cobas CTNG for use on cobas 6800/8800 systems

K202408 · Roche Molecular Systems, Inc. · QEP · Jan 21, 2021 · Microbiology

Device Facts

• Record ID: K202408
• Device Name: cobas CTNG for use on cobas 6800/8800 systems
• Applicant: Roche Molecular Systems, Inc.
• Product Code: QEP · Microbiology
• Decision Date: Jan 21, 2021
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.3393
• Device Class: Class 2

Indications for Use

The cobas® CT/NG for use on the cobas® 6800/8800 system is an automated, qualitative in vitro nucleic acid diagnostic test, that utilizes real-time polymerase chain reaction (PCR), for the direct detection of Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) DNA in male and female urine, clinician-instructed self-collected vaginal swab specimens (collected in a clinical setting), and clinician-collected vaginal swab specimens, endocervical swab specimens, oropharyngeal (throat) swab specimens and anorectal swab specimens all collected in cobas® PCR Media (Roche Molecular Systems, Inc.), and cervical specimens collected in PreservCyt® solution. This test is intended as an aid in the diagnosis of chlamydial and gonococcal disease in both symptomatic and asymptomatic individuals.

Device Story

Automated, qualitative in vitro diagnostic test; utilizes real-time PCR for direct detection of Chlamydia trachomatis and Neisseria gonorrhoeae DNA. Input: urine, vaginal, endocervical, oropharyngeal, or anorectal swab specimens in cobas® PCR Media; cervical specimens in PreservCyt® solution. Operation: automated sample preparation and real-time PCR amplification on cobas® 6800/8800 systems. Output: qualitative detection results based on PCR cycle threshold analysis. Used in clinical settings; operated by laboratory personnel. Healthcare providers use results to aid in diagnosis of chlamydial and gonococcal disease. Benefits: enables rapid, automated identification of infections in diverse anatomical sites, facilitating timely clinical management.

Clinical Evidence

Prospective multi-site clinical study (N=2,390) compared cobas CT/NG performance against a composite reference standard (2/3 rule of three comparator NAATs). For CT: anorectal sensitivity 95.1%, specificity 99.2%; oropharyngeal sensitivity 100%, specificity 99.8%. For NG: anorectal sensitivity 99.0%, specificity 99.3%; oropharyngeal sensitivity 100%, specificity 98.9%.

Technological Characteristics

Automated real-time PCR assay. Targets: CT cryptic plasmid/ompA gene and NG DR-9 region. Uses magnetic glass particle-based nucleic acid extraction. Detection via fluorescent reporter dyes in three channels. System: cobas 6800/8800. Software-controlled automated processing. No calibration required by user.

Indications for Use

Indicated for the qualitative detection of Chlamydia trachomatis and Neisseria gonorrhoeae DNA in male/female urine, clinician-instructed self-collected vaginal swabs, clinician-collected vaginal swabs, endocervical swabs, oropharyngeal swabs, and anorectal swabs. Intended for symptomatic and asymptomatic individuals as an aid in diagnosis.

Regulatory Classification

Identification

A device to detect nucleic acids from non-viral microorganism(s) causing sexually transmitted infections and associated resistance marker(s) is an in vitro diagnostic device intended for the detection and identification of nucleic acids from non-viral microorganism(s) and their associated resistance markers in clinical specimens collected from patients suspected of sexually transmitted infections. The device is intended to aid in the diagnosis of non-viral sexually transmitted infections in conjunction with other clinical and laboratory data. These devices do not provide confirmation of antibiotic susceptibility since mechanisms of resistance may exist that are not detected by the device.

Special Controls

A device to detect nucleic acids from non-viral microorganism(s) causing sexually transmitted infections and associated resistance marker(s) must comply with the following special controls: (1) The intended use for the 21 CFR 809.10 labeling must include a detailed description of targets the device detects, the results provided to the user, the clinical indications appropriate for test use, and the specific population(s) for which the device is intended. (2) Any sample collection device used must be FDA-cleared, -approved, or -classified as 510(k) exempt (standalone or as part of a test system) for the collection of specimen types claimed by this device: alternatively, the sample collection device must be cleared in a premarket submission as a part of this device. (3) The 21 CFR 809.10(b) labeling must include: (i) A detailed device description, including reagents, instruments, ancillary materials, all control elements, and a detailed explanation of the methodology, including all pre-analytical methods for processing of specimens; (ii) Detailed discussion of the performance characteristics of the device for all claimed specimen types based on analytical studies, including, but not limited to. Limit of Detection, inclusivity, cross-reactivity, interfering substances, competitive inhibition, carryover/cross contamination, specimen stability, with-in lab precision, and reproducibility, as appropriate; (iii) Detailed descriptions of the test procedure, the interpretation of test results for clinical specimens, and acceptance criteria for any quality control testing. (iv) Limiting statements indicating that: (A)a negative test result does not preclude the possibility of infection; (B) the test results should be interpreted in conjunction with other clinical and laboratory data available to the clinician; (C) reliable results are dependent on adequate specimen collection, transport, storage, and processing. Failure to observe procedures in any one of these steps can lead to incorrect results; and (D)if appropriate (e.g., recommended by CDC, by current well-accepted clinical guidelines, or by published peer reviewed research), that the clinical performance is inferior in a specific clinical subpopulation or for a specific claimed specimen type. (v) If the device is intended to detect antimicrobial resistance markers, limiting statements, as appropriate, indicating that: (A)negative results for claimed resistance markers do not indicate susceptibility of detected microorganisms, as resistance markers not measured by the assay or other potential mechanisms of antibiotic resistance may be present; (B) detection of resistance markers cannot be definitively linked to specific microorganisms and the source of a detected resistance marker may be an organism not detected by the assay, including colonizing flora; (C) detection of antibiotic resistance markers may not correlate with phenotypic gene expression; and (D) therapeutic failure or success cannot be determined based on the assay results, since nucleic acid may persist following appropriate antimicrobial therapy. (4) Design verification and validation must include: (i) Detailed device description documentation, including, but not limited to, methodology from obtaining sample to result, design of primer/probe sequences, rationale for target sequence selection, and computational path from collected raw data to reported result (e.g., how collected raw signals are converted into a reported result). (ii) Detailed documentation of analytical studies including but not limited to, Limit of Detection, inclusivity, cross-reactivity, microbial interference, interfering substances, competitive inhibition, carryover/cross contamination, specimen stability, with-in lab precision, and reproducibility, as appropriate. (iii) Detailed documentation and performance results from a clinical study that includes prospective (sequential) samples for each claimed specimen type and, when determined to be appropriate by FDA, additional characterized clinical samples. The study must be performed on a study population consistent with the intended use population and compare the device performance to results obtained from FDA accepted comparator methods. Documentation from the clinical studies must include the clinical study protocol (including a predefined statistical analysis plan) study report, testing results, and results of all statistical analyses. (iv) A detailed description of the impact of any software, including, but not limited to, software applications and hardware-based devices that incorporate software, on the device's functions.

