Exhibit 99.1
RXi Pharmaceuticals Announces Departure of Chief Financial Officer
Worcester, MA, August 20, 2009 – RXi Pharmaceuticals Corporation (Nasdaq: RXII) today announced
that Stephen J. DiPalma, has resigned as Executive Vice President of Business Operations and Chief
Financial Officer to pursue other opportunities, effective August 28, 2009.
Tod Woolf, Ph.D. President and CEO said, “We would like to thank Steve for his leadership and
important contributions as RXi expanded its operations, became a public company in early 2008 and
closed subsequent rounds of financing. We wish Steve well in his
future endeavors. ”
The Company will be recruiting a new Chief Financial Officer.
About RXi Pharmaceuticals Corporation
RXi Pharmaceuticals is a discovery-stage biopharmaceutical company pursuing the development and
potential commercialization of proprietary therapeutics based on RNA interference (RNAi) for the
treatment of human diseases. RXi has a comprehensive therapeutic platform that includes both RNAi
compounds and delivery methods. RXi uses its own version of RNAi compounds — rxRNA™ — that
provide an advanced alternative to conventional small interfering RNAs (siRNAs) and define the next
generation of RNAi technology. rxRNA™ compounds are designed specifically for therapeutic use and
contain many of the properties needed to move RNAi based drugs into the clinic. RXi
Pharmaceuticals believes it is well positioned to compete successfully in the RNAi-based
therapeutics market with its accomplished scientific advisors, including Dr. Craig Mello, recipient
of the 2006 Nobel Prize for his co-discovery of RNAi; a management team that is experienced in
developing RNAi products; and a strong early intellectual property position in RNAi chemistry and
delivery. www.rxipharma.com
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities
Litigation Reform Act of 1995. Such statements include, but are not limited to, statements about
future expectations, plan and future development of RXi Pharmaceutical Corporation’s products and
technologies. These forward-looking statements about future expectations, plans and prospects
regarding the ability of the company to attract and retain key employees, plans and prospects of
the development of RXi Pharmaceutical Corporation’s products and technologies involve significant
risks, uncertainties and assumptions, including the risk that the development of our RNAi-based
therapeutics may be delayed or may not proceed as planned and we may not be able to complete
development of any RNAi-based product, the risk that the FDA approval process may be delayed for
any drugs that we develop, risks related to development and commercialization of products by our
competitors, risks related to our ability to control the timing and terms of collaborations with
third parties and the possibility that other companies or organizations may assert patent rights
that prevent us from developing our products. Actual results may differ materially from those RXi
Pharmaceuticals Corporation contemplated by these forward-looking statements. RXi Pharmaceuticals
Corporation does not undertake to update any of these forward-looking statements to reflect a
change in its views or events or circumstances that occur after the date of this release.