CombinatoRx Publishes Clinical Study Results of CRx-102 in Hand Osteoarthritis.

Results Published in Annals of Rheumatic Diseases Finds CRx-102 Effective at Reducing Pain in Hand OA

CAMBRIDGE, Mass. -- CombinatoRx, Incorporated (NASDAQ: CRXX) today announced that Annals of the Rheumatic Diseases has published the results of its CRx-102 Phase 2a hand osteoarthritis trial. The manuscript entitled "Efficacy and Safety of a Novel Synergistic Drug Candidate - CRx-102 - in Hand Osteoarthritis", Kvien, et.al. was pre-published on-line (http://ard.bmj.com/onlinefirst.dtl) and will run in an upcoming print edition. Annals of Rheumatic Diseases is the peer reviewed European League Against Rheumatism (EULAR) journal for rheumatic disease health professionals and researchers.

"This study demonstrated that the synergistic combination drug candidate, CRx-102, is effective at reducing pain in hand osteoarthritis, and warrants further clinical investigation," commented Tore K. Kvien, MD, Professor of Rheumatology, Diakonhjemmet Hospital, Oslo, Norway, and principal investigator of the study.

"Based on the encouraging data summarized in Dr, Kvien's article, we have recently initiated a Phase 2b trial, COMET-1 (CRx-102 Osteoarthritis Multi-center Evaluation Trial), to evaluate the efficacy of CRx-102 in subjects with symptomatic knee osteoarthritis. The COMET-1 trial will further examine the role CRx-102 could play in filling the gap in treatment options for patients with osteoarthritis," added Daniel Grau, Chief Operating Officer of CombinatoRx. CRx-102 will also be tested in rheumatoid arthritis in the Phase 2b MARS-1 study (Multi-center Active RA Study), set to initiate in the 4th quarter of 2007.

About CRx-102

CRx-102 is an oral synergistic combination drug candidate with a novel multi-target mechanism that inhibits key cell mediators of inflammation. CRx-102 combines the cardiovascular agent dipyridamole and an unconventionally low dose of the glucocorticosteroid prednisolone. CRx-102 works through a novel mechanism of action in which dipyridamole selectively amplifies prednisolone's anti-inflammatory and immunomodulatory activities without replicating its side effects. In Phase 2 clinical trials, CRx-102 demonstrated a powerful anti-inflammatory effect and rapid onset of action in patients with osteoarthritis and rheumatoid arthritis, and was generally well tolerated. CRx-102 is being developed in a modified-release commercial formulation to provide enhanced clinical benefit across multiple immuno-inflammatory diseases. CRx-102 is currently in Phase 2b development as an alternative to standard of care anti-inflammatory and pain therapies for the treatment of rheumatoid arthritis and osteoarthritis.

To date, CRx-102 has demonstrated positive results in three placebo-controlled Phase 2 clinical trials. In a previous study of hand osteoarthritis, CRx-102 demonstrated a statistically significant reduction in pain and stiffness (31% vs. 7%) as well as improvements in tender and swollen joints. In a rheumatoid arthritis trial, CRx-102 demonstrated statistically significant improvements in ACR20 (63% vs. 30%) and DAS28 scores (-1.6 vs. -0.7). The anti-inflammatory effect of CRx-102 was further demonstrated in an inflammatory biomarker study, in which subjects treated with CRx-102 experienced a statistically significant reduction in C-reactive protein compared with placebo (-0.65mg/L vs. 0mg/L).

About Osteoarthritis

Osteoarthritis is the most common degenerative joint disease and a frequent cause of physical disability among older adults. According to the Arthritis Foundation, more than 21 million people in the United States suffer from the disease. Osteoarthritis affects the hands, lower back, neck, and weight-bearing joints such as the knees, hips, and feet. Symptoms of osteoarthritis range from stiffness and intermittent mild pain to severe joint pain and impaired biomechanical function. There is no cure for most forms of osteoarthritis. Currently available therapies that are designed to help patients manage symptoms include analgesics, anti-inflammatory drugs such as non-steroidal anti-inflammatory drugs (NSAIDs) and COX-2 inhibitors, opioids such as morphine, intra-articular corticosteroid injection and surgery.

About CombinatoRx

CombinatoRx, Incorporated (CRXX) is pioneering the new field of synergistic combination pharmaceuticals and has a broad product portfolio in phase 2 clinical development. Going beyond traditional combinations, CombinatoRx creates product candidates with novel mechanisms of action striking at the biological complexities of human disease. The lead programs in the CombinatoRx portfolio are advancing into later stage clinical trials based on the strength of multiple positive Phase 2a results. This portfolio is internally generated from the CombinatoRx proprietary drug discovery technology which provides a renewable and previously untapped source of novel drug candidates. The Company was founded in 2000 and is located in Cambridge, Massachusetts. To learn more about CombinatoRx please visit www.combinatorx.com.

Forward-Looking Statement

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 concerning CombinatoRx, its product candidate CRx-102, its clinical, commercial and therapeutic potential, its plans for clinical and formulation development of CRx-102, its business plans and its drug discovery technology. These forward-looking statements about future expectations, plans and prospects of CombinatoRx and CRx-102 involve significant risks, uncertainties and assumptions, including risks related to the Company's ability to enroll and successfully complete its clinical trials of CRx-102, the Company's ability to develop a proprietary formulation of CRx-102, potential difficulty and delays in obtaining regulatory approval for the sale and marketing of CRx-102, the unproven nature of the CombinatoRx drug discovery technology, the Company's ability to obtain additional financing or funding for its research and development and those other risks that can be found in the "Risk Factors" section of the CombinatoRx Annual Report on Form 10-K on file with the Securities and Exchange Commission and the other reports that CombinatoRx periodically files with the Securities and Exchange Commission. Actual results may differ materially from those CombinatoRx contemplated by these forward-looking statements. CombinatoRx 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.

(c) 2007 CombinatoRx, Incorporated. All rights reserved.