Baxter International Inc. says that a blood product it wastesting failed to slow mental decline or to preserve physical function in a major study of 390 patients with mild to moderate Alzheimer's disease.
The company says that people who received 18 months of infusions with its drug, Gammagard, fared no better than others given infusions of a dummy solution.
Gammagard is immune globulin, natural antibodies culled from donated blood. Researchers thought these antibodies might help remove amyloid, the sticky plaque that clogs patients' brains, sapping memory and ability to think.
Patients with moderate disease and those with a gene that raises risk of Alzheimer's who were taking the higher of two doses in the study seemed to benefit, although the study was not big enough to say for sure.
"The study missed its primary endpoints, however we remain interested by the prespecified sub-group analyses" in groups that seemed to benefit, Ludwig Hantson, president of Baxter's BioScience business, said in a statement.
Gammagard is already sold to treat some blood disorders, and the results of the Alzheimer's study do not affect those uses. About 35 million people worldwide have dementia, and Alzheimer's is the most common type. In the U.S., about 5 million have Alzheimer's. Current medicines such as Aricept and Namenda just temporarily ease symptoms. There is no known cure.
Excitement about Gammagard grew last summer, when researchers reported at amedical conference that the drug had stabilized Alzheimer's disease for as much as three years in four patients who had been receiving the highest dose of it for three years in the study. People typically go from diagnosis to death in about eight years, so to be stable for so long was considered remarkable.
The new results on the full group of study participants are disappointing, said the study's leader, Dr. Norman Relkin, head of a memory disorders program at New York-Presbyterian Hospital/Weill Cornell Medical Center.
"The bar was set very high" for the drug to show improvement, and "there does appear to be a signal" that it helped the two-thirds of patients in the study who had the apoE4 gene that raises the risk of developing Alzheimer's, as well as those with moderate versus mild disease, Relkin said.
No new side effects were seen in the study. About 5 percent of patients on the drug had a rash and decreases in hemoglobin, which carries oxygen in the blood. There were 17 serious reactions, 12 in the drug group and five in the placebo group.
Full results will be presented in July at an Alzheimer's conference in Boston.
Meanwhile, other studies are under way to test drugs earlier in the course of the disease. An experimental drug, Eli Lilly & Co.'s solanezumab, showed some promise in that setting in an earlier study.
alt:1Y)?p;(P? ?? d:white'>About 240,000 men in the U.S. are diagnosed with prostate cancer each year, and about half are classified as low risk using current methods. Doctors now base risk estimates on factors such as a man's age and how aggressive cells look from biopsies that give 12 to 14 tissue samples. But tumors often are spread out and vary from one spot to the other.
"Unless you can be sure your biopsy has hit the most aggressive part that's in the prostate, you can't be sure" how accurate your risk estimate is, explained Dr. Eric Klein, chief of urology at the Cleveland Clinic, who led early development of the Oncotype prostate cancer test.
For one study, researchers used prostates removed from 440 men. They measured the activity of hundreds of genes thought to be involved in whether the cancer spread beyond the prostate or proved fatal. A second study of biopsies from 167 patients narrowed it down to 81 genes, and researchers picked 17 that seemed to predict aggressiveness no matter the location in the tumor.
A third study used single needle-biopsy samples from 395 UCSF patients scheduled to have their prostates removed. The gene test accurately predicted the aggressiveness of their cancer once doctors were able to see the whole prostate after surgery.
Using one current method, 37 of the 395 men would have been called very low risk and good candidates for monitoring. Adding the gene test put 100 men into that category, said another study leader, Dr. Matthew Cooperberg of UCSF. The gene test shifted about half of the men into either a lower or a higher risk category.
"It went both ways — that was the remarkable thing. In any category of risk it added independent information compared to the standard criteria we use today," Carroll said. "More work needs to be done, but, in my opinion, this is a very good start."
However, Dr. Kevin McVary, chairman of urology at Southern Illinois University School of Medicine and a spokesman for the Urological Association, said the test must be validated in more men before it can be widely used.
"It's not there yet," he said.
UCSF just got a federal grant to see how men choose treatments and whether this test might sway them.
"We throw all these numbers at them. Are they really going to make a better decision?" Cooperberg said.
Dean Smith, 60, a retired marketing executive from Mill Valley, California, is following his doctor's advice to monitor the cancer he was diagnosed with in March. He said a gene test may have made him more comfortable with that decision.
At least six of his friends suffered side effects ranging from urinary leakage to inability to have sex after having their prostates removed.
"I would suspect that having cancer and having to live with it would be very difficult for them," but it doesn't bother him, Smith said. "I will die from something other than prostate cancer, I guarantee you."