WASHINGTON--A new survey of pharmaceutical and biotechnology companies by the Pharmaceutical Research and Manufacturers of America (PhRMA) has identified 122 drugs and vaccines in testing to prevent HIV infection or to treat AIDS and AIDS-related diseases. These drugs are in addition to the 42 medications already approved and on the market in the United States.
The number of medicines in development increased by 12 from the 110 reported a year ago, the trade association said. The number of drugs on the market increased by 8 during the same period, from 34 to 42.
A breakdown of the medicines and vaccines now in development shows that 41 are antiviral agents. Anticancer agents account for 19; anti-infective agents, 18; vaccines, 13; immunomodulators, 10; and gene therapy approaches, four. Another 17 new pharmaceuticals fall into the "others" category.
"These potential new AIDS medicines use both new and already proven approaches to stopping or mitigating the disease," said PhRMA President Alan F. Holmer. "The progress already made against AIDS is quite remarkable, given the fact that the first US cases were reported in 1981, and the virus was only identified in 1983."
One of the anticancer drugs, Zyrka-mine (mitoquazone, ILEX Oncology/Sanofi Winthrop) has been submitted to the FDA for approval for use against AIDS-related non-Hodgkin's lymphoma, noted John D. Siegfried, PhRMA's deputy vice president for regulatory and scientific affairs.
"Scientists are becoming increasingly optimistic about the prospects for turning AIDS into a manageable chronic disease," Dr. Siegfried said. "Their optimism appears justified."
He noted several reasons for this more hopeful outlook:
- Over the last four years, new medicines have doubled the life expectancy of people infected by HIV.
- The increasing variety of today's AIDS medicines are proving increasingly useful against the HIV problem. These include new immunomodulators to boost the body's immune system, 10 of which are now in testing in humans.
- The new protease inhibitor drugs, which interfere with the protein that HIV needs to replicate, have lowered the HIV viral content in the blood of some patients by up to 99%. Protease inhibitors prove most effective when they are used as part of a three-drug "cocktail."
Research reported at the Third International Congress on Drug Therapy, held in Birmingham, England, is even more encouraging, Mr. Holmer said. Researchers from the University of Amsterdam reported that combination drug therapy eradicated the AIDS virus, not only from the blood of infected individuals but also from the tonsillar tissue.
"This is important new information," he said, "because it had been feared that small amounts of HIV would 'hide' in a patient's cells, such as in tonsillar lymphoid tissue, escaping detection."
While commenting that the cocktail combination therapy is expensive, costing between $10,000 and $16,000 per patient per year, Mr. Holmer also stressed the cost of treating an HIV-infected person who progresses to AIDS. "It costs an estimated $100,000 a year to treat a patient with full-blown AIDS in a hospital," he said. "In the long run, these drugs will not only save lives, they will save money, too."
Besides new drugs, scientists have developed new tests to gauge the amount of HIV virus in the body. Said Dr. Siegfried: "The new tests are important because they help doctors determine how effective a particular drug is and when it may be necessary to change therapy."