It’s My Party and I’ll Cry if I Want to: A Bittersweet Happy 30th Birthday to LDTs

August 3, 2022By Jeffrey N. Gibbs & Allyson B. Mullen

Happy Birthday Laboratory Developed Tests (LDTs).

Thirty years ago today, FDA announced that it had the authority to regulate you.  Not yet understanding how important you’d become, you entered the regulatory world without a name – the Agency simply referred to you as “home brew” products.  It has been a long, strange trip ever since.

There was no fanfare for this momentous “birth.”  If anything, the announcement was remarkably inconspicuous: a seemingly throwaway sentence in a draft compliance policy guide for research use only and investigational use only products.  U.S. Food and Drug Administration, Compliance Policy Guide, Commercialization of Unapproved In Vitro Diagnostic Devices Labeled for Research and Investigation (Aug. 3, 1992) (“It has come to the attention of FDA that laboratories have been manufacturing, “home brew” products, either from products already on the market, or from components, and utilizing these unapproved products for diagnostic purposes. These products are subject to the same regulatory requirements as any unapproved medical device”).  These two sentences turned out to be the opening salvo in a thirty-year battle – and counting – over how LDTs should be regulated.

Of course, FDA’s August 3, 1992 statement that it could regulate LDTs came long after laboratories began offering diagnostic tests.  It came 16 years after Congress passed the Medical Device Amendments of 1976, without saying a word about FDA authority over laboratory testing.  And it came four years after the comprehensive federal legislation governing laboratories, again without mentioning FDA or referring to such tests as devices.

FDA’s claim of authority over LDTs (née “home brews”) prompted a citizen petition disputing FDA’s position.  That was the first of many challenges to FDA’s assertion that it could regulate LDTs at all, let alone through guidance documents.  FDA denied the petition six years after it was submitted.  See FDA Response to Citizen Petition from Jeffrey N. Gibbs, Hyman, Phelps & McNamara, Docket No. 92P-0405 (Aug. 12, 1998) (available here).

Since then, the battle has waxed and waned.  At times, FDA was on the verge of issuing formal guidance, only to retreat.  See our prior posts here and here.  Other times, the issue was quiescent.  Yet thirty years after FDA’s pronouncement that it could regulate LDTs, the Agency’s core position hasn’t changed: it has the legal authority to regulate LDTs.  At the same time, FDA’s basic operational stance hasn’t changed much either.

In the LDT’s “toddler years,” when issuing its analyte specific reagent rule in 1997, FDA stated that it would generally exercise enforcement discretion over LDTS.  Like any good worn down parent of a wild toddler, the Agency perhaps realized it had more than it could handle when it came to its dear, sweet LDTs.  That is still FDA’s core position, albeit with nuances, e.g., FDA reserving the right to regulate tests developed in one lab and licensed to another (see here) and declaring that “direct-to-consumer” tests do not qualify as LDTs (see here).

What has changed since 1992 is the role that LDTs play in the health care system.  As with any “child” they’ve matured and developed as they’ve grown into adulthood.  Tests created by labs were important in 1992, but they play a far more vital role in medicine today.  Nobody knows how many LDTs exist today, but it is clear that many of the most novel, innovative tests are LDTs.  That growth has, unsurprisingly, led to different views about regulation of LDTs.  Advocates of greater regulation point to the proliferation of clinically significant tests as evidence supporting the need for more oversight.  Opponents view the same facts in precisely the opposite way: it is critical that government regulation not stifle this innovation.

As we began to prepare this blog, we thought it might be both birthday card and death notice for LDTs.  Over the years there have been multiple attempts by Congress to pass legislation that would give FDA explicit power to regulate LDTs.  Leib, J. R. (2021). Proposed Federal Legislation on the Oversight of Diagnostics. J. Gibbs & A. Mullen.  Diagnostics at a Crossroads: Navigating IVD Regulation in a Changing Environment. Food & Drug Law Institute.  These efforts have faltered and failed.

More recently, the VALID Act has been wending its way through Congress.  See here.  This comprehensive bill would create a single category of In Vitro Clinical Tests (IVCTs), that would subsume both distributed assays (traditional in vitro diagnostic devices) and LDTs.  (If VALID were enacted, lab tests would have gone from unnamed, to home brews, to LDTs, to IVCTs in roughly 30 years, raising the question of whether an LDT, by any other name, would be as sweet).  For much of the year, it appeared that VALID would pass, and the term LDT would eventually become the answer to an obscure trivia question about obsolete regulatory acronyms.  More recently, the momentum for VALID appears to have stalled, and its fate hangs very much in the balance.

Meanwhile, the controversy remains as vigorous as ever. Proponents continue to urge passage.  See AdvaMed Welcomes Senate Committee Passage of MDUFA V Legislation (June 15, 2022).  On the other side, Sen. Rand Paul (R-Ky) wrote an op ed yesterday promoting his VITAL Act which presents significantly less regulatory burden for lab tests, citing the need for LDTs to address new diseases, such as monkey pox.  Rand Paul, The CDC royally messed up COVID testing and is now botching monkeypox testing, The Washington Examiner (Aug. 2, 2022) (here).  Of course, enactment of VALID will raise a whole host of new issues.  As Stephen Sondheim put it, “Just more questions.  Different kind.”

Whatever the regulatory future holds for tests run in labs, and regardless of their name, there is no doubt that tests developed and run in labs will continue to play an essential role in the U.S. health care system.  Laboratories, paraphrasing the Boss, will continue to say, “Baby, we were born to run – and develop – tests.”  And to paraphrase the Boss again: It remains to be seen whether LDTs soon be sighing that “glory days have passed me by,” or will “LDTs” play an even more pivotal role.