Market research firm Amplion Research has published a report on market trends for in vitro biomarker-based diagnostics that suggests FDA review times have lengthened over time, and are longer for these tests than for IVDs as a whole.
The report also bears out an overall downward trend for approvals for biomarker-based tests over the last ten years. According to the study, clearances granted to biomarker-based tests have fallen in number every year since 2006, from 99 that year to 38 in 2012.
John Audette, Amplion's business director, and Adam Carroll, the company's science director, told PGx Reporter this week that the firm's goal is to be able to tease out some method for predicting which promising biomarkers are more likely to make it through the research and development process and become successful clinical tests.
"The ultimate goal of the research we've been doing is to try to predict … what factors are going to accelerate or block the development of [early stage molecules] into actual clinical biomarkers," Carroll said.
As part of that larger goal, Amplion has been studying available data on those biomarker-based tests that have been successfully approved by the FDA as IVDs. Findings from this research make up the bulk of the company's study released this month.
"This is the first step in the process for us to tease out what all the variables are and what their importance is with the ultimate goal to help test developers negotiate [this process]," said Audette.
The most striking finding, Audette and Carroll said, was that the FDA review process has become longer and approvals less frequent for biomarker-based tests, even more so than for IVDs as a whole.
"The max review time 10 years ago is the median review time today," Carroll said.
According to the study, this has paralleled a two-fold decrease in the percentage of cleared tests that measure specific molecular targets since 2007, when "biomarker-based tests comprised nearly 25 percent of IVD clearances," to 2012, when the number dropped to 12 percent.
While review times increased and overall clearances decreased over the study period, Audette and Carroll said that there was some variation within this overall trend. According to the analysis conducted by Amplion, the specific FDA committee conducting the review appeared to affect the length of the clearance.
For example, the researchers wrote that the Immunology Committee saw the greatest change in its number of clearances, from 37 clearances with a mean review period of 63 days in 2003 to only 10 clearances with an average review period of 344 days in 2012.
In contrast, while review periods for biomarker-based tests?) also increased for the Clinical Chemistry committee, they did so much less dramatically, the authors wrote.
In the study the researchers cautioned that this data shouldn't be interpreted as evidence that one committee would necessarily be more generous to biomarker-based tests than another. "Of course, committees do not duplicate work and review the same tests. As such, there are no control studies that can indicate whether committee-to-committee differences arise due to the committees themselves and their unique processes, or [whether the differences are] due to the nature of the tests typically reviewed by each committee," they wrote.
Carroll and Audette also said the FDA doesn’t release data on clearance rates for specific types of tests, so there is no way to know for sure whether these changes reflect reduction in the amount of tests submitted and approved, or a lower approval rate and higher rejection rate.
The study also highlighted in the study differences among more specific subtypes of biomarker based tests, like diagnostic, prognostic, and other tests, tests with different molecular targets like nucleic acids and proteins, and tests with multiple, versus single, molecular targets.
Interestingly, according to the report, the overall trend over the last 10 years has been toward a reduced mean number of targets per test. This suggests that increased review times are not likely due to greater numbers of muliplex or multi-target tests.
Overall, the study also found that tests measuring nucleic acids are increasing relative to tests measuring proteins, though protein biomarker tests still outnumber other targets.
According to the company, "the best year for nucleic tests was 2011, when these tests accounted for 20 percent of all tests."
Tests for novel targets are being released and approved relatively infrequently, according to the authors, and they reach the market primarily through the 510(k) path to clearance— about three times as often as through the PMA process. "Companies of all sizes were able to secure clearance or approval … [and] very small companies had similar success to much larger companies in securing clearance or approval for tests during the decade," the authors wrote.
The Amplion report also found that most of these novel tests were developed for diagnostic indications, followed by prognostic and companion diagnostic indications. "Nucleic acids were more likely to be the [target] for [novel tests] than they were for biomarker-based tests overall," the group wrote.
The decline in approvals for biomarker-based tests "can be explained in part by company consolidation, market saturation for 'me-too' tests, and competition from [laboratory-developed tests]," the authors wrote.
According to the study, "the top 10 companies, in terms of the number of tests owned, own almost 50 percent of all tests cleared or approved in the decade, and the top five own over 35 percent … [while] a total of 128 companies have 10 or fewer tests that were cleared or approved in the decade, and 58 have only one test."
While the current report didn't address trends in LDTs, Carroll and Audette said the firm is planning to do additional research to track trends in the development of molecular LDTs and is also keeping an eye on progress in the FDA's planned regulation of such tests.
"We are planning on going after [LDTs]," Carroll said. "But because there isn’t a central database that logs those tests, a lot of that will be manual: identifying labs of interest and logging their tests to build up a database."
While the FDA has kept a policy in recent years of “regulatory discretion” over the LDT market, it has maintained that it does have authority over lab-developed tests.