(71 days)
The Cepheid Xpert® Flu Assay, performed on the GeneXpert® Instrument Systems, is an automated, multiplex real-time RT-PCR assay intended for the in vitro qualitative detection and differentiation of influenza A, influenza B and 2009 H1N1 influenza viral RNA. The Xpert Flu Assay uses nasal aspirates/washes and nasopharyngeal swab specimens collected from patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors. The Xpert Flu Assay is intended as an aid in the diagnosis of influenza.
Negative results do not preclude influenza virus infection and should not be used as the sole basis for treatment or other patient management decisions.
Performance characteristics for influenza A were established during the 2009-2010 influenza season when 2009 H1N1 influenza was the predominant influenza A virus in circulation. Performance characteristics for influenza A were confirmed when influenza A/H3 and influenza A/2009 H1N1 were the predominant influenza A viruses in circulation (2009-2010, 2010-2011 and 2011-2012). When other influenza A viruses are emerging, performance characteristics may vary.
If infection with a novel influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
The Xpert Flu Assay is a rapid, automated in vitro diagnostic test for qualitative detection and differentiation of influenza A, influenza B and influenza A, subtype 2009 H1N1. The assay is performed on the Cepheid GeneXpert Instrument Systems. The GeneXpert Instrument Systems automate and integrate sample purification, nucleic acid amplification, and detection of the target sequence in simple or complex samples using real-time PCR and RT-PCR assays. The systems require the use of single-use disposable cartridges that hold the PCR reagents and host the PCR process. Because the cartridges are self-contained and specimens never come into contact with working parts of the instrument modules, cross-contamination between samples is minimized.
The Xpert Flu Assay includes reagents for the detection and differentiation of influenza A, influenza B and influenza A, subtype 2009 H1N1 directly from nasal aspirates/washes (NA/W) and nasopharyngeal (NP) swab specimens from patients suspected of having influenza. A Sample Processing Control (SPC) and a Probe Check Control (PCC) are also included. The SPC is present to control for adequate processing of the target viruses and to monitor the presence of inhibitors in the PCR reaction. The Probe Check Control (PCC) verifies reagent rehydration, PCR tube filling in the cartridge, probe integrity and dye stability.
The liquid specimen (NA/W) or swab specimen (NP) is collected according to the institution's standard procedures and placed into Universal Transport Medium (3mL UTM tubes). Following a brief mixing by inverting the UTM tube five times, the eluted material and one single-use reagent (Reagent 1), that is provided with the assay, are transferred to different, uniquely-labeled chambers of the disposable fluidic cartridge (the Xpert Flu cartridge). The user initiates a test from the system user interface and places the cartridge into the GeneXpert instrument platform, which performs hands-off realtime, multiplex polymerase chain reaction (PCR) for detection of DNA. In this platform, additional sample preparation, amplification, and real-time detection are all fullyautomated and completely integrated.
The single-use, multi-chambered fluidic cartridges are designed to complete sample preparation and real-time PCR for detection and differentiation of influenza A. influenza B and influenza A, subtype 2009 H1N1 in 75 minutes. The GeneXpert Instrument Systems, which consist of the GeneXpert Dx System, the GeneXpert Infinity-48 System, and the GeneXpert Infinity-80 System, have 1 to 80 randomly accessible modules that are each capable of performing separate sample preparation and real-time PCR tests. Each module contains a syringe drive for dispensing fluids (i.e., the syringe drive activates the plunger that works in concert with the rotary valve in the cartridge to move fluids between chambers), an ultrasonic horn for lysing cells or spores, and a proprietary I-CORE® thermocycler for performing real-time PCR and detection.
The Cepheid Xpert® Flu Assay, a molecular diagnostic device, was evaluated through analytical and clinical performance studies to demonstrate its substantial equivalence to a previously cleared predicate device (K120911).
1. Acceptance Criteria and Reported Device Performance
The acceptance criteria for the Xpert Flu Assay, as demonstrated by its performance against a predicate device, are based on positive and negative agreement rates for the detection of influenza A, influenza A subtype 2009 H1N1, and influenza B in different specimen types (Nasal Aspirates/Washes and Nasopharyngeal Swabs). While explicit numerical acceptance criteria are not presented as thresholds, the observed performance values for the modified Xpert Flu Assay are provided as evidence of its substantial equivalence.
Table of Acceptance Criteria and Reported Device Performance:
| Specimen Type | Target | Positive Agreement % (95% CI) | Negative Agreement % (95% CI) |
|---|---|---|---|
| NA/W | Influenza A | 100 (97.5-100) | 98.1 (94.5-99.6) |
| NA/W | Influenza A subtype 2009 H1N1 | 97.1 (89.8-99.6) | 99.6 (97.6-100) |
| NA/W | Influenza B | 100 (84.6-100) | 99.6 (98.0-100) |
| NP Swab | Influenza A | 100 (97.8-100) | 95.2 (91.1-97.8) |
| NP Swab | Influenza A subtype 2009 H1N1 | 98.5 (92.1-100) | 99.6 (98.1-100) |
| NP Swab | Influenza B | 100 (87.2-100) | 99.1 (97.3-99.8) |
The study demonstrates that the modified Xpert Flu Assay exhibits very high positive and negative agreement rates when compared to the predicate Xpert Flu Assay across all targets and specimen types.
