The COBAS AMPLICOR™ Chlamydia trachomatis (CT) Test is a qualitative in vitro diagnostic test for the detection of Chlamydia trachomatis in clinical specimens on the COBAS AMPLICOR analyzer. The test utilizes the Polymerase Chain Reaction (PCR) nucleic acid amplification technique and nucleic acid hybridization for the detection of Chlamvdia trachomatis plasmid DNA in endocervical, urethral (male), and urine (male) samples.

Device Description

The Roche COBAS AMPLICOR™ Chlamydia trachomatis test performed on the COBAS AMPLICOR analyzer is an automated modification of the Roche AMPLICOR Chlamydia trachomatis Microwell Plate Test performed using the Perkin Elmer 9600 thermal cycler and a conventional photometric microwell plate reader (K922906/C). The AMPLICOR™ Chlamydia trachomatis Test was previously shown to be substantially equivalent to tissue culture with immunofluorescent staining for the detection of Chlamydia trachomatis in urogenital swab and male urine The AMPLICOR Chlamydia trachomatis Test has been modified to allow the automation of the samples. amplification and detection test procedure using the COBAS AMPLICOR analyzer. Specimen collection, transport and processing and target amplification with the COBAS AMPLICOR Chlamydia Test are identical to the AMPLICOR Chlamydia Trachomatis Test. COBAS AMPLICOR and microwell AMPLICOR Chlamydia Trachomatis Test detection reagents inentical probes using the appropriate solid support. The clinical and non-clinical performance of the COBAS AMPLICOR Chlamydia Test is substantially equivalent to the AMPLICOR Chlamydia Trachomatis Test.

AI/ML Overview

Here's a breakdown of the acceptance criteria and the study details for the COBAS AMPLICOR Chlamydia Trachomatis Test, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The document primarily focuses on demonstrating substantial equivalence to a predicate device rather than setting explicit, numerical acceptance criteria for a new device. However, based on the non-clinical and clinical performance sections, we can infer some criteria and the device's reported performance against them.

Acceptance Criteria (Inferred)	Reported Device Performance
Non-Clinical:
Analytical Sensitivity (Limit of Detection)	1 Inclusion Forming Unit (IFU) for all 15 Chlamydia serovars.
Analytical Specificity (No cross-reactivity with other organisms)	No organism (from a panel of 105 bacteria, yeasts, and viruses) gave a result greater than 0.016 Assn. (Absorbance). Consistent with predicate device.
Reproducibility (Across operators, days, and analyzers)	For samples spiked at various IFU/PCR Test levels, and positive/negative controls, all test results were 100% correct. Variance analysis (Between Day, Between Operator, Within Operator, Total Variance) showed low CVs, generally below 7% for positive samples and controls, and higher for very low/negative samples where the measurement is near zero.
Clinical:
Substantial Equivalence to Predicate Device (AMPLICOR Chlamydia Trachomatis Test) in Clinical Performance	Equivalent results were obtained for 639 clinical specimens (266 endocervical, 93 male urethral, 280 male urine). The provided table shows high concordance. For example: - Female Swabs (Culture Positive): COBAS Positive: 19, COBAS Negative: 0 (1 false positive by COBAS, 1 inconclusive by MOMP, 2* by MOMP, 0 false negative by COBAS). - Male Swabs (Culture Positive): COBAS Positive: 13, COBAS Negative: 0 (0 false positive/negative by COBAS). - Male Urine (Culture Positive): COBAS Positive: 32, COBAS Negative: 2 (2 false positive by COBAS, 3 false negative by COBAS). Note: Detailed sensitivity/specificity calculations are not presented, but the data is presented to show high agreement.

2. Sample Size Used for the Test Set and Data Provenance

Non-Clinical (Reproducibility):
- Test Samples: Swab samples spiked with Chlamydia at four levels (50, 10, 1, 0 IFU/PCR), plus positive and negative kit controls, and six patient samples spanning the reportable range.
- Replicates: 24 samples per test run, two complete A-tube rings. 27 total replicates for each spiked level and control (implying 3 operators * 3 days * 3 runs, or a similar configuration to achieve 27 total replicates per condition).
- Data Provenance: Not explicitly stated, but likely from an in-house laboratory setting (Roche Molecular Systems, Inc., Somerville, New Jersey). Retrospective or prospective nature is not specified, but the controlled spiking suggests a prospective experimental design for reproducibility.
Clinical Performance:
- Test Set Sample Size: 639 clinical specimens.
  - 266 endocervical swabs (female)
  - 93 male urethral swabs
  - 280 male urine specimens
- Data Provenance: Not explicitly stated regarding country of origin, but it's clinical data presumably collected for this study or a similar comparative validation. The nature (retrospective/prospective) is not specified, though for a comparative study against a predicate, it could be either.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

