Cepheid Xpert Respiratory Control Panel

K190086 · Microbiologics, Inc. · PMN · Oct 7, 2019 · Microbiology

Device Facts

• Record ID: K190086
• Device Name: Cepheid Xpert Respiratory Control Panel
• Applicant: Microbiologics, Inc.
• Product Code: PMN · Microbiology
• Decision Date: Oct 7, 2019
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3920
• Device Class: Class 2

Indications for Use

The Cepheid Xpert®Respiratory Control Panel is intended for use as an external assayed positive and negative quality control to monitor the performance of in vitro laboratory nucleic acid testing procedures for the qualitative detection of Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus and Respiratory Syncytial Virus A performed with the Cepheid Xpert® Xpress Flu/RSV assay on the GeneXpert® Instrument System. The controls comprise cultured and inactivated Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus and Respiratory Syncytial Virus A as the positive control and Coxsackie virus B1 as the negative control. The Cepheid Xpert®Respiratory Control Panel is not intended to replace manufacturer controls provided with the device.

Device Story

The Cepheid Xpert Respiratory Control Panel provides external quality control for nucleic acid testing. It consists of lyophilized swabs containing chemically or radiologically inactivated viruses (Influenza A H1N1, H3N2, Influenza B, RSV A for positive control; Coxsackie B1 for negative control). Used in clinical laboratories, the swabs are processed like patient samples on the GeneXpert Instrument System. The device monitors the entire assay workflow, including RNA extraction, amplification, and detection. By verifying the performance of the Cepheid Xpert Xpress Flu/RSV assay, the control panel helps ensure the accuracy of clinical results, aiding healthcare providers in diagnostic decision-making for respiratory infections.

Clinical Evidence

Bench testing only. Reproducibility study conducted at three sites over five days using three lots of control material; 100% agreement with expected results observed for all analytes (n=90-91 per analyte). Stability studies (accelerated and real-time) and in-use stability (6 hours) confirmed performance consistency. Human factors testing evaluated robustness against incorrect sample volume and mixing deviations; all valid tests yielded expected results.

Technological Characteristics

Lyophilized swab format; contains chemically or radiologically inactivated microorganisms. Monitors extraction, amplification, and detection steps of the Cepheid Xpert Xpress Flu/RSV assay on the GeneXpert Instrument System. Packaged in heat-sealed foil pouches with desiccant.

Indications for Use

Indicated for use as external positive and negative quality control material for monitoring performance of in vitro nucleic acid testing for Influenza A (H1N1), Influenza A (H3N2), Influenza B, and RSV A using the Cepheid Xpert Xpress Flu/RSV assay on the GeneXpert Instrument System.

Regulatory Classification

Identification

An assayed quality control material for clinical microbiology assays is a device indicated for use in a test system to estimate test precision or to detect systematic analytical deviations that may arise from reagent or analytical instrument variation. This type of device consists of single or multiple microbiological analytes intended for use with either qualitative or quantitative assays.

Special Controls

An assayed quality control material for clinical microbiology assays must comply with the following special controls: (1) Premarket notification submissions must include detailed device description documentation and information concerning the composition of the quality control material, including, as appropriate: (i) Analyte concentration; Expected values: (ii) Analyte source: (iii) (iv) Base matrix; (v) Added components; (vi) Safety and handling information; and, (vii) Detailed instructions for use. (2) Premarket notification submissions must include detailed documentation, including line data as well as detailed study protocols and a statistical analysis plan used to establish performance, including: (i) Description of the process for value assignment and validation. (ii) Description of the protocol(s) used to establish stability. (iii) Line data establishing precision/reproducibility. (iv) Where applicable, assessment of matrix effects and any significant differences between the quality control material and typical patient samples in terms of conditions known to cause analytical error or affect assay performance. (v) Where applicable, identify or define traceability or relationship to a domestic or international standard reference material and/or method. (vi) Where applicable, detailed documentation related to studies for surrogate controls. (3) Premarket notification submissions must include an adequate mitigation (e.g., realtime stability program) to the risk of false results due to potential modifications to the assays specified in the device's 21 CFR 809.10 compliant labeling. (4) Your 21 CFR 809.10 compliant labeling must include the following: (i) The intended use in your 21 CFR 809.10(a)(2) and 21 CFR 809.10(b)(2) compliant labeling must include the following: (A) Assayed control material analyte(s); (B) Whether the material is intended for quantitative or qualitative assays: (C) Stating if the material is a surrogate control; (D)The system(s), instrument(s), or test(s) for which the quality control material is intended. (ii) The intended use in your 21 CFR 809.10(a)(2) and 21 CFR 809.10(b)(2) compliant labeling must include the following statement: "This product is not intended to replace manufacturer controls provided with the device." (iii)A limiting statement that reads "Quality control materials should be used in accordance with local, state, federal regulations, and accreditation requirements."

