← Product Code [MZP](/submissions/MI/subpart-d%E2%80%94serological-reagents/MZP) · K221007

# cobas HCV (K221007)

_Roche Molecular Systems, Inc. · MZP · Nov 4, 2022 · Microbiology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/MZP/K221007

## Device Facts

- **Applicant:** Roche Molecular Systems, Inc.
- **Product Code:** [MZP](/submissions/MI/subpart-d%E2%80%94serological-reagents/MZP.md)
- **Decision Date:** Nov 4, 2022
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 866.3170
- **Device Class:** Class 2
- **Review Panel:** Microbiology

## Indications for Use

cobas® HCV is an in vitro nucleic acid amplification test for both the detection and quantitation of hepatitis C virus (HCV) RNA, in human EDTA plasma or serum, of HCV antibody positive or HCV-infected individuals. Specimens containing HCV genotypes 1 to 6 are validated for detection and quantitation in the assay. cobas® HCV is intended for use as an aid in the diagnosis of HCV infection in the following populations: individuals with antibody evidence of HCV with evidence of liver disease, individuals suspected to be actively infected with HCV antibody evidence, and individuals at risk for HCV infection with antibodies to HCV. Detection of HCV RNA indicates that the virus is replicating and therefore is evidence of active infection. cobas® HCV is intended for use as an aid in the management of HCV-infected patients undergoing anti-viral therapy. The assay can be used to measure HCV RNA levels at baseline, during treatment, at the end of treatment, and at the end of follow up of treatment to determine sustained viral response. The results must be interpreted within the context of all relevant clinical and laboratory findings. cobas® HCV has not been approved for use as a screening test for the presence of HCV in blood or blood products. Assay performance characteristics have been established for individuals treated with certain direct-acting antiviral agents (DAA) regimens. No information is available on the assay's predictive value when other DAA combination therapies are used.

## Device Story

In vitro nucleic acid amplification test for HCV RNA detection/quantitation; utilizes cobas 5800 System. Input: human EDTA plasma or serum. Process: automated extraction/purification using magnetic glass particles; real-time PCR amplification using target-specific primers and thermostable DNA polymerase; dual-probe detection with fluorescent reporter dyes. Internal control (armored RNA-QS) monitors sample prep and amplification. Output: quantitative viral load (IU/mL). Used in clinical laboratory settings by trained personnel. Results aid clinicians in diagnosing active HCV infection and monitoring patient response to anti-viral therapy. System features automated barcode scanning, sample handling, and reagent pipetting. Smaller footprint/throughput compared to cobas 6800/8800 systems but maintains identical core technology and performance characteristics.

## Clinical Evidence

Bench testing only. Performance equivalency between cobas® 5800 and 6800/8800 systems established via Technical Equivalency Verification (TEV) studies. Reproducibility assessed using a 7-member panel (1.5E+01 to 1.00E+08 IU/mL) across 3 sites/instruments; total CVs ranged from 0.71% to 25.57%. Method comparison study used 150 positive and 30 negative specimens; 100% agreement for negative samples and 100% of viral load differences within ±0.5 log10.

## Technological Characteristics

Real-time PCR nucleic acid amplification test. Automated extraction/purification using magnetic glass particles. Dual-probe detection with fluorescent reporter dyes. Reportable range: 15 IU/mL – 1.00E+08 IU/mL. Instrumentation: cobas 5800 System (single deck, 24-well processing). Reagents: temperature-controlled storage. Software: automated PCR cycle threshold analysis. Connectivity: automated barcode scanning and processing.

## Regulatory Identification

A nucleic acid-based hepatitis C virus (HCV) ribonucleic acid (RNA) test is identified as an in vitro diagnostic device intended for prescription use as an aid in the diagnosis of HCV infection in specified populations, and/or as an aid in the management of HCV-infected patients including guiding the selection of genotype-specific treatment in individuals with chronic HCV infection. The test is intended for use with human serum or plasma. The test is not intended for use as a donor screening test for the presence of HCV antibodies in blood, blood products, or tissue donors.

