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Project Inform Applauds Approval of Viral Load Tests

Project Inform applauded today’s announcement of the FDA approval of the AMPLICOR HIV MONITOR test, an accurate and precise method of measuring the amount of HIV RNA in blood by using new PCR (polymerase chain reaction) technology. Several recent studies have shown that viral load (the number of copies of HIV RNA circulating in an individual’s blood), both before and during treatment with antiviral drugs, is predictive of clinical progression of HIV disease. Nearly all clinical trials of antiviral drugs use this or a similar test to measure the effect of drugs on viral activity levels. Physicians who have access to the tests routinely use them to monitor the effects of treatment and to assess their patients need for therapy.

Martin Delaney, Project Inform’s Founding Director, commenting on the announcement, said “There has been a tremendous need within the HIV community for wider availability of viral load tests. Many third party payers, as well as the federal government, have refused to make these tests available to HIV-infected people, citing the lack of FDA approval and calling for more proof of their predictive value. This debate ends with the FDA’s action. New studies presented in the last six months have ended most of the scientific debate about these test. Once this test is integrated into common clinical practice, physicians will be able to treat HIV disease in a far more effective and rational manner than ever before.”

“Managed care organizations, Medicare and Medicaid must now begin paying for these tests,” noted Ben Cheng, who has followed the development of viral load testing for several years. “At the same time, Roche must now do its part to make this test available for people who do not have insurance or are under-insured.”

Delaney and Cheng noted that the approval of the test doesn’t mean that all questions have been answered about how to use the test. Delaney commented, “It is still not clear what level of HIV RNA on this test should be used as the threshold to initiate therapy or how often the test should be used, but we may never have precise answers to such questions. Many additional clinical trials are already underway which will help refine the use of the tests over time.” Cheng added “Viral load is one critical component in managing patients, but it is not the only piece of information a physician needs. Other factors, such as CD4+ counts and the patient’s overall condition, will still have to be taken into effect. Just as important, patients and physicians must understand that viral load testing will not help predict the onset of opportunistic infections. Routine CD4+ testing will still be necessary.”

In addition to the AMPLICOR HIV MONITOR test, two other tests are being developed to monitor HIV RNA levels. Chiron is developing bDNA (branched DNA) and Organon Teknika is developing NASBA (nucleic acid sequence-based amplification). Most laboratories in the U.S. have experience with one of these three tests. Preliminary studies comparing the three different tests indicate that these tests give similar results, although NASBA may produce slightly higher HIV RNA copy numbers. Confirmatory studies need to be done to determine whether these three tests can reliably give the comparable HIV RNA copy numbers.