Illicit drugs stay ahead of laboratory science. Just when we think we’ve nabbed a new designer drug in terms of detection, a new form arises. Single compound testing blooms overnight into panels, families of compounds. Combating illicit drug detection – keeping it current – is like battling a hydra.
If we compare the development time and costs involved in bringing a lab-developed illicit drug assay using mass analysis into clinical use, versus the same for immunoassay, it is easy to lean toward mass analysis. Since the 1970’s, mass spectrometry/analysis has been a staple in toxicology laboratories. The technology is limber and elegant, allowing an adept analyst to isolate mass spectra and develop reliable and robust assays relatively quickly – in days to weeks. The explosion of technologic advance in mass analysis has only propelled this ability.
Now, consider immunoassay. The antibodies take time to develop. There are cross-reactivity issues to profile. Usually immunoassays are developed by a major manufacturer, and require FDA review and approvals prior to market release. The timeline for this type of assay is at least a year on an established analytic platform, just for the manufacturer.
For clinical utility, screening is all that’s usually needed, and the send-out costs and time delays for access to mass analysis-based testing can be appreciable for labs that do not possess on-site mass analyzers. Immunoassay is relatively cheap, rapid to implement and use, and is available on the local chemistry platform as a quick menu expansion. But updates to the assay come infrequently, because changes usually require full FDA review. In this environment, calls from concerned clinicians only increase as immunoassay-based testing loses relevance when new class drugs come to market, or new illicits cross-react or have no assay available for screening.
It would seem that laboratories possessing mass analyzers hold the keys to the toxicology kingdom. Rapid online publication adds to the velocity of this development and the widespread availability of comparable “new drug” profile offerings. But there is a possible cloud on the horizon.
The FDA has announced that it will proceed with oversight measures for lab-developed testing.1,2 This includes any assay produced, even in a small two-box, day-shift-only, one-FTE mass analysis lab like mine. Without substantial expansions in FDA infrastructure, this addition to laboratory regulation will undoubtedly slow the ability of new assays – toxicology or others – to come into clinical use.
Thus, there is a possibility that the treadmill effect seen with immunoassay-based toxicology testing will also spell the future for assays that are mass analysis-based…placing the little guys like me either back into the pool of hospitals that outsource testing at great added cost, or putting me into some classes for submitting successful FDA applications and straining my ability to service my other laboratory sections. Adding new compounds to existing profiles won’t be so easy, and it will no longer be a “tweak” to the analysis to update an extraction method when a great new method comes to market. Days of development could, in theory, become months to years…despite continuously impressive developments in mass analysis technology, and that which supports it.
So, what do you think? Am I all doom-and-gloom, and no silver lining? Is the light ahead of me NOT a train? Thoughts are welcome!
- Notification to Congress – FDA’s LDT framework. http://www.fda.gov/downloads/MedicalDevices/ProductsandMedicalProcedures/InVitroDiagnostics/UCM407409.pdf. Accessed 15 December 2014.
- FDA website’s page for Laboratory Developed Tests. http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/InVitroDiagnostics/ucm407296.htm. Accessed 15 December 2014.