*Classification.* Class II (special controls). The special controls for this device are:(1) Premarket notification submissions must include detailed device description documentation and information concerning the composition of the quality control material, including, as appropriate: (i) Analyte concentration; (ii) Expected values; (iii) Analyte source; (iv) Base matrix; (v) Added components; (vi) Safety and handling information; and (vii) Detailed instructions for use. (2) Premarket notification submissions must include detailed documentation, including line data as well as detailed study protocols and a statistical analysis plan used to establish performance, including: (i) Description of the process for value assignment and validation. (ii) Description of the protocol(s) used to establish stability. (iii) Line data establishing precision/reproducibility. (iv) Where applicable, assessment of matrix effects and any significant differences between the quality control material and typical patient samples in terms of conditions known to cause analytical error or affect assay performance. (v) Where applicable, identify or define traceability or relationship to a domestic or international standard reference material and/or method. (vi) Where applicable, detailed documentation related to studies for surrogate controls. (3) Premarket notification submissions must include an adequate mitigation (e.g., real-time stability program) to the risk of false results due to potential modifications to the assays specified in the device's 21 CFR 809.10 compliant labeling. (4) Your 21 CFR 809.10 compliant labeling must include the following: (i) The intended use of your 21 CFR 809.10(a)(2) and (b)(2) compliant labeling must include the following: (A) Assayed control material analyte(s); (B) Whether the material is intended for quantitative or qualitative assays; (C) Stating if the material is a surrogate control; and (D) The system(s), instrument(s), or test(s) for which the quality control material is intended. (ii) The intended use in your 21 CFR 809.10(a)(2) and (b)(2) compliant labeling must include the following statement: “This product is not intended to replace manufacturer controls provided with the device.” (iii) A limiting statement that reads “Quality control materials should be used in accordance with local, state, federal regulations, and accreditation requirements.”

Predicate Devices

• Cepheid Xpert® GBS LB Control Panel (K182472)

Submission Summary (Full Text)

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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

A. 510(k) Number:
K190086

B. Purpose for Submission:
To obtain a substantial equivalence determination for the Cepheid Xpert Respiratory Control Panel for use with the Cepheid Xpert Xpress Flu/RSV Assay on the GeneXpert Instrument System.

C. Measurand:
Nucleic acids from inactivated Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus, and Respiratory Syncytial Virus A.

D. Type of Test:
The Cepheid Xpert Respiratory Control Panel is an external assayed quality control material (positive and negative) designed to monitor the performance of *in vitro* laboratory nucleic acid testing procedures for the qualitative detection of Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus, and Respiratory Syncytial Virus A when used with the Cepheid Xpert Xpress Flu/RSV assay on the Cepheid Xpert Instrument System.

E. Applicant:
Microbiologics, Inc.

F. Proprietary and Established Names:
Trade Name: Cepheid Xpert Respiratory Control Panel

G. Regulatory Information:
1. Regulation section:
21 CFR 866.3920, Assayed quality control material for clinical microbiology assays
2. Classification:
Class II (Special Controls)
3. Product code:

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PMN - Assayed external control material for microbiology nucleic acid amplification assays

4. Panel:
(83) Microbiology

H. Intended Use:

1. Intended use:
The Cepheid Xpert Respiratory Control Panel is intended for use as an external assayed positive and negative quality control to monitor the performance of in vitro laboratory nucleic acid testing procedures for the qualitative detection of Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus and Respiratory Syncytial Virus A performed with the Cepheid Xpert Xpress Flu/RSV assay on the GeneXpert Instrument System. The controls comprise cultured and inactivated Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus and Respiratory Syncytial Virus A as the positive control and Coxsackie virus B1 as the negative control.

