Heart Risks Rise for Kidney Patients on Higher Doses of Amgen's Aranesp
Diabetic patients with chronic kidney disease are more likely to suffer heart complications or die if they need higher doses of Amgen Inc.’s Aranesp to reach current treatment goals, researchers said.
Patients getting increased amounts of Aranesp after they showed a poor response to the two lowest doses were 41 percent more likely to die and 31 percent more likely to have a cardiac complication, including a heart attack, heart failure or stroke, than those with a stronger reaction, the company-funded study in the New England Journal of Medicine found. The researchers tracked hemoglobin, a protein in red blood cells, to determine the patient’s response to treatment.
Safety questions have reduced sales of Aranesp, once the best-selling drug from Thousand Oaks, California-based Amgen, by more than one-third since 2006 when the risks in kidney patients taking anemia drugs were first uncovered. It generated $2.7 billion last year, down from $4.2 billion three years earlier. The lower treatment targets for hemoglobin levels, a marker of anemia, may not fix the problem, researchers said.
“The issue isn’t what target you get to, but how hard you have to work to get there,” said lead researcher Scott Solomon, director of noninvasive cardiology at Brigham and Women’s Hospital in Boston, in a telephone interview. “People in our study who got to the lowest hemoglobin levels, a level the community now thinks might be safe, had the worst outcomes. It really turns upside down this whole issue of targets.”
Target Range
Doctors have been reducing the target range for red blood cells in anemia patients who use drugs such as Aranesp after studies found patients at the high end were at the greatest risk of harm. Individuals who don’t respond well to Aranesp, used to bolster the number of red blood cells, and are given more of the medicine to get to the goal, are most vulnerable, the analysis released today found.
The study confirms other findings that a poor initial response to treatment by patients with chronic kidney disease is associated with a higher risk of death or cardiovascular events, said Amgen spokeswoman Emma Hurley in an e-mailed statement. The researchers didn’t pinpoint what caused the risk, she said.
The study couldn’t determine if patients who didn’t respond well to treatment became sicker because of the higher doses of Aranesp or if they were at a more advanced stage of their illness at the start of the study. Patients with the best response to the drug were the least likely to suffer complications, easing concerns that those patients were particularly vulnerable, the researchers said.
Reducing Risk
The study involved 3,761 patients from 24 countries treated from August 2004 to March 2009. Since anemia has been linked to higher rates of heart problems and death in patients with kidney disease, the researchers were testing to see if they could reduce the risk by raising hemoglobin levels.
None of the patients in the study were on dialysis, a group that has an improved quality of life and less need for blood transfusions when given drugs like Aranesp. The original study, dubbed Treat, didn’t evaluate patients based on their response to the drug and showed those getting it nearly doubled the risk of stroke compared with those on placebo.
“It is really hard to justify this particular therapy, despite the fact that it’s still being used very heavily for people with chronic kidney disease,” Solomon said.
Amgen rose 79 cents, or 1.4 percent, to $55.30 at 4 p.m. New York time in Nasdaq Stock Market composite trading. The shares have lost 2.3 percent this year.
To contact the reporter on this story: Michelle Fay Cortez in Minneapolis at mcortez@bloomberg.net
Rate this Page