Radiopharmaceutical firm Draximage explores targeted imaging agents

Company's parent commits $3.5 million for R&D

Smaller may be better when it comes to focusing on the nuclear medicine radiopharmaceutical marketplace. While revenues from nuclear agents can't match billion-dollar opportunities in the general pharmaceutical business, there is room for growth as new targeting technology gets online and applications expand.

Draximage of Montreal, formerly Frosst Radiopharmaceuticals, plans growth through product development supported by its new parent, Draxis Health of Mississauga, Ontario, according to Raymond Dore, president of Draximage. Draxis reported last month that it will spend about $3.5 million in R&D, with Draximage receiving a substantial chunk of the funds.

Draxis Health purchased the radiopharmaceutical division of Merck Frosst Canada last September. Merck Frosst Canada is one subsidiary of Merck & Co. of Whitehouse Station, NJ, a $20 billion pharmaceutical company.

"Draxis Health is an emerging, young pharmaceutical company that has decided to get into niche markets," Dore said. "It has acquired a small but very old and experienced division."

Merck's Canadian-based radiopharmaceutical business was the only division in that giant company focusing on nuclear medicine, he said. As such, it was hard to gain the attention of its parent. The division operated as a profit center, turning in money earned to the parent at the end of each year.

Draxis, on the other hand, allows Draximage to reinvest its earnings in the radiopharmaceutical business, Dore said. The parent is also open to potential business acquisitions and sales partnerships that could expand the Draximage business.

Draximage has three nuclear medicine agents in its development pipeline. The agent furthest along is Fibrimage, a technetium-99m radiopharmaceutical for use in imaging active thrombus in deep vein thrombosis (SCAN 10/1/97). Draximage is about to enter phase I studies with Fibrimage in the U.S. and is at the phase II level in Canada.

If Fibrimage meets its potential in the detection of acute pulmonary embolism, it would open a new application for nuclear medicine, Dore said. X-ray contrast-based procedures in this area are lengthy, expensive, and often painful, with about 2.5 million tests performed in the U.S. each year, he said. Nuclear medicine would be quicker and relatively painless. More importantly, however, Fibrimage targets active thrombi moving in the bloodstream, which is where the real danger of pulmonary embolism lies.

As a targeting mechanism, Fibrimage uses fibrin binding domain (FBD), a technology developed by Biotechnology General of Israel and licensed to Draximage. FBD is a recombinant polypeptide that binds to fibrin, the primary component of venous thrombus. The Canadian firm developed Fibrimage's technetium labeling itself, Dore said.

The second agent in Draximage's pipeline is Somatoscan, a cancer radiopharmaceutical targeting somatostatin receptors in tumors. Mallinckrodt has a similar product on the market, called OctreoScan, which is indium labeled, but Draximage hopes that its use of technetium in Somatoscan will make the agent less expensive, Dore said.

Draximage aims to file with the Food and Drug Administration for phase I trials of Somatoscan later this year. This technology was developed in cooperation with the University of Pennsylvania, from which Draximage has a worldwide exclusive license.

Finally, laboratory work is being done on Draximage's last product in the pipeline, Atrial Natriuretic Peptide (ANP). ANP is a human peptide that targets receptors in the lung and kidney. Although in its initial stages, this agent could hold the most potential for Draximage. Potentially, it could measure the damage done to the kidney in people with diabetes. If proven, this would open up another new application for nuclear medicine: providing earlier detection than current tests.

Draximage is working with the Clinical Research Institute of Montreal and the Research Institute of Hotel Dieu Hospital in developing the ANP technology. The latter has provided Draximage with an exclusive worldwide license.

"There are about 15 to 20 million diabetic people in the U.S.," Dore said. "Eventually, they would all need a test like this."