## Special Controls

*Classification.* Class II (special controls). The special controls for this device are:(1) For all nucleic acid-based HCV RNA tests, the labeling required under § 809.10(b) of this chapter must include:
(i) A prominent statement that the test is not intended for use as a donor screening test for the presence of HCV RNA from human cells, tissues, and cellular and tissue-based products.
(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. These limitations must include, but are not limited to, statements that indicate:
(A) The specimen types for which the device has been cleared and that use of this test kit with specimen types other than those specifically cleared for this device may result in inaccurate test results.
(B) When applicable, that assay performance characteristics have not been established in populations of immunocompromised or immunosuppressed patients or, other populations where test performance may be affected.
(C) Test results are to be interpreted by qualified licensed healthcare professionals in conjunction with the individual's clinical presentation, history, and other laboratory results.
(2) For all nucleic acid-based HCV RNA tests, the design verification and validation must include:
(i) Detailed device description, including the device components, ancillary reagents required but not provided, and an explanation of the device methodology. Additional information appropriate to the technology must be included such as design of primers and probes, rationale for the selected gene targets, specifications for amplicon size, and degree of nucleic acid sequence conservation.
(ii) For devices with assay calibrators, the design and nature of all primary, secondary, and subsequent quantitation standards used for calibration as well as their traceability to a standardized reference material that FDA has determined is appropriate (
*e.g.,* a recognized consensus standard). In addition, analytical testing must be performed following the release of a new lot of the standard material that was used for device clearance or approval, or when there is a transition to a new calibration standard.(iii) Documentation and characterization (
*e.g.,* determination of the identity, supplier, purity, and stability) of all critical reagents (including nucleic acid sequences for primers and probes) and protocols for maintaining product integrity.(iv) Detailed documentation of analytical performance studies conducted as appropriate to the technology, specimen types tested, and intended use of the device, including, but not limited to, limit of detection (LoD), upper and lower limits of quantitation (ULoQ and LLoQ, respectively), linearity, precision, endogenous and exogenous interferences, cross reactivity, carryover, matrix equivalency, and sample and reagent stability. Samples selected for use in analytical studies or used to prepare samples for use in analytical studies must be from subjects with clinically relevant circulating genotypes in the United States. Cross-reactivity studies must include samples from HCV RNA negative subjects with other causes of liver disease, including autoimmune hepatitis, alcoholic liver disease, chronic hepatitis B virus, primary biliary cirrhosis, and nonalcoholic steatohepatitis, when applicable. The effect of each claimed nucleic-acid isolation and purification procedure on detection must be evaluated.
(v) Risk analysis and management strategies, such as Failure Modes Effects Analysis and/or Hazard Analysis and Critical Control Points summaries and their impact on test performance.
(vi) Final release criteria to be used for manufactured test lots with appropriate evidence that lots released at the extremes of the specifications will meet the claimed analytical and clinical performance characteristics as well as the stability claims.
(vii) Multisite reproducibility study that includes the testing of three independent production lots.
(viii) All stability protocols, including acceptance criteria.
(ix) Final release test results for each lot used in clinical studies.
(x) Analytical sensitivity and specificity of the test must be the same or better than that of other cleared or approved tests.
(xi) Lot-to-lot precision studies, as appropriate.
(3) For devices intended for the qualitative detection of HCV RNA, in addition to the special controls listed in paragraphs (b)(1) and (2) of this section, the design verification and validation must include detailed documentation of performance from a multisite clinical study. Performance must be analyzed relative to an FDA cleared or approved qualitative HCV RNA test, or a comparator that FDA has determined is appropriate. This study must be conducted using appropriate patient samples, with appropriate numbers of HCV positive and negative samples in applicable risk categories. Additional genotypes must be validated using appropriate numbers and types of samples. The samples may be a combination of fresh and repository samples, sourced from within and outside the United States, as appropriate. The study designs, including number of samples tested, must be sufficient to meet the following criteria:
(i) Clinical sensitivity of the test must have a lower bound of the 95 percent confidence interval of greater than or equal to 95 percent.
(ii) Clinical specificity of the test must have a lower bound of the 95 percent confidence interval of greater than or equal to 96 percent.
(4) For devices intended for the quantitative detection of HCV RNA, the following special controls, in addition to those listed in paragraphs (b)(1) and (2) of this section, apply:
(i) Labeling required under § 809.10(b) of this chapter must include a prominent statement that the test is not intended as a diagnostic test to confirm the presence of active HCV infection, when applicable.
(ii) Design verification and validation must include the following:
(A) Detailed documentation of the following analytical performance studies conducted as appropriate to the technology, specimen types tested, and intended use of the device, including but not limited to: LoD, ULoQ and LLoQ. LoD, LLoQ, and linearity studies must demonstrate acceptable device performance with all HCV genotypes detected by the device.
(B) Detailed documentation of clinical performance testing from either:
(
*1* ) A multisite clinical study with an appropriate number of clinical samples from chronically HCV infected patients in which the results are compared to an FDA-cleared or approved quantitative HCV RNA test, or a comparator that FDA has determined is appropriate. This study must include a sufficient number of HCV positive samples containing an analyte concentration near the LLoQ to describe performance at this level. Clinical samples must cover the full range of the device output and must be consistent with the distribution of these genotypes in the U.S. population. Clinical samples may be supplemented with diluted clinical samples for those viral load concentrations that are not sufficiently covered by natural clinical specimens, or(
*2* ) A clinical study with prospectively collected samples demonstrating clinical validity of the device.(C) Detailed documentation of a qualitative analysis near the lower end of the measuring range demonstrating acceptable performance when used as an aid in diagnosis.
(5) For devices intended for HCV RNA genotyping, in addition to the special controls listed in paragraphs (b)(1) and (2) of this section, design verification and validation must include the following:
(i) Detailed documentation of an analytical performance study demonstrating the LoD for all HCV genotypes detected by the device.
(ii) Detailed documentation, including results, of a multisite clinical study that assesses genotyping accuracy (
*i.e.,* the proportion of interpretable results that match with the reference method result) and the genotyping rate (*i.e.,* the proportion of results that were interpretable).(6) For any nucleic acid-based HCV RNA test intended for Point of Care (PoC) use, the following special controls, in addition to those listed in paragraphs (b)(1) and (2) of this section, apply:
(i) Clinical studies must be conducted at PoC sites.
(ii) Additional labeling must include a brief summary of the instructions for use that are appropriate for use in a PoC environment.

## Predicate Devices

- cobas® HCV for use on the cobas® 6800/8800 Systems ([P150015](/device/P150015.md))

## Submission Summary (Full Text)

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FDA

U.S. FOOD & DRUG

ADMINISTRATION

# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

ASSAY AND INSTRUMENT

## I Background Information:

A 510(k) Number

K221007

B Applicant

Roche Molecular Systems, Inc.