*Classification.* Class II (special controls). The special controls for this device are:(1) The intended use for the labeling required under § 809.10 of this chapter must include a detailed description of targets the device detects, the results provided to the user, the clinical indications appropriate for test use, and the specific population(s) for which the device is intended. (2) Any sample collection device used must be FDA-cleared, -approved, or -classified as 510(k) exempt (standalone or as part of a test system) for the collection of specimen types claimed by this device; alternatively, the sample collection device must be cleared in a premarket submission as a part of this device. (3) The labeling required under § 809.10(b) of this chapter must include: (i) A detailed device description, including reagents, instruments, ancillary materials, all control elements, and a detailed explanation of the methodology, including all pre-analytical methods for processing of specimens; (ii) Detailed discussion of the performance characteristics of the device for all claimed specimen types based on analytical studies, including Limit of Detection, inclusivity, cross-reactivity, interfering substances, competitive inhibition, carryover/cross contamination, specimen stability, within lab precision, and reproducibility, as appropriate; (iii) Detailed descriptions of the test procedure, the interpretation of test results for clinical specimens, and acceptance criteria for any quality control testing; (iv) Limiting statements indicating that: (A) A negative test result does not preclude the possibility of infection; (B) The test results should be interpreted in conjunction with other clinical and laboratory data available to the clinician; (C) Reliable results are dependent on adequate specimen collection, transport, storage, and processing. Failure to observe proper procedures in any one of these steps can lead to incorrect results; and (D) If appropriate ( *e.g.,* recommended by the Centers for Disease Control and Prevention, by current well-accepted clinical guidelines, or by published peer reviewed research), that the clinical performance is inferior in a specific clinical subpopulation or for a specific claimed specimen type; and(v) If the device is intended to detect antimicrobial resistance markers, limiting statements, as appropriate, indicating that: (A) Negative results for claimed resistance markers do not indicate susceptibility of detected microorganisms, as resistance markers not measured by the assay or other potential mechanisms of antibiotic resistance may be present; (B) Detection of resistance markers cannot be definitively linked to specific microorganisms and the source of a detected resistance marker may be an organism not detected by the assay, including colonizing flora; (C) Detection of antibiotic resistance markers may not correlate with phenotypic gene expression; and (D) Therapeutic failure or success cannot be determined based on the assay results, since nucleic acid may persist following appropriate antimicrobial therapy. (4) Design verification and validation must include: (i) Detailed device description documentation, including methodology from obtaining sample to result, design of primer/probe sequences, rationale for target sequence selection, and computational path from collected raw data to reported result ( *e.g.,* how collected raw signals are converted into a reported result).(ii) Detailed documentation of analytical studies, including, Limit of Detection, inclusivity, cross-reactivity, microbial interference, interfering substances, competitive inhibition, carryover/cross contamination, specimen stability, within lab precision, and reproducibility, as appropriate. (iii) Detailed documentation and performance results from a clinical study that includes prospective (sequential) samples for each claimed specimen type and, when determined to be appropriate by FDA, additional characterized clinical samples. The study must be performed on a study population consistent with the intended use population and compare the device performance to results obtained from FDA accepted comparator methods. Documentation from the clinical studies must include the clinical study protocol (including a predefined statistical analysis plan) study report, testing results, and results of all statistical analyses. (iv) A detailed description of the impact of any software, including software applications and hardware-based devices that incorporate software, on the device's functions.

Predicate Devices

• cobas® CT/NG for use on the cobas® 6800/8800 systems (K173887)

Submission Summary (Full Text)

{0}

FDA U.S. FOOD & DRUG ADMINISTRATION

# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

## I Background Information:

A 510(k) Number

K202408

B Applicant

Roche Molecular Systems, Inc.

C Proprietary and Established Names

cobas CTNG for use on cobas 6800/8800 systems

D Regulatory Information

| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| QEP | Class II | 21 CFR 866.3393 - Nucleic acid detection system for non-viral microorganism(s) causing sexually transmitted infections | MI - Microbiology |
| MKZ | Class I, reserved | 21 CFR 866.3120 - Chlamydia serological reagents | MI - Microbiology |
| LSL | Class II | 21 CFR 866.3390 - Neisseria spp. direct serological test reagents | MI - Microbiology |
| OOI | Class II | 21 CFR 862.2570 - Instrumentation for clinical multiplex test systems | CH - Clinical Chemistry |

## II Submission/Device Overview:

### A Purpose for Submission:

To expand the indications for use to include oropharyngeal and anorectal swab specimens to the intended use. There have been no changes made to the device to accommodate this claim expansion. The technical characteristics and performance of the cobas CT/NG for use on the cobas 6800/8800 systems are the same as the device cleared under K173887.

Food and Drug Administration

10903 New Hampshire Avenue

Silver Spring, MD 20993-0002

www.fda.gov

{1}

B Measurand:
Chlamydia trachomatis and Neisseria gonorrhoeae DNA

C Type of Test:
Nucleic acid extraction, purification and amplification assay (real-time polymerase chain reaction)

III Intended Use/Indications for Use:

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

B Indication(s) for Use:
The cobas CT/NG for use on the cobas 6800/8800 system is an automated, qualitative in vitro nucleic acid diagnostic test, that utilizes real-time polymerase chain reaction (PCR), for the direct detection of Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) DNA in male and female urine, clinician-instructed self-collected vaginal swab specimens (collected in a clinical setting), and clinician-collected vaginal swab specimens, endocervical swab specimens, oropharyngeal (throat) swab specimens and anorectal swab specimens all collected in cobas PCR Media (Roche Molecular Systems, Inc.), and cervical specimens collected in PreservCyt solution. This test is intended as an aid in the diagnosis of chlamydial and gonococcal disease in both symptomatic and asymptomatic individuals.

Ancillary Collection Kits:
The cobas PCR Media Dual Swab Sample Kit is used to collect and transport endocervical and vaginal swab specimens. The cobas PCR Media serves as a nucleic acid stabilizing transport and storage medium.

Note: This kit has been validated for use with the following tests:
- cobas CT/NG v2.0 Test (for use on cobas 4800 System)
- cobas CT/NG for use on cobas 6800/8800 Systems
- cobas TV/MG for use on the cobas 6800/8800 Systems

The cobas PCR Media Uni Swab Sample Kit is used to collect and transport human specimens. The cobas PCR Media serves as a nucleic acid stabilizing transport and storage medium.

Note: This kit has been validated for use with the following tests:
- cobas CT/NG v2.0 Test (for use on cobas 4800 System)
- cobas CT/NG for use on cobas 6800/8800 Systems
- cobas TV/MG for use on the cobas 6800/8800 Systems

K202408 - Page 2 of 26

{2}

- cobas Cdiff Test for use on the cobas 4800 System

The cobas PCR Urine Sample Kit is used to collect and transport urine specimens. The cobas PCR Media serves as a nucleic acid stabilizing transport and storage medium. Use this collection kit only with the following tests:

- cobas CT/NG v2.0 Test (for use on cobas 4800 System)
- cobas CT/NG for use on cobas 6800/8800 Systems
- cobas TV/MG for use on the cobas 6800/8800 Systems

## C Special Conditions for Use Statement(s):

Rx - For Prescription Use Only

## D Special Instrument Requirements:

cobas 6800/8800

## IV Device/System Characteristics:

## A Device Description:

The cobas CT/NG assay is a fully automated, qualitative real-time PCR assay performed on the cobas 6800 System and cobas 8800 System. cobas CT/NG enables the detection of CT/NG DNA in urogenital and extragenital specimens. Target-specific primers and two probes are used to detect but not discriminate between the CT cryptic plasmid and the ompA gene. Additionally, target-specific primers and two probes are used to detect but not discriminate between two conserved sequences in the NG DR-9 region. The DNA Internal Control, used to monitor the entire sample preparation and PCR amplification process, is introduced into each specimen during sample processing.

There have been no changes made to the device, since 510(k) cleared under K173887, to accommodate this claim expansion to include oropharyngeal and anorectal swab specimens.

K202408 - Page 3 of 26

{3}

cobas 6800 System Instrument

cobas 8800 System Instrument


# B Principle of Operation:

The cobas CT/NG assay is based on fully automated sample preparation (nucleic acid extraction and purification) followed by PCR amplification and detection. The cobas 6800/8800 Systems consist of the sample supply module, the transfer module, the processing module, and the analytic module. Automated data management is performed by the cobas 6800/8800 software which assigns test results for all tests as positive, negative, or invalid. Results can be reviewed directly on the system screen, exported, or printed as a report.

Nucleic acids from patient samples and internal control DNA (DNA-IC), added into the specimens to monitor for inhibition of nucleic acid isolation and amplification, are simultaneously extracted. In summary, bacterial nucleic acid is released by addition of proteinase and lysis reagent to the sample. The released nucleic acids bind to the silica surface of added

K202408 - Page 4 of 26

{4}

magnetic glass particles. Unbound substances and impurities, such as denatured protein, cellular debris and potential PCR inhibitors, are removed with subsequent wash steps and purified nucleic acids are 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-specific forward and reverse primers selected from highly conserved plasmid and genomic regions of CT and NG. A region on the CT cryptic plasmid and the ompA gene (dual target) and two conserved sequences of the NG DR-9 region are amplified. Selective amplification of DNA-IC is achieved by the use of sequence-specific forward and reverse primers which have no homology with either the CT or NG target regions. A thermostable DNA polymerase enzyme is used for PCR amplification. The target and DNA-IC sequences are amplified simultaneously utilizing a universal PCR amplification profile with predefined temperature steps and number of cycles.

The cobas CT/NG master mix contains two detection probes specific for the CT target sequences, two detection probes specific for the NG target sequences and one for the DNA-IC. The probes are labeled with target specific fluorescent reporter dyes allowing simultaneous detection of CT targets, NG targets, and DNA-IC in three different channels. When not bound to the target sequence, the fluorescent signal of the intact probes 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' exonuclease 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 CT and NG targets and DNA-IC, respectively.

C Instrument Description Information:

1. Instrument Name:
cobas 6800/8800

2. Specimen Identification:
cobas 6800/8800 analyzer supports multiple types of barcodes. Loaded samples are automatically moved for barcode scanning and processing.

