New respiratory synctial virus treatment for at-risk infants under study

Nov 14 2005

A new, enhanced-potency onoclonal antibody designed to keep the sniffles from turning into a devasting illness in at-risk babies is under study at the Medical College of Georgia Children's Medical Center.

The international study compares MEDI-493, a monoclonal antibody already approved by the U.S. Food and Drug Administration to treat respiratory synctial virus, or RSV, to the more potent MEDI-524, says Dr. Jatinder Bhatia, chief of the MCG Section of Neonatology and a principal investigator.

"A casual sniffle for adults can be devastating for your premature baby," says Dr. Bhatia. In at-risk babies, the therapies under study can help prevent RSV from quickly progressing from the sniffles to a severe respiratory infection. "Most mothers will tell you, 'My baby is coughing.' That's the first clue. The next thing they know, their baby is not breathing," says Dr. Bhatia.

RSV is a common virus that is a yearlong threat in some parts of the country and a fall-to-spring threat in the Augusta area, said Dr. Chantrapa Bunyapen, MCG neonatologist and a study investigator. The Augusta season peaks in December and January.

By age 2, most children have been infected with the virus that is easily spread by human contact. Since the body doesn't develop a memory for the virus, multiple infections are common. But a single infection can be deadly in a vulnerable baby, Dr. Bhatia says.

Study targets include babies six months and younger born five or more weeks premature and babies with chronic lung disease – often a result of premature birth – under age 2, says Joan Holloway, study coordinator.

Over the next few months, MCG will enroll as many of these babies as possible in the study in which they will get monthly doses of MEDI-493 or the more potent MEDI-524, or NumaxTM, Ms. Holloway says. Parents with babies born at other hospitals who qualify for the study can call Mrs. Holloway at 706-721-2331.

Study participants from MCG's neonatal intensive care unit will get their first shot before they leave the hospital then return to the Continuity Clinic at the Children's Medical Center in subsequent months to see Dr. Bunyapen and get the four remaining shots. In between visits, Ms. Holloway will call study participants' parents weekly. At the first sign of sniffles, babies will be brought back to the clinic and a nasal swab will be sent to a centralized lab to determine the type of infection, Dr. Bhatia says.

MEDI-494, marketed as Synagis, has become a standard treatment that has cut hospitalization of these at-risk infants in half. MCG neonatologists hope the more potent new therapy will further reduce cases in which the common infection turns into a life-threatening disease.

"This therapy helps keep RSV from moving from the nose to the lungs of these babies," Dr. Bhatia says. "If it does spread, they start coughing, then may stop remembering to breathe as they develop bronchiolitis (inflammation of the small airways of the lungs) and potentially respiratory failure. We have actually had to put some of these babies on heart-lung bypass."

The monoclonal antibody therapies target protein F on the surface of RSV which helps the virus spread from cell to cell. The virus' ability to reach the lungs results in hospitalization of about 125,000 babies each year and death in 1 percent to 2 percent percent of those infants, according to data from the National Library of Medicine and the National Institutes of Health.

To help avoid RSV, the MCG neontatologists recommend frequent hand-washing and not smoking around babies.

Tara Garrison, developmental specialist in the Section of Neonatology, is assisting with the study.