Drug for RSV linked to shorter hospital stays

The monoclonal antibody palivizumab (Synagis) appears to be associated with a marked reduction in length of hospital stay for respiratory syncytial virus (RSV), a researcher said, as reported by MedPage.

It also appears to be associated with a slower increase in hospital costs than other illnesses in infants, said Andrew Racine, MD, PhD, of Albert Einstein College of Medicine in New York City.

The finding suggests that the antibody, shown to be efficacious in clinical trials, may have important benefits in the real world, Dr. Racine told a scientific session at the Pediatric Academic Societies meeting in Vancouver, British Columbia, in May.

Dr. Racine cautioned that the study-based on trends in California-is only a preliminary look at how well the drug works in the real world and leaves a key question open.

But it suggests that the period of time during which palivizumab was introduced into the California population was associated with decreased lengths of stay for infants with RSV disease, Dr. Racine told Formulary. “This is consistent with a true population level effect of this new preventive agent but it isn’t a definitive finding,” he said.

The drug retails for about $900 a dose and some children are given 5 doses during the RSV season, Dr. Racine said. In 2007, sales of the drug reached $1.2 billion, he noted. “We’re using a lot of this, so we might as well know if it’s effective,” Dr. Racine told attendees.

To try to find out, he and his colleagues examined the California Patient Discharge Database for 1995 through 1997 and 2005 through 2007-before and after the drug was licensed. They looked at individual hospital records for 343,105 infants <1 year old in the 2 periods.

The outcome measures were changes in both the length of hospital stay for RSV and hospital charges for the condition, compared with those for all other infant illnesses. Analysis showed:

* Between the 2 periods, the average length of stay for RSV dropped 12.9%, compared with 3.4% for other illnesses, a difference that was significant (P<.001).
* In constant 2007 dollars, hospital costs for RSV rose 20.1% between the 2 periods. In contrast, costs for other illnesses rose 58.6%, a difference that was again significant (P<.001).

Dr. Racine tells Formulary that more extensive investigations are needed to clarify the role that palivizumab has played in generating the documented trends. “What needs to be done next is to inquire whether these effects were concentrated among sub-groups of California infants who were eligible to receive this new agent compared with those infants who were not,” he pointed out.