New hope for ill humans Transplant medicine: A Maryland company is helping develop a drug that could pave the way for the routine transplanting of animal organs into humans.

April 07, 1996|By Mark Guidera | Mark Guidera,SUN STAFF

In a laboratory at MedImmune Inc., a Gaithersburg-based biotechnology company, Dr. Scott Koenig slides a sample of pink liquid under a microscope to examine the molecules in a drug that could help shape a revolution in organ transplants.

If approved for the market, the drug, called BTI-322, could pave the way for the routine use of animal organs as replacements for human ones. Such cross-species organ transplants are called xenotransplants.

"If we can show this works, it would be a huge leap forward" for transplant medicine, said Dr. Koenig.

MedImmune has undertaken the BTI-322 project as part of an alliance with BioTransplant of Charlestown, Mass., one of four small biotechnology companies in a race to capitalize on a future xenotransplant industry relying on genetically altered pigs called miniswine.

The miniswine -- a misnomer since the pigs can grow to 500 pounds -- are considered a likely source for xenotransplants because they can be bred rapidly and their organs are similar in size and shape to their human counterparts.

Unlike the other companies -- Nextran of Princeton, N.J.; Alexion Pharmaceuticals of New Haven, Conn.; and Immutran PLC of Cambridge, England -- BioTransplant and MedImmune are focusing on overcoming the human body's rejection of foreign tissue rather than on developing and breeding the pigs themselves.

Under the BioTransplant-MedImmune deal, MedImmune will pay for the next phase of clinical trials, which might begin in 1997, and up to $16 million in licensing fees and other payments.

The work of the small biotechnology companies has caught the eye and the investment dollar of some of the world's best-known medical companies.

Swiss drug giant Sandoz Ltd. will invest $30 million in licensing and research fees at BioTransplant, according to Bioworld Today, a trade magazine. Executives at BioTransplant said they were barred from commenting because the company has filed to raise $23 million in a public offering.

Baxter International and U.S. Surgical, two big American medical companies, have investments with other biotechnology companies in the field.

In another indication that this new industry is on the way, Britain-based Immutran has said it plans to attempt human clinical trials with miniswine organs this year, though many experts believe that time frame is rushed. And the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention are expected to issue guidelines regarding xenotransplant surgery soon.

Driving investment and research in the field is the growing market for transplantable organs, particularly in the United States where there is a severe shortage, said Dr. David Sachs, director of the Transplantation Biology Research Center at Massachusetts General Hospital. He is conducting transplant research sponsored by BioTransplant.

That shortage -- or potential market, from the biotechnology companies' viewpoint -- is the result of two factors: Not enough people in the United States agree to donate their own or deceased family members' organs; and improvements in transplant medicine have made even very sick people acceptable transplant candidates.

In the United States, the gap between the human organs available for transplantation and people needing them is growing, said Dr. Sachs and other experts.

Currently, 45,120 people in the United States are on waiting lists for organ transplants, up from about 15,000 in 1989, according to the United Network for Organ Sharing (UNOS). And that is expected to grow to 60,000 during the next year, said Joel Newman, a spokesman with UNOS.

Meanwhile, about 19,000 organ transplants are being performed annually. About 3,000 people die each year awaiting an organ transplant, according to UNOS.

Industry experts believe that once pig organs are approved by the FDA and are readily available at an estimated cost of $10,000 each, demand will balloon, creating a $1 billion market.

Analysts say it's too early to give specific projections of what new anti-rejection drugs like BTI-322 could generate, but millions of dollars in sales are likely at stake.

The national average cost today per patient for a year's supply of anti-rejection drugs, depending on the organ transplanted, runs

between $2,100 and $13,500, according to UNOS.

The surgeon's view

Some transplant surgeons, such as Dr. Stephen T. Bartlett of the University of Maryland Hospital, say they see pig organs potentially serving as a "bridge" to help very sick patients survive until an appropriate human organ becomes available.

But other transplant experts, such as Dr. Sachs, the transplant ,, surgeon at Massachusetts General, believe that miniswine organs will one day serve as permanent replacements for human organs.

Neither Dr. Bartlett nor Dr. Sachs expects the future market for pig organs to be hindered by patient resistance.

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