The Cepheid Xpert Respiratory Control Panel is not intended to replace manufacturer controls provided with the device.

2. Indication(s) for use:
Same as Intended Use.

3. Special conditions for use statement(s):
For in vitro diagnostic use only.
For prescription use only.

3. Special instrument requirements:
The Cepheid Xpert Respiratory Control Panel is intended for use on the Gene Xpert Instrument System.

I. Device Description:
The Cepheid Xpert Respiratory Control Panel is a quality control material provided to the customer as six individually packaged positive control swabs. Each positive control swab contains cultured and inactivated Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus and Respiratory syncytial virus A. The kit also includes six individually packaged negative controls swabs of cultured and inactivated Coxsackie virus B1.

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J. Substantial Equivalence Information:

1. Predicate device name(s):
Cepheid Xpert GBS LB Control Panel

2. Predicate 510(k) number(s):
K182472

3. Comparison with predicate:

| Characteristic | Cepheid Xpert Respiratory Control Panel | Cepheid Xpert GBS LB Control Panel (K182472) |
| --- | --- | --- |
| Intended Use | The Cepheid Xpert Respiratory Control Panel is intended for use as an external assayed positive and negative quality control to monitor the performance of in vitro laboratory nucleic acid testing procedures for the qualitative detection of Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus and Respiratory Syncytial Virus A performed with the Cepheid Xpert Xpress Flu/RSV assay on the GeneXpert Instrument System. The controls comprise cultured and inactivated Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus and Respiratory Syncytial Virus A as the positive control and Coxsackie virus B1 as the negative control
The Cepheid Xpert Respiratory Control Panel is not intended to replace manufacturer controls provided with the device. | External assayed positive and negative quality control materials to monitor the performance of in vitro laboratory nucleic acid testing procedures for the qualitative detection of Group B Streptococcus (GBS) performed with the Cepheid Xpert GBS LB Assay on the GeneXpert Instrument System. The controls comprise cultured and inactivated Streptococcus agalactiae as the positive control and Lactobacillus acidophilus as the negative control.
The Cepheid Xpert GBS LB Control Panel is not intended to replace the manufacturer controls provided with the device. |
| Physical Format | Swabs | Swabs |
| Composition | Inactivated microorganisms | Inactivated microorganisms |
| Test System | Cepheid GeneXpert System | Cepheid GeneXpert System |
| Directions for Use | Process like patient sample | Process like patient sample |
| Assay Steps Monitored | Extraction, amplification, and detection | Extraction, amplification, detection |

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| Differences | | |
| --- | --- | --- |
| Assay Compatibility | Cepheid Xpert Xpress Flu/RSV Assay | Cepheid Xpert GBS LB Assay |
| Positive Control Analytes | Influenza A (H1N1) virus, Influenza A (H3N2) virus, Influenza B virus and Respiratory Syncytial Virus A | Streptococcus agalactiae |
| Negative Control | Coxsackie virus B1 | Lactobacillus acidophilus |

## K. Standard/Guidance Document Referenced (if applicable):

CLSI. Evaluation of Stability of In Vitro Diagnostic Reagents; Approved Guideline. CLSI Document EP25-A. Wayne, PA: Clinical and Laboratory Standards Institute; 2009.

## L. Test Principle:

Not applicable; this is control material to monitor performance of an in vitro diagnostic test.

## M. Performance Characteristics (if/when applicable):

1. Analytical performance:

a. Reproducibility:

The reproducibility of results obtained with the Cepheid Xpert Respiratory Control Panel was evaluated in a study performed at three testing sites over five days, with two operators per site. Three lots of the control material were tested with the Cepheid Xpert Xpress Flu/RSV Assay on three Cepheid GeneXpert Systems.

