March 1, 1998
Treatment of AIDS has come a long way, says Juan Lertora, professor of medicine and principal investigator of the Tulane/Louisiana State University AIDS Clinical Trials Unit (ACTU). While a decade ago there existed only one drug, AZT, to stem the development of the disease, clinicians at the Tulane/ LSU ACTU are now studying new treatment regimens that use a cocktail of drugs to drive down the levels of the human immunodeficiency virus (HIV) that causes AIDS.
Recent data from the Centers for Disease Control show a steep reduction in AIDS deaths, which dropped by nearly half during the first six months of 1997, largely due to these new treatments, experts say.
"We have made remarkable progress in terms of what we can offer patients to treat them for HIV infection and AIDS, and the mortality of AIDS has declined significantly over the last three years," Lertora says. "Yet we have not achieved complete victory in terms of eradicating this infection."
One of 30 ACTUs funded since 1987 by the National Institute of Allergy and Infectious Diseases, the Tulane/ LSU unit has taken part in nationwide drug studies performed on volunteers to test the safety and effectiveness of new AIDS therapies. Newton Hyslop, chief of infectious diseases, is the co-principal investigator for Tulane University Medical Center, and Rebecca Clark, director of LSU's HIV division, is the co-principal investigator for LSU Medical Center.
Tulane and LSU have also joined in a Pediatric AIDS Clinical Trials Unit. Currently, the adult unit is in the middle of a four-year cycle of studies begun in 1996. The studies range from investigating different drug combinations that stop the HIV virus from making copies of itself to researching ways to treat "AIDS-related wasting syndrome," the extreme weight loss that afflicts some HIV-infected people.
The Tulane/LSU ACTU currently follows approximately 100 patients at its two locations--on the fifth floor of Charity Hospital at the General Clinical Research Center and at the LSU sub-unit on South Roman Street. Clinical studies performed at Tulane and LSU and other units have been instrumental in developing the "triple cocktail" approach to treating AIDS.
This treatment involves three drugs, usually two reverse transcriptase inhibitors, such as AZT, and another drug in a class called protease inhibitors. "A term we use to describe this treatment is HAART, highly active antiretroviral therapy," Lertora says. For roughly two thirds of patients, HAART has proven "to inhibit the replication of HIV to the point that the virus becomes undetectable in plasma, which is how we measure the viral load of a patient," he says. "However, the triple-drug combination does not completely repress viral replication in perhaps a third of the patients. We can lower the viral load, but then these patients reach a plateau."
Another complication is the development of resistant strains of the virus in people who fail to follow the strict regimen of multi-drug therapy or quit taking the drugs because of side effects. Some patients also take other drugs for AIDS-related diseases such as pneumocystis carinii pneumonia, which adds to their already complex treatment.
"The number of pills that a person has to take on a regular basis is significant," Lertora says, "and that is why the patient has to be well-informed in terms of the value of the treatment and in terms of sticking to the schedule."
To adequately curb the virus level in patients, these multi-drug therapies must last indefinitely, he says. "So far we don't have enough data from clinical trials that tell us we can discontinue treatment and still maintain viral suppression," Lertora adds. "I think that day will come, considering all the progress we've made over the last 10 years."
Although he acknowledges significant advances in AIDS treatment, Lertora says, "it's important that we not lower our guard and become complacent about this problem. The greatest challenge ahead is developing therapy for patients who don't respond when treated and those that develop resistant strains of HIV. We still need volunteer patients to develop information that can only be obtained through clinical trials."
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