3. Specimen Sampling and Handling:
Specimens are collected using the appropriate ancillary kits (cobas PCR Media Dual Swab Sample Kit, cobas PCR Media Uni Swab Sample Kit, or cobas PCR Urine Sample Kit) or PreservCyt Solution as per defined instructions. Swab specimens containing a single swab in the cobas PCR Media tube can be directly processed on the cobas 6800/8800 Systems, or the swab may be removed prior to loading onto the instrument. Urine specimens must show a liquid level between two black indicator lines on the cobas PCR Media tube to proceed to testing. Cervical specimens in PreservCyt Solution are to be aliquoted into barcoded cobas PCR Secondary tubes for processing. Only racks of uncapped tubes may be loaded into the

K202408 - Page 5 of 26

{5}

Sample Supply Module of the cobas 6800/8800 Systems for testing. Specimen processing is fully automated.

4. Calibration:

No calibration is required by the user.

5. Quality Control:

Quality Controls are provided as an accessory and must be used in daily operation according to each laboratory's operating procedures.

V Substantial Equivalence Information:

A Predicate Device Name(s):

cobas CT/NG for use on cobas 6800/8800 systems

B Predicate 510(k) Number(s):

K173887

C Comparison with Predicate(s):

| Device & Predicate Device(s): | K202408 | K173887 |
| --- | --- | --- |
| Device Trade Name | cobas CT/NG for use on the cobas 6800/8800 systems | cobas CT/NG for use on the cobas 6800/8800 systems |
| General Device Characteristic Similarities | | |
| Intended Use/Indications for Use | The cobas CT/NG for use on the cobas 6800/8800 system is an automated, qualitative in vitro nucleic acid diagnostic test, that utilizes real-time polymerase chain reaction (PCR), for the direct detection of Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) DNA in male and female urine, clinician-instructed self-collected vaginal swab specimens (collected in a clinical setting), and clinician-collected vaginal swab specimens, | The cobas CT/NG for use on the cobas 6800/8800 system is an automated, qualitative in vitro nucleic acid diagnostic test, that utilizes real-time polymerase chain reaction (PCR), for the direct detection of Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (NG) DNA in male and female urine, clinician instructed self-collected vaginal swab specimens (collected in a clinical setting), clinician-collected vaginal swab specimens, |

K202408 - Page 6 of 26

{6}

K202408 - Page 7 of 26

| | | endocervical swab specimens, oropharyngeal (throat) swab specimens and anorectal swab specimens all collected in cobas PCR Media (Roche Molecular Systems, Inc.), and cervical specimens collected in PreservCyt® solution. This test is intended as an aid in the diagnosis of chlamydial and gonococcal disease in both symptomatic and asymptomatic individuals. | vaginal swab specimens, and endocervical swab specimens, all collected in cobas PCR Media (Roche Molecular Systems, Inc.), and cervical specimens collected in PreservCyt® solution. This test is intended as an aid in the diagnosis of chlamydial and gonococcal disease in both symptomatic and asymptomatic individuals. |
| --- | --- | --- | --- |
| Ancillary Sample Collection Kits | | Same | The cobas PCR Media Dual Swab Sample Kit is used to collect and transport endocervical and vaginal swab specimens. The cobas PCR Media serves as a nucleic acid stabilizing transport and storage medium.

The cobas PCR Media Uni Swab Sample Kit is used to collect and transport human specimens. The cobas PCR Media serves as a nucleic acid stabilizing transport and storage medium.

The cobas PCR Urine Sample Kit is used to collect and transport urine specimens. The cobas PCR Media serves as a nucleic acid stabilizing transport and storage medium. |
| Analytical Targets | CT | Same | CT cryptic plasmid DNA CT ompA gene |
| | NG | Same | NG genomic DNA |
| Sample Preparation | | Same | Automated extraction and purification of nucleic acids |
| Technology | | Same | Real-Time PCR |

{7}

| | | |
| --- | --- | --- |
| Instrument | Same | cobas 6800/8800 systems |
| General Device Characteristic Differences | | |
| Sample Types | 1. Male and female urine,
2. Self-collected/clinician-collected vaginal swab specimens in cobas PCR Media,
3. Endocervical swab specimens in cobas PCR Media,
4. Cervical specimens in PreservCyt® solution
5. Oropharyngeal (throat) swab specimens in cobas PCR Media,
6. Anorectal swab specimens in cobas PCR Media, | 1. Male and female urine,
2. Self-collected/clinician-collected vaginal swab specimens in cobas PCR Media,
3. Endocervical swab specimens in cobas PCR Media,
4. Cervical specimens in PreservCyt® solution |

VI Standards/Guidance Documents Referenced:

None.

VII Performance Characteristics (if/when applicable):

A Analytical Performance:

Note: Only results for oropharyngeal and anorectal specimens are shown in this section. For performance data pertaining to urogenital specimens, refer to K173887.

1. Precision/Reproducibility:

See K173887.

2. Linearity:

Not applicable.

K202408 - Page 8 of 26

{8}

3. Analytical Specificity/Interference:

Cross-reactivity/Microbial interference

Potential cross-reactivity of the cobas CT/NG assay with microorganisms which may be present in patients' specimens at the oropharyngeal and anorectal collection sites was evaluated by testing 178 bacteria, fungi, protozoa and viruses in the respective clinical matrices. Multiple strains were tested for several organisms, including 20 representatives of non-gonorrhoeae Neisseria strains. Each negative matrix was created by pooling individual specimens (i.e., oropharyngeal swabs collected in cobas PCR media and anorectal swabs collected in cobas PCR media) that had tested negative for both CT and NG with the cobas CT/NG Test. The matrix pools were divided into two separate batches, where one batch was set aside as the negative background to be spiked with the cross-reactants, to evaluate specificity. The potentially cross-reacting microorganisms were spiked into each matrix to a concentration level of 10⁶ units/mL (EB or CFU/mL) for bacteria and yeast, and 10⁵ units/mL (as cells/mL for protozoa or as determined by TCID₅₀ Endpoint Dilution Assay for viruses). The other portion was used to spike with CT serovar D at 6 EB/mL and NG strain 2948 at 0.6 CFU/mL, followed by spiking with the same organism stocks (interferents) to evaluate potential microbial interference.

The analysis of the generated Ct values for the low positive samples (i.e., the difference between the baseline Ct values and the Ct values generated after the potential cross reactant was added) showed no evidence of microbial interference. The data also showed that there was no evidence of cross-reactivity with the microbial strains tested where all negative samples returned negative results after the addition of the potential cross-reactants. In summary, all tests returned expected results.

The following organisms were evaluated for cross-reactivity and microbial interference with the cobas CT/NG Test.

Microorganisms Tested for Analytical Specificity/Cross-reactivity

| Achromobacter xerosis | Fusobacterium nucleatum | Norovirus**†† |
| --- | --- | --- |
| Acinetobacter baumannii †† | Gardnerella vaginalis | Pantoea agglomerans |
| Acinetobacter calcoaceticus | Gemella haemolysans | Paracoccus denitrificans |
| Acinetobacter lwoffii | Giardia lamblia†† | Parvinomas micra† |
| Actinomyces israelii | Haemophilus ducreyi | Peptostreptococcus anaerobius |
| Adenovirus† | Haemophilus influenzae | Peptostreptococcus asaccharolyticus |
| Aerococcus viridans | Helicobacter pylori | Peptostreptococcus magnus |
| Aeromonas hydrophila | Herpes simplex virus I | Plesiomonas shigelloides |
| Aggregatibacter actinomycetemcomitans†† | Herpes simplex virus II ** | Porphyromonas gingivalis† |
| Alcaligenes faecalis | HPV16 * | Prevotella bivia††† |

