ADVIA CENTAUR ANTI-HBS READYPACK REAGENTS AND CALIBRATORS

P030029 · Siemens Healthcare Diagnostics · LOM · May 14, 2004 · Microbiology

Device Facts

• Record ID: P030029
• Device Name: ADVIA CENTAUR ANTI-HBS READYPACK REAGENTS AND CALIBRATORS
• Applicant: Siemens Healthcare Diagnostics
• Product Code: LOM · Microbiology
• Decision Date: May 14, 2004
• Decision: APWD
• Regulation: 21 CFR 866.3172
• Device Class: Class 2

Intended Use

The ADVIA Centaur® Anti-HBs assay is an in vitro diagnostic immunoassay for the qualitative determination of total antibodies to hepatitis B surface antigen in human serum or plasma (EDTA or heparinized) using the ADVIA Centaur System. The assay results may be used as an aid in the determination of susceptibility to hepatitis B virus (HBV) infection in individuals prior to or following HBV vaccination or where vaccination status is unknown. Assay results may be used with other HBV serological markers for the laboratory diagnosis of HBV disease associated with HBV infection. A reactive assay result will allow a differential diagnosis in individuals displaying signs and symptoms of hepatitis in whom etiology is unknown.

Device Story

ADVIA Centaur Anti-HBs is a sandwich immunoassay using chemiluminometric technology. It detects total antibodies to hepatitis B surface antigen (anti-HBs) in human serum or plasma. The system uses magnetic latex particles (MLP) coated with HBsAg (ad and ay) and acridinium ester-labeled HBsAg. The automated system dispenses samples, reagents, and calibrators; performs incubation at 37°C; washes cuvettes; and initiates a chemiluminescent reaction. The system measures Relative Light Units (RLU) and converts them to Index values via a factory-set master curve traceable to WHO standards. Used in clinical laboratories by technicians. Results aid physicians in assessing HBV immunity, vaccination efficacy, and differential diagnosis of hepatitis. Benefits include rapid, automated determination of protective immunity (≥10 mIU/mL) and support for clinical decision-making regarding HBV vaccination or infection status.

Clinical Evidence

Prospective multi-center study (N=2197) across high-risk, signs/symptoms, dialysis, and vaccinee populations. Compared ADVIA Centaur results against FDA-approved reference HBV serological markers. Overall positive percent agreement 92.8% (95% CI: 90.7-94.5%) and negative percent agreement 91.8% (95% CI: 90.2-93.3%). Additional studies included cross-reactivity (333 specimens), interference testing (bilirubin, hemoglobin, triglycerides, proteins), and precision/reproducibility studies (20-day protocol).

Technological Characteristics

Sandwich immunoassay; chemiluminometric technology. Solid phase: magnetic latex particles (MLP) covalently coupled with HBsAg (ad and ay). Lite Reagent: acridinium ester-labeled HBsAg. Automated system reads RLU. Connectivity: ADVIA Centaur System. Calibration: factory-set master curve, lot-specific, traceable to WHO anti-Hepatitis B Immunoglobulin 1st Reference Preparation (1977). Cutoff: 1.00 Index value (10 mIU/mL).

Indications for Use

Indicated for qualitative detection of total anti-HBs antibodies in human serum or plasma to determine HBV susceptibility, assess vaccination status, or aid in HBV disease diagnosis. Not for blood/plasma donor screening. Performance not established for immunocompromised patients, neonates, infants, or children.

Regulatory Classification

Identification

A qualitative hepatitis B virus (HBV) antigen assay is identified as an in vitro diagnostic device intended for prescription use for qualitative use with human serum, plasma, or other matrices that aids in the diagnosis of chronic or acute HBV infection. HBV surface antigen (HbsAg) is also used for screening of HBV infection in pregnant women to identify neonates who are at risk of acquiring hepatitis B during perinatal period. The assay is not intended for screening of blood, plasma, cells, or tissue donors.

Special Controls

*Classification.* Class II (special controls). The special controls for this device are:(1) The labeling required under § 809.10(b) of this chapter must include: (i) A prominent statement that the assay is not intended for the screening of blood, plasma, cells, or tissue donors. (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 management. The limitations must include statements that indicate: (A) 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. (B) When appropriate, performance characteristics of the assay have not been established in populations of immunocompromised or immunosuppressed patients or other populations where assay performance may be affected. (C) Diagnosis of hepatitis B infection 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. (D) Detection of HBV antigens indicates a current infection with hepatitis B virus but does not differentiate between acute or chronic infection. False reactive HbsAg result may occur for up to 2 weeks after vaccination with HbsAg containing vaccine. (E) Current methods for the detection of hepatitis B antigens may not detect all potentially infected individuals. A non-reactive assay result does not exclude the possibility of exposure to or infection with hepatitis B virus. A non-reactive assay result in individuals with prior exposure to hepatitis B may be due to but not limited to antigen levels below the detection limit of this assay or lack of antigen reactivity to the antibodies in this assay. HBV mutants lacking the ability to produce antigens have been reported. These may occur as “escape” mutants in the presence of anti-HBV antibodies and such patients may be infectious. (F) 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) A detailed device description, including all parts that make up the device, ancillary reagents required but not provided, an explanation of the device methodology, design of the capture antibody(ies), external controls, and computational path from collected raw data to reported result ( *e.g.,* how collected raw signals are converted into a reported signal and result), as applicable to the detection method and device design.(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.,* supplier, determination of identity, purity, and stability) of all critical reagents (including description of the capture antibody(ies)), and protocols for maintaining product integrity throughout its labeled shelf life.(iv) Risk analysis and management strategies, 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 specifications 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) Final release assay results for each lot used in clinical studies. (ix) Reproducibility study data that includes the testing of three independent production lots. (x) Detailed documentation of analytical performance studies conducted, as appropriate to the technology, specimen types tested, and intended use of the device, including, the limit of blank (LoB), limit of detection (LoD), cutoff, precision (reproducibility) including lot-to-lot and/or instrument-to-instrument precision, interference, cross reactivity, carryover, hook effect, seroconversion panel testing, matrix equivalency, prominent mutants/variants detection ( *e.g.,* for HbsAg), specimen stability, reagent stability, and cross-genotype antigen detection sensitivity, when appropriate.(xi) Analytical sensitivity of the assay that is the same or better than that of other cleared or approved assays. (xii) 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. (xiii) Detailed documentation and results from a clinical study. Performance must be analyzed relative to an FDA cleared or approved HBV antigen assay or a comparator that FDA has determined is appropriate. This study must be conducted using appropriate patient samples, with an appropriate number of HBV reactive and non-reactive samples in applicable risk and disease categories, and any applicable confirmatory testing. Additional relevant patient groups must be validated as appropriate. The samples must include prospective (sequential) samples for each identified specimen type and, as appropriate, additional characterized clinical samples. Samples must be sourced from geographically diverse areas. This study must be conducted in the appropriate settings by the intended users to demonstrate clinical performance.

