Laser Solutions

Additional five-year results, which further confirm the published research, were announced in mid-September 2005 by Axcan Pharma Inc., the pharmaceutical company that markets Photofrin PDT.

Frequent heartburn and acid reflux, also known as gastroesophageal reflux disease (GERD), are the most common risk factors for Barrett's esophagus, a serious condition in which acid reflux causes the normal lining of the lower part of the esophagus to be replaced by another type of cellular lining typically present in the stomach. Barrett's esophagus can progress to cancer of the esophagus. GERD impacts an estimated 7 to 20 percent of people in the Western World, and approximately 10 to 15 percent of this group has Barrett's esophagus.

Autopsy studies suggest an even higher incidence, as high as 1 in 60 people. If Barrett's esophagus progresses to high-grade dysplasia, a pre-cancerous stage of the condition, there is a 30 to 40 fold increased risk of developing esophageal adenocarcinoma, the sixth leading cause of cancer death in the world.

"Photofrin PDT is the only FDA-approved ablation therapy for the treatment of pre-cancerous Barrett's esophagus," said Dr. Overholt. "All other esophageal ablation techniques are still experimental and currently lack the breadth of data necessary for clinical application. Our research results provide strong evidence in support of the appropriate use of Photofrin PDT - as the first treatment of Barrett's with high-grade dysplasia and the prevention of esophageal cancer. Surgery to remove the esophagus can be used for the rare patient who is not suitable for Photofrin PDT."

Thirty clinical research centers and 208 randomized patients participated in the international Phase III clinical trial, which was tracked over two and five years for additional follow-up data. As part of the pivotal research, Photofrin PDT was used in conjunction with a common acid relief medication and then compared to that medication alone. The primary objective was to measure the complete removal of pre-cancerous Barrett's esophagus (dysplasia) at anytime during the study duration. A secondary objective was whether cancer developed during the two-year follow-up period.

According to the two-year results, published in the GIE journal, 77 percent of patients who received Photofrin PDT had complete removal of high-grade dysplasia, while only 39 percent of those who received acid relief medication had no signs of the condition. Even more significant, by the end of the study follow-up period there was an 83 percent chance of being cancer free in the Photofrin PDT group as compared with a 53 percent chance in the medication only group.

"Based on the findings of these studies, my opinion is that gastroenterologists and oncologists should consider Photofrin PDT to treat the entire field of pre-cancerous Barrett's esophagus with a proven ablation treatment, and it eliminates the need for surgery," continued Overholt.

"It boils down to this: by treating high-grade dysplasia, we are reducing the development of esophageal cancer. Primary care physicians can play a key role in the early detection process by staying keenly aware that symptoms related to GERD require investigating," said Dr. Overholt. "Finally, patients at risk - those of any age with repeated heartburn and/or acid reflux - should discuss with their doctor whether they are a candidate for a screening endoscopy."

Photofrin PDT is a minimally invasive ablation technique that combines a light-sensitive drug (porfimer sodium) with a laser light to treat pre-cancerous Barrett's esophagus. Photofrin is marketed by Axcan in North America under the brand Photofrin, and in the European Union under the brand Photobarr. When the drug is injected into the patient, it is absorbed by all cells but remains longest in pre-cancerous and cancer cells.

Within two days of administering the drug, a balloon catheter with fiber optic line is inserted into the esophagus and the light is directed at the pre-cancerous area with the help of an endoscope. A non-thermal laser light is then activated at the appropriate level and works with the photo-sensitive drug to destroy the abnormal tissue. The procedure is covered by most health insurance plans.

Based in Knoxville, Tennessee, the center is committed to delivering the most advanced cancer care available. Consisting of two locations in Knoxville and one in Oak Ridge, the Thompson Cancer Survival Center is internationally recognized for its advanced capabilities in cancer care and treatment. The Thompson Center includes the Center of Excellence for Barrett's Esophagus. PDT was pioneered in 1990 at the Laser Center, located on the 4th floor of the Thompson Cancer Survival Center.

The center is part of Covenant Health, a community-owned health system providing comprehensive health services throughout East Tennessee. Headquartered in Knoxville, Covenant Health includes five acute care hospitals as well as numerous outpatient services and clinics. The system also includes specialty providers of behavioral, oncology and rehabilitation services, along with home care, physicians clinics, and community wellness programs.

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