Update: PXD101

CuraGen Corporation (Nasdaq: CRGN) and TopoTarget A/S (Copenhagen Stock Exchange: TOPO) announced today the initiation of patient dosing in a Phase II clinical trial evaluating the activity of PXD101, a small molecule histone deacetylase (HDAC) inhibitor, for the treatment of mesothelioma. This trial is being sponsored by the National Cancer Institute (NCI) under a Clinical Trials Agreement with CuraGen for the clinical development of PXD101.

PXD101 is a promising small molecule HDAC inhibitor being investigated for its role in the treatment of a wide range of solid and hematologic malignancies either as a single-agent, or in combination with other active anti-cancer agents, including 5-fluorouracil (5-FU), carboplatin, paclitaxel and Velcade(R) (bortezomib) for Injection. HDAC inhibitors represent a new mechanistic class of anti-cancer therapeutics that target HDAC enzymes and have been shown to: arrest growth of cancer cells (including drug resistant subtypes); induce apoptosis, or programmed cell death; promote differentiation; inhibit angiogenesis; and sensitize cancer cells to overcome drug resistance when used in combination with other anti-cancer agents.

PXD101 is currently being evaluated in multiple clinical trials as a potential treatment for multiple myeloma, T-cell lymphoma, and colorectal and ovarian cancers. In August 2004, CuraGen signed a Clinical Trials Agreement with the NCI under which the NCI will sponsor several clinical trials to investigate PXD101 for the treatment of various cancers, both as a single-agent and in combination chemotherapy regimens.