Submission Summary (Full Text)

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# SUMMARY OF SAFETY AND EFFECTIVENESS

## I. GENERAL INFORMATION

Device Generic Name: An immunoassay for the qualitative detection of Antibody to Hepatitis B Surface Antigen (Anti-HBs Assay)

Device Trade Name: ADVIA Centaur® Anti-HBs ReadyPack Reagents
ADVIA Centaur® Anti-HBs ReadyPack Calibrators

Name and Address of Applicant: Bayer Health Care LLC
Diagnostic Division
511 Benedict Avenue
Tarrytown, NY 10591-5097

Date of Panel Recommendation: None

Premarket Approval Application (PMA) Number: P030029

Date of Notice of Approval to Applicant: May 14, 2004

## II. INDICATIONS FOR USE

ADVIA Centaur® Anti-HBs ReadyPack Reagents

The ADVIA Centaur® Anti-HBs assay is an *in vitro* diagnostic immunoassay for the qualitative determination of total antibodies to hepatitis B surface antigen in human serum or plasma (EDTA or heparinized) using the ADVIA Centaur System. The assay results may be used as an aid in the determination of susceptibility to hepatitis B virus (HBV) infection in individuals prior to or following HBV vaccination or where vaccination status is unknown. Assay results may be used with other HBV serological markers for the laboratory diagnosis of HBV disease associated with HBV infection. A reactive assay result will allow a differential diagnosis in individuals displaying signs and symptoms of hepatitis in whom etiology is unknown.

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Summary of Safety and Effectiveness Data

## QC Anti-HBs (aHBs)

For *in vitro* diagnostic use in monitoring the performance of the Anti-HBs assay on the ADVIA Centaur® Systems. The performance of the Anti-HBs quality control material has not been established with any other Anti-HBs assays.

## III. CONTRAINDICATIONS – None Known.

## IV. WARNINGS AND PRECAUTIONS

Assay performance characteristics have not been established for immunocompromised or immunosuppressed patients, cord blood, neonatal specimens, infants, or children.

This assay has not been FDA cleared or approved for the screening of blood or plasma donors.

United States federal law restricts this device ot sale by or on the order of a physician. For in vitro diagnostic use only.

Assay performance characteristics have not been established when the ADVIA Centaur Anti-HBs assay is used in conjunction with other manufacturers’ assays for specific HBV serological markers. Users are responsible for establishing their own performance characteristic.

## V. DEVICE DESCRIPTION

The ADVIA Centaur® Anti-HBs assay is a sandwich immunoassay using direct, chemiluminometric technology. Hepatitis B surface antigen (HBsAg; ad and ay) are covalently coupled to magnetic latex particles (MLP) in the Solid Phase. In the Lite Reagent, the HBsAg (ad and ay) is labeled with acridinium ester. Nonmagnetic latex particles are added from the ancillary well. The sample is incubated simultaneously with Lite Reagent, Solid Phase, and Ancillary Reagent. Antibody-antigen complexes will form if anti-HBs is present in the sample.

The system automatically performs the following steps:

- dispenses 100 µL of sample into a cuvette
- dispenses 50 µL of Ancillary Reagent and incubates for 2.75 minutes at 37°C
- dispenses 100 µL of Solid Phase and 50 µL of Lite Reagent, and incubates the mixture for 6.75 minutes at 37°C
- separates the Solid Phase from the mixture and aspirates the unbound reagent
- washes the cuvette with Wash 1
- dispenses 300 µL each of Acid Reagent and Base Reagent to initiate the chemiluminescent reaction

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Summary of Safety and Effectiveness Data

- reads the results in Relative Light Units (RLU) and converts the RLU to Index values from a stored master curve traceable to the World Health Organization (WHO) anti-Hepatitis B Immunoglobulin 1st - Reference Preparation (1977).

A direct relationship exists between the amount of anti-HBs activity present in the patient sample and the amount of RLUs detected by the system.

Calibration:

The ADVIA Centaur® Anti-HBs assay utilizes a factory set Master Curve. The Master Curve values are contained on the Master Curve card provided with each kit. The master curve and calibration are lot specific. The barcode reader or keyboard is used to enter the Master Curve values into the system. The 2 calibrators in the kit are run when the lot is first used or after expiration of the calibrator interval (28 days). If the calibration run is valid as determined by prearranged parameters, the values are stored and used to "normalize" test values to the Master Curve. The assay utilizes a cutoff of 1.00 Index value, which is equivalent to $10\mathrm{mIU / mL}$ in the anti-Hepatitis B Immunoglobulin 1st Reference Preparation. Individuals whose samples read at or above this level are considered to be immune from infection with HBV.

