Insmed Completes External Assessment of Myotonic Muscular Dystrophy Market

Study Estimates Potential Myotonic Muscular Dystrophy Market Could be as High
as $800 Million to $1.4 Billion

RICHMOND, Va., Jan. 22 /PRNewswire-FirstCall/ -- Insmed Inc.
(Nasdaq: INSM), a developer of follow-on biologics and biopharmaceuticals,
today announced that a leading management consulting firm has completed a
market assessment of the potential market for therapeutic treatments related
to Myotonic Muscular Dystrophy (MMD), also known as dystrophia myotonica or
Steinert's disease. The research was conducted on behalf of Insmed, which is
currently conducting a Phase III enabling trial for its MMD product candidate,
IPLEX(TM). Based on responses from neurologists interviewed, patients
afflicted with MMD could number between 28,300 and 37,000 by 2010, and the
total market for MMD treatments could be as high as between $800 million and
$1.4 billion.
MMD is an inherited disease characterized by prolonged muscle tensing
(myotonia) where certain muscles are not able to relax after use. Muscular
Dystrophy is diagnosed at the rate of 50,000 to 250,000 persons annually in
the U.S., and MMD is the most common form of the disease. DM1, which occurs in
approximately 98% of MMD cases, is caused by an excessive number of cytosine,
thymine and guanine (CTG) repeats on Chromosome 19. Symptoms of MMD include
muscle wasting, weakness, pain, endurance loss, cognitive impairment and
gastro-intestinal dysfunction.
There is currently no cure for the disease, and no specific treatment has
been discovered to satisfactorily reverse or ameliorate the common symptoms
associated with MMD. Current treatments for MMD are directed toward managing
the clinical manifestations of the disease, such as drugs aimed at treating
multiple symptoms with the intent of addressing the delayed muscle relaxation.
"The results of this study highlight that the MMD patient population is
under-served," said Steve Glover, President, Insmed Therapeutic Proteins. "We
intend to continue executing on our regulatory strategy for IPLEX in MMD,
which was recently granted Orphan Drug Designation by the FDA in an attempt to
better serve this patient category. Our recently secured grant of
approximately $2.1 million from the Muscular Dystrophy Association is expected
to cover a substantial portion of the external costs associated with our
24-week Phase III enabling trial in MMD patients, and we are hopeful of making
this important product candidate available to patients as quickly as
possible."
These interviews, seeking information about the current treatment of MMD,
emerging treatments and trends and therapies via a blinded product profile,
were conducted in physician settings ranging from individual practices to
large multi-specialist group practices in rural, urban and academic
environments in different locations in the U.S.
About IPLEX(TM)
IPLEX(TM) was approved in the United States in December 2005 for the
treatment of children with growth failure due to severe primary IGF-I
deficiency (Primary IGFD). IPLEX(TM) (rhIGF-I/rhIGFBP-3), is a complex of
recombinant human insulin-like growth factor-I (rhIGF-I) and its predominant
binding protein IGFBP-3 (rhIGFBP-3). The drug is also being investigated for
various other indications with unmet medical needs.
About Insmed
Insmed Inc. is a biopharmaceutical company with unique protein process
development and manufacturing experience and a proprietary protein platform
aimed at niche markets with unmet medical needs. For more information, please
visit www.insmed.com.
Forward-Looking Statements
This release contains forward-looking statements which are made pursuant
to provisions of Section 21E of the Securities Exchange Act of 1934. Investors
are cautioned that such statements in this release, including statements
relating to planned clinical study design, regulatory and business strategies,
plans and objectives of management and growth opportunities for existing or
proposed products, constitute forward-looking statements which involve risks
and uncertainties that could cause actual results to differ materially from
those anticipated by the forward-looking statements. The risks and
uncertainties include, without limitation, risks that product candidates may
fail in the clinic or may not be successfully marketed or manufactured, we may
lack financial resources to complete development of product candidates, the
FDA may interpret the results of studies differently than us, competing
products may be more successful, demand for new pharmaceutical products may
decrease, the biopharmaceutical industry may experience negative market
trends, our entrance into the follow on biologics market may be unsuccessful,
our common stock could be delisted from the Nasdaq Global Market and other
risks and challenges detailed in our filings with the U.S. Securities and
Exchange Commission, including our Quarterly Report on Form 10-Q for the
quarter ended September 30, 2007. Readers are cautioned not to place undue
reliance on any forward-looking statements which speak only as of the date of
this release. We undertake no obligation to publicly release the results of
any revisions to these forward-looking statements that may be made to reflect
events or circumstances that occur after the date of this release or to
reflect the occurrence of unanticipated events.
SOURCE Insmed Inc.

Brian Ritchie of FD, +1-212-850-5683, or Brian.ritchie@fd.com, for Insmed
Inc.