REG-Elan Corporation PLC Subset Data from Two Randomized Phase 3 Trials Show TYSABRI Significantly Reduces Rates of Hospitalization in Patients with Moderate-to-Severe Crohn’s Disease

DUBLIN, Ireland--(Business Wire)--
Elan Corporation, plc (NYSE:ELN) and Biogen Idec (NASDAQ:BIIB) today announced
data showing that treatment with TYSABRI® (natalizumab) significantly reduced
the rate of hospitalization compared with placebo in patients with
moderate-to-severe Crohn`s disease during both induction and maintenance
treatment. These results were obtained from retrospective subset analyses of
three registrational Phase 3 trials (ENACT-1 [Efficacy of Natalizumab as Active
Crohn`s Therapy]), (ENACT-2 [Evaluation of Natalizumab as Continuous Therapy]
and ENCORE [Efficacy of Natalizumab in Crohn`s Disease Response and Remission]),
and one open-label study (ENABLE [Evaluation of the Natalizumab Antibody for
Long-term Efficacy]). The data were presented for the first time in an oral
session at the American College of Gastroenterology Annual Scientific Meeting in
San Diego.

"Hospitalization accounts for a large proportion of the cost of Crohn`s disease
management," said Corey A. Siegel, M.D., director, Inflammatory Bowel Disease
Center, Dartmouth-Hitchcock Medical Center in Lebanon, N.H., and lead author of
the subset analysis. "Therefore, we were encouraged to see that TYSABRI reduced
hospitalization rates, particularly in the more difficult-to-treat subsets of
patients previously treated with anti-TNFα therapy."

The retrospective subset analysis evaluated the effect of TYSABRI on the rate of
hospitalization during induction and maintenance treatment using pooled data
from the ENACT-1 and ENCORE trials. In those trials, patients with Crohn`s
disease were randomized to intravenous TYSABRI 300 mg or placebo every four
weeks for three doses. The maintenance analysis was conducted on TYSABRI
responders in ENACT-1 who were re-randomized and followed for an additional 48
weeks of therapy in ENACT-2. Data on patients losing response in ENACT-2 who
rolled over to an open-label study (ENABLE) supplemented the ENACT-2 data. Rates
of all-cause hospitalization and Crohn`s disease-related hospitalization per 100
patients over the 84-day induction period and the 336-day maintenance periods
were evaluated.

Results of the subset analysis showed that hospitalization rates were
significantly lower in patients treated with TYSABRI when compared with placebo.
Two physicians, blinded to treatment, reviewed all data to determine
hospitalizations and surgeries and whether they were, or were not, related to
Crohn`s disease. Out of the approximately 1500 patients involved in these
trials, the total number of all-cause hospitalizations was (n=136). In those
patients treated with TYSABRI, the rate of all-cause hospitalizations was
reduced by 35% (p=0.009) during the induction period and 44% (p=0.044) during
the maintenance period. The total number of Crohn`s disease-related
hospitalizations was (n=109). In these Tysabri-treated patients, the rate was
reduced by 31% (p<0.001) during the induction period and 58% (p=0.027) during
the maintenance period.

In patients who had received prior anti-TNF therapy, a more difficult-to-treat
patient population, the benefit of TYSABRI was higher. During the induction
period, the total number of all-cause hospitalizations was (n=57). In these
patients, the rate was reduced by 56% (p=0.031) and Crohn`s disease-related
hospitalization (n=46) the rate was reduced by 55% (p=0.052). During the
maintenance period, all-cause hospitalization rate was reduced by 60% (p=0.034)
and the Crohn`s disease-related hospitalization rate was reduced by 75%
(p=0.029).

"The results of this analysis showing reduced hospitalization rates, together
with subset data previously announced at Digestive Disease Week in May, provide
additional support that TYSABRI is an important treatment option for patients
with this chronic and debilitating disease who have failed anti-TNFα therapies,"
said Elan President Carlos V. Paya, M.D., Ph.D. "TYSABRI continues to show
benefits in improving quality of life, in CD patients, as well as in multiple
sclerosis patients who also exhibit benefits across clinical and radiological
measures."

Natalizumab Reduces the Rate of Hospitalization in Moderate to Severe Crohn`s
Patients: Data from the ENACT and ENCORE Trials, Siegel, CA, Sands BE, Feagan B,
et al. Presented at the American College of Gastroenterology Annual Scientific
Meeting, October 27, 2009. Abstract #41.

About ENACT-1, ENACT-2, ENCORE, and ENABLE

ENACT-1 involved patients with moderately to severely active Crohn's disease who
received either TYSABRI 300 mg or placebo for 3 infusions. The primary endpoint
was clinical response at week 10. Patients who responded to therapy were
eligible to enroll into ENACT-2.

ENACT-2 presented maintenance data for an additional year of TYSABRI therapy
among patients with an initial response to TYSABRI, after 3 months in ENACT-1.
Of patients with response in ENACT-1, sustained response during ENACT-2 was seen
in 61% of patients treated with TYSABRI at every visit through an additional 6
months of therapy, compared to 29% for placebo. This treatment difference was
also sustained through 12 months of additional therapy (54% vs. 20%). Remission
was maintained at every visit with an additional 6 months or 12 months of
TYSABRI in 45% and 40% of patients, respectively, compared to 26% and 15% of
placebo treated patients (p<0.005 at 6 months). Among the patients that had
previously failed anti-TNFα therapy, response and remission was sustained at
every visit through an additional 6 months of TYSABRI in 52% and 30% of
patients, respectively. Given the requirement to discontinue chronic steroids,
among the subset of patients (n=65) on steroids and in whom a clinical response
was achieved, approximately two-thirds were able to discontinue steroids within
10 weeks of beginning to taper steroids. Although permitted in the clinical
trials, combination therapy with immunosuppressants is not recommended.