Non-Clinical (Reproducibility): Ground truth was established by spiking known quantities of Chlamydia organisms (IFU/PCR) into negative samples, or by using known positive/negative controls. No external experts or adjudication for ground truth were explicitly mentioned beyond the device's inherent ability to detect these known quantities. The "operators" performed the tests but did not establish the ground truth itself in this section.
Clinical Performance: The "ground truth" for the clinical study appears to be defined by a combination of Culture and MOMP (Major Outer Membrane Protein) alternative primer pair testing for the predicate device, which is acting as the reference standard here.
- The document does not specify the number of experts or their qualifications involved in performing the "Culture" method or "MOMP alternative primer pair testing." These are laboratory techniques, and their accuracy depends on standardized protocols and trained laboratory personnel, rather than expert "adjudication" in the same sense as image interpretation.

4. Adjudication Method for the Test Set

Non-Clinical (Reproducibility): No adjudication method described; the ground truth was inherently known (spiked samples, kit controls).
Clinical Performance: No explicit adjudication method is described for discrepancies between the two tests in the clinical performance table in the typical sense of expert review. The table notes "inconclusive results by MOMP alternative primer pair testing" and "COBAS negative on repeat testing," suggesting internal procedures for resolving certain outcomes, but not a formal adjudication by a panel of experts. The comparison is done against the results of the predicate device (AMPLICOR) using culture and MOMP.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs without AI Assistance

No, an MRMC comparative effectiveness study was not done. This device is a molecular diagnostic test (PCR), not an imaging device or AI system that involves human readers interpreting results. Therefore, the concept of "human readers improving with AI vs. without AI assistance" is not applicable here.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

The device itself is a standalone diagnostic test kit and automated analyzer system. The "algorithm" here refers to the PCR amplification and hybridization detection process performed by the COBAS AMPLICOR system. The clinical performance study directly evaluates this standalone performance against a predicate device and established diagnostic methods (culture, MOMP). There is no "human-in-the-loop" component for interpretation; the machine provides a qualitative (positive/negative) result.

7. The Type of Ground Truth Used

Non-Clinical (Reproducibility): Controlled spiking of known quantities of C. trachomatis (IFU/PCR) into negative samples, and commercially prepared positive and negative kit controls.
Clinical Performance:
- Culture Positive/Negative: This refers to traditional tissue culture with immunofluorescent staining, which was previously shown to be the reference method for the predicate device.
- MOMP Positive/Negative: This refers to the use of an alternative primer pair testing for the Major Outer Membrane Protein (MOMP) of C. trachomatis. This is another molecular method used to confirm or resolve certain results, particularly in cases of initial discrepancy or low prevalence.

8. The Sample Size for the Training Set

The document describes the COBAS AMPLICOR Chlamydia Trachomatis Test as an automated modification of an existing, already validated test (AMPLICOR Chlamydia Trachomatis Microwell Plate Test). It doesn't use a "training set" in the context of machine learning or AI. Instead, the "training" for such a system would involve optimizing the assay parameters (e.g., thermal cycle profile) to achieve equivalent performance.
The original AMPLICOR Chlamydia Trachomatis Microwell Plate Test itself would have undergone its own development and validation, which would involve experimental optimization. The current submission focuses on demonstrating that the modification (automation) maintains equivalence. Thus, there isn't a "training set" in the common sense for this type of device.

9. How the Ground Truth for the Training Set Was Established

As noted above, there isn't a "training set" in the AI/ML sense. The "ground truth" for the development and optimization of the original AMPLICOR test (which this device is a modification of) would have been established through a combination of:
- Known bacterial cultures (reference strains and clinical isolates).
- Clinical samples characterized by established reference methods like tissue culture with immunofluorescent staining.
- Spiking studies.
- Analytical characterization (sensitivity, specificity) against other organisms.

The focus of this 510(k) submission is on demonstrating that the new automated platform, while having some modifications, performs equivalently to the already cleared predicate device, which itself was proven substantially equivalent to tissue culture.

