New Type of Drug Builds Bone -- and More
Safer Kind of Estrogen May Help Women and Men
Oct. 24, 2002 -- An estrogen-like drug reverses bone loss without estrogen's side effects. The startling discovery promises novel treatments for age-related bone loss, heart disease, and even Alzheimer's disease.
This makes Stavros Manolagas, MD, PhD, one happy scientist. His theories -- once scoffed at -- have opened the floodgates to what promises to be a stream of new drugs for a wide variety of conditions.
Manolagas is director of the Osteoporosis and Metabolic Bone Diseases Center in Little Rock, Ark., funded by the Veterans Administration and the University of Arkansas. For years, he's suggested that the sexual -- and sometimes cancer-promoting -- effects of the female sex hormone estrogen can be separated from its healthy effects on bone, heart, and brain.
"It's not just me -- lots of people for the last 40 years have talked about this, but nobody listened," Manolagas tells WebMD. "There was no evidence until we came upon these striking effects in bone cells. Even after we reported these findings last year, a lot of people weren't convinced."
The world now is taking notice. In the Oct. 25 issue of Science, Manolagas and colleagues report that a new type of drug -- dubbed estren -- rebuilds bone in mice. In fact, it worked even better than estrogen in female mice. Amazingly, it also worked in male mice. And the drug had no effect on sex organs.
"What we are trying to do is keep the beneficial effects of estrogen while eliminating the side effects," Manolagas says. "If we have the bone, heart, and brain protection of hormones without hormone side effects, we can have our cake and eat it, too. This is proof in an animal that not only do these activities exist, but that the synthetic compound can have superior biological effects to the natural hormone."
Jill Carrington, PhD, of the National Institute of Aging's biology of aging program, says the findings may one day lead to treatments for many age-related problems.
"This really points out a new direction to follow in order to develop treatments for osteoporosis -- and it may have broader implications than that," Carrington tells WebMD. "Particularly in light of the questions now being asked about current hormone-replacement therapies, this is very important."
Silvina Levis, MD, director of the osteoporosis center at the University of Miami in Coral Gables, Fla., warns that it remains to be seen whether estren or similar compounds can become safe and effective drugs.
"This is very exciting. We just have to see if whether these findings in mice translate to human beings," Levis tells WebMD. "It is interesting, it is novel, but we are a long way from having a new treatment."
Manolagas says it will be two or three years before an estren-like drug is ready for human safety tests. A start-up firm, Anabonix, shares development rights with the University of Arkansas.
'I think this is a new area of pharmacology," Manolagas says. "We are talking about something that affects all the tissues of the body. As far as we can see these effects are happening across the board."
For example, Manolagas speculates, estren-like compounds might protect brain cells against the toxic effects of beta amyloid -- suspected to be the main culprit in Alzheimer's disease. -->