2. Sample Size Used for the Test Set and Data Provenance
The clinical performance study used a total of 302 Nasal Aspirate/Wash (NA/W) specimens and 352 Nasopharyngeal (NP) swab specimens for the test set.
The data provenance for these specimens is described as:
- Retrospective/Prospective: The specimens included a mix of "frozen leftover, prospectively collected, unlinked prospectively collected archived and/or pre-selected banked" specimens.
- Country of Origin: Not explicitly stated, but assumed to be from locations where standard clinical influenza testing is conducted, given the context of US FDA submission.
Additionally, ten contrived specimens (5 NP swab and 5 NA/W) were prepared and tested separately. These were not included in the primary dataset analysis of agreement rates.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
Not applicable. This is a molecular diagnostic device comparing its performance to a predicate molecular diagnostic device. The ground truth for the clinical performance study was established by the predicate device's results, with sequencing used for discrepant results. No human expert interpretation of images or clinical findings for ground truth establishment is mentioned.
4. Adjudication Method for the Test Set
The adjudication method specifically mentioned for the clinical performance study was sequencing for all discrepant specimens. This means if the modified Xpert Flu Assay result differed from the predicate Xpert Flu Assay result, a third, independent method (sequencing) was used to determine the true positive/negative status for those particular samples.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This device is an automated, standalone diagnostic assay, not an AI-assisted human reading system. Therefore, the concept of human readers improving with AI vs. without AI assistance is not applicable.
6. Standalone Performance Study
Yes, a standalone performance study was done. The entire evaluation of the "modified Xpert Flu Assay" against the "current Xpert Flu Assay" (the predicate device) represents its standalone performance. The device provides a qualitative detection and differentiation of influenza A, B, and 2009 H1N1 viral RNA directly from patient specimens without human interpretation of the assay's primary output beyond reading the automated result.
7. Type of Ground Truth Used
For the clinical performance study, the primary ground truth was implicitly the results from the predicate Xpert Flu Assay. For any discrepancies between the modified device and the predicate, sequencing was used as the confirmatory ground truth.
For the analytical studies (Analytical Reactivity and Limit of Detection), the ground truth for positive results was known viral strains at defined concentrations (TCID50/mL or pg/µL). For Analytical Specificity, the ground truth was known non-target viral, bacterial, and yeast strains.
8. Sample Size for the Training Set
Not applicable. This is a molecular diagnostic test. The concept of a "training set" is typically associated with machine learning or AI models. For this type of device, performance is established through analytical validation (known concentrations of specific strains) and clinical validation (comparison to a predicate or established reference method in patient samples). There is no mention of a machine learning component requiring a distinct training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there was no explicit training set for a machine learning model. For the analytical and clinical studies, ground truth was established as described in section 7.
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510(k) Summary
| As required by 21 CFR Section 807.92(c). | DEC 2 1 2012 |
|---|---|
| Submitted by: | Cepheid904 Caribbean DriveSunnyvale, CA 94089Phone number: (408) 400-8230Fax number: (408) 541-6439 |
| Contact: | Kerry J. Flom, Ph.D. |
| Date of Preparation: | October 9, 2012 |
| Device: | |
| Trade name: | Xpert® Flu |
| Common name: | Xpert Flu Assay |
| Type of Test: | Automated, multiplex real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay intended for thein vitro qualitative detection and differentiation of influenzaA, influenza B and 2009 H1N1 influenza viral RNA. |
| Regulation number/Classification name: | 866.3332/Reagents for detection of specific novel influenza Aviruses, and866.3980/Respiratory viral panel multiplex nucleic acid assay |
| Product code: | OQW, OCC, OOI |
| ClassificationAdvisory Panel | Microbiology (83) |
| Predicate Device: | Cepheid Xpert Flu Assay [510(k) #K120911] |
Device Description:
The Xpert Flu Assay is a rapid, automated in vitro diagnostic test for qualitative detection and differentiation of influenza A, influenza B and influenza A, subtype 2009 HIN1. The assay is performed on the Cepheid GeneXpert Instrument Systems. The GeneXpert Instrument Systems automate and integrate sample purification, nucleic acid amplification, and detection of the target sequence in simple or complex samples using real-time PCR and RT-PCR assays. The systems require the use of single-use disposable cartridges that hold the PCR reagents and host the PCR process. Because the cartridges are self-contained and specimens never come into contact with working parts of the instrument modules, cross-contamination between samples is minimized.
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The Xpert Flu Assay includes reagents for the detection and differentiation of influenza A, influenza B and influenza A, subtype 2009 HIN1 directly from nasal aspirates/washes (NA/W) and nasopharyngeal (NP) swab specimens from patients suspected of having influenza. A Sample Processing Control (SPC) and a Probe Check Control (PCC) are also included. The SPC is present to control for adequate processing of the target viruses and to monitor the presence of inhibitors in the PCR reaction. The Probe Check Control (PCC) verifies reagent rehydration, PCR tube filling in the cartridge, probe integrity and dye stability.
