Firm May Have Found Key to Treating Anemia : Rare Hormone Holds Promise for Kidney Ills
A rare human hormone, produced in large amounts for the first time by a Thousand Oaks biotechnology firm, has alleviated anemia in kidney patients and may be an effective treatment for millions of patients with other types of anemia, doctors have reported.
In a report on preliminary human tests of the hormone, published this month in the New England Journal of Medicine, doctors said the hormone, erythropoietin, reduced anemia in every test subject and eliminated it in most.
Moreover, the need for transfusions of blood to increase a patient’s blood count was completely eliminated, said Dr. John Adamson, a hematologist at the University of Washington, Seattle, who led the study with Dr. Joseph Eschbach, a kidney specialist.
Such transfusions are a frequent source of hepatitis and other infectious diseases in kidney patients and have been blamed for a small number of infections of the deadly AIDS virus.
Improved Quality of Life
The quality of life for the patients--which had been restricted by fatigue, depression and other symptoms of anemia--was also improved, Adamson said.
Hailing the study results, Stuart Kaufer, executive director of the National Assn. of Patients on Hemodialysis and Transplantation, which represents patients with kidney disease, said bio-engineered erythropoietin has the potential to be the “most revolutionary” advance in treatment of kidney failure in 20 years.
The study, along with a British test that recently produced similar results, was financed by Amgen of Thousand Oaks, a small biotechnology company that has pinned many of its hopes for growth on erythropoietin.
Several financial analysts said that the results of the preliminary trials will be a big boon to Amgen, which has more than five bio-engineered drugs in development and testing but none on the market.
Ahead of Competition
Peter F. Drake, a biotechnology analyst at the investment firm Kidder Peabody, said Amgen is two years ahead of Genetics Institute of Boston, which is the only other company well on the way to developing a version of the hormone.
He said Amgen should have no problem getting its erythropoietin approved by the federal Food and Drug Administration by 1988.
As for the potential market, Drake said sales of the hormone for the treatment of dialysis patients alone could top $150 million by 1990.
If a new series of human trials, involving 300 kidney patients at nine medical centers around the country, produces similar results, erythropoietin “will clearly be a major breakthrough,” said Dr. Allen Nissenson, who will be giving the hormone to kidney patients at UCLA.
“That stuff is unbelievable in terms of how potent it is,” Nissenson said.
Cell Stimulation
Erythropoietin is normally produced in the kidneys and increases the blood’s capacity to carry oxygen. It does this by stimulating cells in the bone marrow to divide, a process that produces the trillions of red blood cells that transport oxygen from the lungs to the tissues of the body.
However, virtually all of the estimated 85,000 Americans with severe kidney disease lack the hormone, Adamson said, and thousands more with kidney deficiencies have abnormally low levels.
Because they lack erythropoietin, people with kidney failure frequently have blood counts that are half those of normal individuals, Adamson said. Because of this, their activity is restricted and they frequently suffer from fatigue, depression and weakness, he said.
Although hemodialysis machines, or artificial kidneys, effectively replace the main function of the kidneys for many of these patients--filtering impurities from the blood--no treatment has replaced the loss of erythropoietin, he said.
Ever since erythropoietin was first identified in 1953, scientists have predicted that the hormone someday would be the ideal treatment for anemia, according to Adamson and several kidney specialists. Previously, only minute quantities of the hormone could be extracted from human blood and purified.
Danger of Hepatitis
Until now, the only way to boost the blood count of kidney patients was to give them transfusions, Adamson said. But this increased their risk of contracting hepatitis or other blood-borne diseases.
None of the 18 test subjects who received significant doses of the bio-engineered erythropoietin in Seattle required any transfusions, Adamson said.
The discoverer of the hormone, Dr. Allan Erslev, now a professor of medicine at Jefferson Medical College in Philadelphia, wrote a guest editorial hailing the new research. It also was published in the New England Journal of Medicine.
Erslev said in a telephone interview that the therapeutic use of erythropoietin had to wait for the “wizardry” of biotechnology to produce sufficient quantities of the rare substance for human trials.
In 1983, an Amgen scientist isolated the specific piece of DNA in human genes that contains the “blueprint” for erythropoietin, said Philip Whitcome, Amgen’s director of strategic planning.
Help From Hamsters
Within two years, the company developed a process by which the erythropoietin gene could be inserted into cells taken from hamsters. The animal cells would then churn out the hormone.
Erslev and other doctors at Jefferson Medical College plan this spring to begin trials of bio-engineered erythropoietin produced by Genetics Institute, Erslev said.
Bio-engineered erythropoietin may eventually help raise blood counts in millions of people with anemia caused by a wide range of other medical problems, including some forms of cancer and rheumatoid arthritis, Adamson said.
The hormone may also help speed up the process of “autologous blood donation,” in which a person stockpiles his own blood before surgery to avoid the danger of infection, Adamson said.
Administration of erythropoietin after a person gives blood could shorten the time between donation sessions, he said.
The product may also help patients undergoing medical treatments that cause anemia, Whitcome said.
For example, chemotherapy for cancer tends to curtail red-cell production. Also, AZT, a drug being used to treat some patients with acquired immune deficiency syndrome, causes severe depression of red-blood-cell production, he said.
