Adventrx Pharmaceuticals reached an agreement under a special protocol assessment (SPA) with the US FDA on the design of the company's CoFactor phase III clinical trial protocol.

The company also announced it remains on track to initiate the phase III clinical trial in Q2 2006. CoFactor is a biomodulator drug designed to improve the efficacy and safety of the widely used chemotherapeutic agent, 5-fluorouracil (5-FU).

"We are pleased that the FDA has accepted our phase III clinical protocol for CoFactor," said Evan M. Levine, Adventrx president and CEO. "The protocol for this registrational trial was optimized based on feedback from numerous discussions with thought leading oncologists. We look forward to launching this pivotal clinical trial in the second quarter as we previously announced," he added.

The phase III clinical trial is a multicentre, 1200 patient, controlled study in the first-line therapy of patients with metastatic colorectal cancer. Patients will be equally randomized to treatment with either CoFactor or leucovorin, plus 5-FU and bevacizumab (Avastin). The primary endpoint in the study is progression-free survival.

CoFactor (ANX-510) is a folate-based biomodulator drug designed to enhance the activity and reduce associated toxicity of the widely used cancer chemotherapeutic agent 5-fluorouracil (5-FU). CoFactor creates more stable binding of the active form of 5-FU to the target enzyme, thymidylate synthase (TS), improving 5-FU performance.