This Month in HIV: Breaking HIV/AIDS Research From CROI 2007
Another of your areas of expertise is salvage therapy or, as I prefer to call it, rescue therapy. What was the big news at CROI for people with multidrug-resistant HIV?
This was the best year ever, I think. It reminds me of '96, '97, back in the days where we were so excited about HAART. This is a second wave of HAART. We had data presented about the Merck integrase inhibitor, and about Pfizer's maraviroc, an R5-tropic virus inhibitor. And, yes, we saw some data on TMC278, which is a non-nuke [non-nucleoside reverse transcriptase inhibitor or NNRTI] -- although the data was for naive patients -- and also TMC125 [etravirine], which is also a non-nuke that has been tested in patients with multidrug resistance.
So we're very excited. The response rates are really good, especially for the Merck MK-0518 [raltegravir] integrase inhibitor. [Click here to read coverage of these studies.] We've never seen that kind of response in people with multidrug resistance -- around 79%.
Seventy-nine percent of patients who took MK-0518 plus other durgs selected by their doctors had a viral load under 400 at week 16, I believe.
Seventy-nine percent of people.
What's the usual percentage of people with multidrug resistance who respond? It's like 30, or something?
Even back a year ago, two years ago, the Tibotec TMC114 data: 50. After 48 weeks, 45 to 50 percent of people ...
Yes. Over 45 percent of people taking darunavir had a viral load under 50 at 48 weeks. Tipranavir, actually showed similar results. This is with one additional active agent, by the way. We forget that. We always talk about drugs, but we very seldom talk about their background -- their optimized background therapy: what the patients take with that drug, how many patients actually have one more active agent with that drug. Of course, the more active agents, the better the response.
"The most interesting, and the most exciting, part of this study [on the integrase inhibitor MK-0518], was the side effects, or the lack of side effects. We didn't see any increases in cholesterol or triglycerides ... compared to all the other drugs we've seen in the past, it looks like a very friendly class."
So the 79 percent number was with one [other active agent]?
Yes. I think it came down to 60-some percent without.
The biggest number was 90 percent, with darunavir.
Yes. That's with Fuzeon, with Fuzeon or darunavir. Yes. If you had two active agents and you took the Merck product MK-0518 almost 100 percent of those patients responded. These are patients that had multidrug resistance -- they had an undetectable viral load on this regimen. Of course, let's keep in mind that this is ... I think this was week 16 data. Although some data may actually show in the future that it is a very strong response, anyways. It's too early to judge how useful MK-0518 will be, but it looks very good.
The most interesting, and the most exciting, part of this study, was the side effects, or the lack of side effects. We didn't see any increases in cholesterol or triglycerides with the integrase drug. There's some flatulence and some problems like that, but really, compared to all the other drugs we've seen in the past, it looks like a very friendly class. I'm very excited. I think the integrase class is going to make a huge difference for those that are in what we call rescue or salvage therapy.
The maraviroc R5 inhibitor also looks very strong, very good, so far. We've been afraid of that class for a while because of fears of what happens when you block a receptor on the T cells, what happens long-term. We were afraid of lymphomas. It didn't seem like lymphoma was a big issue there. Of course, as I said, we need more time. Sometimes things show up after a long time. But this is going to be a drug that may help 50 percent of patients with HIV, because not everybody's going to be lucky enough to have an R5-only virus. You know, 50 percent of us may have a dual-tropic strain of HIV -- meaning our virus uses both an R5 and an X4 receptor.
The CCR5 inhibitor only works on people with the R5 virus, but most people who are just diagnosed probably have an R5, right?
Yes, however, it's almost impossible to predict who is going to have R5 or X4 receptors. There are some studies that show the higher your T cells levels the better your chances of being R5 only. The longer survivors like myself: We may be more likely to be dual-tropic, possessing both X4 and R5 receptors. We don't know. But the only way to find out is doing the test, a tropism test -- Trofile, it's called -- that will be provided as part of the expanded access program for maraviroc, which is starting right now.
"Most academic settings, universities, are not providing expanded access, because it's too expensive for them."
Expanded access means that people can get it for free through their doctors?
Yes. Those drugs have not been approved by the U.S. Food and Drug Administration. They are in the process of hopefully being approved. Companies basically provide the drug for free for anybody that needs them, as long as your doctor applies for it. Not every doctor is willing to apply for EAPs [expanded access programs]; it takes a lot of work, and most doctors will not get paid for that work. So not every patient is lucky enough to have a doctor that provides access to new drugs through expanded access. That's very important to make clear, because people assume that expanded access is available to anybody in this country; it is not.
Well, couldn't you bring it to the attention of your doctor, somehow? And see how you can expedite it?
Yes. But he or she can still show no interest, due to manpower. Most academic settings, universities, are not providing expanded access, because it's too expensive for them. So what you have to do if you are a patient and you need help ... Well, I have a Web site: salvagetherapies.org. You can go there and e-mail me, too; my e-mail is there. And there are sites in every city, and every drug has a Web site. Some of them are listed, some of them are not. But you can always go to my Web site, and I can probably help you find somebody in your city that will help you get expanded access if you need it.
However, I tell people: Not everybody needs new drugs. If your viral load is stable and your T cells are not under 250 or 200, you're pretty healthy; you can wait till these drugs get approved. Then, wait. If you're really in dire need, meaning, your health is declining, your T cells are low, your viral load is high, you've tried everything you can, you've tried Fuzeon [enfuvirtide, T-20] then enrolling in an expanded access program is probably a good thing to be thinking about and talking to your doctor about. But as I said, let's not assume that everybody has access to expanded access programs in this country, because it is not true.
Copyright © 2007 Body Health Resources Corporation. All rights reserved. Podcast disclaimer.
This article was provided by TheBody. It is a part of the publication This Month in HIV.
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