Summary

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K964507

Roche Molecular Systems, Inc. Somerville, New Jersey 08876 COBAS AMPLICOR ™ Chlamydia Trachomatis Test 510(k) Summary

510(k) Summary

JUN 1 3 1997

Roche COBAS AMPLICOR™ Chlamydia trachomatis Test Roche Molecular Systems, Inc. 1080 U.S. Highway 202 Somerville, New Jersey 08876-1760 (908) 253-7200

Intended Use:

Description of the Device:

Similarities and Differences to Predicate Device:

The COBAS AMPLICOR Chlamydia trachomatis Test is similar in design, reagent composition, function and intended use to the commercial microwell plate format AMPLICOR Chlamydia trachomatis Test (K922906/C). The COBAS AMPLICOR Chlamydia trachomatis Test uses without modification the AMPLICOR Chlamydia trachomatis Test STD Swab Specimen Collection and Transport Kit, the AMPLICOR STD Swab and the Urine Specimen Preparation Kits for specimen collection, specimen preparation and PCR amplification (see Table 1). The COBAS AMPLICOR Detection Kit reagents are similar in function and formulation to those in the AMPLICOR Chlanydia trachomatis Detection Test. The solid support for the DNA detection probe has been changed from a polystyrene microwell plate to magnetic microparticles to permit automation of the detection on the COBAS AMPLICOR.

Similarities

AMPLICOR STD Specimen Collection and Transport Kit (P/N 83075) for the collection and transport of male ー and female swab specimens.
AMPLICOR STD Specimen Preparation Kits (PN 83002 and 83006) for the processing of swab and urine specimens.
AMPLICOR CT Amplification Kit (P/N 83008). -
Identical biotinylated primers (CP24 and CP27) for defining the CT DNA target sequence for amplification.

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Hybridization of biotinylated amplicon generated in the PCR reaction to the same CP35 CT-specific DNA probe
Identical Detection Reagent formulations (Denaturation Solution, Substrate B and 10-X Wash -Concentrate)
Identical detections based on the measurement chromophore absorbance following oxidation of -3,3',5,5'-tetramethybenzidine by horseradish peroxidase in the presence of hydrogen peroxide.

Differences

Automated pipetting of amples and reagent, washing, thermal cycling, hybridization and detection steps of the test procedure.
-The avidin-HRP Conjugate Buffer in the COBAS AMPLICOR Chlamydia trachomatis Test contains bovine serum albumin compared to bovine gamma globulin in the AMPLICOR Chlamydia trachomatis MWP Test.
Change of solid support from polystyrene microwell plate to magnetic microparticles, -
Slightly modified thermal cycle profile for the COBAS AMPLICOR to give equivalent performance to the -Perkin Elmer 9600 thermal cycler.
No Stop Reagent is required with the COBAS AMPLICOR assay. Since the automated analyzer precisely times each step of the hybridization and detection procedures, it is not necessary to add Stop Reagent at the conclusion of the substrate incubation step. Accordingly, the optical density of the oxidation products from the detection reaction is measured at 660 nm in the COBAS AMPLICOR Chlamydia trachomatis Test as compared to 450 nm in the AMPLICOR Chlamydia trachomatis MWP Test system since the Stop Reagent modifies the oxidation state of the TMB reaction product, from the detection, shifting the absorbance maximum of the chromophore from 660 nm to 450 nm.

Non-Clinical Performance:

The analytical sensitivity (limit of detection) of the COBAS AMPLICOR Chlamydia trachomatis Test is 1 Inclusion Forming Unit for all 15 Chlamydia serovars (A, B, Ba, C, D, E, F, G, H, I, J, K, L1, L2, L3). The analytical specificity for the AMPLICOR Chlamydia trachomatis Test was evaluated using 105 bacteria, yeasts and viruses. No organism gave a result greater than 0.016 Assn. These results are consistent with those observed for the AMPLICOR Chlamvdia Trachomatis Test.

The reproducibility of the Roche COBAS AMPLICOR Chlamvatis Test on the COBAS AMPLICOR analyzer was determined in a multi-operator analysis of swab samples spiked with Chlamydia organism at four levels. AMPLICOR C. trachomatis positive and negative kit controls, and six patient samples spanning the reportable range for the assay (24 samples per test run; two complete A-tube rings). Samples were analyzed by independent operators for three days using three different analyzers. The test results for all samples (STM specimens spiked at 50, 10, 1 and 0 IFUPCR, positive and negative kit controls, and the patient specimens) were 100% correct. The reproducibility of the assay was calculated from the absorbance values obtained from the replicates of the spiked STM specimens and the Kit Controls. The Analysis of Variance calculations for these data are provided in Table 2.

Clinical Performance:

The comparative clinical performance between the COBAS AMPLICOR Chlanydia trachomatis Test and the AMPLICOR Chlamydia Trachomatis Test was determined using 639 clinical specimens (266 endocervical swabs, 93 male urethral swabs, and 280 male urine specimens). Equivalent results were obtained for specimens tested by the two test procedures.

