Guilford Pharmaceuticals Inc. announced that a phase III study of Aquavan Injection in patients undergoing elective colonoscopy procedures met its primary efficacy endpoint without any serious adverse events. The results were based on a randomized, open-label study designed to assess the efficacy of Aquavan and its safety versus midazolam HCl for sedation in patients undergoing colonoscopy procedures. A total of 278 patients were enrolled and randomly assigned to receive Aquavan (N=209) or midazolam (N=69).

The primary efficacy endpoint in the trial was success of sedation, defined as three consecutive Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scores less than or equal to 4, and completing the procedure without employing alternative sedative medications and without requiring manual or mechanical ventilation. Treatment with Aquavan resulted in a sedation success rate of 96 per cent. In general, patients who received Aquavan experienced deeper levels of sedation for longer sustained periods than patients who received midazolam, which led to a higher level of adverse events in the Aquavan treatment group. Patients treated with Aquavan showed a median time to sedation of 2 minutes and a median time to full recovery from the end of the procedure of 11 minutes.

Dean J Mitchell, president and chief executive officer of Guilford, remarked, "Market research supports the need for a new procedural sedation agent that provides rapid onset and recovery from sedation, is easy to administer and control, and can be safely administered without the need for a dedicated anaesthesiologist. Based on these results, we believe Aquavan can satisfy that product profile; however, a lower dose than used in this phase III trial would be more appropriate to meet the characteristics of a drug ideal for procedural sedation. Our intention is to ensure the highest probability of regulatory and commercial success for Aquavan. Accordingly, we have voluntarily suspended enrolling patients in our ongoing clinical trials in order to review dosing levels. With the dosing level data, in addition to the colonoscopy data, we plan to meet with the Food and Drug Administration within the next several weeks to determine the optimal clinical plan to obtain approval and achieve our desired label. While these activities may modestly extend our timeline for filing the NDA, we think it will best enhance the product's commercial opportunity."