Insmed to Join the Russell Global(R) and Russell 3000(R) Indexes

MONMOUTH JUNCTION, NJ -- (Marketwired) -- 06/28/13 -- Insmed Incorporated (NASDAQ: INSM), ("Insmed" or the "Company"), a biopharmaceutical company focused on developing and commercializing an inhaled anti-infective to treat patients battling serious lung diseases that are often life-threatening, today announced that it was included on the list of companies to join the broad-market Russell Global® and the Russell 3000® Indexes when Russell Investments reconstitutes its comprehensive set of U.S. and global equity indexes on June 28, 2013www.russell.com/indexes.

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 large-cap Russell 1000® Index or 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.

Russell indexes are widely used by investment managers and institutional investors for index funds and as benchmarks for both passive and active investment strategies. Approximately $4.1 trillion in assets are benchmarked to the Russell Indexes. Russell calculates more than 700,000 benchmarks daily covering approximately 98 percent of the investable market globally, more than 80 countries and 10,000 securities. 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 (Russell) is a global asset manager and one of only a few firms that offers actively managed multi-asset portfolios and services that include advice, investments and implementation. Russell stands with institutional investors, financial advisors and individuals working with their advisors -- using the firm's core capabilities that extend across capital market insights, manager research, portfolio construction, portfolio implementation and indexes to help each achieve their desired investment outcomes.

Russell has more than $173 billion in assets under management (as of 3/31/2013) and works with over 2,500 institutional clients, independent distribution partners and individual investors globally. As a consultant to some of the largest pools of capital in the world, Russell has $2.6 trillion in assets under advisement (as of 12/31/2012). It has four decades of experience researching and selecting investment managers and meets annually with more than 2,200 managers around the world. Russell traded more than $1.4 trillion in 2012 through its implementation services business.

About Insmed

Insmed Incorporated is a biopharmaceutical company dedicated to improving the lives of patients battling serious lung diseases. Insmed is focused on the development and commercialization of ARIKACE®, or liposomal amikacin for inhalation, for at least two identified orphan patient populations: cystic fibrosis (CF) patients with Pseudomonas aeruginosa lung infections and patients with non-tuberculous mycobacteria (NTM) lung infections. For more information, please visit http://www.insmed.com.

Forward-Looking Statements

This release contains forward-looking statements that are made pursuant to provisions of Section 21E of the Securities Exchange Act of 1934. Words, and variations of words, such as "intend," "expect," "will," "anticipate," "believe," "continue," "propose" and similar expressions are intended to identify forward-looking statements. Investors are cautioned that such statements in this release, including statements relating to the status, results and timing of results of preclinical studies and clinical trials and preclinical and clinical data and the anticipated benefits of Insmed'sproducts, and to the Company's cash position and financing needs, constitute forward-looking statements that involve risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. Such risks and uncertainties include, without limitation, failure or delay of U.S. Food and Drug Administration and other regulatory reviews and approvals, competitive developments affecting the Company's product candidates, delays in product development or clinical trials or other studies, patent disputes and other intellectual property developments relating to the Company's product candidates, unexpected regulatory actions, delays or requests, the failure of clinical trials or other studies or results of clinical trials or other studies that do not meet expectations, inability to successfully develop the Company's product candidates or receive necessary regulatory approvals, inability to make product candidates commercially successful, changes in anticipated expenses, changes in the Company's financing requirements or ability raise additional capital, and other risks and challenges detailed in the Company's filings with the U.S. Securities and Exchange Commission, including its Annual Report on Form 10-K for the year ended December 31, 2012. Investors are cautioned not to place undue reliance on any forward-looking statements that speak only as of the date of this news release. The Company undertakes no obligation to update these forward-looking statements to reflect events or circumstances or changes in its expectations.

Investor Relations Contacts:
LHA
Anne Marie Fields
Senior Vice President
212-838-3777
afields@lhai.com

Bruce Voss
Managing Director
310-691-7100
bvoss@lhai.com