The qualitative results from the reproducibility study are summarized below.

| Analyte | Agreement (%) with Expected Results by Test Site | | | |
| --- | --- | --- | --- | --- |
| | Site 1 | Site 2 | Site 3^{1} | Overall |
| Influenza A (H1N1) | 30/30
(100%) | 30/30
(100%) | 30/30
(100%) | 90/90
(100%) |
| Influenza A (H3N2) | 30/30
(100%) | 30/30
(100%) | 30/30
(100%) | 90/90
(100%) |
| Influenza B | 30/30
(100%) | 30/30
(100%) | 30/30
(100%) | 90/90
(100%) |
| Respiratory Syncytial Virus A | 30/30
(100%) | 30/30
(100%) | 30/30
(100%) | 30/30
(100%) |

1 One No RESULT was observed; a new control was retested and the expected results were obtained.

| Analyte | Agreement (%) with Expected Results by Test Site | | | |
| --- | --- | --- | --- | --- |
| | Site 1 | Site 2 | Site 3 | Overall |
| Coxsackie virus B1 | 30/30
(100%) | 30/30
(100%) | 31/31
(100%) | 91/91
(100%) |

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The calculated average Ct score values and the associated percent coefficient of variation (% CV) across the three testing sites obtained in the reproducibility study are summarized below.

| | Influenza A (H1N1) | Influenza A (H3N2) | Influenza B | Respiratory Syncytial Virus A | SPC |
| --- | --- | --- | --- | --- | --- |
| N | 90 | 90 | 90 | 90 | 90 |
| Mean | 29.9 | 32.1 | 32.1 | 30.1 | 29.6 |
| %CV | 2.8 | 2.4 | 4.2 | 2.7 | 1.7 |

SPC: Sample Processing Control

| | Coxsackie virus B1 | SPC |
| --- | --- | --- |
| N | 91 | 91 |
| Mean | 0 | 29.5 |
| %CV | N/A | 1.7 |

SPC: Sample Processing Control

b. Linearity/assay reportable range:

Not applicable

c. Traceability, Stability, Expected values (controls, calibrators, or methods):

Traceability:

Not applicable

Stability:

1. Accelerated stability study

Shelf life stability was initially evaluated through an accelerated study with three lots of the controls. The product was placed into chambers at elevated temperatures: 43°C, 53°C and 63°C. Each lot was tested in 4 replicates at each of the following time points: Day 0, Day 14, Day 28 and Day 42. The stability of the product was evaluated by calculating the change (delta) in mean Ct value at each time point for the four microbial targets (Flu A1, Flu A2, Flu B and RSV) from the mean Ct value obtained at Day 0. Both Positive and Negative Controls were tested.

For Positive Control, the change in Ct score for all targets, across the three lots, ranged from -0.8 to 1.8 when stored at 43°C, from -0.4 to 2.4 when stored at 53°C, and from -0.8 to 3.1 when stored at 63°C. All valid tests generated expected (positive) results for all analytes.

For Negative Control all valid tests generated expected (negative) results.

The data from the accelerated stability study with three lots of the product is summarized below.

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| Flu A1 | | Lot 1 | | | Lot 21 | | | Lot 3 | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | | 43°C | 53°C | 63°C | 43°C | 53°C | 63°C | 43°C | 53°C | 63°C |
| | Day | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score |
| Mean | 0 | 30.1 | 30.1 | 30.1 | 29.8 | 29.8 | 29.8 | 29.6 | 29.6 | 29.6 |
| Mean Change in Ct score | 14 | 0.1 | 0.5 | -0.1 | 0.4 | 1.8 | 1.1 | 1.1 | 1.2 | 1.2 |
| | 28 | 0.3 | 0.1 | 0.3 | 1.6 | 2.2 | 2.0 | 1.2 | 1.8 | 2.0 |
| | 42 | 0.5 | 0.7 | 1.4 | 1.8 | 2.2 | 2.9 | 1.3 | 1.6 | 1.6 |

1 Lot #2 was used in the study despite that it failed QC release criteria

| Flu A2 | | Lot 1 | | | Lot 21 | | | Lot 3 | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | | 43°C | 53°C | 63°C | 43°C | 53°C | 63°C | 43°C | 53°C | 63°C |
| | Day | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score |
| Mean | 0 | 32.2 | 32.2 | 32.2 | 32.2 | 32.2 | 32.2 | 32.0 | 32.0 | 32.0 |
| Mean Change in Ct score | 14 | 0.1 | 0.8 | 0.0 | 0.3 | 1.6 | 1.0 | 0.9 | 1.2 | 1.3 |
| | 28 | 0.2 | 0.3 | 0.7 | 1.5 | 2.2 | 2.1 | 1.4 | 1.8 | 1.8 |
| | 42 | 0.7 | 1.0 | 1.5 | 1.8 | 2.3 | 2.6 | 1.4 | 1.5 | 1.6 |