K202408 - Page 9 of 26

{9}

K202408 - Page 10 of 26
| Anaerococcus prevotii†† | Human influenza virus A† | Prevotella oralis† |
| --- | --- | --- |
| Arcanobacterium haemolyticum† | Human influenza virus B† | Propionibacterium acnes |
| Atopobium vaginae | Human metapneumovirus† | Proteus mirabilis |
| Bacillus subtilis | Kingella dentrificans | Proteus penneri |
| Bacteriodes fragilis | Kingella kingae | Proteus vulgaris |
| Bacteroides caccae | Klebsiella oxytoca | Providencia rettgeri |
| Bacteroides ureolyticus | Klebsiella pneumoniae | Providencia stuartii |
| Bergeriella denitrificans | Lactobacillus acidophillus | Pseudomonas aeruginosa |
| Bifidobacterium adolescentis | Lactobacillus brevis | Pseudomonas fluorescens |
| Bifidobacterium breve | Lactobacillus crispatus | Pseudomonas putida |
| Bifidobacterium longum | Lactobacillus jensenii | Rahnella aquatilis |
| Blautia producta | Lactobacillus lactis | Respiratory syncytial virus† |
| Bordetella pertussis† | Lactobacillus leichmannii | Rhinovirus**† |
| Branhamella catarrhalis | Lactobacillus oris | Rhizobium radiobacter |
| Brevibacterium linens | Lactobacillus parabuchnerri | Rhodospirillum rubrum |
| Campylobacter coli | Lactobacillus reuteri | Saccharomyces cerevisiae |
| Campylobacter jejuni | Lactobacillus vaginalis | Salmonella choleraesuis |
| Campylobacter rectus† | Lactococcus lactis cremoris | Salmonella minnesota |
| Candida albicans | Legionella pneumophila | Salmonella typhimurium |
| Candida glabrata | Leuconostoc paramensenteroides | Serratia denitrificans |
| Candida parapsilosis | Listeria monocytogenes | Serratia marcescens |
| Candida tropicalis | Micrococcus luteus | Shigella dysenteriae |
| Chlamydophila pneumoniae | Moraxella catarrhalis† | Shigella flexneri †† |
| Chlamydophila psittaci | Moraxella lacunata | Shigella sonnei †† |
| Chromobacter violaceum | Moraxella osloensis | Staphylococcus aureus |
| Citrobacter freundii | Morganella morganii | Staphylococcus epidermidis |
| Clostridioides difficile | Mycobacterium smegmatis | Staphylococcus saprophyticus |
| Clostridium perfringens | Mycoplasma pneumoniae† | Streptococcus agalactiae |
| Coronavirus† | Mycoplasma genitalium*** | Streptococcus anginosus |

{10}

K202408 - Page 11 of 26
| Corynebacterium diphtheriae † | Mycoplasma hominis | Streptococcus bovis |
| --- | --- | --- |
| Corynebacterium genitalium | Neisseria cinerea | Streptococcus dysgalactiae |
| Corynebacterium xerosis | Neisseria elongata subsp. elongata | Streptococcus equinis |
| Cryptococcus neoformans | Neisseria elongata subsp. nitroreducens | Streptococcus mitis |
| Cytomegalovirus ** | Neisseria flava | Streptococcus mutans |
| Deinococcus radiodurans | Neisseria flavescens | Streptococcus pneumoniae |
| Derxia gummosa | Neisseria kochi | Streptococcus pyogenes |
| Eikenella corrodens | Neisseria lactamica | Streptococcus salivarius |
| Entamoeba histolytica**†† | Neisseria macacae | Streptococcus sanguis |
| Enterobacter aerogenes | Neisseria meningitides Serogroup W135 | Streptomyces griseinus |
| Enterobacter cloacae | Neisseria meningitidis Serogroup A | Tannerella forsythia† |
| Enterococcus avium | Neisseria meningitidis Serogroup B | Treponema denticola† |
| Enterococcus casseliflavus | Neisseria meningitidis Serogroup C | Trichomonas vaginalis |
| Enterococcus faecalis | Neisseria meningitidis Serogroup D | Trueperella pyogenes |
| Enterococcus faecium | Neisseria meningitidis Serogroup Y | Ureaplasma urealyticum |
| Enterovirus**†† | Neisseria mucosa | Veillonela parvula |
| Erysipelothrix rhusiopathiae | Neisseria perflava | Vibrio cholerae |
| Escherichia coli | Neisseria polysaccharea | Vibrio parahaemolyticus |
| Escherichia fergusonii | Neisseria sicca | Yersinia enterocolitica |
| Flavobacterium meningosepticum | Neisseria subflava | - |
| Fusobacterium necrophorum† | Neisseria weaverii | - |

* HPV16 was tested as CaSki cells
** Organism was tested at a concentration of 1 x 10⁴ Units/mL
*** Organism was tested at a concentration of 1 x 10⁵ CFU/mL
† Tested in oropharyngeal swabs only
†† Tested in anorectal swabs only
††† Tested in oropharyngeal and anorectal swabs only

{11}

Analytical Interference

The interference studies (endogenous and exogenous interferents) included four test samples for each specimen type, oropharyngeal swabs and rectal swabs, each collected in cobas PCR media.

- CT/NG positive specimen matrix spiked with each interfering substance
- CT/NG negative specimen matrix spiked with each interfering substance
- CT/NG negative specimen matrix without interfering substance
- CT/NG positive specimen matrix without interfering substance

CT serovars D and I, and NG strains 2948 and 891 at 3x LoD concentrations were used to prepare the positive specimens in each matrix for this study.

Each sample was tested in five replicates with each interferent.

a. Endogenous Substances

Interference from the following endogenous substances, potentially present at the oropharyngeal and rectal sites of collection, was evaluated. No evidence of interference was noted with the following substances at the concentrations shown.

Endogenous Substances Tested for Interference in Oropharyngeal and Anorectal Samples

| Interferent | Oropharyngeal Swab | Anorectal Swab |
| --- | --- | --- |
| Mucus (% w/v) | 1.0% | 1.0% |
| Peripheral Blood Mononuclear Cells (PBMCs as cells/mL) | 1.00E+06 | 1.00E+06 |
| Saliva (% w/v) | 2.0% | NT |
| Stool (% w/v) | NT | 0.3%* |
| Whole Blood (% v/v) | 10% | 10% |

*Stool caused interference at 0.4% (w/v) in anorectal swab specimens collected in cobas PCR Media
NT = Not Tested

b. Exogenous Substances

The performance of the cobas CT/NG Test was evaluated when testing oropharyngeal and rectal swabs in the presence of potentially interfering exogenous substances, e.g., over-the-counter products, that may be found at the respective sites of collection. The interferents were spiked at levels expected through typical product use. No evidence of interference was noted with the following substances at the concentrations shown.

Substances Tested for Interference in Oropharyngeal Samples

| Product Name | Oropharyngeal Swabs (mg/mL) |
| --- | --- |
| Cepacol Maximum Strength Throat Drop Lozenges | 7.5 |
| Colgate Total Toothpaste | Residual * |

K202408 - Page 12 of 26

{12}

| Product Name | Oropharyngeal Swabs (mg/mL) |
| --- | --- |
| Robitussin Cough / Chest Congestion Cough Syrup | 4.4 |
| Listerine Ultra Clean Antiseptic Mouthwash | 15.8 |
| Scope Mouthwash | 20.1 |
| Sucrets Complete Lozenges | 5.8 |
| Vicks - Chloraseptic Sore Throat Spray Menthol | 18.1 |
| Zicam Oral Mist | 12.2 |

* Amount of toothpaste present on a swab collected immediately following a subject’s brushing of their teeth

## Substances Tested for Interference in Anorectal Samples

| Product Name | Anorectal Swabs (mg/mL) |
| --- | --- |
| ANUSOL® Plus Ointment | 5.3 |
| CB Fleet® Mineral Oil Enema | 4.8 |
| Doproct Suppositories/ Hemorrhoidal Treatment | 4.9 |
| K-Y Jelly | 5.0 |
| Lotrimin Antifungal Cream | 4.2 |
| Preparation H Hemorrhoidal Ointment | 4.9 |
| PREPARATION H Hemorrhoidal Suppositories | 6.0 |
| Driminate Generic for Dramamine Motion Sickness - Major Pharmaceuticals | 0.6 |
| Target – Triple Paste Diaper Rash Ointment | 4.3 |
| Tucks Medicated Cooling Hemorrhoidal Pads | 35.6 |
| Vaseline Original Petroleum Jelly | 4.7 |

## 4. Assay Reportable Range:

Not applicable.

## 5. Sample Stability

The following specimen types were included in this study:

- Oropharyngeal swabs collected in cobas PCR media
- Anorectal swabs collected in cobas PCR media

For each matrix, individual specimens that had tested negative for both CT and NG with the cobas® 6800/8800 CT/NG Test were pooled to prepare test samples. Positive samples were prepared by spiking individual CT and NG positive specimens into the negative samples to produce Ct values of approximately 35 for both CT and NG, which correspond to concentrations of $\sim 3\mathrm{X}$ the limit of detection of the test. Five pools of positive samples and five pools of negative samples were prepared. Each sample pool was then split into two primary specimen containers which were filled to the volume of a freshly collected specimen, and placed into storage at $2 - 8^{\circ}\mathrm{C}$

K202408 - Page 13 of 26

{13}

and 32°C. The samples (5 positive and 5 negative) were tested at time 0 (baseline), and then after 3 months, 6 months, and 12 months after storage. Each timepoint was tested at least one day beyond the scheduled test date within its calendar month. There was no evidence of deterioration in positive samples based on the Ct values generated over the period of 12 months, as compared to the Ct values generated at time 0. All negative specimens tested negative at all timepoints. The data showed that oropharyngeal and anorectal swab specimens may be stored up to 12 months at either 2-8°C or 32°C prior to testing with the cobas CT/NG test.