C Proprietary and Established Names

cobas HCV

D Regulatory Information

|  Product Code(s) | Classification | Regulation Section | Panel  |
| --- | --- | --- | --- |
|  MZP | Class II | 21 CFR 866.3170 - Nucleic Acid-Based Hepatitis C Virus Ribonucleic Acid Tests | MI - Microbiology  |

## II Submission/Device Overview:

A Purpose for Submission:

To allow use of the cobas 5800 system with the cobas HCV assay. The cobas HCV assay was originally approved under P150015 for use with the cobas 6800 and cobas 8800.

B Measurand:

Hepatitis C virus (HCV) RNA

C Type of Test:

Nucleic acid amplification test

## III Intended Use/Indications for Use:

Food and Drug Administration

10903 New Hampshire Avenue

Silver Spring, MD 20993-0002

www.fda.gov

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K221007 - Page 2 of 3

A Intended Use(s):
See Indications for Use below.

B Indication(s) for Use:
cobas® HCV is an in vitro nucleic acid amplification test for both the detection and quantitation of hepatitis C virus (HCV) RNA, in human EDTA plasma or serum, of HCV antibody positive or HCV-infected individuals. Specimens containing HCV genotypes 1 to 6 are validated for detection and quantitation in the assay.

cobas® HCV is intended for use as an aid in the diagnosis of HCV infection in the following populations: individuals with antibody evidence of HCV with evidence of liver disease, individuals suspected to be actively infected with HCV antibody evidence, and individuals at risk for HCV infection with antibodies to HCV. Detection of HCV RNA indicates that the virus is replicating and therefore is evidence of active infection.

cobas® HCV is intended for use as an aid in the management of HCV-infected patients undergoing anti-viral therapy. The assay can be used to measure HCV RNA levels at baseline, during treatment, at the end of treatment, and at the end of follow up of treatment to determine sustained or non-sustained viral response. The results must be interpreted within the context of all relevant clinical and laboratory findings.

cobas® HCV has not been approved for use as a screening test for the presence of HCV in blood or blood products.

Assay performance characteristics have been established for individuals treated with certain direct-acting antiviral agents (DAA) regimens. No information is available on the assay’s predictive value when other DAA combination therapies are used.

C Special Conditions for Use Statement(s):
Rx - For Prescription Use Only

D Special Instrument Requirements:
For use on the cobas 5800/6800/8800 Systems

IV Device/System Characteristics:

A Device Description:
The cobas HCV assay is a quantitative test performed on the cobas 5800 System, cobas 6800 System or cobas 8800 System. The test detects and quantitates HCV RNA in EDTA plasma or serum of infected patients. Dual probes are used to detect and quantify, but not discriminate genotypes 1–6. The viral load is quantified against a non-HCV armored RNA quantitation standard (RNA-QS), which is introduced into each specimen during sample preparation. The RNA-QS also functions as an internal control to assess substantial failures during the sample preparation and PCR amplification processes.

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B Principle of Operation:

Nucleic acid from patient samples, external controls and added armored RNA-QS molecules are simultaneously extracted by addition of proteinase and lysis reagent to the sample. The released nucleic acid binds to the silica surface of the added magnetic glass particles. Unbound substances and impurities, such as denatured protein, cellular debris and potential PCR inhibitors are removed with subsequent wash buffer steps and purified nucleic acid is eluted from the magnetic glass particles with elution buffer at elevated temperature.

Selective amplification of target nucleic acid from the sample is achieved by the use of target virus-specific forward and reverse primers which are selected from highly conserved regions of HCV. Selective amplification of RNA-QS is achieved by the use of sequence-specific forward and reverse primers which are selected to have no homology with the HCV genome. A thermostable DNA polymerase enzyme is used for both reverse-transcription and PCR amplification. The target and RNA-QS sequences are amplified simultaneously utilizing a universal PCR amplification profile with predefined temperature steps and number of cycles. The master mix includes deoxyuridine triphosphate (dUTP), instead of deoxythimidine triphosphate (dTTP), which is incorporated into the newly synthesized DNA (amplicon). 1-3 Any contaminating amplicon from previous PCR runs are eliminated by the AmpErase enzyme, which is included in the PCR mix, during the first thermal cycling step. However, newly formed amplicon are not eliminated since the AmpErase enzyme is inactivated once exposed to temperatures above 55°C.

The cobas HCV master mix contains dual detection probes specific for the HCV target sequences and one for the RNA-QS. The probes are labeled with target-specific fluorescent reporter dyes allowing simultaneous detection of HCV target and RNA-QS in two different target channels.

When not bound to the target sequence, the fluorescent signal of the intact probe is suppressed by a quencher dye. During the PCR amplification step, hybridization of the probes to the specific single-stranded DNA template results in cleavage of the probe by the 5'-to-3' nuclease activity of the DNA polymerase resulting in separation of the reporter and quencher dyes and the generation of a fluorescent signal. With each PCR cycle, increasing amounts of cleaved probes are generated and the cumulative signal of the reporter dye increases concomitantly. Real-time detection and discrimination of PCR products is accomplished by measuring the fluorescence of the released reporter dyes for the viral targets and RNA-QS.

