Company: CSTL
Filing Date: 2025-08-04
Form Type: 10-Q
Source: 0001447362-25-000097
Chunk: 70

Company: CASTLE BIOSCIENCES INC
Filing Date: 2025-08-04
Form: 10-Q
Item: Item 4
Chunk 70
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DTs, which amends 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. Under this final rule, the FDA issued a policy to phaseout, over the course of four years, its general enforcement discretion approach to LDTs and also issued targeted enforcement discretion policies for certain categories of LDTs, including LDTs marketed as of the date of publication of the final rule on May 6, 2024, as well as LDTs that have received approval from the NYSDOH. 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 deadline to do so has passed; therefore, the court’s decision stands.

Even if the LDT final rule were reinstated, we do not believe it would have a material impact on our existing test offerings given all of our tests were marketed before May 6, 2024. We believe that our tests would continue to be subject to FDA enforcement discretion in their current forms. Additionally, pursuant to the LDT final rule, the FDA would gradually end its general enforcement discretion approach in five stages over a four-year period for other LDTs not approved by NYSDOH or not already on market. Each stage of the proposed phaseout period would subject LDTs to a set of regulatory requirements. For example, the first stage of the phaseout would require LDT developers to comply with medical device reporting requirements and correction and removal reporting requirements by May 6, 2025. LDTs considered higher-risk IVDs would be subject to premarket review requirements within three and a half years, and LDTs considered low to moderate risk IVDs would be subject to premarket submission requirements within four years after publication of the LDT final rule. While the enforcement policy is 

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phased out, the FDA could still decide to pursue enforcement action at any time against LDTs that it deemed to be violative of its regulations when appropriate.

All of our existing tests were marketed prior to May 6, 2024 and are conducted in labs licensed by the NYSDOH. If the FDA were to determine that our tests, or modifications thereof, are not within the scope of the FDA's enforcement discretion policy for LDTs for any reason, including based on the LDT final rule,