Investigational Use: Laboratory Developed Tests FAQs
A: Even though FDA has generally expected compliance with Investigational Use requirements for LDTs, we have included compliance with investigational use requirements for IVDs offered as LDTs in stage 2 in recognition that there has been some confusion about our enforcement approach in this area. Note that investigations of diagnostic devices are exempt from most part 812 requirements, provided that certain labeling requirements are met and the testing:
- is noninvasive,
- does not require an invasive sampling procedure that presents significant risk,
- does not by design or intention introduce energy into a subject, and
- is not used as a diagnostic procedure without confirmation of the diagnosis by another, medically established diagnostic product or procedure (§ 812.2(c)(3)).
Requirements under 21 CFR parts 50 and 56, relating to IRB approval and informed consent, generally apply to these studies.
A: As discussed in the preamble to the LDT Final Rule, the Investigational Device Exemption requirements under section 520(g) of the FD&C Act and 21 CFR part 812 apply to clinical investigations of devices. However, certain categories of clinical investigations of devices are exempt from most IDE requirements under § 812.2(c), and certain other categories of device investigations are deemed to have an approved IDE application under § 812.2(b) if the conditions therein are met. Sponsors and investigators of investigational devices have obligations under the IDE regulations (and related regulations such as parts 50 and 56 (21 CFR parts 50 and 56), regarding protection of human subjects and institutional review boards, respectively). Thus, if a laboratory is a sponsor or investigator of an investigational IVD (including a reagent or instrument), that laboratory is responsible for ensuring compliance with all applicable requirements under the FD&C Act and FDA's regulations. Investigational IVDs may include an IVD that was previously labeled research use only (RUO) by a third-party manufacturer, an IVD that was previously labeled by a third-party manufacturer for a use different from the use in the clinical investigation, or an IVD manufactured by a third party but modified by the laboratory for purposes of the clinical investigation.
As discussed in the preamble to the LDT Final Rule, FDA has generally expected compliance with investigational use requirements for LDTs, though we understand that laboratories often are not complying with them currently. Therefore, we have included these requirements in the phaseout policy. FDA expects compliance with investigational use requirements for IVDs offered as LDTs in Stage 2 of the phaseout, which begins on May 6, 2026.
As discussed in the preamble, FDA notes that investigations of diagnostic devices are exempt from most IDE requirements, provided that certain labeling requirements are met and the testing: is noninvasive, does not require an invasive sampling procedure that presents significant risk, does not by design or intention introduce energy into a subject, and is not used as a diagnostic procedure without confirmation of the diagnosis by another, medically established diagnostic product or procedure (§ 812.2(c)(3)). Additionally, investigations of diagnostic devices that are not significant risk are deemed to have an approved IDE (without submission of an IDE application) if the conditions in § 812.2(b) are met.
FDA has several resources available to help sponsors comply with IDE requirements in the context of clinical investigations of IVDs, including a final guidance document entitled "In Vitro Diagnostic (IVD) Device Studies - Frequently Asked Questions," which has been available to stakeholders since June 2010, and a webpage on Investigational Device Exemptions.
FDA is planning a webinar in 2025 relating to IVDs for investigational use.