Cambridge, MA
December 12, 2006

Gloucester Pharmaceuticals, Inc., a privately held cancer therapeutics development company, today announced interim data for romidepsin (formerly known as depsipeptide, FK228) as a treatment for peripheral T-cell lymphoma (PTCL) at the American Society of Hematology Annual Meeting held in Orlando, FL. The data presented are part of an interim analysis of a phase II study sponsored by the National Cancer Institute (NCI) under a Cooperative Research and Development Agreement (CRADA) with Gloucester.

Dr. Richard L. Piekarz of the National Cancer Institute and a principal investigator in the NCI’s ongoing clinical trial of romidepsin presented Abstract #2469 “Phase II Trial of Romidepsin, FK228, in Cutaneous and Peripheral T-Cell Lymphoma: Clinical Activity and Medical Markers” in a general poster session on Sunday, December 10th.

The interim results reported on 36 patients with PTCL. An overall response rate of 30% (11/36) was reported, with 3 complete responses (8%) and 8 partial responses (22%). The median duration of response in PTCL was reported as 12+ months. Overall, the most common adverse events reported were fatigue, nausea, and vomiting. In a separate release issued today Gloucester announced the interim results from this trial for 42 patients with cutaneous T-cell lymphoma (CTCL).

Commenting on the Piekarz poster presentation, Jean Nichols, Ph.D., Executive Vice President and Chief Scientific Officer at Gloucester said, “We are quite encouraged with the results reported for peripheral T-cell lymphoma. Significant clinical responses have now been observed in peripheral T-cell and cutaneous T-cell lymphoma patients, suggesting that romidepsin has activity in multiple T-cell lymphomas.” Dr. Nichols further commented, “Based on this encouraging data, we expect to initiate a Gloucester-sponsored international pivotal study in PTCL in the first quarter of 2007.”

About PTCL
Peripheral T-cell lymphoma accounts for about 10-15% of all cases of non-Hodgkin’s lymphoma. It can occur at any age from young adulthood to old age and is slightly more common in men than in women. PTCL is a particularly aggressive form of lymphoma with a short median duration of life expectancy (approximately two years) from diagnosis.

About Romidepsin (Depsipeptide)
In July 2006 the International Nonproprietary Names (INN) body of the World Health Organization (WHO) and the United States Adopted Names (USAN) Council approved the nonproprietary (generic) name romidepsin for depsipeptide (FK228). Romidepsin is a novel agent in a new class of anti-cancer drugs known as histone deacetylase inhibitors. The Company is conducting a pivotal study of romidepsin for patients with cutaneous T-cell lymphoma (CTCL). Romidepsin has received both Fast Track and Orphan Drug Designation by the Food and Drug Administration (FDA), and Orphan Drug Designation from the European Agency for the Evaluation of Medicinal Products (EMEA). Romidepsin is also in clinical trials for a variety of other hematologic malignancies and solid tumors including peripheral T-cell lymphoma, hormone refractory prostate cancer and multiple myeloma. These trials and others are being conducted by the Company or the National Cancer institute (NCI), under a Cooperative Research and Development Agreement (CRADA) with the Company.

About Gloucester Pharmaceuticals, Inc.
Gloucester Pharmaceuticals, Inc. is a privately held, venture-backed company that develops and commercializes innovative products for the treatment of cancer patients. Gloucester is headquartered in Cambridge, MA. For more information on Gloucester and our clinical development program visit our website at www.gloucesterpharma.com or call 888-GPI-CTCL (888-474-2825).