Antiretroviral agents have prolonged thousands of American lives, but researchers continue to seek treatment improvements and new classes of drugs, hoping one day to tailor treatments based on patients’ genetics as the burgeoning pharmacogenomics research movement enhances individualized health care options.
And while many patients benefit from current treatment options, there has been no decline in the number of patients becoming infected with HIV in the last decade – approximately 40,000 new infections are reported each year in the United States. What has changed is the demographics of those who become infected – women and minorities are more likely to become infected with the virus than white men, with women representing one-third of the new reported cases of HIV infection.
That’s an important component of current research, says Dr. Michael Para, a nationally recognized AIDS expert and infectious diseases specialist at OSU Medical Center. Para is co-principal investigator for the AIDS Clinical Trials Unit at OSU Medical Center, where scientists supported by federal funding are seeking the next generation of agents able to fight the most resistant strains of the HIV virus and exploring ways to reduce the damaging side effects of current medications.
“As we look for new therapies for all diseases, if we just study their effectiveness in men, then we really don’t know if they work in women. If we just study whites, we’re not going to know how well they will work in African Americans. The problem is, we have too few African Americans participating in trials. We need more minorities and women to be in studies to know if the treatments will work for them,” Para said.
One example, he noted, is an anti-HIV drug that has been in use for over six years, which was just recently noted to have higher toxicity in African-Americans patients. Once AIDS researchers noted this difference, they then discovered the drug was eliminated from the body more slowly in blacks.
The AIDS Clinical Trials Unit at OSU Medical Center conducts numerous studies, examining the effectiveness and safety of new agents as well as how patients who have never taken antiretroviral drugs tolerate newer drugs. In addition, the researchers are exploring ways to counter some of the most complicated side effects of the current drug regimens, especially ways to keep cholesterol levels in check.
“We also look at genetics, because people metabolize drugs differently. When medicines appear not to be working, we usually suspect poor medication adherence. But it may turn out that it’s not really the patient’s fault – it’s just that their metabolism has excreted the medication faster,” said Para, also associate dean for clinical research and the Pomerene Professor of Infectious Diseases at OSU.
Though the New York case raised awareness of the possibility of drug-resistant strains of HIV, the phenomenon in general is not new, Para said. Resistance to the three classes of anti-HIV drugs develops like other types of antibiotic resistance: People who have low levels of anti-HIV medications or antibiotics do not completely eradicate their infection. With HIV, like bacteria, the viruses that are not killed by these lower levels of drug are the viruses that are more resistant to the medication.
“A virus or bacteria that’s not easily killed is more resistant,” Para said. “What’s different between drug-resistant HIV and drug-resistant bacteria is that the resistant HIV virus is transmissible. So if someone carries or develops a drug-resistant strain of the virus, that is what they will spread.”
In all, about 10 percent to 15 percent of patients with HIV are infected by a virus that is resistant to one of the three classes of antiviral drugs. About 5 percent are resistant to two classes of drugs. A smaller percentage of patients are infected with a strain resistant to all three classes of the most commonly prescribed anti-HIV drugs, as was found in the New York patient.
“Our biggest concern is that these drug-resistant viruses will continue to be increasingly common,” Para said.
In general, treatment has done a good job of keeping HIV-positive patients alive, including celebrities who have become infected, which may contribute to a public sense of complacency about the disease.
“I think because there is treatment out there, and there is not as much press about those dying from AIDS, people no longer consider this infection a death sentence and they think prevention isn’t as important,” Para said. “Ten or 15 years ago, surveys showed that personally knowing someone who had died of AIDS was the strongest motivator to change behavior and act to prevent infection.
Fewer patients dying of the virus is a good outcome, of course, but public education about prevention should not stop because of that.”
Ohio State HIV and AIDS experts are working on that front, as well. Para is the principal investigator on a federal grant to provide AIDS education and training to health care providers in Ohio. He and colleagues travel the state to educate doctors, nurses, physician assistants, pharmacists and other providers who treat and care for patients with HIV infection or who are at risk for HIV, sharing the latest treatment information and offering prevention training as well.