C Instrument Description Information:

1. Instrument Name: cobas 5800 System
2. Specimen Identification: The cobas 5800 supports multiple types of barcodes. Loaded samples are automatically moved for barcode scanning and processing.
3. Specimen Sampling and Handling: Specimen processing is fully automated on the cobas 5800 system.

K221007 - Page 3 of 4

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4. Calibration:
No instrument calibration is required by the user.

5. Quality Control:
Refer to cobas HCV assay labeling.

V Substantial Equivalence Information:

A Predicate Device Name(s):
cobas HCV

B Predicate 510(k) Number(s):
P150015

C Comparison with Predicate:

|  Device & Predicate Device(s): | K221007 | P150015  |
| --- | --- | --- |
|  Device Trade Name | cobas HCV | cobas HCV  |
|  General Device Characteristic Similarities |  |   |
|  Intended Use/Indications For Use | The cobas HCV is an in vitro nucleic acid amplification test for both the detection and quantitation of hepatitis C virus (HCV) RNA, in human EDTA plasma or serum, of HCV antibody positive or HCV-infected individuals. Specimens containing HCV genotypes 1 to 6 are validated for detection and quantitation in the assay. cobas HCV is intended for use as an aid in the diagnosis of HCV infection in the following populations: individuals with antibody evidence of HCV with evidence of liver disease, individuals suspected to be actively infected with HCV antibody evidence, and individuals at risk for HCV infection with antibodies to HCV. Detection of HCV RNA indicates that the virus is replicating and therefore is evidence of active infection. cobas HCV is intended for use as an aid in the management of | The cobas HCV is an in vitro nucleic acid amplification test for both the detection and quantitation of hepatitis C virus (HCV) RNA, in human EDTA plasma or serum, of HCV antibody positive or HCV-infected individuals. Specimens containing HCV genotypes 1 to 6 are validated for detection and quantitation in the assay. cobas HCV is intended for use as an aid in the diagnosis of HCV infection in the following populations: individuals with antibody evidence of HCV with evidence of liver disease, individuals suspected to be actively infected with HCV antibody evidence, and individuals at risk for HCV infection with antibodies to HCV. Detection of HCV RNA indicates that the virus is replicating and therefore is evidence of active infection. cobas HCV is intended for use as an aid in the management of  |

K221007 - Page 4 of 5

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K221007 - Page 5 of 6
|   | HCV-infected patients undergoing anti-viral therapy. The assay can be used to measure HCV RNA levels at baseline, during treatment, at the end of treatment, and at the end of follow up of treatment to determine sustained or non-sustained viral response. The results must be interpreted within the context of all relevant clinical and laboratory findings. cobas HCV has not been approved for use as a screening test for the presence of HCV in blood or blood products. Assay performance characteristics have been established for individuals treated with certain direct-acting antiviral agents (DAA) regimens. No information is available on the assay’s predictive value when other DAA combination therapies are used. | HCV-infected patients undergoing anti-viral therapy. The assay can be used to measure HCV RNA levels at baseline, during treatment, at the end of treatment, and at the end of follow up of treatment to determine sustained or non-sustained viral response. The results must be interpreted within the context of all relevant clinical and laboratory findings. cobas HCV has not been approved for use as a screening test for the presence of HCV in blood or blood products. Assay performance characteristics have been established for individuals treated with certain direct-acting antiviral agents (DAA) regimens. No information is available on the assay’s predictive value when other DAA combination therapies are used.  |
| --- | --- | --- |
|  Conditions for Use | For Prescription Use | For Prescription Use  |
|  Sample Types | EDTA Plasma and Serum | EDTA Plasma and Serum  |
|  Analyte Targets | Hepatitis C RNA genotypes 1-6 | Hepatitis C RNA genotypes 1-6  |
|  Sample Preparation | Automated RNA extraction & purification | Automated RNA extraction & purification  |
|  Amplification Technology | Real Time PCR | Real Time PCR  |
|  Detection Chemistry | Dual detection probes labeled with target-specific fluorescent reporter dyes allowing simultaneous detection of HCV target and RNA-QS in two different target channels. Real time detection and discrimination of PCR products is accomplished by measuring the fluorescence of the released reporter dyes. | Dual detection probes labeled with target-specific fluorescent reporter dyes allowing simultaneous detection of HCV target and RNA-QS in two different target channels. Real time detection and discrimination of PCR products is accomplished by measuring the fluorescence of the released reporter dyes.  |
|  Assay Controls | RNA-QS functions as an internal control. Three external controls: High Titer Positive, Low Titer Positive, Negative Control | RNA-QS functions as an internal control. Three external controls: High Titer Positive, Low Titer Positive, Negative Control  |

