MedImmune's Motavizumab Reduced RSV Hospitaliza...

GAITHERSBURG, Maryland, August 23 /PRNewswire/ --

    MedImmune, Inc. today announced that in a Phase 3 study, motavizumab was
shown to reduce hospitalizations due to respiratory syncytial virus (RSV) by
83 percent as compared to placebo (8.3 percent in placebo arm vs. 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.


    Motavizumab is an investigational monoclonal antibody (MAb) being
evaluated for its potential to prevent serious disease caused by RSV in
high-risk pediatric patients. This Phase 3 trial involved 1,410 full-term
infants less than six months of age in two Native American populations. In
previous medical studies these populations were shown to have high rates of
hospitalization due to RSV.


    The randomized (2:1), double-blind study was designed to compare monthly
intramuscular injections of motavizumab against placebo. After an interim
analysis conducted by an independent data safety monitoring committee, the
study was unblinded early due to statistical evidence demonstrating that
motavizumab reduced RSV hospitalizations and LRIs requiring outpatient
medical management within this population. Kate O'Brien, M.D., associate
professor at the Center for American Indian Health, Johns Hopkins Bloomberg
School of Public Health, served as the study's principal investigator.


    "We are pleased with the results of this study which support the positive
results seen in our Phase 3 pivotal trial comparing motavizumab and
Synagis(R) (palivizumab) that were previously reported at the Pediatric
Academic Societies meeting in May 2007," said Genevieve Losonsky, M.D., vice
president, clinical development, infectious disease, MedImmune.


    Motavizumab was well tolerated in these Native American infants, with an
overall incidence and severity of adverse events (AEs) that were similar
between the motavizumab and the placebo groups. 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 hypersensitivity related
skin rashes within two days of dosing were seen in about one percent of
treated children in the motavizumab group.



MedImmune's Commitment to RSV Prevention

    MedImmune is a world leader in the development of innovative therapeutic
biologic products to prevent RSV disease. In 1996, MedImmune launched the
first anti-RSV drug, RespiGam(R) (respiratory syncytial virus immune globulin
intravenous (human) (RSV-IGIV)), which was a polyclonal antibody administered
via four-hour intravenous infusion. In 1998, MedImmune introduced Synagis,
which was a significant product improvement as a monthly intramuscular
injection for the prevention of severe RSV, as well as being the first MAb to
receive U.S. Food and Drug Administration (FDA) approval for an infectious
disease. With the development of motavizumab, MedImmune continues to
reinforce its commitment to developing anti-RSV products. In a head-to-head
comparative Phase 3 trial with Synagis, motavizumab met its primary endpoint
of reducing RSV-related hospitalizations in high-risk pediatric patients and
met its secondary endpoint of reducing medically attended, outpatient
respiratory tract infections in that patient group. MedImmune is also
developing a small-molecule product candidate to prevent RSV as well as a
vaccine against RSV, both of which are in Phase 1 clinical trials.



About RSV

    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).



About Motavizumab

    Motavizumab, formerly known as Numax(R), 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 and Phase 2 study data have been reported showing that
motavizumab appears to have a similar safety and pharmacokinetic profile to
Synagis in infants. Additionally, in early phase studies children treated
with motavizumab had reduced RSV replication in the upper respiratory tract.
In its first pivotal trial, which was a head-to-head comparative trial with
Synagis, motavizumab demonstrated a 26-percent reduction in RSV
hospitalizations due to RSV and a 50-percent reduction in the incidence of
RSV lower respiratory tract infections requiring outpatient management, its
secondary endpoint.



About Synagis

    Synagis is the only monoclonal antibody approved by the FDA to help
prevent an infectious disease. Synagis was approved for use in the United
States in 1998, Europe in 1999, and Japan in 2002. Synagis is currently
available in 62 countries.


    Synagis is indicated for the prevention of serious lower respiratory
tract disease caused by respiratory syncytial virus (RSV) in pediatric
patients at high risk of RSV disease and is administered by intramuscular
injection. The safety and efficacy of Synagis were established in infants
with bronchopulmonary dysplasia (BPD), infants with a history of prematurity
(less than or equal to 35 weeks gestational age), and children with
hemodynamically significant congenital heart disease. The first dose of
Synagis should be administered prior to commencement of the RSV season, which
usually starts in the fall and runs through the spring. Patients, including
those who develop an RSV infection, should continue to receive monthly doses
throughout the season.


    Very rare cases (<1 per 100,000 patients) of anaphylaxis and rare
(<1 per 1,000 patients) hypersensitivity reactions have been reported with
Synagis. Cases of anaphylaxis were reported following re-exposure to Synagis
and rare severe hypersensitivity reactions occurred on initial exposure or
re-exposure. If a severe hypersensitivity reaction occurs, therapy with
Synagis should be permanently discontinued. If milder hypersensitivity
reaction occurs, caution should be used on re-administration of Synagis.


    In clinical trials, the most common adverse events occurring at least one
percent more frequently in Synagis-treated patients than controls were upper
respiratory infection, otitis media, fever and rhinitis. Cyanosis and
arrhythmia were seen in children with CHD.


    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
study's follow-up.


    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
at: http://www.medimmune.com/products/synagis/index.asp.



About International RSV Prophylaxis

    Outside the United States, Synagis is distributed by Illinois-based
Abbott, a global, broad-based health care company. Abbott also has the
ex-U.S. distribution rights to motavizumab.



About MedImmune, Inc.

    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 the areas of infectious diseases, cancer and inflammatory
diseases. 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
http://www.medimmune.com.



Web site: http://www.medimmune.com