FDA Classifies Hematopoietic Cell Enrichment Kits as Class II Under 21 CFR 866.6120

FDA Final Order: Hematopoietic Cell Enrichment Kits Classified as Class II

On October 9, 2026, the U.S. Food and Drug Administration (FDA) published a final order in the Federal Register (Docket No. FDA-2026-N-10994) formally classifying the device generic type "hematopoietic cell enrichment kit" as Class II, together with associated special controls. The order took effect on October 9, 2026, and the classification is codified at 21 CFR 866.6120, within Subpart G of Part 866.

What These Devices Are

Under FDA's definition, a hematopoietic cell enrichment kit is an in vitro diagnostic device used to select and enrich specific hematopoietic cells, by immunomagnetic bead-based methods, from peripheral blood and/or bone marrow specimens of patients with hematologic malignancies. It serves as a pre-analytical step in the diagnostic workflow: it does not itself produce a diagnostic conclusion, but instead provides processed specimen for downstream testing. This identification is set out in 21 CFR 866.6120(a).

How the Classification Came About

The classification followed the De Novo pathway. FDA records that STEMCELL Technologies Canada Inc. submitted a De Novo classification request on December 12, 2022 for the EasySep Human Bone Marrow CD138 Positive Selection Kit, and that FDA issued an order on November 6, 2023 classifying the device as Class II. The purpose of this final order is to formally write that classification into the regulations — classification was established first, codification followed. Accordingly, the order text states that the classification applies as of November 6, 2023, while the order itself takes effect on October 9, 2026.

Risks and Special Controls

In Table 1 of the order, FDA lists two categories of health risks: first, errors in the enrichment step that lead to false positives or false negatives in downstream testing, or even to failure to produce a result; and second, misinterpretation of enrichment results by the laboratory. Three special controls correspond to these risks.

• Specimen collection device: the specimen collection device used must be an FDA-cleared, approved, or 510(k)-exempt device that covers the specimen types intended for use with this device.
• Indications for use statement: must state the specimen type and minimum volume for each malignancy, must require a 95% correct determination rate at the limit of detection concentration, must provide a detailed description of the enrichment target, and must include a statement that the end user is responsible for validating this device with the specific test method.
• Labeling: must provide detailed specifications and procedures for specimen collection, handling, and storage in accordance with 21 CFR 809.10(b), supported by repeatability and stability data.

Is a 510(k) Exemption Available?

FDA states in the order that it has not determined at this time to exempt hematopoietic cell enrichment kits from 510(k) requirements. In other words, these devices remain within the scope of 510(k) premarket notification and must be submitted through the 510(k) pathway rather than being treated as exempt. This point is especially critical for companies seeking to simplify market entry through an exemption.

What This Means for Subsequent Products

Once the classification is codified, these devices have a citable regulatory identity. FDA explains that a device classified as Class I or Class II through the De Novo process may serve as a predicate device for subsequent devices of the same type, which can then follow the less burdensome 510(k) pathway instead of each filing a new De Novo request or a premarket approval (PMA). This is a common FDA rationale for moving devices into a lower class in order to reduce regulatory burden.

Sources and Applicability

Source: U.S. Food and Drug Administration (FDA), final order published in the Federal Register, Medical Devices; Immunology and Microbiology Devices; Classification of the Hematopoietic Cell Enrichment Kit, FR Doc 2026-20725, published at 91 FR 64609, dated October 9, 2026.

Scope of verification and access date: the Federal Register document page and its official full text (including the added 21 CFR 866.6120 text and Table 1 on risks and mitigation measures) were verified, with an access date of October 12, 2026.

Applicability note: this article is an interpretation of publicly available FDA regulatory information and does not constitute a conclusion or commitment regarding any specific product, company, or registration application. The official text prevails, and the information may change with subsequent official updates.

Sources

• U.S. Food and Drug Administration (FDA) — Federal Register, October 9, 2026
• Federal Register / U.S. Government Publishing Office

AIMEILI Regulatory Interpretation and Business Impact

Regulatory Interpretation

This final order resolves a long-standing gap in the classification of hematopoietic cell enrichment kits. The De Novo grant of November 6, 2023 created a Class II classification in FDA's records, but until the codification order took effect the classification had no directly citable regulatory text. With the addition of 21 CFR 866.6120 and the identification of special controls, manufacturers now have a defined regulatory identity for both the device type and its predicate pathway. Two points deserve particular attention. First, FDA has expressly declined, at this stage, to exempt these devices from 510(k); manufacturers cannot rely on an exemption and must prepare a 510(k) submission. Second, the special controls are substantive, not procedural: they impose specific design-input and labeling obligations, including specimen types and minimum volumes per malignancy, a 95% correct determination rate at the limit of detection, a detailed description of the enrichment target, and end-user validation language on the label. The retrospective applicability date of November 6, 2023 also means that devices placed on the U.S. market in the interim should be reviewed against these requirements.

Business Impact

• Clearer, faster route to market for followers: once a first device is cleared under this classification, subsequent devices of the same type can use it as a predicate and pursue a 510(k) rather than a De Novo or PMA — typically a shorter, less costly, and more predictable pathway.
• 510(k) preparation is mandatory: exemption-dependent launch strategies are not viable for this device type. Budget, timelines, and testing plans should assume a full 510(k) submission.
• Analytical performance expectations are fixed: the 95% correct determination rate at the limit of detection for each malignancy and specimen type functions as a design and verification target, and should be reflected in study protocols and acceptance criteria from the outset.
• Labeling and instructions for use carry heightened scrutiny: specimen collection, handling, and storage specifications, repeatability and stability data, and the end-user validation statement must all be consistent across the submission and the final label.
• Compatibility with specimen collection devices: the requirement to use an FDA-cleared, approved, or exempt collection device covering the intended specimen types creates a supply-chain and documentation dependency that should be addressed early with partners and raw-material suppliers.
• Global knock-on effects: a codified U.S. Class II classification with defined special controls provides a useful reference point for regulatory strategy in other jurisdictions and for preparing comparable technical documentation.