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Injections, gene therapy and treatment for infants raise hope for fighting AIDS

March 6, 2014 at 6:19 PM EST
News of three promising approaches raised hope at an AIDS conference this week: the prevention of HIV infections in monkeys through intravenous injections; the second successful treatment of a baby born with HIV; and a study showing the safety of genetically altering cells to prevent infection. Jeffrey Brown turns to Dr. Anthony Fauci of the National Institutes of Health to walk through the developments.
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GWEN IFILL: For all of the progress made in the fight against AIDS, it still takes a terrible toll. More than 35 million people are infected with HIV around the world. More than two million people are newly infected each year. And well over a million die from it annually.

But research released at an AIDS conference this week is raising hope about new inroads into treating it and preventing infections.

Jeffrey Brown has the story.

JEFFREY BROWN: Three reports attracted attention. One involved injections of drugs into monkeys that helped stop infections. A second revealed promising news of a baby born with the virus and given aggressive treatment. A third concerned so-called gene editing, altering cells to resist HIV.

The NIH’s Institute of Allergy and Infectious Diseases has been funding much of this work. Dr. Anthony Fauci is its longtime director, and he joins me now.

And welcome back.

So, let’s walk through some of this. First, the injections of long-lasting drugs into monkeys, explain the work and why it’s so important.

DR. ANTHONY FAUCI, National Institutes of Health: Well, the reason — the reason the work is important is that we know, in human studies, several human studies, that if you give a drug to an uninfected person who’s practicing risk behavior, we call it preexposure prophylaxis, that if they take the drug every day, it absolutely works and prevents infection in over 90 percent of the people.

The problem with the approach is that people don’t like to take medicine every day or before or after a sexual encounter. So, a modality of prevention that you know works 90-plus percent doesn’t work that well, purely because people don’t adhere.

The experiments that have been reported recently now show that, in a monkey model, if you take a long-acting drug, a drug that’s used in a different form to treat HIV infection, in a monkey model, and give an injection every so often, like every couple of months, you can actually prevent challenging that monkey with infection with the monkey version of HIV by exposing them rectally or vaginally.

It works in a very highly effective way. The extrapolation of that, is we now move that into human studies, we can take prevention in a way that people would adhere to it, because they don’t have to come for maybe three or so injections a year, and then be protected throughout the year.

So this addresses the real stumbling block of adherence in people with a drug that you know works. So, it’s really quite an important study.

JEFFREY BROWN: You know, I know we have talked about this several times over the years, about this problem of people taking the drugs regularly enough.

The key question, of course, now moving from monkeys to humans. What — where are we on that continuum?

DR. ANTHONY FAUCI: Well, they’re going to go right into studies now, in phase one studies in humans to determine if it works.

And the data in the monkey, Jeff, strongly, strongly suggests that it’s going to work in humans, but the proof of the pudding would be to do it and to see, in fact, if it does. So we’re right now gearing up to going into human studies.

JEFFREY BROWN: OK.

The second report, a lot of attention to this. There was a second case really of a baby born with HIV given aggressive treatment right away with great impact. So, tell us about that.

DR. ANTHONY FAUCI: Well, everyone remembers the story around the Mississippi baby from a few years ago, where a baby came in with a mother who was infected, but not treated during pregnancy, and the pediatricians immediately treated the baby within 30 hours.

And then the baby was treated for months, but the mother stopped therapy because she was lost to follow-up. And when the baby came back, the baby had been off therapy for many months, and there was no evidence at all of virus, which would indicate that the baby was cured.

What’s recently been reported now is a second baby that again came from an infected mother, but who didn’t have any anti-HIV treatment during pregnancy. The pediatricians treated the baby within the first four hours of birth. And now, eight, nine months later, there’s no indication of infection in the baby by trying to examine the cells.

What the investigators haven’t done is, they haven’t discontinued the drug yet, so it hasn’t been proven definitively that the baby’s cured, but it’s highly suggestive that you now have a second baby, because, even though the baby’s still on therapy, there’s no way of looking for the virus. It’s just not there. They have looked in the cells, and they can’t find it, strongly suggesting the baby is cured.

JEFFREY BROWN: And I understand, in this case, there’s going to be a new trial that will determine whether and how to apply this to all babies born with the virus?

DR. ANTHONY FAUCI: Exactly.

JEFFREY BROWN: Exactly.

DR. ANTHONY FAUCI: Exactly.

In order to have a real widespread utilization of this approach, you have got to prove its safety and the fact that it’s effective in a large number of babies. And the trial that will start in April or the beginning of May is going to do just that, look at babies who are born of infected mothers who aren’t treated and immediately, within the period of 48 hours, to treat them aggressively with anti-HIV drugs and to see if you can duplicate what we have seen in these two children.

JEFFREY BROWN: All right, and, finally, and this ones sounds — I think I’m right that it’s a little further away perhaps scientifically — but gene therapy, explaining — explain this idea of gene editing. The idea really is to make cells resistant to the HIV virus, right?

DR. ANTHONY FAUCI: Well, exactly.

What it is, you have someone who’s HIV-infected, who’s on therapy, suppressing the virus very well, and you want to ask the question, can you get the person off therapy or can you cure the person? One of the ways that’s been tried now in 12 patients is to take the blood out of the patient, take their cells, and in the test tube modify it, genetically manipulate it, so that it cannot be infected with HIV, grow it up in large amounts, and re-infuse it back into the person, with the hope that those modified cells will ultimately replace the normal, unmodified cells, and the body will be left with cells that are incapable of being infected with HIV.

So they have shown now, that, A., it’s safe, B., they have successfully modified the cells, they successful re-infuse them, and the cells seem to be surviving. We haven’t gotten to the endgame of showing that you have actually cured the person, but it’s a very important incremental step in that attempt to ultimately be able to protect people from the virus that’s in them, so that you don’t have to treat them with antiretroviral drug. It’s an important proof of concept.

JEFFREY BROWN: All right, well, it’s a very exciting week in AIDS research.

Dr. Anthony Fauci, thanks so much.

DR. ANTHONY FAUCI: Good to be with you.