VI. ALTERNATE PRACTICES AND PROCEDURES

Determination of the presence of anti-HBs in patients may be achieved by using a number of commercially available, FDA licensed/approved, serological tests. When the results of such tests are evaluated in conjunction with a physician's assessment and biochemical test results, susceptibility to HBV can be excluded.

VII. MARKETING HISTORY

The ADVIA Centaur® Anti-HBs Assay is currently being marketed internationally in accordance with Section 802 of the FD & C Act in the following countries: Britian, Israel, Sweden, Australia, Austria, Italy, India, Greater China (Hong Kong), Singapore, Canada, South Korea, Africa, Poland, Germany, France, and the Netherlands.

This product has not been withdrawn from any of these markets for any reason.

VIII. POTENTIAL ADVERSE EFFECTS OF THE DEVICE ON HEALTH

Failure of the product to perform as intended, or errors in the use of the product, may lead to a false result. A false nonreactive result cannot be considered a public health risk, as the individual would either unnecessarily be vaccinated, or would be considered to have not recovered from an acute HBV infection.

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Summary of Safety and Effectiveness Data

A false reactive result could be considered a public health risk due to the fact that an individual would be considered to have been previously vaccinated, or had been previously exposed, and would be therefore immune to HBV. The risk is that an individual would not be vaccinated and would be at a higher risk of infection if exposed to HBV.

## IX. SUMMARY OF NON-CLINICAL STUDIES

The applicant performed in-house studies in order to evaluate the following performance characteristics of the ADVIA Centaur® Anti-HBs assay: analytical sensitivity, cutoff determination and verification, potential cross-reactivity, interference, stability, microbiological contamination, matrix effects, sample handling and collection, sample carryover, and precision.

## Analytical Sensitivity

The ADVIA Centaur® Anti-HBs assay standardization is traceable to anti-Hepatitis B Immunoglobulin 1st International Reference Preparation (IRP, 1977) with the assay cut off value of 1.00 Index assigned at 10 mIU/mL. A study was performed to verify the standardization to the IRP across the dynamic range of the assay, using dilutions of the IRP. The study data demonstrates good agreement between the ADVIA Centaur® Anti-HBs calibration and the WHO anti-Hepatitis B Immunoglobulin IRP (lot 17-2-77):

In a second study, the analytical sensitivity of ADVIA Centaur® Anti-HBs assay was evaluated at the assay cut-off value. The assay cut-off value is set to 10 mIU/mL, which is the internationally accepted threshold of protective immunity. The activity at the cut-off value was defined by using 3 kit lots to assay a series of dilutions of the IRP near the cut-off value. The activity at the cut-off value in the ADVIA Centaur® Anti-HBs assay was 10.53 mIU/mL (95% confidence interval = 10.03 to 11.03 mIU/mL) as estimated by linear regression.

## Cross-Reactivity

The ADVIA Centaur® Anti-HBs assay was evaluated for potential cross-reactivity to other disease states, viruses, microorganisms or historically problematic specimens. Three hundred thirty-three distinct serum and plasma specimens from 15 groups of potential cross-reactants were tested. The nonreactive anti-HBs status of each specimen was verified using a commercially available FDA approved anti-HBs assay. The following results were obtained on the ADVIA Centaur Anti-HBs assay:

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Summary of Safety and Effectiveness Data

ADVIA Centaur Anti-HBs Results

| Clinical Category | Number Tested | Nonreactive | Reactive |
| --- | --- | --- | --- |
| Hepatitis A Infection (HAV) | 15 | 15 | 0 |
| Hepatitis C Infection (HCV) | 11 | 11 | 0 |
| Cytomegalovirus (CMV) | 49 | 49 | 0 |
| Epstein-Barr Virus (EBV) | 15 | 15 | 0 |
| Herpes Simplex Virus (HSV) | 10 | 10 | 0 |
| Varicella Zoster Virus (VZV) | 18 | 18 | 0 |
| Parvovirus B19 Infection | 3 | 3 | 0 |
| Rubella | 85 | 85 | 0 |
| Human Immunodeficiency Virus (HIV-1 & HIV-2) | 41 | 40 | 1 |
| Toxoplasmosis | 9 | 9 | 0 |
| Syphilis | 15 | 14 | 1 |
| Non Viral Liver Disease | 10 | 10 | 0 |
| Rheumatoid Arthritis | 12 | 12 | 0 |
| Autoimmune Disease (Systemic Lupus & ANA) | 7 | 7 | 0 |
| Influenza Vaccine Recipients | 33 | 33 | 0 |
| Total Samples Tested | 333 | 331 | 2 |

## Interfering Substances

A study was performed to evaluate the ADVIA Centaur® Anti-HBs assay for interference to high levels of endogenous substances, specifically, conjugated bilirubin @ 20 mg/dL, unconjugated bilirubin @ 40 mg/dL, hemoglobin @ 500 mg/dL, triglycerides @ 1000 mg/dL, and human serum albumin @ 12 g/dL (ie, high total protein). The study was designed using the protocol described in guidance document NCCLS EP7-P¹. The interference testing was performed using specimens from 5 individuals and evaluated in 4 specimen matrices: serum, serum gel-barrier tubes, EDTA plasma, and lithium heparin. The anti-HBs activity of the specimens spanned a range of approximately 8 mIU/mL to 48 mIU/mL. There was 1 negative specimen. Average dose recoveries of the spiked test specimens were within 15% of the average matched control specimens. No clinically significant changes were observed.

A study was performed to evaluate the ADVIA Centaur® Anti-HBs assay for interference in specimens with high levels of immunoglobulin (6 g/dL) or low total protein (3 g/dL). The study was designed via the protocol described in guidance document NCCLS EP7-P¹. The interference testing was performed using 9 serum and EDTA specimens (8 anti-HBs positives, 1 anti-HBs negative). The anti-HBs activity in these samples spanned a range from approximately

¹ National Committee for Clinical Laboratory Standards; Interference Testing in Clinical Chemistry; Proposed Guidelines (1986); NCCLS document EP7-P.

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Summary of Safety and Effectiveness Data

13 mIU/mL to >1000 mIU/mL. Average dose recoveries of the spiked test specimens were within 15% of the average matched control specimens. No clinically significant changes were observed.

Interference Table.

| Serum specimens that are... | Demonstrate <15% change in results up to... |
| --- | --- |
| hemolyzed | 500 mg/dL of hemoglobin |
| lipemic | 1000 mg/dL of triglycerides |
| icteric | 20 mg/dL of conjugated bilirubin |
| icteric | 40 mg/dL of unconjugated bilirubin |
| proteinemic (high) | 12 g/dL of total protein |
| proteinemic (low) | 3 g/dL of total protein |
| hyper IgG | 6 g/dL of immunoglobulin G |

Interference testing was determined according to NCCLS Document EP7-P.¹

## Stability Studies

Five lots of anti-HBs reagents and 4 lots of calibrators and controls were placed on real-time stability studies. All kits and reagents were stored at the recommended storage temperature of 2°C to 8°C. Reagents and calibrators were monitored at several checkpoints after the manufacturing date. Shipping studies of the reagents found that the anti-HBs reagents could withstand 3 freeze/thaw cycles (-40°C to 4°C) without aggregation of the solid phase and with acceptable performance. Studies also tested for shipment of upside-down packs. ReadyPack reagents stored upside down could tolerate up to 52 weeks in this position, although the recommended shipping condition is upright at 2°C to 8°C. The anti-HBs calibrators and controls also underwent 3 freeze/thaw cycles with no adverse effects.

The studies support a claim of 52-week expiration dating for the anti-HBs ReadyPack reagents, calibrators, and controls. The recommended shipping and storage conditions are to ship the ReadyPack reagents upright at 2°C to 8°C and store at 2°C to 8°C.

## Reagent On-Board Stability Studies

Three lots of reagent were tested as part of reagent on-board stability (OBS) studies on 5 ADVIA Centaur® instruments. On-Board Stability testing on the instruments occurred at several checkpoints after the pack seal was pierced. A fresh (unpierced pack) served as the control for each time point. The dose recovery within 10% of the fresh pack defined acceptable performance.

Similarly, evaluation of the dose recovery results from the pierced pack compared to the fresh pack at the first calibration point set the re-calibration interval on the ADVIA Centaur® instrument.

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Summary of Safety and Effectiveness Data

The OBS studies for the reagents support 41 days OBS for the ADVIA Centaur® Anti-HBs reagents. The OBS studies also support a re-calibration interval of 28 days.

## Stress Studies of Calibrators and Controls

A calibrator and control OBS study was performed to evaluate the length of time a calibrator or control sample could remain in an open sample tube at an elevated temperature (30°C). The acceptance criteria were RLU recovery within 15% of the time-zero result. The high calibrator and positive controls were most sensitive to elevated temperature. The data supports 8 hours OBS for the anti-HBs calibrators and controls.

The calibrator and control open bottle use study examined the length of time the calibrators or controls were stable once the vial was opened. Open vials were stored at the recommended storage conditions of 2°C to 8°C. The open bottles were sampled periodically up to 95 days after the initial opening. Fresh (unopened) bottles were evaluated at each time point and served as controls. The acceptance criteria for this study were dose recovery within 10% (or 2SD) of the fresh bottle dose. The study supports an open bottle use lifetime of up to 90 days.

## Microbiology Studies

The ADVIA Centaur® Anti-HBs reagents and controls contain a preservative to protect against adventitious contamination by microorganisms. Reagents and controls were challenged in a study conducted according to USP 23/NF 18. The preservative study results indicated complete and effective elimination of all of the microorganisms. The study was repeated with the reagents and controls after 24 months of storage with the same level of preservative efficacy. The reagents were tested against the product release panel after challenge with the microorganisms and passed all specifications.

## Matrix Studies

The ADVIA Centaur Anti-HBs assay can use plasma specimens collected using either heparin or EDTA anticoagulants. In a matched matrix study of 25 specimens around the cutoff (Index Value 1.0), drawn in three tube types including serum, EDTA and Li-heparin vacutainer tubes, the recovery of the heparinized samples was 84% and the recovery of the EDTA samples was 94% of the serum control. N = 25 samples: (12 &gt; 1.0 Index, 13 &lt; 1.0 Index)

Index Range: approximately 0.4 to 2.0 Index

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Summary of Safety and Effectiveness Data

Matrix Bias Study of Samples Near the Cutoff

| Statistic | Serum (Index) | EDTA (Index) | Li Heparin (Index) |
| --- | --- | --- | --- |
| Mean | 1.05 | 1.00 | 0.89 |
| SD | 0.53 | 0.56 | 0.56 |
| Bias to Serum (Index) | NA | -0.06 | 0.16 |
| SD of Bias | NA | 0.05 | 0.05 |
| Bias to Serum (% recovery) | NA | -5.3 % | -15.0% |

The data demonstrated that Na and Li heparinized samples may cause lower Index Values in some anti-HBs reactive samples. High negative results (0.50–0.74 Index Value) obtained in samples collected with these anticoagulants should therefore be interpreted accordingly. It is recommended that additional testing be performed in either a serum or EDTA plasma. This information is provided in the Caution section of the labeling.

## Precision Studies

The ADVIA Centaur Anti-HBs precision and reproducibility in various sample matrices was examined in a 20-day precision protocol (NCCLS EP5-A) using a single lot of reagents. Twenty spiked specimens in four matrices were prepared to measure the precision of the assay at different dose levels. In addition to serum matrix, the anticoagulants tested were K₂-EDTA, Na heparin, and Li heparin. The specimens were assayed in duplicate twice per day for 20 time points. A single instrument was used in this study over the course of 35 days. The matrix reproducibility results are presented in the following table. The precision estimates were derived from variance component analysis. Calculations for within run, between day, and total precision were performed as recommended by the guidance protocol.

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Summary of Safety and Effectiveness Data

Precision Estimates for Matrix Study

| Member | Matrix | Mean Index Value² | Within Run³ | | Between Days⁴ | | Total⁵ | | Number of Observations |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | | | SD | CV (%) | SD | CV (%) | SD | CV (%) | |
| S-7 | Serum | 0.77 | 0.123 | 16.3 | 0.05 | 6.8 | 0.14 | 17.7 | 80 |
| S-12 | | 1.19 | 0.09 | 7.5 | 0.00 | 0.0 | 0.12 | 10.0 | 80 |
| S-15 | | 1.49 | 0.08 | 5.4 | 0.00 | 0.0 | 0.12 | 8.3 | 80 |
| S-100 | | 9.24 | 0.27 | 2.9 | 0.00 | 0.0 | 0.46 | 5.0 | 80 |
| S-200 | | 19.87 | 0.64 | 3.2 | 0.21 | 1.1 | 0.87 | 4.4 | 80 |
| E-7 | EDTA | 0.66 | 0.10 | 15.3 | 0.06 | 9.0 | 0.12 | 18.3 | 80 |
| E-12 | plasma | 1.14 | 0.11 | 9.7 | 0.04 | 3.5 | 0.12 | 10.4 | 80 |
| E-15 | | 1.53 | 0.07 | 4.5 | 0.05 | 3.4 | 0.11 | 7.4 | 82* |
| E-100 | | 9.68 | 0.26 | 2.7 | 0.00 | 0.0 | 0.58 | 5.9 | 80 |
| E-200 | | 19.41 | 0.51 | 2.6 | 0.23 | 1.2 | 0.73 | 3.7 | 80 |
| Na-7 | Na heparin | 0.75 | 0.07 | 9.3 | 0.05 | 6.1 | 0.12 | 15.5 | 80 |
| Na-12 | plasma | 1.13 | 0.07 | 6.5 | 0.03 | 2.3 | 0.09 | 8.2 | 80 |
| Na-15 | | 1.51 | 0.11 | 7.1 | 0.05 | 3.5 | 0.12 | 8.0 | 82* |
| Na-100 | | 9.31 | 0.31 | 3.3 | 0.24 | 2.6 | 0.44 | 4.7 | 80 |
| Na-200 | | 19.54 | 0.63 | 3.2 | 0.15 | 0.8 | 1.37 | 7.0 | 80 |
| Li-7 | Li heparin | 7.14 | 0.11 | 14.7 | 0.05 | 5.7 | 0.11 | 15.8 | 82* |
| Li-12 | plasma | 1.19 | 0.07 | 5.8 | 0.02 | 1.6 | 0.09 | 7.7 | 80 |
| Li-15 | | 1.40 | 0.14 | 9.6 | 0.00 | 0.0 | 0.17 | 12.0 | 80 |
| Li-100 | | 10.06 | 0.32 | 3.2 | 0.18 | 1.8 | 0.60 | 6.0 | 80 |
| Li-200 | | 19.92 | 0.67 | 3.3 | 0.43 | 2.2 | 0.97 | 4.8 | 80 |

1 It is recommended that laboratories establish their own precision and reproducibility

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Summary of Safety and Effectiveness Data

ranges for plasma specimens.

2. Arithmetic mean of all results
3. Variability of the assay performance within run
4. Variability of the assay performance between days
5. Variability of the assay performance incorporating all days and runs.

* - Differences in the number of observations were due to routine laboratory practices.

## Reproducibility

The ADVIA Centaur Anti-HBs reproducibility study was performed at 3 external sites using 2 reagent lots per site. A 5-member panel and controls were assayed in replicates of 5 on a single run per day over 6 days for each lot. The study was completed with a single calibration of the assay. The data from all 3 sites and from all 3 reagent lots were combined to obtain SD and percent CV for within run, between run, between testing site, between lot, and total. The precision estimates were derived from variance component analysis. The reproducibility results are presented in the following table:

Reproducibility Estimates for All Testing Sites and Reagent Lots

| Panel Member | Mean Index Value^{1} | Within Run^{2} | | Between Run^{3} | | Between Testing Site^{4} | | Between Lot^{5} | | Total^{6} | | Number of Observations |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | | SD | CV (%) | SD | CV (%) | SD | CV (%) | SD | CV (%) | SD | CV (%) | |
| 1 | 0.02 | 0.023 | NA | 0.03 | NA | 0.012 | NA | 0.001 | NA | 0.04 | NA | 180 |
| 2 | 0.72 | 0.08 | 11.5 | 0.04 | 5.3 | 0.10 | 14.2 | 0.034 | 5.0 | 0.14 | 19.6 | 180 |
| 3 | 1.24 | 0.08 | 6.2 | 0.034 | 3.2 | 0.13 | 10.8 | 0.04 | 3.3 | 0.16 | 13.3 | 179* |
| 4 | 1.50 | 0.089 | 5.8 | 0.05 | 3.0 | 0.123 | 8.5 | 0.04 | 2.9 | 0.17 | 11.1 | 178* |
| 5 | 19.41 | 0.61 | 3.1 | 0.18 | 0.9 | 1.11 | 5.7 | 0.701 | 3.6 | 1.46 | 7.5 | 180 |
| Negative Control | 0.06 | 0.04 | NA | 0.05 | NA | 0.05 | NA | 0.00 | NA | 0.08 | NA | 179* |
| Positive Control | 12.69 | 0.38 | 3.0 | 0.26 | 2.1 | 0.65 | 5.1 | 0.00 | 0.0 | 0.79 | 6.3 | 180 |