1 Lot #2 was used in the study despite that it failed QC release criteria

| Flu B | | Lot 1 | | | Lot 21 | | | Lot 3 | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | | 43°C | 53°C | 63°C | 43°C | 53°C | 63°C | 43°C | 53°C | 63°C |
| | Day | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score |
| Mean | 0 | 32.5 | 32.5 | 32.5 | 33.3 | 33.3 | 33.3 | 31.8 | 31.8 | 31.8 |
| Mean Change in Ct score | 14 | 0.0 | 0.1 | -0.2 | -0.1 | 1.7 | 0.6 | 1.3 | 1.2 | 1.2 |
| | 28 | 0.2 | 0.1 | 0.3 | 2.0 | 2.0 | 1.8 | 1.3 | 1.9 | 2.0 |
| | 42 | 0.7 | 0.4 | 1.6 | 1.5 | 2.4 | 3.1 | 1.7 | 1.6 | 2.2 |

1 Lot #2 was used in the study despite that it failed QC release criteria

| RSV | | Lot 1 | | | Lot 21 | | | Lot 3 | | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | | 43°C | 53°C | 63°C | 43°C | 53°C | 63°C | 43°C | 53°C | 63°C |
| | Day | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score |
| Mean | 0 | 29.7 | 29.7 | 29.7 | 29.9 | 29.9 | 29.9 | 30.0 | 30.0 | 30.0 |
| Mean Change in Ct score | 14 | 0.0 | -0.4 | -0.8 | -0.8 | 1.1 | -0.8 | -0.1 | 0.3 | 0.5 |
| | 28 | 0.3 | 0.8 | 0.3 | 0.8 | 0.6 | 1.0 | -0.1 | 1.0 | 0.7 |
| | 42 | 0.8 | 0.7 | 1.9 | 0.8 | 1.5 | 1.3 | 1.6 | -0.2 | 0.2 |

1 Lot #2 was used in the study despite that it failed QC release criteria

# 2. Real-time stability study

Real-time shelf life stability study with three lots of the controls is in progress. Data for 2 and 3 months of storage at $4^{\circ}\mathrm{C}$ and $25^{\circ}\mathrm{C}$ were submitted. The product was placed into chambers at two temperatures: $4^{\circ}\mathrm{C}$ and $25^{\circ}\mathrm{C}$ . Each lot was tested in 4 replicates at each of the following time points: Day 0, 2 months, and 3 months. The stability of the product was

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evaluated by calculating the change (delta) in mean Ct value at each time point for the four microbial targets (Flu A1, Flu A2, Flu B and RSV) from the mean Ct value obtained at Day 0. Both Positive and Negative Controls were tested.

For Positive Control, the change in Ct score for all targets, across the three lots, ranged from -0.3 to 2.3 when stored at $4^{\circ}\mathrm{C}$ , and from 0.4 to 1.5 when stored at $25^{\circ}\mathrm{C}$ . All valid tests generated expected (positive) results for all analytes.

For Negative Control all valid tests generated expected (negative) results.

The data from the real time stability study with three lots of the product are summarized below.

