CombinatoRx Set To Join The Russell 3000 Index

CombinatoRx, Incorporated (NASDAQ: CRXX) announced today that it is set to join the broad-market Russell 3000 ^® Index when Russell Investments reconstitutes its comprehensive set of U.S. and global equity indexes on June 25, according to a preliminary list of additions posted June 11 on www.russell.com. CombinatoRx will likely also be included in the Russell 2000, a subset of the Russell 3000 index for 2,000 of the smaller companies based on market capitalization. Initial inclusion in the Russell indexes may lead to an increase in trading volume when investment funds that track the index add CombinatoRx shares to their portfolios.

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.

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 $3.9 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.

Total returns data for the Russell 3000 and other Russell Indexes is available at http://www.russell.com/Indexes/performance/default.asp.

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 $179 billion in assets under management as of March 31, 2010, 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.