Results 1 to 3 of 3

Thread: Drugs to Spur New Cells, and Without the Politics

  1. #1
    Senior Member Jeremy's Avatar
    Join Date
    Jul 2001

    Drugs to Spur New Cells, and Without the Politics

    Thursday December 13 09:07 AM EST

    Drugs to Spur New Cells, and Without the Politics

    By ANDREW POLLACK The New York Times
    As debate again heats up over cloning and stem cell research, several biotechnology companies are trying to develop a far less controversial approach to cell regeneration.

    IRVINE, Calif. As debate again heats up over cloning and stem cell research, several biotechnology companies are trying to develop a far less controversial approach to cell regeneration.

    The companies are actively working on drugs that stimulate the brain and other organs to grow new cells and repair themselves.

    Drugs do not face the same problems with rejection by a recipient's immune system that cells and tissues often do. And in most cases, giving drugs would not require the surgery that might be needed to implant new cells grown from stem cells.

    "It's certainly a lot easier to swallow a pill or take a spoonful of liquid than to have a hole drilled in your head and have embryonic stem cells put in," said Alvin J. Glasky, chief executive of NeoTherapeutics, a small biotechnology company based here that is working on a berry-favored medicine to stimulate the brain to grow new cells.

    In addition, big pharmaceutical companies, which have been largely uninvolved in stem cell research, might be more interested in developing drugs to promote new cell growth. While cell therapies often require the use of a patient's own cells a customized approach that is a departure for big drug companies drugs that promote new cell growth could be mass-produced.

    "We can look forward to the time when any cell in the body can be regulated with natural factors to grow or be inhibited from growing," said William A. Haseltine, chief executive of Human Genome Sciences. The company, based in Rockville, Md., is using a process of gene-hunting to find proteins that act as growth factors and is already testing in patients a protein that stimulates the healing of wounds.

    "That is the medicine that will be the new medicine for the next 20 years," he said. "Stem cells and their uses will be very limited because we don't know much about them."

    The drug approach to new cell growth has already produced some successes. The biotechnology industry's most lucrative drug, for example, is Amgen's Epogen, which fights anemia through a human protein that stimulates the body to produce red blood cells. A protein developed by Curis Inc. of Cambridge, Mass., stimulates bone growth and is used as an alternative to a bone graft to treat fractures that do not heal.

    Still, using growth factors is not as easy as it sounds. Human Genome Sciences' wound-healing protein just failed to work in two clinical trials. And Regeneron Pharmaceuticals of Tarrytown, N.Y., has tested various nerve growth factors to treat illnesses like Lou Gehrig's disease and Parkinson's disease. The company's trials, some done in partnership with Amgen, have all failed. "We are experts in all this, and we've only been increasingly humbled by how difficult it is to create structure," said George D. Yancopoulos, Regeneron's chief scientific officer.

    The interest in stimulating the body to heal itself has been spurred by discoveries in recent years that organs like the brain and heart, which were thought not to have the ability to regenerate, appear to do so in certain circumstances. Various organs have been found to harbor small quantities of stem cells that can turn into specific types of cells to repair damage.

    But many scientists and biotechnology executives say they doubt that the drug strategy will work. The fact that people do not recover on their own from brain injuries or heart attacks probably indicates that the body cannot produce enough stem cells to make a difference.

    "Certainly being able to deliver the required number of cells directly from laboratory-isolated stem cells seems more straightforward technically," said Karl Johe, chief scientist at NeuralStem Biopharmaceuticals, a company working on cell therapies for brain disease.

    Some scientists say drugs will work better for some diseases, cells for others. Pancreatic cells are already restoring the ability of some diabetics to produce insulin.

    Growth factors can also stimulate the wrong cells, causing unintended effects. In Regeneron's tests, nerve growth factors in some cases made people sensitive to pain or changed their behavior, Dr. Yancopoulos said. Yet some of those unintended effects may help salvage Regeneron's business. One nerve growth factor, instead of alleviating a disease, made people feel full, and is now being tested as an obesity drug.

    Both Genentech and Chiron failed in clinical trials using growth factors to stimulate the body to grow new blood vessels and bypass clogged arteries.

    But despite the setbacks with growth factors, work is continuing. James H. Fallon, professor of anatomy and neurobiology at the University of California at Irvine, reported that a protein called transforming growth factor alpha stimulated the stem cells in the brains of rats to proliferate and migrate to the site of injuries similar to those caused by Parkinson's disease. The stem cells turned into neurons and repaired some of the damage. The work was partly sponsored by Stem Cell Pharmaceuticals, a private company in Seattle that wants to harness the growth factor as a drug.

    Dr. Piero Anversa and colleagues at New York Medical College in Valhalla, N.Y., used drugs to treat mice with heart attacks. The two drugs stem cell factor and granulocyte colony stimulating factor stimulated the bone marrow to produce numerous stem cells, which entered the bloodstream, migrated to the damaged heart, and turned into new heart muscle. Only 4 of 27 mice given the drugs died from their heart attacks, compared with 43 of 52 that had not been given the drugs.

    In some cases, drugs will not be any easier for patients than cell implants. The brain, for instance, is protected by a barrier that keeps out large proteins, so growth factors must be injected directly into the brain, just as for a cell implant.

    Several companies are trying to develop so-called small-molecule drugs that can be taken orally and can pass through the blood brain barrier, but this has not proved easy. Amgen and Guilford Pharmaceuticals announced in July that such a drug was not effective in a clinical trial in treating Parkinson's disease.

    NeoTherapeutics now seems to be the front-runner in the oral drug approach. Its drug, Neotrofin, appears to be able to stimulate the production of certain nerve growth factors and stem cells in animals. The drug is being tested on Alzheimer's disease patients in a late-stage clinical trial and, if all goes well, it could reach the market by 2004. NeoTherapeutics has also begun testing the drug on patients with Parkinson's disease and spinal cord injuries.

    Many investors and other scientists are skeptical, saying that Dr. Glasky has a reputation for making premature claims of success. For instance, he said in an interview that Neotrofin might work for every neurological disease, potentially becoming the biggest-selling drug ever.

    Neotrofin failed in the first big clinical trial, though the company says it now realizes it used too small a dose. Its shares closed yesterday at $3.80, down from a high around $24 early in 2000.

    "It's like the boy who cried wolf," said Harry M. Tracy, publisher of NeuroInvestment, a newsletter that follows companies developing treatments for neurological diseases. "People are very wary of taking him seriously." Still, he thinks there is a chance that the company will succeed. Results of the Alzheimer's clinical trial are expected early next year. Whether the drug works or not, he said, "they are going to know that a whole lot sooner than they'll know that about embryonic stem cells."

    "If the wind could blow my troubles away. I'd stand in front of a hurricane."

  2. #2
    Yayyyyyy! Neotrophin could be on the market by 2004!

  3. #3
    Senior Member vgrafen's Avatar
    Join Date
    Sep 2001
    chico, ca, usa
    Could be. I'd add at least a year to that claim, probably more. Call me pessimistic but...


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts