Merck announced the U.S. launch of an expanded access program (EAP) for MK-0518, becoming the first experimental integrase inhibitor provided to patients outside of traditional clinical trials. For patients whose HIV is resistant to the three classes of drugs currently on the market, this EAP offers the possibility of controlling their viral load. “The data from the studies we’ve seen so far on MK-0518 can only be described as striking,” said Martin Delaney, Founding Director of Project Inform.

Integrase inhibitors block a middle step in HIV’s lifecycle. After HIV has entered a CD4 cell (T cell) and its RNA has been reverse transcribed to viral DNA, it must then be integrated into the CD4 cell’s DNA. The HIV DNA can then hijack the CD4 cell, turning it into a viral factory. MK-0518 blocks the viral DNA integration, hence its classification as an integrase inhibitor.

The EAP is essentially an open-label study of the drug. It will continue until approximately three months after MK-0518 has been approved by the U.S. Food and Drug Administration and made available through pharmacies.

To be eligible to participate in the EAP, which provides the drug, free of charge, to patients in need, candidates must have limited or no treatment options available to them due to resistance or intolerance to multiple HIV regimens, are not achieving adequate viral load reductions on a current regimen, and are at risk of serious disease progression.

Patients in the EAP will take 400mg of MK-0518, twice daily. It will need to be combined with other anti-HIV drugs selected by patients and their healthcare providers (Merck will not pay for the drugs being combined with MK-0518 in the EAP). The program will be managed by a clinical research organization (CRO). The CRO will collect all case report information including serious side effects.

Merck is calling the program “EARMRK,” which stands for Expanded Access Research Program from Merck. Patients and doctors interested in the program should call 1-877-EARMRK1 or go to

Delaney, who has been an AIDS treatment activist since before the first anti-HIV drug, AZT, was approved, said that the EAP of this integrase inhibitor “marks the beginning of new era in the treatment of HIV disease, particularly for people in the most advanced stages of the disease. Never before have we been in a position to offer people not one, but two of the most powerful new drugs at the same time, both of which show a striking ability to treat previously resistant virus. Just a little more than a month ago, the new protease inhibitor Prezista was approved, though for many people it still offered only one potent new drug. But the addition of an entirely new class of drugs, integrase inhibitors, takes us to a new place.”

Delaney adds, “even when used with regimens that are clearly failing and to which the virus is resistant, the integrase inhibitor brings a majority of people to the goal of ’undetectable’ virus. Moreover, it seems to suppress viral load more quickly than any drug we’ve ever seen. People who had given up all hope of ever becoming undetectable should routinely reach that goal.”