The US Food and Drug Administration last week approved two HIV-1 viral load prognostic tests from Roche and Abbott.
Following the approval of its Cobas AmpliPrep/Cobas TaqMan HIV-1 Test, Roche highlighted that its fully automated HIV-1 diagnostic tool using PCR technology is the first of its kind and an improvement over earlier-generation tests because it yields a wider range of viral load data.
The Cobas AmpliPrep/Cobas TaqMan HIV-1 Test “is the first fully automated HIV-1 diagnostic tool using real-time PCR technology in the US,” Roche said in a statement.
Roche’s test can be use to assess patient prognosis by measuring the baseline HIV-1 (Group M subtypes) RNA level or to monitor the effects of antiretroviral therapy by measuring changes in EDTA plasma HIV-1 RNA levels during the course of antiretroviral treatment, the company said.
Abbott Laboratories' HIV-1 viral load prognostic test for use on its m2000 RT-PCR platform measures the levels of HIV circulating in a patient's bloodstream, including the three common HIV-1 groups and non-B subtypes. Similar to Roche’s product, Abbott said the test is used for disease prognosis and to assess response to antiretroviral treatment.
PCR-based testing of HIV-1 viral load was introduced to the market more than a decade ago, and has been the standard of care ever since. Roche holds the distinction of launching the first standardized quantitative PCR kit in the US in 1995, which the FDA approved the following year.
Although both Abbott’s and Roche’s products are PCR-based viral load tests used to assess patients’ prognosis and response to antiretroviral treatment, the similarities and differences between the two tests were not immediately clear. Abbott did not return requests for an interview prior to deadline. However, following FDA approval of the products, each company chose to highlight different aspects of its test, with Roche focusing on automation and Abbott touting the sensitivity of its diagnostic.
Roche’s Cobas AmpliPrep/Cobas TaqMan HIV-1 Test
According to Roche, the advantage of its product lies in its automation. “Roche is the only automated real-time PCR system with ready-to-use and easy-to-load reagent casettes, eliminating manual preparation steps required on other systems,” Jeff Heimburger, international business leader at Roche Molecular Diagnostics, told Pharmacogenomics Reporter this week in an e-mail.
The Cobas AmpliPrep/Cobas TaqMan HIV-1 Test “provides a broader range of viral load data than earlier-generation tests, quantifying the amount of virus in the blood from very high to very low levels.” Additionally, the new test will allow laboratories to deliver results faster than older versions of the test.
In his e-mail Heimburger noted that the drug is not linked to any particular antiretroviral therapy and it is up to drug manufacturers to mention the viral load test used in clinical studies.
However, the company didn’t appear particularly concerned about adoption of the PCR test, as Roche is an established player in the HIV diagnostics market.
“[V]irtually all anti-HIV drugs that have received FDA approval have performed their clinical studies using Roche PCR tests,” Heimburger said. “We are proud of this history and certainly expect that drug development companies will continue to find value in Roche’s automated real-time PCR tests.”
The company studied the efficacy of the Cobas AmpliPrep/Cobas TaqMan HIV-1 Test in 18 trials enrolling over 5,000 participants and found that viral load monitoring with the test showed “a significant association between a decrease in plasma viremia and improved clinical outcome.”
Combining two technologies to automate analyses of HIV-1 viral load data, the test uses the Cobas AmpliPrep instrument for sample preparation, and the Cobas TaqMan analyzer or smaller Cobas TaqMan 48 analyzer for real-time PCR amplification and detection.
“There are a number of advantages that help labs get high-quality results to doctors faster and with greater efficiency,” Heimburger said. By automating each step of analysis, lab technicians need only to pre-load the instrument with samples and reagents. This so-called “walk-away” automation feature through real-time PCR reduces potential human error, cross contamination, and improves workflow efficiency, the company said.
Additionally, the test avoids sample and reagent waste by tracking samples using a bar code scanner linked to Roche’s AmpliLink software. This ensures that there is enough material for the number of samples that will be analyzed, and that the reported results are linked to the right patient sample.
“[V]irtually all anti-HIV drugs that have received FDA approval have performed their clinical studies using Roche PCR tests. We are proud of this history and certainly expect that drug development companies will continue to find value in Roche’s automated real-time PCR tests.”
Roche said the test should be used “in conjunction with clinical presentation and other laboratory markers of disease progress for the clinical management of HIV-1 infected patients.” The test is not intended for screening for the presence of HIV-1 in blood or blood products or for use as a diagnostic test to confirm the presence of HIV-1 infection, Roche specified.
Roche Diagnostics Corp., the US sales affiliate to Roche Molecular Diagnostics based in Indianapolis, will sell the Cobas AmpliPrep/Cobas TaqMan HIV-1 test and began taking orders for the test this week.
The Cobas AmpliPrep/Cobas TaqMan HIV-1, HCV, and HBV tests have been available in Europe since 2005. Roche’s applications for the HCV and HBV tests are currently pending at FDA.
Abbott's RT-PCR HIV-1 Viral Load Test
Abbott and development partner Celera’s RealTime HIV-1 assay was approved around the same time as Roche’s product by FDA last week.
The companies said the RealTime HIV-1 assay measures the levels of HIV circulating in a patient's bloodstream, including the three common HIV-1 groups and non-B subtypes. Abbott said the test is used for disease prognosis and to assess response to antiretroviral treatment.
Abbott developed the technology for its HIV-1 program through a research alliance with Celera, through which the companies develop nucleic acid-based diagnostic products.
“As the viral diversity of HIV-1 continues to increase, the need for highly sensitive tests to monitor patient response to antiviral therapies becomes even more important," said John Robinson, senior director of research and development at Abbott Molecular, in a statement.
While Roche highlighted the automation, ease of use, and human error reduction components of its diagnostic, Abbott touted the sensitivity of its product. Abbott said the assay can measure HIV-1 in plasma "down to as few as 40 RNA molecules per milliliter, and up to as many as 10 million molecules per milliliter."
According to Roche’s Heimburger, standard of care is quantification of HIV-1 at 50 copies/mL. In Europe the Cobas AmpliPrep/Cobas TaqMan HIV-1 Test claims quantification of 40 copies/mL. However, in the US, based on differences in how the FDA performed statistical analyses on the data, the test claims 48 copies/mL, Heimburger said.
The m2000 system is made of two components; one that automates the extraction, purification, and preparation of DNA and RNA, and a PCR instrument that "amplifies, detects and measures minute levels of infectious agents," the companies said.
Abbott is also developing assays for hepatitis C virus, hepatitis B virus, HCV genotyping, chlamydia, and gonorrhea for the m2000.