Company: CSTL
Filing Date: 2025-11-03
Form Type: 10-Q
Source: 0001628280-25-048254
Chunk: 90

Company: CASTLE BIOSCIENCES INC
Filing Date: 2025-11-03
Form: 10-Q
Item: Item 1A
Chunk 90
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 These tests are referred to as LDTs. We currently market our products as LDTs which are subject to various coverage and reimbursement regulations and policies from governmental and commercial, third-party payors, as described in our 2024 10-K, and are subject to change from time to time.

On May 6, 2024, the FDA published a final rule on the regulation of LDTs, which amended the FDA regulations under 21 CFR Part 809 to make explicit that LDTs are IVDs and are regulated as devices under the FD&C Act. However, on March 31, 2025, the United States District Court for the Eastern District of Texas vacated the FDA’s LDT final rule. The U.S. government did not appeal the ruling, and the FDA rescinded the rule on September 19, 2025.

However, it is uncertain whether or when the FDA may be able to otherwise exercise its medical device authority with respect to LDTs or their components. This uncertainty could adversely affect the FDA’s ability to apply and enforce its medical device requirements with respect to diagnostic tests more broadly, including any LDTs for which we have obtained or plan to obtain marketing authorization. Such uncertainty and the FDA’s actions in response could have a material adverse effect on our business and operation.

In light of this uncertainty, we do not know if or when our offerings could become or will remain subject to FDA medical device requirements, including the need to seek and obtain marketing authorization. If we were unable to comply with any medical device requirements applicable to LDTs if and when any such requirements become applicable, we could be required to cease marketing any tests that we market as LDTs. In addition, further efforts by the FDA or Congress to impose more regulation on LDTs could create a negative public perception about the validity, safety, effectiveness, or performance of LDTs, including our tests, which could adversely affect patient, provider, and customer perception about, and confidence in our tests.

Moreover, the FDA may assert that we are improperly marketing our tests as LDTs or otherwise assert that we do not comply with applicable requirements, and in such cases may take enforcement action against us and/or require premarket review and marketing authorization, which may require us to cease marketing any commercially marketed tests that are marketed as LDTs until such marketing authorization is obtained or the applications are submitted. There can be no assurance that we will be able to obtain such marketing authorization or that any labeling claims would be