Will New Anemia Drug Top Current Treatments?

A new drug designed to treat patients with a rare form of anemia could possibly have wider applications, perhaps replacing other anemia treatments that have been linked to an increased risk of death, cancer and stroke, experts say.

The drug, Hematide, was successful in treating patients who have pure red-cell aplasia, a condition caused by antibodies to a hormone needed to produce red blood cells. It's a "devastating condition that many patients have died from and ties patients to blood transfusions every two weeks for the rest of their life," said lead researcher Dr. Iain C. Macdougall, from King's College Hospital, London.

But the real breakthrough is being able to make drugs in a new way that could have wide application for many diseases, he said.

"It is possible to create drugs that are cheaper and simpler to make," he said. "The question is whether all expensive protein therapeutics can get peptide mimetics. This is what we call a peptide mimetic -- it mimics the protein," he said.

The report is published in the Nov. 5 issue of the New England Journal of Medicine.

For the study, Macdougall's group treated 14 patients with chronic kidney disease who were anemic because of antibodies that prevented other anemia treatments from making red blood cells.

Twelve weeks after the first dose of Hematide, a synthetic peptide-based erythropoietin agonist, none of the patients needed blood transfusions, the researchers found. In addition, the amount of antierythropoietin antibodies decreased and in six patients became undetectable.

One patient developed antibodies to the drug and had to go back to receiving regular transfusions, the researchers noted.

Some experts think Hematide could replace other anemia drugs used to treat anemia caused by kidney disease or chemotherapy, if it turns out to have fewer adverse side effects. However, Macdougall is cautious about making such claims.

"That's speculation," he said. "There is no way our paper suggests that, and there is no hard scientific evidence that would suggest that."

Dr. H. Franklin Bunn, research director of the hematology division at Brigham and Women's Hospital and Harvard Medical School, both in Boston, and author of an accompanying journal editorial, said that "down the road this drug may have some advantages over regular erythropoietin drugs."

But he said it is too early to tell whether Hematide can replace the erythropoietin drugs Procrit and Aranesp, which are associated with heightened risk of heart attack, cancer and stroke.

For now, Hematide is "the treatment of choice for patients who have developed antibodies against erythropoietin. And that's all you can say at this point. but I am curious to find out whether this drug will be able to be used and be effective and safe in a wider setting," Bunn said.

Other experts are more optimistic. Dr. Charles Bennett, a hematologist/oncologist at Northwestern Memorial Hospital and Jesse Brown VA Medical Center in Chicago, said that "we are going to look at this in five years and see that it's a breakthrough paper."

It's hoped this drug will take the place of erythropoietin drugs and not have the side effects associated with them, Bennett said.

Dr. Jochen Reiser, chief of nephrology and hypertension at the Leonard M. Miller School of Medicine of the University of Miami, voiced similar hopes. "In some patients where Procrit has proven not to be beneficial, maybe this peptide has an additional potential that Procrit doesn't have or works better."

Whether Hematide will overcome the side effects associated with Procrit is still hard to say, Reiser said.

"If the side effects come from increasing the amount of red blood cells, then no, it would have the same effects, but if they are substance-related side effects that have nothing to do with the red blood cells, then yes -- that can be looked at now," he said.