## 6. Detection Limit:

The limit of detection of the cobas CT/NG assay, testing anorectal and oropharyngeal swabs was evaluated by testing 3 reagent lots, 3 sample dilution series and 4 cobas® 6800/8800 Systems. Testing included 23-30 replicates for each target positive level per reagent lot. The resulting data were analyzed to identify the lowest target concentration (Limit of Detection) that resulted in ≥ 95% positive rate.

The following specimen types were included in this study:

- Oropharyngeal swabs collected in cobas PCR media
- Anorectal swabs collected in cobas PCR media

Negative background was prepared for each specimen type by pooling individual specimens that had tested negative for both CT and NG with the cobas® 6800/8800 CT/NG Test.

Quantified stocks of Chlamydia trachomatis, serovars D and I, and two strains of Neisseria gonorrhoeae (2948 (ATCC 19424) and 891) were used to produce panels in each specimen type. Each panel consisted of 5 target positive levels prepared from three independent dilution series.

Test Panels used in the Limit of Detection Study

| Organism | Level 1 | | Level 2 | | Level 3 | | Level 4 | | Level 5 | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| CT Serovar D | 12 | EB/mL | 4.0 | EB/mL | 2.0 | EB/mL | 1.0 | EB/mL | 0.40 | EB/mL |
| NG #2948 | 1.2 | CFU/mL | 0.4 | CFU/mL | 0.2 | CFU/mL | 0.1 | CFU/mL | 0.04 | CFU/mL |
| CT Serovar I | 60 | EB/mL | 20 | EB/mL | 10 | EB/mL | 5.0 | EB/mL | 2.0 | EB/mL |
| NG #891 | 0.48 | CFU/mL | 0.16 | CFU/mL | 0.08 | CFU/mL | 0.04 | CFU/mL | 0.016 | CFU/mL |

EB = Elementary Bodies
CFU = Colony Forming Unit

For each target, specimen type, and reagent lot, the LoD was calculated using Probit analysis and the LoD was confirmed by testing at least 23 replicates of each dilution with three lots of reagents.

The final LoD claimed is the lowest concentration level where the detection rate was ≥ 95%, as defined by the worst performing lot tested. The summary of results is shown below.

K202408 - Page 14 of 26

{14}

Analytical Sensitivity (Limit of Detection) for Oropharyngeal and Anorectal Specimens

| Matrix | Serovar D | | Serovar I | | NG 2948 | | NG 891 | |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | Mean Ct Value | EB/mL | Mean Ct Value | EB/mL | Mean Ct Value | CFU/mL | Mean Ct Value | CFU/mL |
| Oropharyngeal Swabs | 37.3 | 2 | 36.5 | 40 | 38.0 | 0.2 | 37.3 | 0.08 |
| Anorectal Swabs | 37.2 | 2 | 37.2 | 20 | 37.0 | 0.2 | 37.2 | 0.08 |

EB = Elementary Body; CFU = Colony Forming Unit

## 7. Inclusivity

Inclusivity and verification of the LoD were performed for 14 additional CT serovars and an additional 43 independently isolated strains of NG using one lot of reagents. The following serovars were included in the study: A, B, Ba, C, E, F, G, H, j, K, LGV Type 1, LGV Type 2, LGV Type 3, and nvCT (the "Swedish variant"). Testing was performed using CT and NG cultures diluted into pools of negative specimens; each organism was tested in both, rectal and in oropharyngeal matrix. All CT serovars were tested at a concentration of 40 EB/mL, each in 20 replicates, and all tests generated positive results (100% positivity). Of the 43 NG strains tested, 39 were detected at 0.4 CFU/mL concentration in ≥19 out of 20 replicates in both matrices. Four NG strains were re-titered and re-tested at 1.0 CFU/mL, resulting in 100% detection rate.

## 8. Assay Cut-Off:

See K173887

## 9. Carry-Over:

See K173887

## 10. Matrix Comparison/Bridging Study

Because of the unique clinical study design, which included four manufacturers, where all specimens were collected in a common collection vial containing 10 mL PreservCyt medium, followed by aliquoting into each of the manufacturer's collection/transport tube, the sponsor compared analytical sensitivity of the cobas CT/NG when using swab samples collected in PreservCyt Solution and those collected with the cobas PCR Media Uni Swab Sample Kit. A bridging study was conducted to demonstrate that detection of low levels of CT and NG in extragenital swab samples collected with the cobas PCR Media Uni Swab Sample Kit was at least as sensitive as in swab samples collected in PreservCyt.

The following sample matrices were tested in this study:

K202408 - Page 15 of 26

{15}

- Oropharyngeal swabs collected and placed into PreservCyt Solution
- Oropharyngeal swabs collected using the cobas PCR Media Uni Swab Sample Kit
- Anorectal swabs collected and placed into PreservCyt Solution
- Anorectal swabs collected using the cobas PCR Media Uni Swab Sample Kit

Negative background for each sample matrix was prepared by pooling individual specimens that had tested negative for both CT and NG with the cobas 6800/8800 CT/NG Test. Quantified stocks of Chlamydia trachomatis serovar D and Neisseria gonorrhoeae strain 2948 (ATCC 19424) were spiked concurrently into each sample matrix. Each matrix panel consisted of 5 target positive levels and one negative level as shown in the table below. Each sample was tested in 20 replicates.

CT and NG Concentrations (each matrix panel)

| Organism | Level 1 (10x LOD) | Level 2 (5x LOD) | Level 3 (2.5x LOD) | Level 4 (1.25x LOD) | Level 5 (0.625x LOD) | Level 6 (Negative) |
| --- | --- | --- | --- | --- | --- | --- |
| CT | 20 EB/mL (3 IFU/mL) | 10 EB/mL (1.5 IFU/mL) | 5 EB/mL (0.75 IFU/mL) | 2.5 EB/mL (0.38 IFU/mL) | 1.25 EB/mL (0.19 IFU/mL) | Not spiked |
| NG | 2 CFU/mL | 1 CFU/mL | 0.5 CFU/mL | 0.25 CFU/mL | 0.13 CFU/mL | Not spiked |

The lowest concentration which resulted in $\geq 95\%$ detection rate ($\geq 19/20$) for each sample type in each collection medium is shown below.

Summary of results: Limit of Detection in Oropharyngeal and Anorectal Swabs

| Organism | Oropharyngeal | | | | Rectal | |
| --- | --- | --- | --- | --- | --- | --- |
| | PCR Media | PreservCyt | | | PCR Media | PreservCyt |
| | ≥95% Detection Level | | | | ≥95% Detection Level | |
| CT | 2.5 EB/mL (0.38 IFU/mL) | 10 EB/mL (1.5 IFU/mL) | | | 2.5 EB/mL (0.38 IFU/mL) | 20 EB/mL (3 IFU/mL) |
| NG | 0.25 CFU/mL | 1 CFU/mL | | | 0.5 CFU/mL | 2 CFU/mL |

The study showed that the cobas CT/NG assay is more sensitive for the detection of CT and NG when testing extragenital swab samples (oropharyngeal/throat and anorectal/rectal) collected with the cobas PCR media as compared to those collected in PreservCyt solution. The superior sensitivity of the assay when using cobas PCR media rather than the PreservCyt collection media indicates no risk of a lower sensitivity for detection of CT and NG in a clinical setting than was demonstrated in the clinical study.

## B Comparison Studies:

1. Method Comparison with Predicate Device:

See Clinical Studies section below.

2. Matrix Comparison:

K202408 - Page 16 of 26

{16}

Not applicable.

## C Clinical Studies:

The clinical performance of the cobas CT/NG test for the detection of *C. trachomatis* and *N. gonorrhoeae* in oropharyngeal (throat) and anorectal (rectum) swab specimens was established in a multi-site, prospective collection. The clinical study was uniquely designed, in collaboration and agreement between academic institutions and FDA, to facilitate the evaluation of assay performance for the detection of CT and NG infections in extragenital specimens by simultaneous comparison of the performance among four previously FDA-cleared NAATs for the detection of CT and NG in urogenital specimens.

