korenblat, in turn, disputed that. "This is a revolutionary way to treat asthma," he said. "Patients do not complain about it."
In some people, asthma is caused by an allergic reaction gone awry: The immune system stimulates the production of IgE antibodies. Subsequent exposure to the allergen or allergens causes the IgE antibodies to set off an inflammatory response, which leads to the wheezing and other breathing difficulties associated with asthma.
Xolair (generic name omalizumab) is a monoclonal antibody that interrupts this process at the start.
"It is modifying a disease that can go on to have life-threatening complications," Bassett said. "It controls allergic inflammation at the onset."
The seven trials considered in the analysis involved 4,308 patients, 2,511 of whom were treated with Xolair and 93 percent of whom had severe persistent asthma. Five of the trials were double-blind and two were open-label. The researchers looked at the annual rate of emergency visits, including hospital admissions, visits to the emergency room and unscheduled doctor's visits.
Individuals who used Xolair on top of their usual treatment had a 47 percent reduction in total emergency visits. That meant a 52 percent reduction in hospital admission, a 61 percent reduction in trips to the emergency room and a 47 percent reduction in unscheduled doctor visits.
"About 50 percent of all costs from asthma is attributable to severe asthma," Korenblat said. "If we can impact hospital stays, emergency room visits and unscheduled doctor's visits, this is terrific for the patient, and we should be impacting significantly on the cost of asthma care."
For more on IgE-mediated asthma, visit the American Academy of Allergy, Asthma and Immunology.