The liquid specimen (NA/W) or swab specimen (NP) is collected according to the institution's standard procedures and placed into Universal Transport Medium (3mL UTM tubes). Following a brief mixing by inverting the UTM tube five times, the eluted material and one single-use reagent (Reagent 1), that is provided with the assay, are transferred to different, uniquely-labeled chambers of the disposable fluidic cartridge (the Xpert Flu cartridge). The user initiates a test from the system user interface and places the cartridge into the GeneXpert instrument platform, which performs hands-off realtime, multiplex polymerase chain reaction (PCR) for detection of DNA. In this platform, additional sample preparation, amplification, and real-time detection are all fullyautomated and completely integrated.
The single-use, multi-chambered fluidic cartridges are designed to complete sample preparation and real-time PCR for detection and differentiation of influenza A. influenza B and influenza A, subtype 2009 H1N1 in 75 minutes. The GeneXpert Instrument Systems, which consist of the GeneXpert Dx System, the GeneXpert Infinity-48 System, and the GeneXpert Infinity-80 System, have 1 to 80 randomly accessible modules that are each capable of performing separate sample preparation and real-time PCR tests. Each module contains a syringe drive for dispensing fluids (i.e., the syringe drive activates the plunger that works in concert with the rotary valve in the cartridge to move fluids between chambers), an ultrasonic horn for lysing cells or spores, and a proprietary I-CORE® thermocycler for performing real-time PCR and detection.
Device Intended Use:
The Cepheid Xpert® Flu Assay, performed on the GeneXpert® Instrument Systems, is an automated, multiplex real-time RT-PCR assay intended for the in vitro qualitative detection and differentiation of influenza A, influenza B and 2009 H1N1 influenza viral RNA. The Xpert Flu Assay uses nasal aspirates/washes and nasopharyngeal swab specimens collected from patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors. The Xpert Flu Assay is intended as an aid in the diagnosis of influenza.
Negative results do not preclude influenza virus infection and should not be used as the sole basis for treatment or other patient management decisions.
Performance characteristics for influenza A were established during the 2009-2010 influenza season when 2009 HIN1 influenza was the predominant influenza A virus in circulation. Performance characteristics for influenza A were confirmed when influenza
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A/H3 and influenza A/2009 H1N1 were the predominant influenza A viruses in circulation (2009-2010, 2010-2011 and 2011-2012). When other influenza A viruses are emerging, performance characteristics may vary.
If infection with a novel influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
Substantial Equivalence:
The Xpert Flu Assay is substantially equivalent to the current Xpert Flu Assay [510(k) #K120911].
Similarities and differences between the Cepheid Xpert Flu Assay and the predicate device are shown in Table 5.1.
A clinical comparison study was conducted using prospectively collected archived and/or pre-selected banked specimens to compare the modified Xpert Flu Assay performance to the previously cleared Xpert Flu Assay.
| Device | Predicate | |
|---|---|---|
| Item | Modified Cepheid Xpert Flu | Cepheid Xpert Flu |
| 510(k) Number | #K123191 | #K120911 |
| Regulation | Same | 866.3332 and 866.3980 |
| Product Code | Same | OQW, OCC, OOI |
| Device Class | Same | II |
| Technology/Detection | Same | Multiplex real time RT/PCR |
| Intended Use | The Cepheid Xpert® Flu Assay,performed on the GeneXpert®Instrument Systems, is an automated,multiplex real-time RT-PCR assayintended for the in vitro qualitativedetection and differentiation ofinfluenza A, influenza B and 2009H1N1 influenza viral RNA. The XpertFlu Assay uses nasal aspirates/washesand nasopharyngeal swab specimenscollected from patients with signs andsymptoms of respiratory infection in | The Cepheid Xpert® Flu Assay is anautomated, multiplex real-time RT-PCRassay intended for the in vitro qualitativedetection and differentiation of influenzaA, influenza B and 2009 H1N1 influenzaviral RNA. The Xpert Flu Assay usesnasal aspirates/washes andnasopharyngeal swab specimens collectedfrom patients with signs and symptoms ofrespiratory infection in conjunction withclinical and epidemiological risk factors. |
| Table 5.1: Comparison of Similarities and Differences of the modified Xpert Flu | ||||
|---|---|---|---|---|
| Assay with the Predicate Device, Xpert Flu Assay |
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| Device | Predicate | |
|---|---|---|
