Cellestis公司对潜伏性结核病的检测方法得到FDA审议
WASHINGTON (Reuters Health) - An advisory panel to the US Food and Drug Administration (FDA) voted unanimously on Friday to endorse the approval of Quantiferon, Cellestis Ltd's test for latent tuberculosis (TB).
Quantiferon is designed to detect infection before patients become symptomatic, increasing the chance that infected individuals can be identified before they spread the disease.
The laboratory-based blood test identifies gamma interferon, an immune compound believed to be indicative of a cellular response to TB infection.
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At present, the only FDA-approved method for detection of latent TB is a skin test. By looking at the immune response in whole blood, the new test may provide greater accuracy.
The FDA's Microbiology Devices Panel made its recommendation based on clinical trials involving almost 3,000 participants worldwide. Panel members raised some questions about the validity of the data, but prevailing in the end was the simple need for another test to detect latent TB.
, http://www.100md.com
"Anything has to be better than the skin test," said Dr. Valerie L. Ng, a panel member from San Francisco General Hospital, whose opinion reflected that of the majority.
The studies showed that Quantiferon almost always agreed with the skin test on negative samples, but might be far more sensitive on positive samples.
But comparing Quantiferon results to those produced by the skin test presents difficulties, since the skin test is considered largely inaccurate absent a confirming microbial culture. Because of the lack of a "gold standard" by which to measure the new test, panel members raised questions about the validity of the clinical results and worried that healthy individuals might receive unnecessary therapy due to false-positive tests.
, http://www.100md.com
Still, the correlation between the negative results for the two test methods at least demonstrated that Quantiferon would be able to screen out low-risk individuals, Cellestis Chief Scientific Officer Dr. Jim Rothel maintained. Moreover, the presence of an immune response in affected patients has been noted in numerous clinical studies, he said.
A confirmatory study conducted by the Centers for Disease Control and Prevention also showed that the test was more than 80% effective at identifying patients known to have TB, Rothel observed. In contrast, the skin test's predictive value can be as low as 50%, he pointed out.
, 百拇医药
In making the decision to endorse the test, the panel recommended that the company be required to stratify the data on the label to ensure that laboratories recognize that results may vary depending on the risk level of the population being tested. Because Quantiferon may be more accurate in producing negative results than positive results, it is likely to be more accurate in low-risk groups than in high-risk groups, they noted.
The panel also recommended that the agency require follow-up studies in at-risk populations, such as patients with HIV and those with organ transplants.
, http://www.100md.com
Although not bound by its panels' recommendations, the FDA usually does follow their advice.
An estimated 40 million screening tests for TB are conducted in the developed world each year, of which over 10 million are conducted in the US. Quantiferon is already sold in Australia, where Cellestis is based. The company recently went public., http://www.100md.com
Quantiferon is designed to detect infection before patients become symptomatic, increasing the chance that infected individuals can be identified before they spread the disease.
The laboratory-based blood test identifies gamma interferon, an immune compound believed to be indicative of a cellular response to TB infection.
, http://www.100md.com
At present, the only FDA-approved method for detection of latent TB is a skin test. By looking at the immune response in whole blood, the new test may provide greater accuracy.
The FDA's Microbiology Devices Panel made its recommendation based on clinical trials involving almost 3,000 participants worldwide. Panel members raised some questions about the validity of the data, but prevailing in the end was the simple need for another test to detect latent TB.
, http://www.100md.com
"Anything has to be better than the skin test," said Dr. Valerie L. Ng, a panel member from San Francisco General Hospital, whose opinion reflected that of the majority.
The studies showed that Quantiferon almost always agreed with the skin test on negative samples, but might be far more sensitive on positive samples.
But comparing Quantiferon results to those produced by the skin test presents difficulties, since the skin test is considered largely inaccurate absent a confirming microbial culture. Because of the lack of a "gold standard" by which to measure the new test, panel members raised questions about the validity of the clinical results and worried that healthy individuals might receive unnecessary therapy due to false-positive tests.
, http://www.100md.com
Still, the correlation between the negative results for the two test methods at least demonstrated that Quantiferon would be able to screen out low-risk individuals, Cellestis Chief Scientific Officer Dr. Jim Rothel maintained. Moreover, the presence of an immune response in affected patients has been noted in numerous clinical studies, he said.
A confirmatory study conducted by the Centers for Disease Control and Prevention also showed that the test was more than 80% effective at identifying patients known to have TB, Rothel observed. In contrast, the skin test's predictive value can be as low as 50%, he pointed out.
, 百拇医药
In making the decision to endorse the test, the panel recommended that the company be required to stratify the data on the label to ensure that laboratories recognize that results may vary depending on the risk level of the population being tested. Because Quantiferon may be more accurate in producing negative results than positive results, it is likely to be more accurate in low-risk groups than in high-risk groups, they noted.
The panel also recommended that the agency require follow-up studies in at-risk populations, such as patients with HIV and those with organ transplants.
, http://www.100md.com
Although not bound by its panels' recommendations, the FDA usually does follow their advice.
An estimated 40 million screening tests for TB are conducted in the developed world each year, of which over 10 million are conducted in the US. Quantiferon is already sold in Australia, where Cellestis is based. The company recently went public., http://www.100md.com