(a) Identification. A nucleic acid-based hepatitis B virus (HBV) assay is identified as an in vitro diagnostic device intended for prescription use in the detection of HBV nucleic acid in specimens from individuals with antibody evidence of HBV infection. In these devices, the detection of HBV nucleic acid is used as an aid in the management of HBV-infected individuals. The assay is intended for use with human serum or plasma (and other matrices as applicable) from individuals with HBV. The assay is not intended for use as a donor screening assay for the presence of HBV nucleic acids in blood, blood products, plasma, cells, or tissue donors, or as a diagnostic assay to confirm the presence of HBV infection.

(b) Classification. Class II (special controls). The special controls for this device are:

(1) Labeling required under § 809.10(b) of this chapter must include:

(i) A prominent statement that the assay is not intended for use as a screening assay for the presence of HBV DNA in blood or blood products, plasma, cells, or tissue donors, or as a diagnostic assay to confirm the presence of HBV infection.

(ii) A detailed explanation of the principles of operation and procedures for performing the assay.

(iii) A detailed explanation of the interpretation of results.

(iv) Limitations, which must be updated to reflect current clinical practice and disease presentation and/or management. These limitations must include statements that indicate:

(A) Management of patients undergoing HBV treatment should not be established on the basis of a single assay result but should be determined by a licensed healthcare professional in conjunction with the clinical presentation, history, and other diagnostic procedures, e.g., HBV serologic testing, liver function assays, liver elastography, etc.

(B) The specimen types for which the device has been cleared, and that use of this assay with specimen types other than those specifically cleared for this device may result in inaccurate assay results.

(C) The results obtained with this assay may not be used interchangeably with results obtained with a different manufacturer's assay.

(2) Design verification and validation must include the following:

(i) Detailed device description, including the device components, ancillary reagents required but not provided, and an explanation of the device methodology. Additional information appropriate to the technology must be included such as design of primers and probes, rationale for the selected gene targets, specifications for amplicon size, and degree of nucleic acid sequence conservation.

(ii) For devices with assay calibrators, the design and composition of all primary, secondary, and subsequent quantitation standards used for calibration as well as their traceability to a standardized reference material that FDA has determined is appropriate (e.g., a recognized consensus standard). In addition, analytical testing must be performed following the release of a new lot of the standard material that was used for device clearance or approval, or when there is a transition to a new calibration standard.

(iii) Documentation and characterization (e.g., determination of the identity, supplier, purity, and stability) of all critical reagents (including nucleic acid sequences for primers and probes) and protocols for maintaining product integrity.

(iv) Risk analysis and management strategies demonstrating how risk control measures are implemented to address device system hazards, such as Failure Modes Effects Analysis and/or Hazard Analysis and Critical Control Points summaries and their impact on assay performance.

(v) Final release criteria to be used for manufactured assay lots with appropriate evidence that lots released at the extremes of the specification will meet the identified analytical and clinical performance characteristics as well as stability.

(vi) Stability studies for reagents must include documentation of an assessment of real-time stability for multiple reagent lots using the indicated specimen types and must use acceptance criteria that ensure that analytical and clinical performance characteristics are met when stability is assigned based on the extremes of the acceptance range.

(vii) All stability protocols, including acceptance criteria.

(viii) Detailed documentation of analytical performance studies conducted as appropriate to the technology, specimen types tested, and intended use of the device, including limit of detection (LoD), linearity, precision, endogenous and exogenous interferences, cross-reactivity, carryover, matrix equivalency, sample and reagents stability, and as applicable, upper and lower limits of quantitation (ULoQ and LLoQ, respectively). Samples selected for use must be from subjects with clinically relevant circulating genotypes in the United States. Cross-reactivity studies must include samples from HBV nucleic acid negative subjects with other viral or non-viral causes of liver disease, including autoimmune hepatitis, alcoholic liver disease, chronic hepatitis C virus, primary biliary cirrhosis, and nonalcoholic steatohepatitis, when applicable. The effect of each identified nucleic-acid isolation and purification procedure on detection must be evaluated.

(ix) Analytical sensitivity of the assay that is the same or better than that of other cleared or approved assays.

(x) For devices with associated software or instrumentation, documentation must include a detailed description of device software, including software applications and hardware-based devices that incorporate software. The detailed description must include documentation of verification, validation, and hazard analysis and risk assessment activities, including an assessment of the impact of threats and vulnerabilities on device functionality and end users/patients as part of cybersecurity review.

(xi) Detailed documentation of performance from a clinical study with a design and number of clinical samples (appropriately statistically powered) that is appropriate for the intended use of the device as well as conducted in the appropriate settings by the intended users. The samples must include prospective (sequential) samples for each claimed specimen type and, as appropriate, additional characterized clinical samples. Samples must be sourced from geographically diverse areas.