| Item | Modified Cepheid Xpert Fluconjunction with clinical andepidemiological risk factors. The XpertFlu Assay is intended as an aid in thediagnosis of influenza.Negative results do not precludeinfluenza virus infection and should notbe used as the sole basis for treatment orother patient management decisions.Performance characteristics forinfluenza A were established during the2009-2010 influenza season when 2009H1N1 influenza was the predominantinfluenza A virus in circulation.Performance characteristics forinfluenza A were confirmed wheninfluenza A/H3 and influenza A/2009H1N1 were the predominant influenzaA viruses in circulation (2009-2010,2010-2011 and 2011-2012). Whenother influenza A viruses are emerging,performance characteristics may vary.If infection with a novel influenza Avirus is suspected based on currentclinical and epidemiological screeningcriteria recommended by public healthauthorities, specimens should becollected with appropriate infectioncontrol precautions for novel virulentinfluenza viruses and sent to state orlocal health department for testing. Viralculture should not be attempted in thesecases unless a BSL 3+ facility isavailable to receive and culturespecimens. | The Xpert Flu Assay is intended as an aidin the diagnosis of influenza.Negative results do not preclude influenzavirus infection and should not be used asthe sole basis for treatment or otherpatient management decisions.Performance characteristics for influenzaA were established during the 2009-2010influenza season when 2009 H1N1influenza was the predominant influenzaA virus in circulation. When otherinfluenza A viruses are emerging,performance characteristics may vary.If infection with a novel influenza A virusis suspected based on current clinical andepidemiological screening criteriarecommended by public healthauthorities, specimens should be collectedwith appropriate infection controlprecautions for novel virulent influenzaviruses and sent to state or local healthdepartment for testing. Viral cultureshould not be attempted in these casesunless a BSL 3+ facility is available toreceive and culture specimens. |
| Indication for Use | Same | Patients with signs and symptoms ofrespiratory infection in conjunction withclinical and epidemiological risk factors. |
| Assay Targets | Same | Influenza A, influenza B, and influenzaA, subtype 2009 H1N1 |
| Specimen Types | Same | Nasal aspirates/washes (NA/W) andNasopharyngeal (NP) swabs |
| TechnologicalPrinciples | Same | RT/PCR |
| Nucleic AcidExtraction | Same | Yes |
| Device | Predicate | |
| Item | Modified Cepheid Xpert Flu | Cepheid Xpert Flu |
| ExtractionMethods | Same | Sample preparation integrated inGeneXpert Cartridge and GeneXpertInstrumentation System |
| Assay Results | Same | Qualitative |
| Instrument System | Same | Cepheid GeneXpert® Instrument Systems |
| Assay Controls | Same | Encapsulated (armored) RNApseudovirus as a sample processingcontrol.Available but not provided are inactivatedvirus controls for Flu A/B and Flu A 2009H1N1 as external positive controls andCoxsackie virus as an external negativecontrol. |
| Rapid test results | Same | Total 75 minutes for sample preparationand rRT-PCR |
| Primers andprobes forinfluenza A,influenza B, andinfluenza Asubtype 2009H1N1 | Same plus an additional primer forInfluenza A | Original primers and probes to detect thepresence of nucleic acid sequences ofinfluenza A, influenza B, and influenza,subtype 2009 H1N1 |
| Laboratory Users | Same | CLIA Moderate or High Complexity |
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Non-Clinical Studies:
Analytical Sensitivity
Analytical Reactivity (Inclusivity)
The analytical reactivity of the Xpert Flu Assay was evaluated against forty (40) strains of influenza A (HINI, H3N2, H5N2, H5N1 and H7N3 subtypes), influenza A 2009 HINI and influenza B. Of these, influenza A subtype HINI (11), influenza A subtype H3N2 (9), influenza A subtype 2009 H1N1 (6), influenza A subtype H5N1 (1), influenza A subtype H5N2 (1), influenza A subtype H7N3 (1), and influenza B (11) were included. Twelve of the 40 influenza strains evaluated in this study were tested at the LoD concentration while all remaining strains were tested using viral stocks at 5-250 TCID50 mL. Three (3) replicates were tested for each strain. Results are shown in Table 5.2.
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| Viral Strain | Concentration(TCID50/mL) | InfluenzaA | Influenza A2009 H1N1 | InfluenzaB |
|---|---|---|---|---|
| Influenza A/Denver/1/57 (H1N1)a | 250 | + | - | - |
| Influenza A/Hawaii/15/2001 (H1N1)a | 50 | + | - | - |
| Influenza A/Mal/302/54 (H1N1)a | 50 | + | - | - |
| Influenza A/New Jersey/8/76 (H1N1)a | 250 | + | - | - |
| Influenza A/NWS/33 (H1N1)a | 5 | + | - | - |
| Influenza A/PR/8/34 (H1N1)a | 50 | + | - | - |
| Influenza A/Taiwan/42/06 (H1N1)a | 50 | + | - | - |
| Influenza A/Swine/1976/31 (SwineH1N1)a | 250 | + | - | - |
| Influenza A/Swine/Iowa/15/30 (SwineH1N1)a | 50 | + | - | - |
| Influenza A/Brisbane/59/07 (H1N1)a, b | 1 | + | - | - |
| Influenza A/NewCaledonia/20/1999(H1N1)a,b | 5 | + | - | - |
