By Chris Delporte

Vasogen Inc. received approval from the FDA to begin a pivotal clinical trial for the treatment of peripheral arterial disease (PAD).

The study, which will enroll 500 patients throughout the U.S. and Canada, will be a randomized, double-blind, placebo-controlled trial of the company¿s immune modulation therapy in patients with PAD. The trial, the company said, is designed to support regulatory approval and marketing. The technology, according to Vasogen, would be regulated as a medical device.

¿We¿re obviously thrilled that the FDA has approved the trial,¿ Vasogen President and CEO David Elsley told BioWorld Today. ¿This bodes well for additional applications such as for congestive heart failure, psoriasis and ischemia/reperfusion injury.¿

Elsley said the trial would take a total of 18 months, enrolling patients over the next 12 months with a six-month endpoint. He said the company should be able to report results by the second quarter of 2003, and file a premarket approval application with the FDA by the third quarter of the same year. Elsley also said this trial would lead to CE mark approval in the European Union. ¿This is a major milestone for the company,¿ he said.

The primary endpoint of the trial is to demonstrate the impact of the company¿s immune modulation therapy on maximal treadmill walking distance (absolute claudication distance), which is the endpoint recognized by the FDA for approving new PAD treatments. Secondary endpoints include the change in pain-free treadmill walking distance (initial claudication distance); the percentage of patients who improve their treadmill walking distances by 50 percent and 100 percent; impact on ankle brachial index, which is a measure of blood flow in the legs; and improvements in the quality of life.

¿Current therapies for patients with PAD do not provide satisfactory management of the disease and fall short in terms of the effectiveness and safety that we would like to see for this growing health concern,¿ Jeffrey Olin, lead trial investigator, said in a press release.

PAD is characterized by reduced blood flow to the lower extremities due to atherosclerosis. This often results in pain, cramps, fatigue or muscle ache in the legs upon walking, which can lead to reduced mobility. The company said there are roughly 200,000 reported cases each year in North America and Europe. Some of the more severe cases result in amputation. Vasogen said that, according to studies, PAD patients are three times as likely to suffer a heart attach and stroke as the general population.

According to Vasogen, research indicated that the normal removal of stressed cells from the body by the immune system is an anti-inflammatory process. Immune modulation therapy is designed to exploit this anti-inflammatory response to stressed cells. Delivered during a 20-minute outpatient procedure, immune modulation therapy involves the stressing of a small sample of a patient¿s blood cells using a proprietary medical device technology, followed by the administration of the stressed cells to the patient.

In November of last year, Vasogen, of Toronto, reported positive results from a clinical trial in 81 patients with advanced PAD. The company said that the trial met its primary endpoint and demonstrated that the immune modulation therapy was long lasting, well tolerated and free of adverse side effects.

The company¿s technology currently is in clinical trials for other indications characterized by immune system dysfunction and inflammation, including psoriasis, congestive heart failure, ischemia/reperfusion injury, chronic lymphocytic leukemia and graft-vs.-host disease.