1. Arithmetic mean of all results (all testing sites and reagent lots)
2. Variability of the assay performance within day (all testing sites and reagent lots)
3. Variability of the assay performance between days (all testing sites and reagent lots)
4. Variability of the assay performance between testing sites (from testing site to testing site)
5. Variability of the assay performance between reagent lots (from reagent lot to reagent lot, across all testing sites)
6. Variability of the assay performance incorporating all testing sites, all reagent lots, and all days

* - Differences in the number of observations were due to routine laboratory practices.

NOTE: 5 replicates per panel in 1 run per day for 6 days

NA = not applicable.

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## X. SUMMARY OF CLINICAL STUDIES

**Study Design:**

A multi-center prospective study for the ADVIA Centaur® Anti-HBs assay consisted of 2197 patients. Of these 2197 patients, 966 patients (43.97%) were from the high risk population, 846 patients (38.51%) were from the signs and symptoms population, 212 patients (9.65%) were from the dialysis population, and 173 patients (7.87%) were from the vaccinee population. The prospective study population was 42.47% Caucasian, 22.58% Black, 25.81% Hispanic, 4.37% Asian, and 4.78% from unknown or other ethnicity. The majority of patients were male (52.48% male and 47.52% female). The mean age was 45.3 years (range of 12 to 82 years). Patients in the prospective study population were from the following geographic regions: Florida (36.96%), Texas (33.41%), New York (21.53%), California (7.74%), and Illinois (0.36%).

The ADVIA Centaur® Anti-HB expected value results for the prospective population for all sites combined by age group and gender are summarized in the following table.

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Summary of Safety and Effectiveness Data

Distribution of High Risk, Signs and Symptoms, Dialysis, and Vaccinee Population by Age Group and Gender (All Testing Sites)

| Age (Years) | Gender | Reactive (N) | Nonreactive (N) | Total (N) |
| --- | --- | --- | --- | --- |
| 0-9 | Male | 0 | 0 | 0 |
| | Female | 0 | 0 | 0 |
| 10-19 | Male | 3 | 4 | 7 |
| | Female | 9 | 7 | 16 |
| 20-29 | Male | 56 | 51 | 107 |
| | Female | 83 | 45 | 128 |
| 30-39 | Male | 89 | 125 | 214 |
| | Female | 104 | 103 | 207 |
| 40-49 | Male | 154 | 239 | 393 |
| | Female | 164 | 161 | 325 |
| 50-59 | Male | 115 | 183 | 298 |
| | Female | 94 | 139 | 233 |
| 60-69 | Male | 34 | 54 | 88 |
| | Female | 49 | 57 | 106 |
| 70 | Male | 10 | 35 | 45 |
| | Female | 8 | 20 | 28 |
| Unknown | Male | 1 | 0 | 1 |
| | Female | 0 | 1 | 1 |
| Total | Male | 462 | 691 | 1153 |
| | Female | 511 | 533 | 1044 |
| | All | 973 | 1224 | 2197 |

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Summary of Safety and Effectiveness Data

The HBV disease classification for each patient in the high risk, signs and symptoms, and dialysis populations (total of 2024 patients) was determined by serological assessment using resultant hepatitis marker profiles obtained from results of commercially available, FDA-approved reference assays. The serological assessment included the following 6 HBV markers: hepatitis B virus surface antigen (HBsAg), hepatitis B virus e antigen (HBeAg), total antibody to hepatitis B virus core antigen (Anti-HBc Total), IgM antibody to hepatitis B virus core antigen (Anti-HBc IgM), total antibody to HBeAg (Anti-HBe), and total antibody to hepatitis B virus surface antigen (anti-HBs) (quantitative). Testing of these specimens occurred at hospital associated diagnostic laboratories located in Miami, FL (34%), Dallas, TX (33%), and New York City, NY (33%). The individual ADVIA Centaur® HBV assay result was compared to the reference HBV assay result and to the patient classification. No patients were excluded from the complete study set due to incomplete reference HBV serological results.

Each patient’s HBV infection was classified based on the reactive (+)/ nonreactive (-) patterns of the 6 HBV reference serological markers. Disease classification for each patient was based only on the HBV serological marker results, and was not affected by additional laboratory or clinical information. There were 31 unique reference marker patterns observed using the ADVIA Centaur® Anti-HBs assay. These patterns are presented in the following table.