| Influenza A/Brisbane/10/07 (H3N2)b | 1.25 | + | - | - |
| Influenza A/Victoria/361/2011(H3N2)b | 1.25 | + | - | - |
| Influenza A/Victoria/3/75 (H3N2) | 250 | + | - | - |
| Influenza A/Aichi2/68 (H3N2) | 50 | + | - | - |
| Influenza A/Hong Kong/8/68 (H3N2) | 50 | + | - | - |
| Influenza A/NewYork/55/2004 (H3N2) | 50 | + | - | - |
| Influenza A/Port Chalmers/1/73(H3N2) | 50 | + | - | - |
| Influenza A/Wisconsin/67/05 (H3N2)b | 10 | + | - | - |
| Influenza A/Perth/16/2009 (H3N2) | 50 | + | - | - |
| Influenza A/SwineNY/01/2009(09 H1N1)b | 25 | + | + | - |
| Influenza A/SwineNY/02/2009(09 H1N1)b | 1.25 | + | + | - |
| Influenza A/SwineNY/03/2009(09 H1N1)b | 1.25 | + | + | - |
| Viral Strain | Concentration(TCID50/mL) | InfluenzaA | Influenza A2009 H1N1 | InfluenzaB |
| Influenza A/California/7/2009(09 H1N1) | 5 | + | + | - |
| Influenza A/Canada/6294(09 H1N1) | 50 | + | + | - |
| Influenza A/Wisconsin/629-S1(09 H1N1) | 1 | + | + | - |
| Influenza A/Mallard/WI/34/75 (H5N2) | 3 pg/µL | + | - | - |
| Influenza A/Anhui/02/2005/PR8-IBCDC-RG5 (H5N1) | 0.122 pg/µL | + | - | - |
| Influenza A/chicken/NJ/15086-3/94(H7N3) | 50 pg/µL | + | - | - |
| Influenza B/Allen/45 | 50 | - | - | + |
| Influenza B/Florida/02/06b | 5 | - | - | + |
| Influenza B/Florida/04/06 | 50 | - | - | + |
| Influenza B/Florida/07/04b | 5 | - | - | + |
| Influenza B/GL/1739/54 | 50 | - | - | + |
| Influenza B/Hong Kong/5/72 | 50 | - | - | + |
| Influenza B/Lee/40 | 50 | - | - | + |
| Influenza B/Malaysia/2506/04 | 50 | - | - | + |
| Influenza B/Maryland/1/59 | 5 | - | - | + |
| Influenza B/Panama/45/90 | 250 | - | - | + |
| Influenza B/Taiwan/2/62 | 50 | - | - | + |
Table 5.2: Analytical Reactivity (Inclusivity) Results of the Xpert Flu Assay
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ªSeasonal influenza A H1N1 (not 2009 H1N1)
b Strains (12) used in analytical LOD study and tested at limit of detection
°Concentration expressed in picograms/UL
Analytical Sensitivity
Limit of Detection
Studies were performed to determine the analytical limit of detection (LoD) of 2 seasonal influenza A (H1N1), 3 seasonal influenza A (H3N2), 5 influenza A 2009 H1N1 and 2 influenza B strains diluted into a surrogate nasopharyngeal matrix. The surrogate matrix consisted of 1% human blood, 2.5% mucin and 0.85% sodium chloride. The LoD is defined as the lowest concentration (tissue culture infective dose [TCID]50/mL) per sample that can be reproducibly distinguished from negative samples with 95%
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confidence or the lowest concentration at which 19 of 20 replicates were positive. Each strain was tested in replicates of 20 per concentration of virus.
The LoD was determined empirically as the first concentration that had 19/20 or 20/20 positive results. The LoD values for each strain tested are summarized in Tables 5.3 -5.6.
| Strain ID - Influenza A subtypeH1N1 | Confirmed LoD(TCID50/mL)(at least 19/20 positive) |
|---|---|
| Influenza A/H1/Brisbane/59/07 | 1 (20/20) |
| Influenza A/H1/NewCaledonia/20/1999 | 5 (20/20) |
Table 5.3: Confirmed LoD (TCID50/mL) – Seasonal Influenza A H1N1
Table 5.4: Confirmed LoD (TCID50/mL) – Seasonal Influenza A H3N2
| Strain ID - Influenza A subtypeH3N2 | Confirmed LOD(TCID50/mL) (at least 19/20 positive) |
|---|---|
| Influenza A/H3/Brisbane/10/07 | 1.25 (20/20) |
| Influenza A/Victoria/361/2011 | 1.25 (20/20) |
| Influenza A/H3/Wisconsin/67/05 | 10 (20/20) |
Table 5.5: Confirmed LoD (TCID50/mL) – Influenza A 2009 H1N1
| Strain ID - Influenza Asubtype 2009 H1N1 | Confirmed LOD(TCID50/mL) (at least 19/20 positive) |
|---|---|
| Influenza A/SwineNY/01/2009(Lot #1) | 25 (19/20) |
| Influenza A/SwineNY/01/2009(Lot #2) | 0.125 (19/20) |
| Influenza A/SwineNY/02/2009 | 1.25 (20/20) |
| Influenza A/SwineNY/03/2009 | 1.25 (20/20) |
| Influenza A/Canada/6294/2009 | 35 (19/20) |
| Influenza A/WI/629-S1/2009(D00015) | 1 (20/20) |
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| Strain ID - Influenza B | Confirmed LOD(TCID50/mL) (at least 19/20 positive) |
|---|---|
| Influenza B/Florida/02/06 | 2 (19/20) |
| Influenza B/Florida/07/04 | 5 (20/20) |
Table 5.6: Confirmed LoD (TCID50/mL) - Influenza B
Analytical Specificity (Exclusivity)
The analytical specificity of the Xpert Flu Assay was evaluated by testing a panel of 40 cultures consisting of 18 viral, 21 bacterial, and one yeast representing common respiratory pathogens or those potentially encountered in the nasopharynx. Three replicates of all bacterial and yeast strains were tested at concentrations ≥10° CFU/mL. Three replicates of all viruses were tested at concentrations ≥10° TCID30/mL. Purified nucleic acids (copies/mL) were tested for one virus strain (Cytomegalovirus) and one bacterial strain (Bordetella pertussis). Positive and negative controls were included in the study. The analytical specificity was 100%. Results are shown in Table 5.7.
