Subspecialty News

Wet AMD Incidence Alarms Specialists
Early Diagnosis, More Treatment Options are Key Goals.

In a recent survey conducted by Eyetech Pharmaceuticals and Pfizer in consultation with Lighthouse International, an overwhelming majority of the 100 retina specialists who responded said they are alarmed at the increasing number of cases of wet AMD. Some of the physicians said that wet AMD is reaching epidemic proportions as baby boomers age and more people live into their 80s and 90s. The specialists called for greater public awareness of the disease and its effects, efforts aimed at earlier diagnosis, and new treatment options to help them better fight the disease.

"Everyone, including physicians, health authorities and the aging public, needs to better understand that wet AMD is putting our vision at risk," says William F. Mieler, M.D., professor and chairman of the Department of Ophthalmology and Visual Science, University of Chicago, and president of the Macula Society. "We need to collectively take steps to minimize vision loss and prolong the independent function of older adults threatened by wet AMD."

Dr. Mieler says medical science is on the threshold of a new era in the pharmacological treatment of macula disease. He says more treatment options will be available "very soon."

"We are making significant progress with new treatments, and this necessitates retina specialists keeping up with the new developments," he notes. "Not only is the education of referring physicians important, there needs to be an increased awareness among patients, caregivers and the general public about AMD and its risk factors and symptoms."

Bruce P. Rosenthal, O.D., chief of Low-Vision Programs, Lighthouse International, offers several specific suggestions that could lead to earlier diagnosis and treatment.

"A great way to help raise public awareness of the disease is through informative Internet sites such as www.visionconnection.org, www.lighthouse.org and www.amdalliance.org, which can readily be accessed by the visually impaired," says Dr. Rosenthal. "In my practice, I primarily see patients above the age of 80 and you'd be surprised how many of them are now using the Internet."

Dr. Rosenthal says eyecare providers should make sure all of their older patients are given or sent educational literature describing the symptoms and effects of AMD and the need for early diagnosis. Such literature is available to physicians through Lighthouse International by calling (800) 829-0500.

Both Dr. Mieler and Dr. Rosenthal would like to see more older patients routinely screened for wet AMD as part of a comprehensive eye exam, especially those with risk factors such as family history and smoking. Currently, AMD screening requires a dilated fundus exam but new diagnostic instruments that could provide easier and more cost-effective screening are now being developed.

"Medicare is now paying for a certain amount of glaucoma screening," notes Dr. Rosenthal. "Why can't they fund the same kind of screening program for AMD?"

On the bright side, Dr. Rosenthal says public awareness campaigns have been effective.

"Five years ago, only 27% of Americans were aware of the dangers of AMD. In a recent survey by the AMD Alliance, that number had jumped to 46%."

QLT to Acquire Atrix Labs
Atrix Technology has Ophthalmic Applications.

When QLT Inc. recently said it planned to acquire Atrix Labs for about $855 million in cash and stock, analysts saw the move as a way for QLT to beef up its R&D pipeline in urology, oncology and dermatology, three therapeutic areas of strategic interest. Until now, QLT has primarily been known as the co-developer of Visudyne therapy for wet AMD.

However, Atrix, which is headquartered in Fort Collins, Colo., could also expand QLT's presence in ophthalmology with a potentially promising new treatment for diabetic retinopathy.

Atrix is currently developing sustained-release formulations of octreotide, a small peptide that suppresses the release of growth hormone from the pituitary gland. Currently marketed octreotide products are approved for use in patients with carcinoid syndrome, VIP tumors and acromegaly.

Octreotide also has antiangiogenic properties that inhibit the formation of new blood vessels.

"Given octreotide's antiangiogenic activity, and it's capacity to down-regulate the growth hormone/insulin-like growth factor-1 axis, investigators have become increasingly interested to test this peptide as a systemic agent to slow down the progression of diabetic retinopathy," says Stephen Warren, M.D., vice president of R&D and chief scientific officer of Atrix. "A major challenge has been to develop a drug-delivery system that's sufficiently robust to constantly release therapeutic levels of octreotide into the blood over the course of many days or weeks.

Atrix believes it may have such a drug-delivery system in Atrigel. Atrigel, which is already being used in several of Atrix's marketed products, has many potential sustained-release applications. It's a bioabsorbable polymer system that's mixed with a drug, peptide or protein just prior to subcutaneous injection. The Atrigel/drug mixture enters the subcutaneous tissue as a liquid and almost immediately transforms into a solid pellet that gradually releases drug as the polymers are absorbed. Dr. Warren says an almost endless number of Atrigel formulations can be prepared to release drugs, peptides or proteins over a period ranging from a couple of weeks to 6 months.

Atrix is currently conducting early clinical studies with a 1-month formulation of Atrigel/octreotide. The company is also developing a 3-month formulation of Atrigel/octreotide, which should be in the clinic sometime next year.

"Published studies indicate that octreotide has definite biological activity in diabetic retinopathy, and our Atrigel-based products have an excellent safety profile, based upon the performance of our FDA-approved products," notes Dr. Warren. "We believe Atrigel/octreotide may help to solve a key drug-delivery problem that has precluded the use of octreotide as a systemic treatment for diabetic retinopathy."

Dr. Warren says that there are many other potential applications for the Atrigel drug-delivery technology platform, including its use to deliver drugs into various ocular tissues.

"Preclinical studies show that Atrigel can be injected into numerous tissues throughout the body, including tissues in and around the eye. It appears to be well-tolerated in most sites of injection," he notes. "So Atrigel may find many applications including the systemic or local delivery of drugs to treat numerous diseases and conditions."