| Flu A1 | | Lot 1 | | Lot 2 | | Lot 3 | |
| --- | --- | --- | --- | --- | --- | --- | --- |
| | | 4°C | 25°C | 4°C | 25°C | 4°C | 25°C |
| | Month | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score |
| Mean | 0 | 27.9 | 27.9 | 29.8 | 29.8 | 29.3 | 29.3 |
| Mean Change in Ct score | 2 | -0.3 | 0.7 | 0.1 | 0.7 | 1.9 | 1.4 |
| | 3 | 1.2 | 0.6 | 0.5 | 1.0 | 1.2 | 0.5 |
| Flu A2 | | Lot 1 | | Lot 2 | | Lot 3 | |
| --- | --- | --- | --- | --- | --- | --- | --- |
| | | 4°C | 25°C | 4°C | 25°C | 4°C | 25°C |
| | Month | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score |
| Mean | 0 | 30.2 | 30.2 | 32.2 | 32.2 | 31.8 | 31.8 |
| Mean Change in Ct score | 2 | -0.2 | 0.8 | 0.1 | 0.8 | 1.7 | 1.5 |
| | 3 | 1.3 | 0.6 | 0.4 | 0.8 | 1.3 | 0.5 |
| Flu B | | Lot 1 | | Lot 2 | | Lot 3 | |
| --- | --- | --- | --- | --- | --- | --- | --- |
| | | 4°C | 25°C | 4°C | 25°C | 4°C | 25°C |
| | Month | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score |
| Mean | 0 | 30.7 | 30.7 | 30.1 | 30.1 | 29.6 | 29.6 |
| Mean Change in Ct score | 2 | 0.0 | 1.2 | 0.1 | 0.8 | 0.4 | 1.5 |
| | 3 | 1.5 | 0.8 | 0.5 | 0.9 | 1.2 | 0.5 |
| RSV | | Lot 1 | | Lot 2 | | Lot 3 | |
| --- | --- | --- | --- | --- | --- | --- | --- |
| | | 4°C | 25°C | 4°C | 25°C | 4°C | 25°C |
| | Month | Ct score | Ct score | Ct score | Ct score | Ct score | Ct score |
| Mean | 0 | 30.6 | 30.6 | 28.2 | 28.2 | 27.8 | 27.8 |
| Mean Change in Ct score | 2 | 0.2 | 0.5 | 0.4 | 0.6 | 2.3 | 1.3 |
| | 3 | 0.7 | 0.8 | 0.3 | 1.1 | 0.6 | 0.4 |

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3. In use stability study

An in-use stability of the hydrated control swabs (i.e., placed in the Transport Reagent Tube from the Cepheid Xpert Xpress Flu/RSV Assay Kit) was evaluated at room temperature (20°C) over 6 hours. The controls were tested in three replicates immediately after hydration (t=0), and then again at 4 hours and at 6 hours. All positive and negative samples produced expected results after 4 and 6 hours. The summary of the data collected over 6 hours is shown below.

| Target | Mean Ct | SD | %CV |
| --- | --- | --- | --- |
| Flu A1 | 30.1 | 0.4 | 1.4 |
| Flu A2 | 32.2 | 0.3 | 1.0 |
| Flu B | 32.9 | 0.2 | 0.5 |
| RSV | 29.7 | 0.5 | 1.7 |

4. Shipping stability

The Cepheid Xpert Respiratory Controls are packaged in sealed foil pouches with desiccants to prevent effects of high humidity. However, the product may be exposed and affected by high temperatures. The product is shipped by FedEx for delivery in 2 days, however, delays may be encountered. The effect of exposure to high temperatures was evaluated at 43°C after 14 days (the worst-case delay scenario) in the accelerated stability study described above. The observed change in Ct score for all targets, across the three lots, ranged from -0.8 to 1.8. For Negative Control all valid tests generated expected (negative) results upon the storage at 43°C for 14 days.

Human Factors/Operator Errors

The Cepheid Xpert Respiratory Control Panel tested with the Cepheid Xpert Xpress Flu/RSV assay may be used in CLIA waived settings, therefore the controls were evaluated to determine the risk of erroneous results due to incorrect volume of the sample added to the cartridge and deviations from the recommended sample mixing conditions. Both Positive and Negative Controls were tested. All valid tests generated expected results.

Expected Values:

The Cepheid Xpert Respiratory Control Panel is a qualitative positive and negative controls. The following are the expected assay results.

| Control | Expected Assay Result | Interpretation |
| --- | --- | --- |
| Positive Control | Flu A Positive
Flu B Positive
RSV Positive | Flu A, Flu B, and RSV target RNA sequences are detected |
| Negative Control | Flu A Negative
Flu B Negative
RSV Negative | Neither Flu A, Flu B, nor RSV target RNA sequences are detected |

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d. Detection limit:
Not applicable.

e. Analytical Specificity:
Not applicable.

f. Assay cut-off:
Not applicable.

2. Comparison studies:
a. Method comparison with predicate device:
Not applicable.
b. Matrix comparison:
Not applicable.

3. Clinical studies:
a. Clinical Sensitivity:
Not applicable.
b. Clinical specificity:
Not applicable.

4. Clinical cut-off:
Not Applicable.

N. Proposed Labeling:
The labeling supports the finding of substantial equivalence for this device.

O. Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

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