| Table 5.7: Analytical Specificity for Xpert Flu Assaya | ||
|---|---|---|
| Strain | Concentration(per Cartridge) | InfluenzaA | Influenza A2009 H1N1 | InfluenzaB |
|---|---|---|---|---|
| Positive Control 1 – InfluenzaA/Influenza B | N/Ab | + | - | + |
| Positive Control 2 - Influenza A2009 H1N1 | N/Ab | + | + | - |
| Negative Control | N/Ab | - | - | - |
| Adenovirus Type 7A | $1.1 x10^5$ TCID50/mL | - | - | - |
| Adenovirus Type 1 | $1.0 x10^7$ TCID50/mL | - | - | - |
| Human Coronavirus 229E | $2.5x10^4$ TCID50/mL | - | - | - |
| Human Coronavirus OC43 | $5.6 x10^4$ TCID50/mL | - | - | - |
| Cytomegalovirusc | $4.7x10^7$ Copies /mL | - | - | - |
| Enterovirus Type 71 | $3.5 x10^5$ TCID50/mL | - | - | - |
| Epstein-Barr Virus | $7.1x10^8$ TCID50/mL | - | - | - |
| Parainfluenzavirus Type 1 | $1.1 x10^5$ TCID50/mL | - | - | - |
| Strain | Concentration(per Cartridge) | InfluenzaA | Influenza A2009 H1N1 | InfluenzaB |
| Parainfluenzavirus Type 2 | 3.1 x107 TCID50/mL | - | - | - |
| Parainfluenzavirus Type 3 | 1.9 x106 TCID50/mL | - | - | - |
| Measles Virus | 6.3 x104 TCID50/mL | - | - | - |
| Human Metapneumovirus | 3.8 x105 TCID50/mL | - | - | - |
| Mumps Virus | 6.3 x106 TCID50/mL | - | - | - |
| Respiratory Syncytial Virus A | 5.3 x107 TCID50/mL | - | - | - |
| Respiratory Syncytial Virus B | 1.2 x107 TCID50/mL | - | - | - |
| Human HSV Type 1 | 3.1 x106 TCID50/mL | - | - | - |
| Human Rhinovirus Type 4 | 1.2 x105 TCID50/mL | - | - | - |
| Echovirus 11 | 3.3 x108 TCID50/mL | - | - | - |
| Bordetella pertussisc | 5000 ng/mL | - | - | - |
| Chlamydia pneumoniae | 5 x106 CFU/mL | - | - | - |
| Corynebacterium xerosis | 1x106 CFU/mL | - | - | - |
| Escherichia coli | 1x106 CFU/mL | - | - | - |
| Proteus vulgaris | 1x106 CFU/mL | - | - | - |
| Proteus mirabilis | 1x106 CFU/mL | - | - | - |
| Klebsiella pneumoniae | 1x106 CFU/mL | - | - | - |
| Haemophilus influenzae | 1x106 CFU/mL | - | - | - |
| Lactobacillus crispatus | 1x106 CFU/mL | - | - | - |
| Legionella pneumophila | 1x106 CFU/mL | - | - | - |
| Moraxella catarrhalis | 1x106 CFU/mL | - | - | - |
| Mycobacterium tuberculosis(BCG strain) | 1x106 CFU/mL | - | - | - |
| Mycoplasma pneumoniae | 1x106 CFU/mL | - | - | - |
| Neisseria meningitides | 1x106 CFU/mL | - | - | - |
| Neisseria cinneria | 1x106 CFU/mL | - | - | - |
| Pseudomonas aeruginosa | 1x106 CFU/mL | - | - | - |
| Strain | Concentration(per Cartridge) | InfluenzaA | Influenza A2009 H1N1 | InfluenzaB |
| Staphylococcus aureus | 1x106 CFU/mL | - | - | - |
| Staphylococcus epidermidis | 1x106 CFU/mL | - | - | - |
| Streptococcus pneumoniae | 1x106 CFU/mL | - | - | - |
| Streptococcus pyogenes | 1x106 CFU/mL | - | - | - |
| Streptococcus salivarius | 1x106 CFU/mL | - | - | - |
| Candida albicans | 1x106 CFU/mL | - | - | - |
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·
Page 10
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4Cross reactivity with other swine-origin strains has not been tested. Concentration not available because these are inactivated viruses.
"Nucleic acid was tested for Cytomegalovirus and Bordetella pertussis.
