CombinatoRx Licenses CRx-026 Territory Right to HenKan

Partnership Accelerates Development and Commercialization of CRx-026 in Taiwan, China and South Korea

BOSTON, MA and TAIPEI, TAIWAN -- July 18, 2005 - CombinatoRx, Incorporated, a privately held biopharmaceutical company, and HenKan Pharmaceutical Company today announced the signing of a territorial license agreement for CRx-026, a novel dual action anti-cancer agent in clinical development for solid tumors.

Under the terms of the agreement, HenKan receives the exclusive right to develop and commercialize CRx-026 in Taiwan, China, and South Korea. The agreement provides for CombinatoRx to receive a $500,000 upfront payment and up to $23 million in development and commercial milestone payments, plus royalties on sales within the territory. In collaboration with CombinatoRx, HenKan will also fund additional Phase II clinical trials targeting oncology indications characterized by high unmet medical need in key Asian markets.

CRx-026 is a novel dual-action anti-tumor drug candidate, currently in phase I/II clinical trials. CRx-026 is believed to have a synergistic anti-cancer effect through the coordinated inhibition of the mitotic kinesin, hsEg5/KSP, and the PRL phosphatases. In CombinatoRx’s preclinical studies, CRx-026 reduced tumor growth rates in multiple animal models. Clinical data on CRx-026 was recently presented at the 2005 American Society of Clinical Oncology Conference in a poster by Dr. Daniel Von Hoff, et al, entitled "A Phase I study with CRx-026, a novel dual action agent, in patients with advanced solid tumors."

About CombinatoRx

CombinatoRx, Incorporated is a biopharmaceutical company focused on developing new medicines built from synergistic combinations of approved drugs, designed to attack disease on multiple fronts. CombinatoRx applies its proprietary combination drug discovery technology to identify new combination product candidates in a number of disease areas, including immuno-inflammatory disease, oncology and metabolic disease. By applying our proprietary screening technology, we have discovered and advanced into clinical trials a portfolio of seven product candidates targeting multiple diseases. For further information, please visit the CombinatoRx website at http://www.combinatorx.com.

About HenKan Pharmaceutical

HenKan Pharmaceutical Company is a specialty pharmaceutical company focused on acquiring pharmaceutical products for clinical and commercial development in Asia, including Taiwan, China and South Korea. The company seeks to serve as a bridge between pharmaceutical companies with innovative products and product candidates and the unmet medical needs of the Asian market. HenKan also participates in sourcing and transferring Asian products of proven efficacy to the Western market. The company is currently funded by CDIB BioScience Venture Fund I, the largest life science venture fund in Taiwan. For further information, please visit the HenKan website at http://www.henkanpharma.com.

Forward-Looking Statement

Statements in this press release regarding CombinatoRx, Incorporated's business, including statements concerning CombinatoRx’s out-licensing partnership for CRx-026 with HenKan Pharmaceuticals, which are not historical facts are "forward-looking statements" that involve risks and uncertainties. Forward-looking statements can be identified by, among other things, the use of forward looking language, such as "anticipate," "believe," "could," "estimate," "expect," "future," "intends," "may," "plans," "should," "seeks," "potential," "will," or the negative of those terms, or other variations of those terms of comparable language, or by discussions of strategy or intentions. A number of important factors could cause actual results to differ materially from those projected or suggested in the forward looking statements including, but not limited to, the inability of CombinatoRx or HenKan to: (i) successfully conduct clinical trials of CRx-026, or (ii) successfully develop, obtain regulatory approval for and commercialize CRx-026. In particular, CombinatoRx could fail to obtain any royalties or contingent milestone payments. For a discussion of additional risks and uncertainties, which could cause actual results to differ from those contained in the forward-looking statements, see "Risk Factors" in CombinatoRx’s Registration Statement on form S-1 filed with the Securities and Exchange Commission.

(c) 2005 CombinatoRx, Incorporated. All rights reserved.

Contacts

CombinatoRx, Incorporated
Robert Forrester
Executive Vice President,
Chief Financial Officer
1-617-425-7000
rforrester@combinatorx.com

HenKan Pharmaceutical Company
Marty May
President
(8862)-2325-0556
marty@henkanpharma.com