Eight diverse clinic sites (STD, HIV, Family Planning, and STD Research), located at geographically distributed locations, were utilized for sample collection. There were 2390 subjects available for testing, representing sexually active men and women, ranging in age from 15 to 77 years old. The study population consisted of 1256 males, 1108 females, and 26 transgender individuals. Both symptomatic and asymptomatic individuals were included in the study population following informed consent.

Specimens were tested for CT and NG using cobas CT/NG and three commercially available NAATs. All tests were run according to the respective manufacturers' Instructions for Use. For each subject enrolled in the study, three swab specimens were collected from each anatomic site (rectum and throat) using the Specimen Collection Swab from the Abbott multi-Collect™ Specimen Collection Kit. Swabs from each anatomical site were subsequently placed into a common collection vial containing 10 mL PreservCyt medium. Samples were sent to a central aliquoting laboratory, where they were vortexed and transferred into each of the four manufacturer's collection/transport tube prior to being transported to a testing laboratory.

The clinical performance of cobas CT/NG testing oropharyngeal and rectal specimens was determined by comparing the results obtained with the cobas CT/NG Test to a site-specific Infection Status (IS) derived by algorithm of results from the three comparator NAATs. The anatomic site was considered to be infected if at least two of the three comparator assays, were positive (2/3 rule). The three comparator NAATs, referred to as A, B, and C in this document, were identified in the marketing submission to FDA.

### Comparator Algorithm for Determination of Infection Status for Each Specimen Type

| NAAT A | NAAT B | NAAT C | IS Interpretation |
| --- | --- | --- | --- |
| + | + | + | + |
| + | + | - | + |
| + | - | + | + |
| - | + | + | + |
| U | + | + | + |
| + | U | + | + |
| + | + | U | + |
| + | - | - | - |

K202408 - Page 17 of 26

{17}

| NAAT A | NAAT B | NAAT C | IS Interpretation |
| --- | --- | --- | --- |
| - | + | - | - |
| - | - | + | - |
| - | - | - | - |
| + | + | + | + |
| + | + | - | + |
| + | - | + | + |
| - | + | + | + |
| + | - | - | - |
| - | + | - | - |
| - | - | + | - |
| - | - | - | - |
| U | - | - | - |
| - | U | - | - |
| - | - | U | - |
| + | U | - | U |
| + or - | U | U | U |

IS = Infection status; U = Uninterpretable test result.
+ denotes Positive; - denotes Negative;

Note: Uninterpretable test results occurred when retesting of invalid or equivocal results failed to yield a positive or negative result.

A total of 2,439 subjects were consented to participate in this study, however, a total of 49 subjects were excluded, based on exclusion/inclusion criteria, that led to a total subject enrollment of 2,390.

Of the 2,390 subjects contributing specimens, there were 2365 rectal swabs and 2382 oropharyngeal swabs submitted for testing (rectal specimens from 25 subjects and oropharyngeal swabs from 8 subjects were either not collected or not aliquoted).

A total of 4794 tests were initially performed on the cobas instruments. Among those, there were 22 specimens that yielded no results in the initial run. Of those, 20 samples were re-tested of which 19 returned valid results. There were four final invalid results due to processing errors. Therefore, in total, 4814 tests were performed on the cobas instruments. The rate of invalid results observed in the study was 0.48% (23/4814, with 95% CI of 0.32%-0.72%).

1. *Chlamydia trachomatis*: Clinical Performance of the cobas CT/NG Test in Extragenital Specimens.

Of the 2365 anorectal (rectal) swabs submitted for testing, 12 samples were excluded from final data analysis due to protocol deviations and 18 subjects had uninterpretable comparator results, leaving 2,335 evaluable samples for inclusion in data analysis.

K202408 - Page 18 of 26

{18}

Similarly, of the 2382 oropharyngeal swabs submitted for testing, 11 samples were excluded from final data analysis due to protocol deviations, three oropharyngeal swabs were excluded due to the lack of final valid results from the cobas CT/NG test, and 23 subjects had uninterpretable comparator results, leaving 2,345 evaluable samples for inclusion in data analysis.

Chlamydia trachomatis: Summary of Infection Status Interpretation for Anorectal and Oropharyngeal Specimens

| Specimen Typea | NAAT A | NAAT B | NAAT C | IS^{b} Interpretation | cobas CT/NG | SS^{c} Sympd | SS^{c} Asympd | SS^{c} Unknd | Total |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| AR | Inv | + | + | Positive | + | 1 | 3 | 0 | 4 |
| AR | - | + | + | Positive | - | 0 | 3 | 0 | 3 |
| AR | - | + | + | Positive | + | 4 | 12 | 0 | 16 |
| AR | + | - | + | Positive | - | 0 | 1 | 0 | 1 |
| AR | + | + | - | Positive | + | 1 | 0 | 0 | 1 |
| AR | + | + | + | Positive | - | 2 | 1 | 0 | 3 |
| AR | + | + | + | Positive | + | 47 | 68 | 0 | 115 |
| AR | | | | Total Positive | | 55 | 88 | 0 | 143 |
| AR | Inv | - | - | Negative | - | 29 | 45 | 1 | 75 |
| AR | - | NA | - | Negative | - | 7 | 2 | 3 | 12 |
| AR | - | NA | - | Negative | + | 0 | 1 | 0 | 1 |
| AR | - | Inv | - | Negative | - | 3 | 3 | 0 | 6 |
| AR | - | - | Inv | Negative | - | 0 | 1 | 0 | 1 |
| AR | - | - | Inv | Negative | + | 1 | 0 | 0 | 1 |
| AR | - | - | - | Negative | - | 635 | 1,411 | 13 | 2,059 |
| AR | - | - | - | Negative | + | 5 | 2 | 0 | 7 |
| AR | - | - | + | Negative | - | 4 | 12 | 0 | 16 |
| AR | - | - | + | Negative | + | 0 | 6 | 0 | 6 |
| AR | - | + | - | Negative | - | 1 | 5 | 0 | 6 |
| AR | - | + | - | Negative | + | 1 | 1 | 0 | 2 |
| AR | | | | Total Negative | | 686 | 1,489 | 17 | 2,192 |
| OP | Inv | + | + | Positive | + | 0 | 1 | 0 | 1 |
| OP | - | + | + | Positive | + | 1 | 2 | 0 | 3 |
| OP | + | + | - | Positive | + | 0 | 1 | 0 | 1 |
| OP | + | + | + | Positive | + | 8 | 15 | 0 | 23 |
| OP | | | | Total Positive | | 9 | 19 | 0 | 28 |
| OP | Inv | - | - | Negative | - | 32 | 46 | 1 | 79 |
| OP | - | NA | - | Negative | - | 5 | 7 | 2 | 14 |
| OP | - | Inv | - | Negative | - | 1 | 6 | 0 | 7 |
| OP | - | - | Inv | Negative | - | 1 | 0 | 0 | 1 |
| OP | - | - | - | Negative | - | 679 | 1,486 | 14 | 2,179 |
| OP | - | - | - | Negative | + | 2 | 0 | 0 | 2 |
| OP | - | - | + | Negative | - | 13 | 16 | 0 | 29 |
| OP | - | + | - | Negative | - | 1 | 1 | 0 | 2 |
| OP | - | + | - | Negative | + | 0 | 2 | 0 | 2 |
| OP | + | - | - | Negative | - | 1 | 1 | 0 | 2 |
| OP | | | | Total Negative | | 735 | 1,565 | 17 | 2,317 |

aAR = Anorectal; OP=Oropharyngeal
b IS = Infection Status.
cSS = Symptom Status;
$^{\mathrm{d}}$ Symp = Symptomatic, Asymp = Asymptomatic, Unkn = Unknown symptom status.

K202408 - Page 19 of 26

{19}

Note: NA = Not available, Inv = Invalid.

Note: Infection Status (IS) is determined for each specimen type. The IS of a sample was established by the concordance results from at least 2 out of 3 comparator assays (NAAT A, NAAT B, NAAT C). If one of the comparator assays is Uninterpretable/Invalid/Failed, the two remaining assays must be concordant to define the IS as Positive (+) or Negative (-). Any other combination of Uninterpretable/Invalid/Failed and valid results are excluded from the analyses.

Note: Of the 2,365 contributing subjects for Rectum, 18 subjects had CT uninterpretable IS (3 samples were discordant between the two available comparator assay results). Similarly, of the 2,382 contributing subjects for Oropharyngeal, 23 subjects had CT uninterpretable IS (7 samples were discordant between the two available comparator assay results).