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K221007 - Page 6 of 7
|  Results Analysis | PCR cycle threshold analysis. | PCR cycle threshold analysis.  |
| --- | --- | --- |
|  **General Device Characteristic Differences** |  |   |
|  Instrumentation | cobas 5800 System | Cobas 6800/8800 Systems  |
|  Design Concept | Same | Sample loading, sample prep, and PCR amplification/detection in one instrument  |
|  Throughput | ~144 tests in 8 hours | ~384 / 960 tests in 8 hours  |
|  Configuration | Single deck rather than separate modules. Same technology but fewer components. | Separate modules (sample supply, transfer, processing, analytic), duplicate components for high throughput.  |
|  Consumables | 24-well sample prep and amplification/detection plates with same material, geometry, and volume per well. Same disposable pipette tips. | 48 and 96-well sample preparation and amplification/detection plates. Disposable pipette tips.  |
|  Sample Pipetting | Single two-channel pipettor, smaller but using same technology and volumes | Single four-channel pipettor  |
|  Reagent Pipetting | Smaller reagent pipetting head with 2 reagent needles, smaller but same technology | Reagent pipetting head with a single 8 channel pipettor  |
|  Process Pipetting | 24-well processing plate and single 24-channel process pipettor, smaller but same technology | 48-well processing plate and single 48-channel process pipettor  |
|  Controls | Default setting the same (positive and negative controls on every plate), but due to smaller plates, options for alternate control frequency can be implemented based on lab requirements and local regulations, e.g., time-based (every 24 hours). Controls will be required at least for each reagent lot change. | Positive control and negative control included on every amplification/detection plate  |
|  Reagent Storage | Temperature-controlled (not refrigerated) | On-board refrigerated reagent storage  |
|  Sample Prep | Minor changes in timing of reagent pipetting steps due to smaller batches; same incubation times and temps | Sample Setup, Lysis Binding, Washing and Elution  |
|  Amplification/ Detection | Same technology but smaller thermal cycler
Same temperatures and times for | Real-time PCR using fluorescence spectroscopy  |

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K221007 - Page 7 of 9

## VI Standards/Guidance Documents Referenced:

CLSI: Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures; Approved Guideline- 2nd Edition, EP17-A2, Wayne, PA: Clinical and Laboratory Standards Institute

CLSI: Evaluation of Precision of Quantitative Measurement Procedures; Approved Guideline—Third Edition. CLSI document EP05-A3. Wayne, PA: Clinical and Laboratory Standards Institute; 2014.

## VII Performance Characteristics (if/when applicable):

### A Analytical Performance:

1. Precision/Reproducibility:

Precision: See P150015

Reproducibility was assessed with a multi-site study testing a prepared panel ranging from 1.50E+01 IU/mL to 1.00E+08 IU/mL. A dilution series consisting of a clinical specimen and plasmid RNA sample was used to generate the reproducibility panel. HCV positive material was serially diluted in plasma to create a panel of 7 members that includes concentration levels at, below, and above medical decision points. Panel members were tested in 3 replicates/run, 2 runs/day, over 5 days, using 3 cobas 5800 instruments at 3 different sites (1 internal and 2 external) and 3 cobas 6800/8800 instruments at 1 internal site, 2 runs per day per instrument and by using overall three different lots of the cobas HCV kits

### Results:

Table 1: Standard Deviation and Coefficient of Variance (%) for cobas HCV on cobas 5800 and cobas 6800/8800. Three Systems at three Sites combined (Absolute and Percentage)

|  Platform | Panel Member | Standard Deviation (SD) and Percent Coefficient of Variation (CV)  |   |   |   |   |   |   |   |   |   |   |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|   |   |  Mean observed log10 Titer (IU/mL) | N | Site |   | Day |   | Run |   | Within-Run |   | Total  |
|   |   |   |   |  SD | CV [%] | SD | CV [%] | SD | CV [%] | SD | CV [%] | SD  |
|  cobas 5800 | PM1 | 7.80 | 90 | 0.18 | 2.31 | 0.08 | 1.00 | 0.02 | 0.26 | 0.05 | 0.66 | 0.20  |
|   |  PM2 | 6.65 | 90 | 0.14 | 2.17 | 0.07 | 1.03 | 0.01 | 0.12 | 0.04 | 0.67 | 0.17  |
|   |  PM3 | 5.79 | 90 | 0.15 | 2.65 | 0.06 | 1.11 | 0.00 | 0.00 | 0.06 | 1.04 | 0.18  |
|   |  PM4 | 4.07 | 90 | 0.11 | 2.65 | 0.07 | 1.77 | 0.04 | 1.07 | 0.06 | 1.54 | 0.15  |
|   |  PM5 | 2.01 | 90 | 0.15 | 7.68 | 0.00 | 0.00 | 0.04 | 1.96 | 0.16 | 8.17 | 0.23  |
|   |  PM6 | 1.50 | 89 | 0.09 | 5.70 | 0.00 | 0.00 | 0.05 | 3.65 | 0.23 | 15.14 | 0.25  |

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K221007 - Page 8 of 9

|   | PM7 | 1.28 | 90 | 0.16 | 12.20 | 0.09 | 6.94 | 0.00 | 0.36 | 0.27 | 21.37 | 0.33 | 25.57  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
|  cobas 6800/8800 | PM1 | 7.99 | 90 | 0.00 | 0.00 | 0.04 | 0.50 | 0.01 | 0.07 | 0.04 | 0.49 | 0.06 | 0.71  |
|   |  PM2 | 6.78 | 90 | 0.01 | 0.09 | 0.03 | 0.39 | 0.02 | 0.27 | 0.04 | 0.65 | 0.05 | 0.81  |
|   |  PM3 | 5.93 | 89 | 0.01 | 0.24 | 0.04 | 0.59 | 0.02 | 0.35 | 0.03 | 0.58 | 0.06 | 0.93  |
|   |  PM4 | 4.12 | 90 | 0.00 | 0.00 | 0.02 | 0.41 | 0.00 | 0.00 | 0.06 | 1.51 | 0.06 | 1.57  |
|   |  PM5 | 2.14 | 90 | 0.01 | 0.64 | 0.07 | 3.26 | 0.00 | 0.00 | 0.12 | 5.66 | 0.14 | 6.56  |
|   |  PM6 | 1.58 | 90 | 0.00 | 0.00 | 0.05 | 3.20 | 0.00 | 0.00 | 0.24 | 15.21 | 0.25 | 15.55  |
|   |  PM7 | 1.26 | 88 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.25 | 19.80 | 0.25 | 19.80  |

