Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, May 28, 1995 TAG: 9505270004
SECTION: BUSINESS PAGE: F2 EDITION: METRO
SOURCE: LAURAN NEERGAARD ASSOCIATED PRESS
DATELINE: SAN FRANCISCO LENGTH: Medium
Called cidofovir, the drug's early promise is starting to attract attention to this class of medicines to fight not just AIDS infections but the HIV virus itself, experts say.
``We believe this class of drugs does confer some real advantages to patients,'' said Dr. Howard Jaffe of Gilead Sciences, which is preparing to seek Food and Drug Administration approval of cidofovir to treat cytomegalovirus, an infection that blinds one-third of patients with advanced AIDS.
Cidofovir was one of several early but promising biotechnology drugs - including a test to predict who gets osteoporosis and possible leukemia fighters - unveiled at a meeting of the Biotechnology Industry Organization, which once a year gives a peek at what's in the pipeline.
Much research remains to be done on most of the products, the companies and outside experts cautioned, although FDA approval of the osteoporosis test is expected this year.
The new antivirals are nucleotide analogs, a cousin to the nucleoside analogs AZT and others already on the market. Existing AIDS drugs have a major problem: They cannot protect uninfected cells for very long.
Nucleotides, however, last possibly three times as long. Also, drugs for AIDS co-infections often cannot protect uninfected cells, allowing some diseases to spread rapidly. Nucleotides have a different chemical structure that allows them to enter any cell and immediately begin working without waiting to be ``turned on,'' explained Dr. Arnold Friedland of St. Jude's Children's Hospital.Tests at 10 hospitals show cidofovir fought progression of blindness for 120 days, vs. just 50 days for the standard treatment now in use, Jaffe said. Prompted by this success, Gilead is starting early human testing of an oral HIV drug that would work similarly, although results are several years away.
``Prompted by this new data, people are beginning to think these compounds might work,'' said Friedland, who is beginning tests with the HIV drug in children. ``There is cautious optimism.''
Also in the pipeline:
A quick, cheap urine test to tell who is most at risk of devastating osteoporosis, the bone-destroying disease that afflicts 25 million Americans, mostly post-menopausal women.
The test, developed by Metra Biosystems of San Francisco, could detect how much bone is lost daily to osteoclasts, bone-eating cells that go out of control in osteoporosis, explained Dr. Claude Arnaud of the University of California, San Francisco.
Doctors now predict osteoporosis with a bone density scan, a complicated and expensive test that doesn't detect a problem until patients already have lost a lot of bone, Arnaud said. The urine test could tell the rate of bone destruction before large losses occur, letting doctors know which women could benefit most from taking estrogen, a hormone that fights osteoporosis but that isn't given to everyone because of side effects.
Much earlier in development are two drugs that might prolong survival of patients with acute myeloid leukemia, which hits 10,000 Americans a year, only up to 20 percent of whom survive long-term.
Chemotherapy to kill the cancer also kills the bone marrow that makes people's immune cells, and often misses hidden leukemia cells.
Patients with compatible bone-marrow donors often can survive, but others are forced to save part of their own cancer-infected bone marrow to keep them alive after chemotherapy.
Medarex Inc. has genetically engineered an immune fighter called a monoclonal antibody that, when added to a patient's stored marrow, binds to and kills remaining cancer cells, said company President Dr. Donald Drakeman.
One test found patients survived 2 1/2 to seven times longer than with standard chemotherapy. Clinical trials should begin later this year.
``This is very exciting,'' said Jean Whalen of the Leukemia Society of America. ``With AML there is almost no hope, and this product could be critical'' if this year's testing confirms it works.
by CNB