Peptide-T Shows Promise as Anti-AIDS Drug

Peptide-T, a protein that some scientists believe may work as an anti-AIDS drug, has passed its first tests in humans, proving itself nontoxic but also showing tentative signs it reduces symptoms of the fatal disease.

Dr. Peter Bridge, deputy AIDS coordinator of National Institute of Mental Health’s intramural research program, said peptide-T now has been tested for a month in six AIDS patients and three people who are not infected with the human immunodeficiency virus, which causes AIDS.

The patients were given doses of the tiny protein every eight hours to see if it was toxic. The peptide is chemically synthesized in a laboratory, but is similar to part of a protein on the outside of the AIDS virus.

Effect on Infection Rate

Scientists at the NIMH believe this portion of the AIDS virus enables it to bind to and wreak havoc with human immune cells and brain cells. They also think the synthetic peptide-T may reduce the virus’ ability to infect cells and damage the nervous system by blocking its binding sites.

While the NIMH scientists have found that peptide-T was able to block the virus in test-tube studies, scientists at the Dana Farber Cancer Institute and Harvard Medical School in Boston were unable to duplicate the result under different conditions. NIMH scientists said the other lab used test levels of HIV that were unrealistic and swamped the protective effect of peptide-T.

In human trials, conducted at the University of Southern California-Los Angeles County Medical Center, the patients receiving the drug got increasingly higher doses, but showed no signs of toxic side effects, even at the highest concentrations used.

Symptoms Reduced

Although the test was not designed to see if peptide-T is effective as a treatment for acquired immune deficiency syndrome, Bridge said it did show signs of reducing symptoms. There was no evidence of the return of critical T4 lymphocytes--key immune cells killed by the HIV--but the patients did show improvement in brain and nerve function.

Bridge said the AIDS patients had better memory, motor speed, mood and other neuropsychiatric factors measured in a battery of tests given every 10 days. In addition to these encouraging findings, Bridge said the study also showed the “real merit” of neuropsychiatric tests in studying early effects of AIDS and drugs for treating it.

In addition, Bridge said, five patients gained from 2 pounds to 13 pounds while getting injections of peptide-T. Three of the patients were able to maintain this gain after they ended the month’s treatment.

Patients Less Fatigued

The AIDS patients said they felt more vigorous and less fatigued while getting peptide-T. A few patients who had impaired reflexes, watery diarrhea or psoriasis before starting peptide-T showed improvement in these symptoms while getting the drug.

Bridge said he “found these outcomes encouraging” and said he believes they were caused by the peptide-T, not chance effects. But he stressed, “It’s a preliminary study,” and said the effects would have to be confirmed in comparative blind trials.

But Wynne Beebe, a guest worker at the NIMH, said the drug deserved more attention. “It has been a source to me of growing horror and dismay that peptide-T has not received the prompt attention and excitement that it deserves. The scientific evidence that peptide-T is a logical, scientifically sound possible therapy for AIDS is compelling and overwhelming,” said Beebe, who is also an administrator for Integra Institute, a non-profit medical research organization in Delaware.

Testing in Sweden

Studies of peptide-T are also under way in Sweden, with data on a handful of patients supporting the California findings. Bridge said the next phase of the U.S. studies would commence this month and involve 36 patients. These will identify the maximum dose of peptide-T that can be given. If the drug continues to prove safe, larger trials of its effectiveness could start in 1989.

Dr. Candace Pert of the NIMH has led much of the research on peptide-T, and the Bristol-Myers Co. of New York, is likely to have exclusive marketing rights if it someday is approved as an AIDS drug.