Insmed Announces Addition to the Russell 3000(R) Index

RICHMOND, Va., June 30 /PRNewswire-FirstCall/ -- Insmed Inc. (Nasdaq: INSM), a
biopharmaceutical company, today announced that it has been added to the
Russell 3000 Index following Russell Investments' reconstitution of its
comprehensive set of U.S. and global equity indexes on June 26, 2009. Insmed
was also added to the Russell Microcap(R) Index.

Annual reconstitution of Russell's U.S. indexes captures the 4,000 largest
U.S. stocks as of the end of May, ranking them by total market capitalization.
Membership in the Russell 3000, which remains in place for one year, means
automatic inclusion in the small-cap Russell 2000 Index, as well as the
appropriate growth and value style indexes. Russell determines membership for
its equity indexes primarily by objective, market-capitalization rankings and
style attributes. The Russell 3000 also serves as the U.S. component to the
Russell Global Index, which Russell launched in 2007.

Russell indexes are widely used by investment managers and institutional
investors for index funds and as benchmarks for both passive and active
investment strategies. An industry-leading $4 trillion in assets currently
are benchmarked to them. These investment tools originated from Russell's
multi-manager investment business in the early 1980s when the company saw the
need for a more objective, market-driven set of benchmarks in order to
evaluate outside investment managers.

About Russell
Russell Investments provides strategic advice, world-class implementation,
state-of-the-art performance benchmarks and a range of institutional-quality
investment products. Russell has $136 billion in assets under management as of
March 31, 2009, and serves individual, institutional and advisor clients in
more than 40 countries. Founded in 1936, Russell is a subsidiary of The
Northwestern Mutual Life Insurance Company.

About Insmed
Insmed Inc. is a biopharmaceutical company with unique protein development
experience and a proprietary protein platform aimed at niche markets with
unmet medical needs. For more information, please visit
http://www.insmed.com.

Investor Relations Contact:
Brian Ritchie - FD
212-850-5683
brian.ritchie@fd.com

Media Relations Contact:
Irma Gomez-Dib - FD
212-850-5761
irma.gomez-dib@fd.com

SOURCE Insmed Incorporated

Investor Relations, Brian Ritchie of FD, +1-212-850-5683,
brian.ritchie@fd.com; or Media Relations, Irma Gomez-Dib of FD,
+1-212-850-5761, irma.gomez-dib@fd.com