Note: Any IS interpretation that is Uninterpretable/Invalid/Failed/Protocol deviations are excluded from performance analyses.

The overall point estimate sensitivity of cobas CT/NG for CT detection in anorectal specimens was 95.1% with a 95% CI of 90.2% to 97.6%. The overall point estimate specificity of cobas CT/NG for CT detection in anorectal specimens was 99.2% with a 95% CI of 98.8% to 99.5%.

C. trachomatis Clinical Performance in Anorectal Specimens

| CT in Rectal Swabs | | Infection Status (composite algorithm) | |
| --- | --- | --- | --- |
| | | Positive | Negative |
| Cobas CT/NG Test | Positive | 136 | 17 |
| | Negative | 7 | 2175 |
| Total | | 143 | 2192 |
| Sensitivity: 95.1% (136/143; 95% CI: (90.2%-97.6%) | | | |
| Specificity: 99.2% (2175/2192); 95% CI: (98.8%-99.5%) | | | |

The overall point estimate sensitivity of cobas CT/NG for CT detection in oropharyngeal specimens was 100% with a 95% CI of 87.9% to 100%. The overall point estimate specificity of cobas CT/NG for CT detection in oropharyngeal specimens was 99.8% with a 95% CI of 99.6% to 99.9%.

C. trachomatis Clinical Performance in Oropharyngeal Specimens

| CT in Throat Swabs | | Infection Status (composite algorithm) | |
| --- | --- | --- | --- |
| | | Positive | Negative |
| Cobas CT/NG Test | Positive | 28 | 4 |
| | Negative | 0 | 2313 |
| Total | | 28 | 2317 |
| Sensitivity: 100.0% (28/28); 95% CI: (87.9%-100.0%) | | | |
| Specificity: 99.8% (2313/2317); 95% CI: (99.6%-99.9%) | | | |

The cobas CT/NG clinical performance for C. trachomatis, by sample type and symptom status, is shown below.

K202408 - Page 20 of 26

{20}

Chlamydia trachomatis: Clinical Performance in Extragenital Specimens, by Sample Type and Symptom Status

| Sample Type^{a} | Symptom Status^{b} | Total (N) | SENS | 95% Score CI | SPEC | 95% Score CI |
| --- | --- | --- | --- | --- | --- | --- |
| AR | Symp | 741 | 96.4% (53/55) | (87.7%, 99.0%) | 99.0% (679/686) | (97.9%, 99.5%) |
| AR | Asymp | 1,577 | 94.3% (83/88) | (87.4%, 97.5%) | 99.3% (1479/1489) | (98.8%, 99.6%) |
| AR | Unknown | 17 | NE | NE | 100.0% (17/17) | (81.6%, 100.0%) |
| AR | Overall | 2,335 | 95.1% (136/143) | (90.2%, 97.6%) | 99.2% (2175/2192) | (98.8%, 99.5%) |
| OP | Symp | 744 | 100.0% (9/9) | (70.1%, 100.0%) | 99.7% (733/735) | (99.0%, 99.9%) |
| OP | Asymp | 1,584 | 100.0% (19/19) | (83.2%, 100.0%) | 99.9% (1563/1565) | (99.5%, 100.0%) |
| OP | Unknown | 17 | NE | NE | 100.0% (17/17) | (81.6%, 100.0%) |
| OP | Overall | 2,345 | 100.0% (28/28) | (87.9%, 100.0%) | 99.8% (2313/2317) | (99.6%, 99.9%) |

aAR = Anorectal; OP=Oropharyngeal
bSymp = Symptomatic, Asymp = Asymptomatic, Unkn = Unknown symptom status
Note: CI = Confidence Interval NE = Non-estimable

2. Neisseria gonorrhoeae: Clinical Performance of the cobas CT/NG Test in Extragenital Specimens.

Of the 2365 anorectal (rectal) swabs submitted for testing, 12 samples were excluded from final data analysis due to protocol deviations and 15 subjects had uninterpretable comparator results, leaving 2,338 evaluable samples for inclusion in data analysis.

Similarly, of the 2382 oropharyngeal swabs submitted for testing, 11 samples were excluded from final data analysis due to protocol deviations, three oropharyngeal swabs were excluded due to the lack of final valid results from the cobas CT/NG test, and 19 subjects had uninterpretable comparator results, leaving 2,349 evaluable samples for inclusion in data analysis.

K202408 - Page 21 of 26

{21}

Neisseria gonorrhoeae: Summary of Infection Status Interpretation for Anorectal and Oropharyngeal Specimens

| Specimen Typea | NAAT A | NAAT B | NAAT C | IS^{b} Interpretation | cobas CT/NG | SS^{d} Symp^{c} | SS^{d} Asymp^{c} | SS^{d} Unkn^{c} | Total |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| AR | Inv | + | + | Positive | + | 2 | 0 | 0 | 2 |
| AR | - | + | + | Positive | - | 1 | 0 | 0 | 1 |
| AR | - | + | + | Positive | + | 3 | 4 | 0 | 7 |
| AR | + | NA | + | Positive | + | 0 | 1 | 0 | 1 |
| AR | + | Inv | + | Positive | + | 0 | 1 | 0 | 1 |
| AR | + | - | + | Positive | + | 0 | 1 | 0 | 1 |
| AR | + | + | + | Positive | + | 37 | 50 | 1 | 88 |
| AR | | | | Total Positive | | 43 | 57 | 1 | 101 |
| AR | Inv | - | - | Negative | - | 27 | 50 | 1 | 78 |
| AR | Inv | - | - | Negative | + | 1 | 0 | 0 | 1 |
| AR | - | NA | - | Negative | - | 7 | 2 | 3 | 12 |
| AR | - | Inv | - | Negative | - | 3 | 2 | 0 | 5 |
| AR | - | - | - | Negative | - | 646 | 1,461 | 12 | 2,119 |
| AR | - | - | - | Negative | + | 3 | 3 | 0 | 6 |
| AR | - | - | + | Negative | - | 5 | 0 | 0 | 5 |
| AR | - | - | + | Negative | + | 6 | 1 | 0 | 7 |
| AR | - | + | - | Negative | - | 0 | 2 | 0 | 2 |
| AR | + | - | - | Negative | - | 0 | 1 | 0 | 1 |
| AR | + | - | - | Negative | + | 1 | 0 | 0 | 1 |
| AR | | | | Total Negative | | 699 | 1,522 | 16 | 2,237 |
| OP | Inv | + | + | Positive | + | 1 | 1 | 0 | 2 |
| OP | - | + | + | Positive | + | 9 | 8 | 0 | 17 |
| OP | + | NA | + | Positive | + | 0 | 1 | 0 | 1 |
| OP | + | Inv | + | Positive | + | 0 | 1 | 0 | 1 |
| OP | + | - | + | Positive | + | 1 | 2 | 0 | 3 |
| OP | + | + | - | Positive | + | 0 | 1 | 0 | 1 |
| OP | + | + | + | Positive | + | 41 | 30 | 0 | 71 |
| OP | | | | Total Positive | | 52 | 44 | 0 | 96 |
| OP | Inv | - | - | Negative | - | 30 | 53 | 1 | 84 |
| OP | - | NA | - | Negative | - | 5 | 6 | 2 | 13 |
| OP | - | Inv | - | Negative | - | 0 | 5 | 0 | 5 |
| OP | - | - | Inv | Negative | - | 2 | 0 | 0 | 2 |
| OP | - | - | Inv | Negative | + | 1 | 0 | 0 | 1 |
| OP | - | - | - | Negative | - | 631 | 1,452 | 13 | 2,096 |
| OP | - | - | - | Negative | + | 6 | 7 | 1 | 14 |
| OP | - | - | + | Negative | - | 4 | 3 | 0 | 7 |
| OP | - | - | + | Negative | + | 4 | 4 | 0 | 8 |
| OP | - | + | - | Negative | - | 5 | 15 | 0 | 20 |
| OP | - | + | - | Negative | + | 0 | 1 | 0 | 1 |
| OP | + | - | - | Negative | - | 1 | 0 | 0 | 1 |
| OP | + | - | - | Negative | + | 0 | 1 | 0 | 1 |
| OP | | | | Total Negative | | 689 | 1,547 | 17 | 2,253 |

aAR = Anorectal; OP = Oropharyngeal.
bIS= Infection Status
cSymp = Symptomatic, Asymp = Asymptomatic, Unkn = Unknown symptom status.
dSS=Symptom Status

K202408 - Page 22 of 26

{22}

Note: NA = Not available, Inv = Invalid.