Data from the second induction trial, ENCORE, showed that TYSABRI induced
response and remission among patients with moderately to severely active Crohn's
disease, and objective evidence of inflammation, as measured by elevated
C-reactive protein.

After 12 weeks of therapy, 60% of TYSABRI-treated patients attained response,
compared to 44% of placebo treated patients, and 48% of patients showed a
response at both weeks 8 and 12, compared to 32% of placebo treated patients
(p<0.005 for both). Among the patients who had inadequate response to prior
treatment with inhibitors of TNFα, 38% achieved a response at weeks 8 and 12.

ENABLE was an open-label extension study, which treated over 1000 patients with
TYSABRI, for up to an additional 12 months.

About Crohn's disease

An estimated 500,000 people in the United States have Crohn's disease, a chronic
and progressive inflammatory disease of the gastrointestinal tract, which
commonly affects both men and women.

The disease usually causes diarrhea and crampy abdominal pain, often associated
with fever, and at times rectal bleeding. Loss of appetite and weight loss also
may occur. Complications include narrowing of the intestine, obstruction,
abscesses, and fistulas (abnormal channels connecting the intestine and other
organs, including the skin), and malnutrition. Most patients eventually require
surgery, which has both risks and potential short- and long-term complications.

Crohn's disease can have a devastating impact on the lifestyle of patients, many
of whom are young and active. Currently there is no medical or surgical cure for
Crohn's disease. Many patients fail to respond to current therapies, including
biological therapies such as agents that inhibit tumor necrosis factor alpha
(TNF-alpha). Due to this failure of current therapies in CD, therapies that have
alternate biological targets provide patients and physicians with therapeutic
options.

About TYSABRI®

In early 2008, TYSABRI was approved in the U.S. to induce and maintain clinical
response and remission in adult patients with moderately to severely active
Crohn's disease (CD) with evidence of inflammation who have had an inadequate
response to, or are unable to tolerate, conventional CD therapies and inhibitors
of TNF-alpha. According to the U.S. full prescribing information, among patients
who responded to TYSABRI in a clinical trial, 54 percent sustained their
response through the one year visit compared to 20 percent of patients receiving
placebo (p<0.001), for a treatment difference of 34 percent.

In the U.S., TYSABRI is approved for relapsing forms of multiple sclerosis (MS)
and in the European Union for relapsing-remitting MS. TYSABRI is approved for MS
in more than 40 countries. According to data from the Phase III AFFIRM trial
published in the New England Journal of Medicine, after two years, TYSABRI
treatment led to a 68 percent relative reduction (p<0.001) in the annualized
relapse rate, when compared with placebo, and reduced the relative risk of
disability progression by 42-54 percent (p<0.001).

TYSABRI increases the risk of progressive multifocal leukoencephalopathy (PML),
an opportunistic viral infection of the brain. Other serious adverse events that
have occurred in TYSABRI-treated patients include hypersensitivity reactions
(e.g., anaphylaxis) and infections, including opportunistic and other atypical
infections. Clinically significant liver injury has been reported in patients
treated with TYSABRI in the post-marketing setting. Common adverse events
reported in TYSABRI-treated MS patients include headache, fatigue, infusion
reactions, urinary tract infections, joint and limb pain and rash.

TYSABRI is co-marketed by Biogen Idec Inc. and Elan Pharmaceuticals, Inc. For
more information about TYSABRI, please visit www.tysabri.com, www.biogenidec.com
or www.elan.com, or call 1-800-456-2255.

About Elan

Elan Corporation, plc is a neuroscience-based biotechnology company committed to
making a difference in the lives of patients and their families by bringing
innovations in science to fill significant unmet medical needs. Elan shares
trade on the New York and Dublin Stock Exchanges. For additional information
about the company, please visit www.elan.com.

About Biogen Idec

Biogen Idec creates new standards of care in therapeutic areas with high unmet
medical needs. Founded in 1978, Biogen Idec is a global leader in the discovery,
development, manufacturing, and commercialization of innovative therapies.
Patients in more than 90 countries benefit from Biogen Idec's significant
products that address diseases such as lymphoma, multiple sclerosis, and
rheumatoid arthritis. For product labeling, press releases and additional
information about the company, please visit www.biogenidec.com.

Safe Harbor/Forward-Looking Statements

This press release contains forward-looking statements regarding TYSABRI. These
statements are based on the companies' current beliefs and expectations. The
commercial potential of TYSABRI is subject to a number of risks and
uncertainties. Factors which could cause actual results to differ materially
from the companies' current expectations include the risk that we may be unable
to adequately address concerns or questions raised by the FDA or other
regulatory authorities, that concerns may arise from additional data, that the
incidence and/or risk of PML or other opportunistic infections in patients
treated with TYSABRI may be higher than observed in clinical trials, that the
companies may encounter other unexpected hurdles, or that new therapies for MS
with better efficacy or safety profiles or more convenient methods of
administration are introduced into the market. Drug development and
commercialization involves a high degree of risk.

For more detailed information on the risks and uncertainties associated with the
companies' drug development and other activities, see the periodic and current
reports that Elan has filed with the Securities and Exchange Commission. The
companies assume no obligation to update any forward-looking statements, whether
as a result of new information, future events or otherwise.

INVESTOR:
Elan
Chris Burns, 800-252-3526
David Marshall, 353-1-709-4444
or
Biogen Idec
Eric Hoffman, 617-679-2812
or
MEDIA:
Elan
Miriam Mason, 650-278-7113
Mary Stutts, 650-823-5255 (on-site)
or
Biogen Idec
Jennifer Neiman, 617-914-1201

Elan Corporation

Copyright Business Wire 2009