- In Clinical Trial, Motavizumab Reduced Hospitalizations Due to Respiratory
Syncytial Virus by 83 Percent Compared to Placebo -
HONOLULU, May 4 /PRNewswire/ -- MedImmune today announced that researchers
are currently presenting results from a MedImmune-sponsored Phase 3 study
involving motavizumab, an investigational monoclonal antibody (MAb) that is
being evaluated for its potential to prevent serious disease caused by
respiratory syncytial virus (RSV) in high-risk pediatric patients. Kate
O'Brien, M.D., M.P.H., associate professor at the Center for American Indian
Health, Johns Hopkins Bloomberg School of Public Health, is the study's
principal investigator. Aruna Chandran, M.D., M.P.H., a trial
co-investigator, presents the data today at the Pediatric Academic Societies
(PAS) Annual Meeting in Honolulu, HI.
This randomized Phase 3 study demonstrated that motavizumab reduced
hospitalizations due to RSV by 83 percent as compared to placebo (8.3 percent
in placebo arm versus 1.4 percent in motavizumab; p<0.001), as the trial's
primary endpoint. In addition, the trial showed a 71-percent reduction in the
incidence of RSV-specific lower respiratory infections (LRIs) requiring
outpatient management (9.5 percent in placebo group and 2.8 percent in the
motavizumab group; p<0.001), which was a secondary endpoint.
The randomized, double-blind Phase 3 study involving 1,410 full-term
healthy infants less than six months of age in some Southwest Native American
populations was designed to compare monthly intramuscular injections of
motavizumab against placebo. In previous epidemiologic studies these
populations were shown to have high rates of hospitalization due to RSV. This
study confirmed the high rates of serious RSV disease in this population. An
interim analysis, reviewed by an independent data safety monitoring committee,
concluded there was statistical evidence demonstrating that motavizumab
reduced RSV hospitalizations and LRIs requiring outpatient medical management
within this population.
The overall incidence and severity of adverse events (AEs) were similar
between the motavizumab and the placebo groups in these Native American
infants. The mortality rates were not statistically different between groups
(0.4 percent in the placebo arm, n=2 and 0.3 percent in the motavizumab arm,
n=3) and were not considered to be related to the study drug. As was suggested
in the pivotal Phase 3 trial conducted in high-risk, preterm infants, rates of
skin reactions were more common following Motavizumab than placebo (by an
approximately 2 percent increase in frequency). Motavizumab was otherwise well
Each year, up to 125,000 infants in the U.S. are hospitalized with severe
RSV infections, the leading cause of lower respiratory tract infections in
infants in the United States. RSV is the most common respiratory infection in
infancy or childhood. Approximately one-half of all infants are infected with
RSV during the first year of life, and nearly all children have been infected
at least once by the time they reach their second birthday. Children born
prematurely as well as those with chronic lung disease (CLD) or congenital
heart disease (CHD) are at highest risk for severe disease and hospitalization
due to RSV. The virus may also cause severe illness in other high-risk groups
such as the elderly, those with underlying respiratory or cardiac disease, and
those with compromised immune systems (e.g., bone marrow transplant patients).
Otherwise healthy infants in some Native American populations have
demonstrated rates of RSV hospitalization that are similar to those among
children with underlying medical conditions in the general U.S. population.
Motavizumab is an investigational humanized MAb being evaluated for its
potential to prevent serious lower respiratory tract disease caused by RSV in
pediatric patients at high risk of RSV disease. Phase 1, 2 and 3 study data
have been reported showing that motavizumab appears to have a similar safety
and pharmacokinetic profile to Synagis(R) (palivizumab) in infants.
Additionally, in early phase studies children treated with motavizumab had
reduced RSV replication in the upper respiratory tract. In its pivotal
clinical trial, which was a head-to-head comparative trial with Synagis,
motavizumab demonstrated non-inferiority with a 26-percent relative reduction
in RSV hospitalizations due to RSV, which was its primary endpoint, and a 50-
percent relative reduction in the incidence of RSV lower respiratory tract
infections requiring outpatient management, one of its secondary endpoints.
Rates of adverse events, serious adverse events and study drug
discontinuations were balanced between treatment groups.
Synagis (palivizumab) is indicated for the prevention of serious lung
infections caused by respiratory syncytial virus (RSV) in children at high
risk of RSV disease. Synagis is given as a shot, usually in the thigh muscle,
each month during the RSV season. The first dose of Synagis should be given
before RSV season begins. Children who develop an RSV infection while
receiving Synagis should continue the monthly dosing schedule throughout the
season. Synagis has been used in more than one million children in the U.S.
since its introduction in 1998.
Synagis is not currently recommended as a preventive measure among Native
American infants at high risk for serious RSV disease.
Very rare cases (<1 per 100,000 patients) of severe allergic reactions
such as anaphylaxis and rare (<1 per 1,000 patients) hypersensitivity
reactions have been reported with Synagis. These rare reactions may occur when
any dose of Synagis is given, not just the first one. Also, rare but serious
side effects can occur, which may lead to unusual bruising and/or groups of
pinpoint red spots found on the skin.
Other side effects with Synagis may include upper respiratory tract
infection, ear infection, fever, and runny nose. In children born with heart
problems, Synagis was associated with reports of low blood oxygen levels and
abnormal heart rhythms. Synagis should not be used in patients with a history
of a severe prior reaction to Synagis or its components. Side effects, such
as, skin reactions around the area where the shot was given (like redness,
swelling, warmth, or discomfort) can also occur.
The pivotal trial for Synagis was called the IMpact trial and comprised a
total of 1,502 children who were randomized (500 placebo, 1,002 Synagis) in a
double-blind, placebo-controlled protocol where 1,486 children completed the
In the IMpact trial, monthly prophylaxis with Synagis via intramuscular
injections was associated with a 55-percent reduction in hospitalization as a
result of RSV (p=<0.001). Reductions were observed in both children with
bronchopulmonary dysplasia (38 percent reduction) and premature children
without BPD (78 percent reduction). Approximately 50 percent of the children
in the analysis had BPD.
For full prescribing information for Synagis, see the company's website
MedImmune strives to provide better medicines to patients, new medical
options for physicians and rewarding careers to employees. Dedicated to
advancing science and medicine to help people live better lives, the company
is focused on infection, oncology, respiratory disease and inflammation,
cardiovascular/gastrointestinal disease, and neuroscience. With approximately
3,000 employees worldwide and headquarters in Maryland, MedImmune is wholly
owned by AstraZeneca plc (LSE: AZN.L, NYSE: AZN). For more information, visit
MedImmune's website at www.medimmune.com.
/CONTACT: Tor Constantino, +1-301-398-5801, or Investors, Peter Vozzo,
+1-301-398-4358, both of MedImmune/
/Web site: http://www.medimmune.com/
CO: MedImmune; AstraZeneca plc
IN: MTC HEA
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8301 05/04/2008 17:00 EDT http://www.prnewswire.com