Note: Infection Status (IS) is determined for each specimen type. The IS of a sample was established by the concordance results from at least 2 out of 3 comparator assays (NAAT A, NAAT B, NAAT C). If one of the comparator assays is Uninterpretable/Invalid/Failed, the two remaining assays must be concordant to define the IS as Positive (+) or Negative (-). Any other combination of Uninterpretable/Invalid/Failed and valid results are excluded from the analyses.

Note: Of the 2,365 contributing subjects for Rectum, 15 subjects had NG uninterpretable IS. Similarly, of the 2,382 contributing subjects for Oropharyngeal, 19 subjects had NG uninterpretable IS (4 samples were discordant between the two available comparator assay results).

Note: Any IS interpretation that is Uninterpretable/Invalid/Failed/Protocol deviations are excluded from performance analyses.

The overall point estimate sensitivity of cobas CT/NG for NG detection in anorectal specimens was 99.0% with a 95% CI of 94.6% to 99.8%. The overall point estimate specificity of cobas CT/NG for NG detection in anorectal specimens was 99.3% with a 95% CI of 98.9% to 99.6%.

N. gonorrhoeae Clinical Performance in Anorectal Specimens

| NG in Rectal Swabs | | Infection Status (composite algorithm) | |
| --- | --- | --- | --- |
| | | Positive | Negative |
| Cobas CT/NG Test | Positive | 100 | 15 |
| | Negative | 1 | 2222 |
| Total | | 101 | 2237 |
| Sensitivity: 99.0% (100/101); 95% CI: (94.6%-99.8%) | | | |
| Specificity: 99.3% (2222/2237); 95% CI: (98.9%-99.6%) | | | |

The overall point estimate sensitivity of cobas CT/NG for NG detection in oropharyngeal specimens was 100% with a 95% CI of 96.2% to 100%. The overall point estimate specificity of cobas CT/NG for NG detection in oropharyngeal specimens was 98.9% with a 95% CI of 98.4% to 99.3%.

N. gonorrhoeae Clinical Performance in Oropharyngeal Specimens

| NG in Throat Swabs | | Infection Status (composite algorithm) | |
| --- | --- | --- | --- |
| | | Positive | Negative |
| Cobas CT/NG Test | Positive | 96 | 25 |
| | Negative | 0 | 2228 |
| Total | | 96 | 2253 |
| Sensitivity: 100.0% (96/96); 95% CI: (96.2%-100.0%) | | | |
| Specificity: 98.9% (2228/2253); 95% CI: (98.4%-99.3%) | | | |

The cobas CT/NG clinical performance for N. gonorrhoeae, by sample type and symptom status, is shown below.

K202408 - Page 23 of 26

{23}

N. gonorrhoeae: Clinical Performance in Extragenital Specimens, by Sample Type and Symptom Status

| Sample Type^{a} | Symptom Status^{b} | Total (N) | SENS | 95% Score CI | SPEC | 95% Score CI |
| --- | --- | --- | --- | --- | --- | --- |
| AR | Symp | 742 | 97.7% (42/43) | (87.9%, 99.6%) | 98.4% (688/699) | (97.2%, 99.1%) |
| AR | Asymp | 1,579 | 100.0% (57/57) | (93.7%, 100.0%) | 99.7% (1518/1522) | (99.3%, 99.9%) |
| AR | Unknown | 17 | 100.0% (1/1) | (20.7%, 100.0%) | 100.0% (16/16) | (80.6%, 100.0%) |
| AR | Overall | 2,338 | 99.0% (100/101) | (94.6%, 99.8%) | 99.3% (2222/2237) | (98.9%, 99.6%) |
| OP | Symp | 741 | 100.0% (52/52) | (93.1%, 100.0%) | 98.4% (678/689) | (97.2%, 99.1%) |
| OP | Asymp | 1,591 | 100.0% (44/44) | (92.0%, 100.0%) | 99.2% (1534/1547) | (98.6%, 99.5%) |
| OP | Unknown | 17 | NE | NE | 94.1% (16/17) | (73.0%, 99.0%) |
| OP | Overall | 2,349 | 100.0% (96/96) | (96.2%, 100.0%) | 98.9% (2228/2253) | (98.4%, 99.2%) |

aAR = Anorectal; OP=Oropharyngeal
bSymp = Symptomatic, Asymp = Asymptomatic, Unkn = Unknown symptom status
Note: CI = Confidence Interval, NE = Non-estimable

D Clinical Cut-Off:

Not applicable.

E Expected Values/Reference Range:

The observed positivity rate for C. trachomatis during the clinical study, as determined by the cobas CT/NG Test, was 1.4% and 6.6% for oropharyngeal and anorectal swabs, respectively. The positivity rate for CT for each site and overall is shown below.

CT Positivity Rate as Determined by cobas CT/NG for Oropharyngeal and Anorectal Specimens

| Collection Site ID | OP^{a} No. of Samples Tested with cobas valid results (N) | OP^{a} No. of Positive Results by cobas CT/NG (n) | OP^{a} Positivity Rate (%)^{c} (n/N) | AR^{b} No. of Samples Tested (N) | AR^{b} No. of Positive Results by cobas CT/NG (n) | AR^{b} Positivity Rate (%)^{c} (n/N) |
| --- | --- | --- | --- | --- | --- | --- |
| 10 | 170 | 2 | 1.2% | 170 | 6 | 3.5% |
| 11 | 90 | 1 | 1.1% | 89 | 4 | 4.5% |
| 12 | 388 | 6 | 1.5% | 385 | 49 | 12.7% |
| 13 | 171 | 1 | 0.6% | 170 | 3 | 1.8% |
| 14 | 259 | 2 | 0.8% | 256 | 18 | 7.0% |

K202408 - Page 24 of 26

{24}

| Collection Site ID | OPa
No. of Samples Tested with cobas valid results (N) | OPa
No. of Positive Results by cobas CT/NG (n) | OPa
Positivity Rate (%)^{c} (n/N) | AR^{b}
No. of Samples Tested (N) | AR^{b}
No. of Positive Results by cobas CT/NG (n) | AR^{b}
Positivity Rate (%)^{c} (n/N) |
| --- | --- | --- | --- | --- | --- | --- |
| 15 | 433 | 10 | 2.3% | 426 | 36 | 8.5% |
| 16 | 394 | 6 | 1.5% | 395 | 19 | 4.8% |
| 17 | 457 | 5 | 1.1% | 456 | 21 | 4.6% |
| Total | 2362 | 33 | 1.4% | 2347 | 156 | 6.6% |

a OP= Oropharyngeal / Throat specimen type.
b AR= Anorectal specimen type.
c Positivity Rate (%) = (Number of valid Positive cobas results/Total number of cobas valid results) x100.

Similarly, the observed positivity rate for *N. gonorrhoeae*, as determined by the cobas CT/NG test, was 5.2% and 4.9% for oropharyngeal and anorectal swabs, respectively. The positivity rate for NG for each site and overall is shown below.

**NG Positivity Rate as Determined by cobas CT/NG for Oropharyngeal and Anorectal Specimens**

| Collection Site ID | OPa
No. of Samples Tested with cobas valid results (N) | OPa
No. of Positive Results by cobas CT/NG (n) | OPa
Positivity Rate (%)^{c} (n/N) | AR^{b}
No. of Samples Tested (N) | AR^{b}
No. of Positive Results by cobas CT/NG (n) | AR^{b}
Positivity Rate (%)^{c} (n/N) |
| --- | --- | --- | --- | --- | --- | --- |
| 10 | 170 | 6 | 3.5% | 170 | 4 | 2.4% |
| 11 | 90 | 7 | 7.8% | 89 | 4 | 4.5% |
| 12 | 388 | 51 | 13.1% | 385 | 48 | 12.5% |
| 13 | 171 | 0 | 0% | 170 | 3 | 1.8% |
| 14 | 259 | 21 | 8.1% | 256 | 18 | 7.0% |
| 15 | 433 | 14 | 3.2% | 426 | 15 | 3.5% |
| 16 | 394 | 10 | 2.5% | 395 | 8 | 2.0% |
| 17 | 457 | 14 | 3.1% | 456 | 15 | 3.3% |
| Total | 2362 | 123 | 5.2% | 2347 | 115 | 4.9% |

a OP= Oropharyngeal / Throat specimen type.
b AR= Anorectal specimen type.
c Positivity Rate (%) = (Number of valid Positive cobas results/Total number of cobas valid results) x100.

## F Other Supportive Instrument Performance Characteristics Data:

Refer to K173887 for details on the instrument operation and the applicable software.

K202408 - Page 25 of 26

{25}

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.

K202408 - Page 26 of 26