REPORTER: At the International AIDS conference, delegates were presented with data from a new class of drugs that attack HIV at a different place from current medications. The drugs are called integrase inhibitors. Dr. Daria Hazuda explains how they work and why they are important.

Tell me a bit about integrase inhibitors -- the sort of the theory behind all of this.

REPORTER: Delegates at the International AIDS Conference were shown data from an experimental new drug called T-20. T-20 is part of a new class of drugs that attack HIV in a way different from current medications. Results from two trials in more than 1,000 patients worldwide are so positive that the FDA is expected to approve the drug within the year.

DANI BOLOGNESI: It’s a new class of antiretroviral agents, probably the first class -– major class since the protease inhibitors back in the 1990s. And like the protease inhibitors it addresses a medical need that cannot be met by existing drugs. It’s active against viruses that have developed resistance to all of the existing agents.

REPORTER: But there’s something new about it, right?

DANI BOLOGNESI: Yes. We just completed the first phase of two large phase three trials. This is the basically the registration information that we will submit to the NDA, and the results came out exceptionally well.

DR. JAMES TOMMAS: Many patients, especially in these two pivotal trials, have been under treatment for at least seven years and most of them on average have taken 12 medications. So these two studies are critical because it’s really the first time that a very treatment advanced – a treatment experienced patient population who are pretty much running out of options. Other therapeutic options have been studied with a new agent that has a new mechanism of action, and used with the available agents that we have can actually bring down viral load, result in some immune recovery and offers them some hope for staying well for a longer period of time.

DR. DANI BOLOGNESI: This is an agent that targets a completely different mechanism from the existing drugs. It prevents the virus from actually entering the cell, where as all the currently existing agents blocks steps in the virus cycle after the virus has infected the cell. So, it’s a different target. It’s outside the cell. It confers some important advantages for this struggle with the existing agent.

REPORTER: What are some of those advantages?

DR. DANI BOLOGNESI: Well number one, as a different genetic target it is non-cross resistant with the existing drugs. That means it’s going to be active against viruses that have developed resistance mutations to all three classes of existing agents. Secondly, it’s a large molecule. It cannot enter cells. It acts in the extra cellular space and that makes it non-pharmacologically active, which means that it does not interfere with intercellular processes and that endows it with a very benign safety profile, which is also unique in this field where management of toxicity with these very potent cocktails of drugs is really getting to be a problem.

DR. JAMES TOMMAS: T-20 because as Dr. Bolognesi indicated -- because it is a large molecule and doesn’t enter cells. It’s not processed in the normal way that other medications are so those systemic types of side effects, many of which patients have to deal with, those usually are not seen with T-20.

MALE SPEAKER: What are the side effects though?

DR. JAMES TOMMAS: Well, the primary side effect that we’ve seen in almost all the patients and consistently has been this small reaction of a redness and itching around the site of injection. T-20 has to be injected, much like the diabetic who has to take insulin.