Interfering Substances
Potentially interfering substances that may be present in the nasopharynx were evaluated on representative Flu strains directly relative to the performance of the Xpert Flu Assay. Potentially interfering substances in the nasopharynx may include, but are not limited to: blood, nasal secretions or mucus, and nasal and throat medications used to relieve congestion, nasal dryness, irritation, or asthma and allergy symptoms, as well as antibiotics and antivirals. These substances are listed in Table 5.8 with active ingredients and concentrations tested shown. Highly viscous samples resulting from the addition of 1.5% (w/v) and 2.5% (w/v) mucin yielded false-negative test results from the Xpert Flu Assay. Inhibition of the Xpert Flu Assay was also observed from the addition of 1% (w/v) mucin, resulting in delayed detection of influenza A, influenza A subtype 2009 H1N1, and influenza B.
| Substance | Description/Active Ingredient | Concentration Tested in one or more Flu strains |
|---|---|---|
| Blood (human) | N/A | 2% (v/v) |
| Mucin | Purified mucin protein (Bovine or porcine submaxillary gland) | 2.5%, 1.5%, 1%, and 0.5% (w/v) |
| Neo-Synephrine® Nasal Drops | Phenylephrine HCl | 15% (v/v) |
| Anefrin Nasal Spray | Oxymetazoline Hydrochloride | 15% (v/v) |
| Zicam® Nasal Gel | Luffa opperculata, Galphimia glauca, Histaminum hydrochloricum Sulfur | 5% (v/v) |
| Saline Nasal Spray | Sodium Chloride with preservatives | 15% (v/v) |
| Antibiotic, nasal ointment | Mupirocin | 10 mg/mL |
| Antibacterial, systemic | Tobramycin | 4.0 $ \mu $ g/mL |
| Antiviral | Oseltamivir (TamiFlu) | 7.5 mg/mL |
Table 5.8: Potentially Interfering Substances in Xpert Flu Assay.
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| Substance | Description/Active Ingredient | Concentration Tested inone or more Flu strains |
|---|---|---|
| Throat lozenges,oral anestheticand analgesic | Menthol | 1.7 mg/mL menthol |
Carry-Over Contamination Study
Please refer to the previously FDA-cleared 510(k) #K103766 for additional information.
Linearity
Please refer to the previously FDA-cleared 510(k) #K103766 for additional information.
Clinical Performance Characteristics:
Reproducibility
Please refer to the previously FDA-cleared 510(k) #K103766 for additional information.
Instrument System Reproducibility
Please refer to the previously FDA-cleared 510(k) #K103766 and #K120911 for additional information.
Clinical Performance Characteristics
Clinical Performance Study
Performance characteristics for influenza A were established during the 2009-2010 influenza season when 2009 HINI influenza was the predominant influenza A virus in circulation. Performance characteristics for influenza A were confirmed when influenza A/H3 and influenza A/2009 H1N1 were the predominant influenza A viruses in circulation (2009-2010, 2010-2011 and 2011-2012).
Specimens included frozen leftover, prospectively collected, unlinked prospectively collected archived and/or pre-selected banked nasal aspirates/washes (NA/W) and nasopharyngeal (NP) swab specimens collected as standard of care (SOC) for patients suspected of influenza infection.
Additionally, ten contrived specimens (five each, NP swab and NA/W) were prepared and tested during this study. Specimens consisted of influenza A/Victoria/361/2011 (H3H2) strain spiked into NP and NA/W matrices, and were included due to the potential low prevalence of this strain in the archived specimen set. These ten specimens (tested
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blindly as part of the overall specimen cohorts) are analyzed separately and not included in the primary dataset.
The modified Xpert Flu Assay performance was compared to the current Xpert Flu Assay. Sequencing was performed for all discrepant specimens.
Overall Results
Relative to the Xpert Flu Assay, the modified Xpert Flu Assay demonstrated a positive and negative agreement for detection of influenza A with NA/W specimens of 100% and 98.1%, respectively (Table 5.9). The modified Xpert Flu Assay positive and negative agreement for influenza A subtype 2009 H1N1 with NA/W specimens were 97.1% and 99.6% (Table 5.9). The modified Xpert Flu Assay positive and negative agreement for influenza B with NA/W specimens were 100% and 99.6%, respectively (Table 5.9).
Relative to the Xpert Flu Assay, the modified Xpert Flu Assay demonstrated a positive and negative agreement for detection of influenza A with NP swabs of 100% and 95.2%, respectively (Table 5.9). The modified Xpert Flu Assay positive and negative agreement for influenza A subtype 2009 H1N1 with NP swabs were 98.5% and 99.6% (Table 5.9). The modified Xpert Flu Assay positive and negative agreement for influenza B with NP swabs were 100% and 99.1%, respectively (Table 5.9).
| Table 5.9: Xpert Flu Assay Performance on Prospectively Collected Archived NA/W | |
|---|---|
| and NP Swab Specimens |
| SpecimenType | Target | n | TP | FP | TN | FN | PositiveAgreement %(95 CI) | NegativeAgreement %(95 CI) |
|---|---|---|---|---|---|---|---|---|
| NA/W | Flu A | 302 | 145 | 3a | 154 | 0 | 100(97.5-100) | 98.1(94.5-99.6) |
| H1N1 | 302 | 66 | 1b | 233 | 2b | 97.1(89.8-99.6) | 99.6(97.6-100) | |
| Flu B | 302 | 22 | 1c | 279 | 0 | 100(84.6-100) | 99.6(98.0-100) | |
| NP Swab | Flu A | 352 | 165 | 9d | 178 | 0 | 100(97.8-100) | 95.2(91.1-97.8) |
| H1N1 | 352 | 67 | 1b | 283 | 1b | 98.5(92.1-100) | 99.6(98.1-100) | |
| Flu B | 352 | 27 | 3b | 322 | 0 | 100(87.2-100) | 99.1(97.3-99.8) |
"Discrepant testing results by sequencing: 2 of 3 Flu A/Perth/16/2009-like; 1 of 3 no sequencing results available, biscrepant testing results by sequencing: no sequencing results available.
