(ARA) - A decade ago, research into angiogenesis-inhibiting compounds was still in a relative state of infancy. The principle itself was not new -- as far back as the early '70s, there was speculation that human cancer tumors could not grow beyond a few millimeters in diameter without obtaining their own blood supply. But opinion was still divided in the scientific community.

Angiogenesis itself is a natural and necessary physiological function, which refers to the process by which new blood vessels form and develop. In its pathological form, however, angiogenesis is also implicated in the progression of more than 20 different diseases, including cancer.

In order to grow, solid tumors need to be supplied by blood vessels that act as conduits for oxygen and nutrients. Once a vascular network has been generated around a tumor, cancerous cells can then invade the rest of the body, a process called metastasis. Angiogenesis inhibitors block the formation of new blood vessels, without which cancerous cells are starved and tumors cannot grow.

In recent years, the therapeutic potential of angiogenesis inhibitors has gained wide acceptance. Indeed, the scientific community now believes that more than 90 percent of all cancer cases are angiogenesis dependent. The industry spends nearly $4 billion annually in angiogenic research and more than 100 research organizations and companies are currently developing angiogenesis-blocking drugs.

Æterna Laboratories Inc. is at the forefront of this effort. In fact, it is one of the very few biotechnology companies in the world with an angiogenesis-blocker in Phase lll clinical development. Its proprietary compound, Neovastat, is currently the subject of Phase III trials in lung and kidney cancer and a Phase ll trial in multiple myeloma, a form of blood cancer.

Neovastat possesses multiple mechanisms of action that counteract the angiogenic process. Among competing products, this makes it unique. It has also shown an excellent safety profile in clinical trials. Further advantages of Neovastat are that it is orally administered, which makes it convenient for patients who must receive treatment on a long-term basis, and it may be taken in association with standard therapies such as chemotherapy.

Angiogenesis blockers are not a cure for cancer. They are a form of treatment -- in the same way that insulin is a treatment for diabetes -- that should allow patients to lead a more normal life, without suffering from the often debilitating side-effects that some treatments can produce.

Æterna's clinical trials strategy has targeted forms of cancer for which there is an urgent need for new therapies. Since 1996, Neovastat has been tested in more than 850 patients in North American and European countries. Currently, Neovastat is the subject of three clinical trials, targeting three forms of cancer. For multiple myeloma, the second most common form of blood cancer, the drug is in Phase II trials with 125 patients in the United States, Canada and Europe. This trial should be completed in early 2003. For progressive renal cell carcinoma, the drug is in Phase III trials with 302 patients in the United States, Canada and Europe, which should be completed in early 2003. For non-small cell lung cancer, Neovastat is in a Phase III trial sponsored by the National Cancer Institute with 760 patients in the United States and Canada. This trial should be completed in 2005.

Once the clinical trials are complete, health authorities in various countries can then assess these results and make decisions on approval.