March 31, 1997

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PRECISION	TEST SAMPLE
MEASUREMENT	C. trachomatis Spiked STM (IFU/PCR Test)	Kit Controls
	0	1	10	50	Negative	Positive
Total Replicates	27	27	27	27	27	27
Mean Absorbance	0.004	3.856	3.685	3.639	0.004	3.831
Minimum	0.000	3.646	3.220	3.220	0.000	3.279
Maximum	0.017	4.000	4.000	4.000	0.011	4.000
Between Day Variance	0.0000	0.0000	0.0040	0.0037	0.0000	0.0022
Standard Deviation	0.0013	0.0000	0.0632	0.0610	0.0000	0.0468
CV (%)	32.0	0.0	1.7	1.7	0.0	1.2
Between Operator Variance	0.0000	0.0145	0.0271	0.0230	0.0000	0.0587
Standard Deviation	0.0029	0.1206	0.1647	0.1517	0.0027	0.2422
CV (%)	72.4	3.1	4.5	4.2	69.7	6.3
Within Operator Variance	0.0000	0.0059	0.0162	0.0125	0.0000	0.0109
Standard Deviation	0.0035	0.0767	0.1274	0.1118	0.0026	0.1045
CV (%)	87.0	2.0	3.5	3.1	67.4	2.7
Total Variance	0.0000	0.0204	0.0474	0.0392	0.0000	0.0718
Standard Deviation	0.0047	0.1429	0.2176	0.1980	0.0037	0.2679
CV (%)	117.6	3.7	5.9	5.4	97.0	7.0

TABLE I COBAS AMPLICOR Chlamydia trachomatis Test Reproducibility Analysis of Variance - Statistical Summary

TABLE 2 Comparative Clinical Performance COBAS AMPLICOR vs AMPLICOR Chlamydia Trachomatis Test

	Culture Positive		Culture Negative
	AMPLICORPositive	AMPLICORNegative	MOMPPositive	MOMPNegative	AMPLICORNegative
FEMALE SWABS
COBAS Positive	19	1	13	2*	0
COBAS Negative	0	1	0	1	229
MALE SWABS
COBAS Positive	13	0	3	0	1**
COBAS Negative	0	0	0	0	76
MALE URINE
COBAS Positive	32	2	30	1	2
COBAS Negative	2	3	3	0	202

inconclusive results by MOMP alternative primer pair testing

** COBAS negative on repeat testing

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Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is a stylized symbol that resembles a human figure in profile, with three overlapping heads or faces. The logo is rendered in black and white.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

JUN 1 3 1997

Alex Wesolowski Director, Regulatory and Clinical Affairs Roche Molecular Systems, Inc. . . . . . 1080 U.S. Highway 202 Branchburg, NJ 08876-1760

"Re: K964507

Trade Name: Roche Cobas Amplicor™ Chlamydia Trachomatis Test Regulatory Class: I Product Code: MKZ Dated: November 7, 1996 Received: November 8, 1996

Dear Mr. Wesolowski:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent to devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Good Manufacturing Practice for Medical Devices: General (GMP) regulation (21 CFR Part 820) and that, through periodic GMP inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to complv with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

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Page 2

Under the Clinical Laboratory Improvement Amendments of 1988 (CLIA-88), this device may require a CLIA complexity categorization. To determine if it does, you should contact the Centers for Disease Control and Prevention (CDC) at (770)488-7655.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll free number (800) 638-2041 or at (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html"

Sincerery yours.

Steven Sutman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Page_ 1 of 1

510(k) Number (if known)

Device Name: COBAS AMPLICOR™ Chlamydia Trachomatis Test... ...................................................................................................................

Indications for Use:

» The COBAS AMPLICORTM Chlamydia trachomatis Test is a qualitative in vitro diagnostic test for the detection of Chlamydia trachomatis in clinical specimens on the COBAS AMPLICOR analyzer. The test utilizes the Polymerase Chain Reaction (PCR) nucleic acid amplification technique and nucleic acid hybridization for the detection of Chlamydia trachomatis plasmid DNA in endocervical, male urethral, and male urine samples.

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(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use (Per 21 CFR 801.109)

Over-The-Counter Use (Optional Format 1-2-96)

Oleamlhausen

Division of Clinical Laboratory Devices
510(k) Number K964502

Regulation Number and Section

§ 866.3120 Chlamydia serological reagents.

(a)
Identification. Chlamydia serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies to chlamydia in serum. Additionally, some of these reagents consist of chlamydia antisera conjugated with a fluorescent dye used to identify chlamydia directly from clinical specimens or cultured isolates derived from clinical specimens. The identification aids in the diagnosis of disease caused by bacteria belonging to the genusChlamydia and provides epidemiological information on these diseases. Chlamydia are the causative agents of psittacosis (a form of pneumonia), lymphogranuloma venereum (a venereal disease), and trachoma (a chronic disease of the eye and eyelid).(b)
Classification. Class I (general controls).