2. Linearity:

Assay linearity was assessed using the predominant genotype (GT1) in plasma. The linearity panels were prepared as serial dilutions designed to cover the entire linear range of the assay. The dilution series consisted of 16 concentration levels spanning the intended linear range. The dilution series were prepared by diluting an arHCV-MS08-pCP1 specimen and an HCV positive clinical specimen in negative pooled EDTA-plasma. The Titer assignment of the study panels has been performed via Calibrator Bracketing Method (CBM). The panels were tested with three different lots of the cobas HCV kits. The dilution series covered a total of 36 replicates per concentration level in negative pooled EDTA plasma which were tested with 3 kit lots and tested on 2 cobas 5800 Systems over the course of 6 days.

Table 2: Linearity Panel Layout

|  Panel Member | Concentration level description | Concentration aRNA (IU/mL) | Concentration clinical specimen (IU/mL)  |
| --- | --- | --- | --- |
|  PM01 | above upper limit of quantification (ULoQ) | 2.00E+08 | -  |
|  PM02 | ULoQ | 1.00E+08 | -  |
|  PM03 | intermediate level | 1.00E+07 | -  |
|  PM04 | intermediate level | 1.00E+06 | -  |
|  PM05 | intermediate level | 4.00E+05 | -  |
|  PM06 | intermediate level | - | 5.00E+04  |
|  PM07 | intermediate level | 1.00E+04 | -  |
|  PM08 | intermediate level | - | 1.00E+04  |
|  CBMaRNA* | for calibrator bracketing method | 5.50E+03 | -  |
|  CBMclin* | for calibrator bracketing method | - | 5.50E+03  |
|  PM09 | intermediate level | 4.00E+03 | -  |
|  PM10 | intermediate level | - | 1.00E+03  |
|  PM11 | intermediate level | 1.00E+03 | -  |
|  PM12 | intermediate level | - | 1.00E+02  |
|  PM13 | intermediate level | 1.00E+02 | -  |
|  PM14 | intermediate level | - | 5.00E+01  |
|  PM15 | lower limit of quantification (LLoQ) | - | 1.50E+01  |

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Table 3: Linearity Results

|  Panel Member | Nominal Titer [IU/mL] | Assigned Titer [IU/mL] | Assigned log10 Titer | Mean Observed log10 Titer | Predicted log Titer |   | Absolute Difference | Meets Acceptance Criterion?  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
|   |   |   |   |   |  1stOrder | 3rdOrder  |   |   |
|  PM01 | 2.00E+08 | 1.66E+08 | 8.22 | 8.29 | 8.31 | 8.26 | -0.05 | Yes  |
|  PM02 | 1.00E+08 | 8.31E+07 | 7.92 | 7.99 | 8.01 | 8.00 | -0.01 | Yes  |
|  PM03 | 1.00E+07 | 8.31E+06 | 6.92 | 7.02 | 7.01 | 7.07 | 0.06 | Yes  |
|  PM04 | 1.00E+06 | 8.31E+05 | 5.92 | 6.07 | 6.01 | 6.07 | 0.06 | Yes  |
|  PM05 | 4.00E+05 | 3.32E+05 | 5.52 | 5.68 | 5.61 | 5.65 | 0.05 | Yes  |
|  PM06 | 5.00E+04 | 6.54E+04 | 4.82 | 4.90 | 4.90 | 4.92 | 0.02 | Yes  |
|  PM07 | 1.00E+04 | 8.31E+03 | 4.12 | 4.19 | 4.20 | 4.18 | -0.02 | Yes  |
|  PM08 | 1.00E+04 | 1.31E+04 | 3.92 | 3.99 | 4.01 | 3.98 | -0.03 | Yes  |
|  PM09 | 4.00E+03 | 3.32E+03 | 3.52 | 3.58 | 3.61 | 3.57 | -0.04 | Yes  |
|  PM10 | 1.00E+03 | 1.31E+03 | 3.12 | 3.17 | 3.20 | 3.15 | -0.05 | Yes  |
|  PM11 | 1.00E+03 | 8.31E+02 | 2.92 | 2.96 | 3.01 | 2.95 | -0.05 | Yes  |
|  PM12 | 1.00E+02 | 1.31E+02 | 2.12 | 2.15 | 2.20 | 2.17 | -0.03 | Yes  |
|  PM13 | 1.00E+02 | 8.31E+01 | 1.92 | 2.00 | 2.00 | 1.99 | -0.02 | Yes  |
|  PM14 | 5.00E+01 | 6.54E+01 | 1.82 | 1.83 | 1.90 | 1.89 | -0.01 | Yes  |
|  PM15 | 1.50E+01 | 1.96E+01 | 1.29 | 1.38 | 1.38 | 1.42 | 0.04 | Yes  |
|  PM16 | 5.00E+00 | 6.54E+00 | 0.82 | 1.09 | 0.90 | 1.01 | 0.11 | Yes  |

Regression Plot:

![img-0.jpeg](img-0.jpeg)

3. Analytical Specificity/Interference:

See P150015

K221007 - Page 9 of 10

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4. Assay Reportable Range:

The results of the linearity study and calculation of the Lower and Upper Limits of Quantitation confirm the assay reportable range is consistent across analyzer platforms: 15 IU/mL – 1.00E+08 IU/mL.