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Summary of Safety and Effectiveness Data

| Bayer ADVIA Centaur® Anti-HBs Assay Classification by HBV Reference Markers (All Testing Sites) | | | | | | |
| --- | --- | --- | --- | --- | --- | --- |
| HBV Reference Markers | | | | | | HBV Classification |
| HBsAg^{a} | HBeAg | IgM Anti-HBc | Total Anti-HBc | Anti-HB e | Anti-HBs (>10 mIU/mL) | |
| + | + | + | + | + | - | Acute |
| + | + | + | + | - | - | Acute |
| + | - | + | + | + | - | Acute |
| + | + | - | + | + | - | Chronic |
| + | + | - | + | - | + | Chronic |
| + | + | - | + | - | - | Chronic |
| + | - | - | + | + | + | Chronic |
| + | - | - | + | + | - | Chronic |
| + | - | - | + | - | + | Chronic |
| + | + | + | + | - | + | Chronic |
| - | - | + | + | + | + | Early Recovery |
| - | - | + | + | + | - | Early Recovery |
| - | - | + | + | - | + | Early Recovery |
| - | - | - | + | + | - | Early Recovery |
| - | - | - | + | + | - | Early Recovery |
| - | - | - | + | + | + | Recovery |
| - | - | - | - | + | + | Recovery |
| - | - | - | + | - | + | Recovered |
| - | - | - | + | - | - | Recovered |
| - | - | - | - | - | + | HBV Vaccine Response |
| - | - | - | - | - | - | Not Previously Infected |
| + | - | - | - | - | + | Uninterpretable |
| + | - | - | - | - | - | Uninterpretable |
| + | + | - | - | - | + | Uninterpretable |
| + | + | - | - | - | - | Uninterpretable |
| - | + | - | - | + | - | Uninterpretable |
| - | + | - | + | + | + | Uninterpretable |

+ = Reactive
- = Nonreactive
a Reactive (+) = Reference HBsAg assay result was reactive and confirmed to be reactive by neutralization
Nonreactive (-) = Reference HBsAg assay result was nonreactive, or reactive, but non-confirmed by neutralization
Note: when the result was 'EQUIVOCAL', it was assumed to be nonreactive (-)

Following the assignment of specimen classification, the HBV results obtained using the ADVIA Centaur® method were compared with results obtained using the reference method for each result category (reactive and nonreactive). The HBV

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Summary of Safety and Effectiveness Data

results from the ADVIA Centaur Anti-HBs assay and the reference assay for all testing sites combined is presented in the following table.

Comparison of Results in High Risk, Signs and Symptoms, and Dialysis Populations by HBV Classification

ADVIA Centaur Anti-HBs Assay versus Reference Anti-HBs Assay (All Testing Sites)¹

| | Reference Anti-HBs Assay Negative | | Reference Anti-HBs Assay Positive | | |
| --- | --- | --- | --- | --- | --- |
| HBV Classification | ADVIA Centaur Anti-HBs Assay | | ADVIA Centaur Anti-HBs Assay | | |
| | Reactive (N) | Nonreactive (N) | Reactive (N) | Nonreactive (N) | Total (N) |
| Acute | 0 | 11 | 0 | 0 | 11 |
| Chronic | 4 | 100 | 5 | 3 | 112 |
| Early Recovery | 20 | 95 | 8 | 0 | 123 |
| Recovery | 0 | 0 | 198 | 13 | 211 |
| Recovered | 18 | 136 | 156 | 14 | 324 |
| HBV Vaccine Response | 0 | 0 | 359 | 26 | 385 |
| Not Previously Infected | 58 | 779 | 0 | 0 | 837 |
| Uninterpretable | 1 | 14 | 5 | 1 | 21 |
| Total | 101 | 1135 | 731 | 57 | 2024 |

¹ In this study, 84 of 2024 specimens fell within the retest zone. Thirty-seven (44%) of these specimens were determined to be reactive after retesting.

The percent agreement between the ADVIA Centaur® Anti-HBs assay and the reference anti-HBs assay for the high risk, signs and symptoms, and dialysis populations across all testing sites is summarized in the following table.

ADVIA Centaur Anti-HBs Assay versus Reference Anti-HBs Assay (All Testing Sites) by HBV Classification in High Risk, Signs and Symptoms, and Dialysis Populations

| HBV Classification | Positive Percent Agreement % (x/n) | 95% Exact Confidence Interval | Negative Percent Agreement % (x/n) | 95% Exact Confidence Interval |
| --- | --- | --- | --- | --- |
| Acute | | | 100 (11/11) | 71.5 to 100 |
| Chronic | 62.5 (5/8) | 24.5 to 91.5 | 96.1 (100/104) | 90.4 to 98.9 |
| Early Recovery | 100 (8/8) | 63.1 to 100 | 82.6 (95/115) | 74.4 to 89.0 |
| Recovery | 93.8 (198/211) | 89.7 to 96.7 | | |
| Recovered | 91.8 (156/170) | 86.6 to 95.4 | 88.3 (136/154) | 82.2 to 92.9 |
| HBV Vaccine Response | 93.3 (359/385) | 90.3 to 95.5 | | |
| Not Previously Infected | | | 93.1 (779/837) | 91.1 to 94.7 |
| Uninterpretable | 83.3 (5/6) | 35.9 to 99.6 | 93.3 (14/15) | 68.1 to 99.8 |
| Overall | 92.8 (731/788) | 90.7 to 94.5 | 91.8 (1135/1236) | 90.2 to 93.3 |

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Summary of Safety and Effectiveness Data

## HBV Vaccinee Population Study

A study was conducted using 173 serum samples from individuals who had received a full course of injections of either Engerix-B® HBV vaccine (GlaxoSmithKline), Recombivax HB® HBV vaccine (Merck &amp; Company, Inc.), the Twin RX Hepatitis A and B vaccine (GlaxoSmithKline), or another type of hepatitis B vaccine. All samples were assayed with a reference Anti-HBc total assay and found to be negative. Testing of these specimens occurred at hospital associated diagnostic laboratories located in Miami, FL (20%), Dallas, TX (37%), and New York City, NY (43%). Samples were tested using both the ADVIA Centaur® Anti-HBs assay and the reference anti-HBs assay, and the results were compared.