CDiscrepant testing results by sequencing: Flu B.
4Discrepant testing results by sequencing: 4 of 9 Flu A/Victoria/361-like; 1 of 9 Flu A/Perth/16/2009-like; 4 of 9 no sequencing results available.
Contrived Specimens
As expected the ten contrived specimens were Flu A Positive: 2009 H1N1 NOT DETECTED; Flu B Negative by the modified Xpert Flu Assay, and Flu A Negative;
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2009 H1N1 NOT DETECTED; Flu B Negative by the current Xpert Flu Assay. Sequencing results for all ten of these specimens were positive for the A/Victoria/361/2001 strain of influenza.
Conclusions
The results of the nonclinical analytical and clinical performance studies summarized above demonstrate that the modified Xpert Flu Assay is substantially equivalent to the predicate Xpert Flu Assay.
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DEPARTMENT OF HEALTH & HUMAN SERVICES
Image /page/14/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized depiction of an eagle or bird-like figure with three curved lines forming its body and wings. The logo is surrounded by the text "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" in a circular arrangement.
Public Health Service
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-002
Cepheid C/O Kerry J. Flom, Ph.D. 904 Caribbean Drive · Sunnyvale, CA 94089
DEC 2 1 2012
Re: K123191
Trade/Device Name: Xpert® Flu Regulation Number: 21 CFR 866.3980 Regulation Name: Respiratory viral panel multiplex nucleic acid assay Regulatory Class: Class II Product Code: OCC, OQW, OOI Dated: October 9, 2012 Received: October 11, 2012
Dear Dr. Flom:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. ·
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA 's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807): labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
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Page 2 - Kerry J. Flom, Ph.D.
If you desire specific advice for your device on our labeling regulation (21 CFR Parts 801 and 809), please contact the Office of In Vitro Diagnostics and Radiological Health at (301) 796-5450. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address http://www.fda.gov/cdrh/industrv/support/index.html.
Sincerely yours.
Uwe Scherf for
Sally A. Hojvat, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health
Enclosure
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Indications for Use Form
510(k) Number (if known): K123191
Device Name: Xpert® Flu
Indications for Use:
The Cepheid Xpert® Flu Assay, performed on the GeneXpert® Instrument Systems, is an automated, multiplex real-time RT-PCR assay intended for the in vitro qualitative detection and differentiation of influenza A, influenza B and 2009 HINI influenza viral RNA. The Xpert Flu Assay uses nasal aspirates/washes and nasopharyngeal swab specimens collected from patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors. The Xpert Flu Assay is intended as an aid in the diagnosis of influenza.
Negative results do not preclude influenza virus infection and should not be used as the sole basis for treatment or other patient management decisions.
Performance characteristics for influenza A were established during the 2009-2010 influenza season when 2009 H1N1 influenza was the predominant influenza A virus in circulation. Performance characteristics for influenza A were confirmed when influenza A/H3 and influenza A/2009 H1N1 were the predominant influenza A viruses in circulation (2009-2010, 2010-2011 and 2011-2012). When other influenza A viruses are emerging, performance characteristics may vary.
If infection with a novel influenza A virus is suspected based on current clinical and enidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to state or local health department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
Prescription Use _ × (Part 21 CFR 801 Subpart D) AND/OR Over-The-Counter Use (21 CFR 801 Subpart C)
Tauans, Fielde
Division Sign-Off
Office of In Vitro Diagnostic Device Evaluation and Safety
510(k) K123191
Volume I Page 4-1
§ 866.3980 Respiratory viral panel multiplex nucleic acid assay.
(a)
Identification. A respiratory viral panel multiplex nucleic acid assay is a qualitative in vitro diagnostic device intended to simultaneously detect and identify multiple viral nucleic acids extracted from human respiratory specimens or viral culture. The detection and identification of a specific viral nucleic acid from individuals exhibiting signs and symptoms of respiratory infection aids in the diagnosis of respiratory viral infection when used in conjunction with other clinical and laboratory findings. The device is intended for detection and identification of a combination of the following viruses:(1) Influenza A and Influenza B;
(2) Influenza A subtype H1 and Influenza A subtype H3;
(3) Respiratory Syncytial Virus subtype A and Respiratory Syncytial Virus subtype B;
(4) Parainfluenza 1, Parainfluenza 2, and Parainfluenza 3 virus;
(5) Human Metapneumovirus;
(6) Rhinovirus; and
(7) Adenovirus.
(b)
Classification. Class II (special controls). The special controls are:(1) FDA's guidance document entitled “Class II Special Controls Guidance Document: Respiratory Viral Panel Multiplex Nucleic Acid Assay;”
(2) For a device that detects and identifies Human Metapneumovirus, FDA's guidance document entitled “Class II Special Controls Guidance Document: Testing for Human Metapneumovirus (hMPV) Using Nucleic Acid Assays;” and
(3) For a device that detects and differentiates Influenza A subtype H1 and subtype H3, FDA's guidance document entitled “Class II Special Controls Guidance Document: Testing for Detection and Differentiation of Influenza A Virus Subtypes Using Multiplex Nucleic Acid Assays.” See § 866.1(e) for the availability of these guidance documents.