5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):

See P150015

6. Detection Limit:

The Limit of Detection (LoD) was assessed with a sample panel prepared with an HCV secondary standard and HCV negative pooled EDTA plasma. The dilution series was prepared with 6 concentration levels - 3 levels below the expected LoD, 1 level near the expected LoD and 2 levels above the expected LoD by diluting the secondary standard in pooled negative EDTA plasma. The panel was tested with 3 kit lots, on 7 days, on 3 cobas 5800 systems and 1 cobas 6800/8800 system over multiple runs, with multiple operators and with multiple replicates per run.

Table 4: Results Summary HCV on the cobas 6800/8800

|  Concentration HCV (IU/mL) | HCV  |   |   |
| --- | --- | --- | --- |
|   |  Number of Valid Replicates | Number of Positives | % Positives  |
|  20.0 | 66 | 66 | 100.00%  |
|  15.0 | 66 | 63 | 95.45%  |
|  10.0 | 66 | 57 | 86.36%  |
|  8.0 | 66 | 57 | 86.36%  |
|  5.0 | 66 | 46 | 69.70%  |
|  2.5 | 66 | 27 | 40.91%  |
|  LoD by PROBIT analysis (95% Hit Rate) |   | 13.70 IU/mL (95% CI: 11.19 – 18.31 )  |   |
|  LoD by Hit Rate |   | 15 IU/mL  |   |
|  log10 Probit 95% |   | 1.14 log10 IU/mL  |   |

Table 5: Results Summary on the cobas 5800

|  Concentration HCV (IU/mL) | HCV  |   |   |
| --- | --- | --- | --- |
|   |  Number of Valid Replicates | Number of Positives | % Positives  |
|  20.0 | 66 | 65 | 98.48%  |
|  15.0 | 66 | 63 | 95.45%  |
|  10.0 | 66 | 59 | 89.39%  |
|  8.0 | 66 | 55 | 83.33%  |

K221007 - Page 10 of 11

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|  5.0 | 65* | 47 | 72.31%  |
| --- | --- | --- | --- |
|  2.5 | 66 | 30 | 45.45%  |
|  LoD by PROBIT analysis (95% Hit Rate) |   | 14.41 IU/mL
(95% CI: 11.55 – 19.99)  |   |
|  LoD by Hit Rate |   | 15 IU/mL  |   |
|  log10 Probit 95% |   | 1.16 log 10 IU/mL  |   |

*one (1) sample was invalid

7. Assay Cut-Off:
See P150015

8. Carry-Over:
Sample carryover on the cobas 5800 was evaluated with the cobas HBV assay. Alternating negative and HBV high positive samples were processed and detected with several checkerboard configurations on the cobas 5800 Systems. A high titer HBV plasmid sample used in this study was prepared by diluting in pooled negative EDTA plasma to yield a mean titer of $9.11 \times 10^{8}$ IU/mL.

Eighty-three runs were performed yielding 1926 valid sample results.

Table 6: Summary of Cross Contamination Study
|   | Total Positive Results from Negative Samples | Total Samples |   | Cross Contamination Rate | Acceptance Criteria  |
| --- | --- | --- | --- | --- | --- |
|   |   |  positive samples | negative samples  |   |   |
|  Total | 1 | 960 | 966 | 0.104 %
(upper one-sided 95% CI of 0.490%) | met  |

B Comparison Studies:

1. Method Comparison with Predicate Device:
A method comparison study was conducted using 150 archived, well-characterized HCV positive plasma specimens and 30 HCV negative individual plasma specimens. Some of the individual positive specimens were diluted to achieve the desired number of samples at specified concentrations: $\sim 50$ HCV specimens between $1.5\mathrm{E} + 01$ to $3\mathrm{E} + 03$ IU/mL, $\sim 50$ specimens between $3\mathrm{E} + 03$ to $5\mathrm{E} + 05$ IU/mL and $\sim 50$ specimens between $5\mathrm{E} + 05$ to $1\mathrm{E} + 08$ IU/mL. Each specimen was tested on the cobas 5800 System at three different sites (1 internal and 2 external) and on a cobas 6800/8800 System at one site (internal) using three reagent lots.

Results:
For the 30 samples with target not detected (TND) results by cobas 6800/8800, one sample (1/30) by cobas 5800 test at one site was positive (with concentration $< 1.5\mathrm{E} + 01$, out of the linear range). At the other two sites the $\mathrm{NPA} = 100\%$ (30/30).

All of the positive samples were within the linear range of $1.5\mathrm{E} + 1$ IU/mL to $1\mathrm{E} + 8$ IU/mL by cobas 6800/8800 (150/150 = 100%) and by cobas 5800 (450/450 = 100%). Among the three

K221007 - Page 11 of 12

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categories (low, medium, and high viral loads) within the linear range, the test results between the two systems were highly concordant.

Table 7 summarizes the parameter estimates (slope and intercept) of Deming regression between cobas 5800 and cobas 6800/8800 by site.