### Comparison in Results in Vaccinee Population
**ADVIA Centaur® Anti-HBs Assay vs. Anti-HBs Reference Assay {All Testing Sites}**

| | Reference Anti-HBs Negative | | Reference Anti-HBs Positive | | Total |
| --- | --- | --- | --- | --- | --- |
| | ADVIA Centaur® Anti-HBs Assay | | ADVIA Centaur® Anti-HBs Assay | | |
| | Reactive^{1} | Nonreactive | Reactive | Nonreactive | |
| | N | N | N | N | N |
| Vaccinee | 9 | 30 | 132 | 2 | 173 |

1. In this study, 6 of 173 specimens fell within the retest zone. Four (67%) of these specimens were determined to be reactive after retesting.

The percent agreement between the ADVIA Centaur® Anti-HBs assay and the reference anti-HBs assay for the vaccinee population is summarized in the following table.

### Percent Agreement and Confidence Intervals in Vaccinee Population
**ADVIA Centaur® Anti-HBs Assay and Reference Anti-HBs Assay**

| Testing Site | Positive Percent Agreement % (x/n)^{a} | 95% Exact Confidence Interval | Negative Percent Agreement % (x/n)^{b} | 95% Exact Confidence Interval |
| --- | --- | --- | --- | --- |
| All Testing Sites | 98.5 (132/134) | 94.7 to 99.8 | 76.9 (30/39) | 60.7 to 88.9 |

## HBV Vaccination Panel Study

A study was conducted using 40 well-characterized, commercially available serum samples from 20 individuals prior to vaccination and after vaccination. Testing was

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Summary of Safety and Effectiveness Data

performed at one testing site in Miami, Florida. Samples were tested using both the ADVIA Centaur® Anti-HBs assay and the reference anti-HBs assay, and the results were compared. The method comparison for the vaccination panel population across all testing sites is presented in the following table.

Comparison of ADVIA Centaur Anti-HBs and Reference Anti-HBs Results in Pre- and Post-Vaccinated Populations¹

Reference AntiHBs Results

| ADVIA Centaur AntiHBs Results | Nonreactive (N) | Reactive (N) | Total (N) |
| --- | --- | --- | --- |
| **Pre-vaccination** | | | |
| Nonreactive, N (%) | 20 (100%) | 0 | 20 (100%) |
| Reactive, N (%) | 0 | 0 | 0 |
| Percent agreement: 100% | | | |
| 95% confidence interval: 83.2 to 100 | | | |
| **Post-vaccination** | | | |
| Nonreactive, N (%) | 0 | 0 | 0 |
| Reactive, N (%) | 0 | 20 (100%) | 20 (100%) |
| Percent agreement: 100% | | | |
| 95% confidence interval: 83.2 to 100 | | | |

1. For the vaccinee panel (samples from 20 patients), the percent agreement between ADVIA Centaur Anti-HBs results and reference results was determined for pre-vaccination and for post-vaccination.

Based on all of the clinical laboratory study information presented, the following ADVIA Centaur® Anti-HBs assay result interpretation was established:

| ADVIA Centaur® Anti-HBs Assay Result | | | |
| --- | --- | --- | --- |
| | | Status | Interpretation |
| <1.00 | Negative | Patient is assumed to not have immunity to HBV infection. | |
| ≥0.75 and <1.25 | Retest Zone | If results are within the retest zone after initial testing, samples are to be retested. After retesting, if 3 results are available and 2 results are ≥ 1.0, then the sample is considered to be reactive. If 3 results are available and 2 results are < 1.0, then the sample is considered to be nonreactive. | |
| ≥1.00 | Positive | Anti-HBs is detected at >10 mIU/mL. Patient is considered to have immunity to HBV infection. | |

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Summary of Safety and Effectiveness Data

## XI. CONCLUSIONS DRAWN FROM STUDIES

The data from the non-clinical studies demonstrated acceptable analytical sensitivity and specificity, reproducibility, and stability of the ADVIA Centaur® Anti-HBs assay when used according to the instructions for use as stated in the labeling, the warnings and precautions, the Specimen Collection and Preparation and Limitations section of the labeling.

## RISK BENEFIT ANALYSIS:

The nonclinical and clinical studies contained in this application demonstrated that the device is safe and effective as indicated. It can therefore be concluded that the benefits of the ADVIA Centaur® Anti-HBs assay, when used according to the provided directions and in conjunction with other serological and clinical information outweigh any risk that may be associated with its use.

The clinical studies in this application indicate that the ADVIA Centaur® Anti-HBs assay is safe and effective when used according to the directions for use in the labeling. The sponsor has provided scientific data to support the utility of this assay in conjunction with other laboratory results and clinical information as an aid in the laboratory determination for individual’s susceptibility to HBV infection, for individuals prior to or following HBV vaccination, or where vaccination status is unknown. A reactive assay result will allow a differential diagnosis in individuals displaying signs and symptoms of hepatitis in whom etiology is unknown.

## XII. PANEL RECOMMENDATIONS

In accordance with the provisions of section 515(c)(2) of the act as amended in the Safe Medical Devices Act of 1990, this PMA was not referred to the Microbiology Devices Panel, an FDA advisory committee, for review and recommendation because the information in the PMA substantially duplicates information previously reviewed by this panel.

## XIII. CDRH DECISION

FDA issued an approval order on May 14, 2004.

The applicant’s manufacturing facilities were inspected on October 27, and November 11, 2003 and found to be in substantial compliance with the Quality Systems Regulation (21 CFR 820).

## XIII. APPROVAL SPECIFICATIONS

Directions for Use: Refer to the labeling

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Hazards to Health from Use of the Device: See Indications, Contraindications, Warnings, Cautions, Precautions and Limitations statements in the labeling.

Postapproval Requirements and Restrictions: See approval order.

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