Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

HIV & AIDS Health Center

Font Size

New AIDS Drug 'Incredibly Encouraging'

Isentress Works When All Other AIDS Drugs Fail, Study Shows
WebMD Health News
Reviewed by Louise Chang, MD

March 1, 2007 -- "Incredibly exciting." "Road to hope." "Very exciting." "A very important milestone in HIV treatment history."

That's what major AIDS researchers are saying about Isentress, the first of a new class of HIV drugs. Early results from two major clinical trials of Isentress were reported this week at the largest annual U.S. HIV conference.

Patients in the studies had run out of treatment options. After a decade of treatment, the HIV in their bodies had become resistant to at least one drug in each of the three classes of AIDS therapies. Their immune systems had begun to fail and they had high blood levels of HIV.

But when these patients took Isentress in combination with other powerful AIDS drugs, nearly 80% of patients saw their HIV levels plummet to near-undetectable levels after 16 weeks of treatment. Without Isentress, state-of-the-art treatment helped only 43% of patients to this degree.

Joseph J. Eron Jr., MD, of the University of North Carolina-Chapel Hill, reported the combined findings from the studies at the 14th annual Conference on Retroviruses and Opportunistic infections.

"This is a very important milestone in HIV treatment history," Eron tells WebMD. "These are results we would have been happy with in treatment-naive patients. And these are our most drug-experienced, drug-resistant patients -- the ones for whom it is most difficult to come up with treatment options.

"It really moves us into an era where even our most treatment-experienced patients have the opportunity to get their virus below detectable limits," Eron adds.

New AIDS Drug, New HIV Target

HIV makes three proteins, called enzymes, which it needs to infect human cells. The AIDS virus uses its reverse transcriptase enzyme to translate its RNA genetic code into DNA. Later, after it has made human cells produce new viral proteins, it uses its protease enzyme to snip the proteins into the right size.

Nearly all existing HIV drugs block either reverse transcriptase or protease. But Isentress blocks an enzyme called integrase. HIV needs integrase to integrate its newly translated DNA into the DNA of human cells.

Researchers have worked for years to develop an integrase inhibitor. Until recently, that goal was elusive. Now that work is paying off. Isentress, from Merck, is the first of its kind. But others are on the way.

1 | 2 | 3

Today on WebMD

How much do you know?
contemplative man
What to do now.
Should you be tested?
HIV under microscope
What does it mean?
HIV AIDS Screening
man opening condom wrapper
HIV AIDS Treatment
Discrimination Stigma
Treatment Side Effects
grilled chicken and vegetables
obese man standing on scale
cold sore