Table 7: Parameter estimates from Deming regression analysis by site

|  Site | Parameter | Number of Pairs within Linear Range | Parameter Estimate | Standard Error | 95% CI | r²  |
| --- | --- | --- | --- | --- | --- | --- |
|  1 | Intercept | 150 | -0.044 | 0.029 | (-0.102, 0.014) | 0.996  |
|   |  Slope |   | 1.011 | 0.006 | (1.000, 1.022)  |   |
|  2 | Intercept | 150 | -0.055 | 0.037 | (-0.127, 0.018) | 0.996  |
|   |  Slope |   | 1.014 | 0.007 | (1.000, 1.028)  |   |
|  3 | Intercept | 150 | -0.031 | 0.032 | (-0.094, 0.032) | 0.996  |
|   |  Slope |   | 1.010 | 0.006 | (0.998, 1.023)  |   |

The figure below shows the scatter plot of the average of $\log_{10}$-transformed viral load concentration across 3 sites from the cobas 5800 versus $\log_{10}$-transformed viral load concentration from the cobas 6800/8800 with fitted lines created by Deming regression for all sites combined using bootstrap method.

![img-1.jpeg](img-1.jpeg)

Using Deming regression analysis, an estimate of the systematic bias between the $\log_{10}$-transformed viral load concentration of the two systems (cobas 5800 and cobas 6800/8800) was calculated at medical decision levels for each site. Jackknife method was used to estimate the $95\%$ CI of systematic bias.

K221007 - Page 12 of 13

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Table 8 presents the estimated systematic bias between the two systems at the medical decision points by site. The biases are very close to zero in all cases, ranging from -0.035 to 0.040 and are all below the SDs observed in the reproducibility study for cobas 6800/8800 (range from 0.098 to 0.244).

Table 8: Systematic bias at medical decision point by site

|  Site | Medical Decision Point (IU/mL) | Number of Pairs within Linear Range | Medical Decision Point in log10(IU/mL) | Predicted Value at Medical Decision Point in log10(IU/mL)1 | Bias in log10(IU/mL) | 95% CI of Bias  |
| --- | --- | --- | --- | --- | --- | --- |
|  1 | 25 | 150 | 1.398 | 1.369 | -0.029 | (-0.072, 0.015)  |
|   |  800,000 | 150 | 5.903 | 5.924 | 0.021 | (0.004, 0.038)  |
|   |  6,000,000 | 150 | 6.778 | 6.808 | 0.030 | (0.007, 0.053)  |
|  2 | 25 | 150 | 1.398 | 1.363 | -0.035 | (-0.089, 0.019)  |
|   |  800,000 | 150 | 5.903 | 5.931 | 0.028 | (0.009, 0.046)  |
|   |  6,000,000 | 150 | 6.778 | 6.818 | 0.040 | (0.013, 0.067)  |
|  3 | 25 | 150 | 1.398 | 1.382 | -0.016 | (-0.064, 0.031)  |
|   |  800,000 | 150 | 5.903 | 5.934 | 0.031 | (0.013, 0.048)  |
|   |  6,000,000 | 150 | 6.778 | 6.818 | 0.040 | (0.015, 0.065)  |
|  1Estimated from the linear equation established by Deming regression method.  |   |   |   |   |   |   |

A Bland-Altman (BA) plot between the results of the two systems (cobas 5800 and cobas 6800/8800 instrument) with allowable total difference (ATD) zone were created for each site and for all sites combined.

Table 9 shows the percentage of samples falling within the ATD zone at low, medium and high viral load ranges and over the entire range along with the one-sided  $95\%$  CIs for all sites combined. Over the entire range,  $100\%$  of the samples fell within the ATD zone and the lower bound of the one-sided  $95\%$  CI was  $100\%$ .

Table 9: Percentage of samples within the ATD zone and  $\pm  {0.5}\log {10}$  -range - all sites combined

|  Viral Load Range Category | Viral Load Range (IU/mL) | Percentage of Samples within ATD Zone (95% One-Sided CI) | Percentage of Samples with difference within ±0.5 log10(95% One-Sided CI)  |
| --- | --- | --- | --- |
|  Low | 1.5E+1 - 3.0E+3 | 100.00% (47/47) (94.56%) | 100.00% (47/47) (94.56%)  |
|  Medium | 3.0E+3 - 5.0E+5 | 100.00% (46/46) (94.45%) | 100.00% (46/46) (94.45%)  |
|  High | 5.0E+5 - 1.0E+8 | 100.00% (57/57) (95.47%) | 100.00% (57/57) (95.47%)  |
|  Overall |  | 100.00% (150/150) (98.23%) | 100.00% (150/150) (98.23%)  |

# 2. Matrix Comparison:

See P150015

K221007 - Page 13 of 14

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C Clinical Studies:

1. Clinical Sensitivity:
See P150015

2. Clinical Specificity:
See P150015

D Expected Values/Reference Range:
See P150015

E Reagent Stability:
Studies were conducted to determine the On-Board and Open Kit stability for the cobas HCV assay when used on the cobas 5800 System. The results of the studies demonstrate the cobas HCV reagent kit cassette for use on the cobas 5800 System are stable for up to 90 days at 2 –8°C once opened and remain stable for up to 36 days at 25°C (On Board Stability), and can be used up to 40 times.

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

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

K221007 - Page 14 of 14

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**Source:** [https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/MZP/K221007](https://fda.innolitics.com/submissions/MI/subpart-d%E2%80%94serological-reagents/MZP/K221007)

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