Cyclacel Reports Interim Seliciclib Phase IIa Data At 2005 ASCO

Dundee , Scotland , UK - 15 May 2005 - Cyclacel Group plc (“Cyclacel”), the cell cycle-based biopharmaceutical company, today reported interim data from a multicenter, European Phase IIa trial of its lead cancer drug candidate, seliciclib (CYC202), administered in combination with gemcitabine and cisplatin in advanced Non-Small Cell Lung Cancer (NSCLC) patients. The data was presented at the 2005 American Society of Clinical Oncology (ASCO) Annual Meeting in Orlando , Florida .

Seliciclib is the leading orally-available CDK inhibitor in Phase II clinical development. It is a small molecule drug that inhibits the cell cycle targets CDK2/E, CDK2/A, CDK7/H and CDK9/T. The interim data indicated that the combination treatment did not appear to increase the frequency or severity of the known toxicities of gemcitabine and cisplatin and that the combination is active in NSCLC.

Specifically, the preliminary data presented at ASCO described the effects of seliciclib on the first 27 patients treated in this ongoing study. As expected from Phase I trials of seliciclib, patients on the combination treatment experienced seliciclib-induced adverse events of nausea, vomiting, transient elevations in serum creatinine and liver function parameters and transient hypokalemia. Among 14 patients evaluable for response, six were reported to have partial responses (PR), seven stable disease (SD) and one progressive disease (PD).

The Phase IIa interim data followed a Phase I trial of seliciclib which suggested that the drug may have antitumor activity in NSCLC. In the Phase I study two heavily pre-treated NSCLC patients that failed multiple therapies experienced prolonged disease stabilization of 13 and 18 months, respectively, after being given seliciclib as a single agent. Seliciclib was synergistic with gemcitabine in an in vivo NSCLC xenograft study.

Dr. Judy Chiao, Cyclacel's VP Clinical Development and Regulatory Affairssaid, “We are pleased that the initial data from this trial demonstrates the feasibility of combining seliciclib with standard doses of gemcitabine and cisplatin and the combination appears to be active in NSCLC. Seliciclib has been administered to over 200 subjects to date and does not appear to induce myelosuppression. We expect to complete treatment of the remaining patients in this study shortly. Following analysis of the final data we will formulate our plans for the next stage of clinical development.”

In a separate ASCO presentation, researchers from Dana-Farber Cancer Institute and Harvard Medical School reported preclinical data showing that seliciclib caused apoptosis in myeloma cells that were sensitive or resistant to chemotherapy in part by down regulating the anti-apoptotic gene MCL-1. The investigators also reported that combinations of seliciclib tested in vitro with either bortezomib or doxorubicin were synergistic and examination of these combinations in clinical trials is warranted.

Spiro Rombotis, Cyclacel's Chief Executive Officer , said: “These results, along with the data presented earlier on our second candidate, CYC682, underscore the steady progress we are making in advancing our clinical pipeline. The development of these drug candidates is in line with our strategy to pursue compounds with novel mechanisms that target different points within the cell cycle.”

About Cyclacel ( www.cyclacel.com )
Cyclacel is a biopharmaceutical company dedicated to the discovery, development and commercialization of novel, mechanism-targeted drugs to treat human cancers and other serious disorders. The company is currently evaluating seliciclib (CYC202), an orally-available Cyclin Dependent Kinase inhibitor, in Phase II clinical trials for the treatment of Non-Small Cell Lung Cancer and B-cell hematological malignancies. CYC682 is an orally-available, cell cycle modulating nucleoside analog in Phase I clinical trials for the treatment of cancer. Cyclacel has eight additional programs at preclinical stages.

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