The AMPLICOR® CT/NG Test for Neisseria gonorrhoeae is a qualitative in vitro test for the detection of Neisseria gonorrhoeae in clinical specimens. The test utilizes polymerase chain reaction (PCR) for the multiplex nucleic acid amplification of Neisseria gonorrhoeae and Chlamydia trachomatis DNA in endocervical and male urethral swab specimens and in male and female urine specimens from symptomatic and asymptomatic patients, and target-specific probe hybridization capture for the detection of the amplified Neisseria gonorrhoeae DNA.

Device Description

The AMPLICOR CT/NG Test for Neisseria gonorrhoeae is a multiplex in vitro diagnostic test that enables the simultaneous amplification of Neisseria gonorrhoeae, Chlamydia trachomatis and an Internal Control sequence in a sample. The Test is designed for use with the Perkin Elmer 2400 or the Perkin Elmer 9600 thermal cycler for nucleic acid amplification of target DNA by polymerase chain reaction, and colorimetric detection using a conventional microwell plate washer and reader. The AMPLICOR CT/NG Test also incorporates an Internal Control for the identification of specimens that contain inhibitory substances to the PCR amplification reaction.

AI/ML Overview

Here's an analysis of the acceptance criteria and study detailed in the provided K974503 submission for the Roche AMPLICOR® CT/NG Test for Neisseria gonorrhoeae:

Acceptance Criteria and Device Performance for Roche AMPLICOR® CT/NG Test for Neisseria gonorrhoeae

1. Table of Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly state quantitative acceptance criteria in a table format. However, based on the clinical performance data presented, the implicit acceptance criteria would relate to demonstrating substantial equivalence to culture methods, with acceptable sensitivity and specificity values across different specimen types and patient populations.

The reported device performance metrics are as follows:

Metric	Category / Specimen Type	Symptom Status	Reported Device Performance
Sensitivity	Female CTM	Asymptomatic	98.0% (95% CI: 89.3-99.9)
	Female CTM	Symptomatic	94.5% (95% CI: 86.6-98.5) (with IC) / 91.9% (95% CI: 85.7-98.1) (without IC)
	Male CTM (Total)	(Combined)	98.6% (95% CI: 96.6-99.5)
	Male Urine	Asymptomatic	72.7% (95% CI: 39.0-94.0)
	Male Urine	Symptomatic	95.1% (95% CI: 92.7-97.4) (with IC) / 89.2% (95% CI: 85.8-92.5) (without IC)
Specificity	Female CTM	Asymptomatic	98.9% (95% CI: 98.2-99.5)
	Female CTM	Symptomatic	98.5% (95% CI: 97.7-99.2)
	Male CTM (Total)	(Combined)	95.8% (95% CI: 94.4-97.1) (Note: Site #6 had lower specificity at 89.5% for frozen specimens)
	Male Urine	Asymptomatic	99.4% (95% CI: 98.5-99.8)
	Male Urine	Symptomatic	97.1% (95% CI: 96.0-98.2)

Analytical Performance (Limit of Detection):

Sensitivity (LoD): 5 CFU/test for each of 15 isolates tested. The device gave positive results for all strains at 20, 10, and 5 CFU/test. At 1 CFU/test, at least one replicate was positive for all 15 strains, and at 2 CFU/test, all three replicates were positive for 14 of 15 strains.

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

Test Set Sample Size: A total of 5374 specimens were collected and tested in the clinical study. After excluding 33 repeatedly inhibitory specimens, 5341 specimens were used in the primary analyses (when the Internal Control result was used).
Data Provenance: The clinical study was conducted at six geographically diverse sites. The document does not specify the country of origin, but given the submission to the US FDA, it is highly likely the data includes, or is primarily from, studies conducted in the United States. The study appears to be prospective, as it describes the evaluation of the test comparing its results to culture, implying these were collected and processed specifically for this evaluation.

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

The ground truth was established by Neisseria gonorrhoeae culture results. The document does not specify the number of individuals or "experts" involved in performing and interpreting these culture results, nor their specific qualifications (e.g., medical technologists, microbiologists). However, culture with confirmation by biochemical and immunologic assays is referred to as "the international gold standard methods," implying established and accepted laboratory practices were followed.

4. Adjudication Method for the Test Set:

For specimens with discrepant results between the AMPLICOR CT/NG Test and the Neisseria gonorrhoeae culture, an alternate primer (16S rRNA) PCR test was used.
Crucially, the alternate primer PCR test results were not used to calculate the clinical performance characteristics (sensitivity, specificity) of the AMPLICOR test. They were reported "for information purposes only," primarily to investigate apparent false positives and potential true positives missed by culture. This suggests a form of modified discrepant analysis, where the third method (16S rRNA PCR) helped to understand discrepancies but did not directly alter the primary performance calculations derived solely from comparison to culture.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:

No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted as part of this submission. This is a diagnostic test where the output is directly reported by the instrument based on molecular detection, not interpreted by a human reader in the traditional MRMC sense. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not applicable here.

6. Standalone Performance:

Yes, a standalone performance study was done. The entire clinical performance section describes the algorithm-only performance (AMPLICOR CT/NG Test) against the culture-based ground truth. There is no human-in-the-loop component for interpretation or decision-making inherent in the device described.

7. Type of Ground Truth Used:

The primary ground truth used was Neisseria gonorrhoeae culture results. This is considered the "international gold standard methods for detection" at the time of the submission.
For discrepant analysis, an alternate primer (16S rRNA) PCR test was used, but its results did not directly modify the primary calculation of sensitivity and specificity based on culture.

8. Sample Size for the Training Set:

The document does not explicitly state a separate training set sample size. This is common for older diagnostic assay submissions, where a "discovery" or "development" phase dataset might have been used but is not formally disclosed as a "training set" in the same way machine learning models typically define it. The non-clinical performance (analytical sensitivity, specificity, precision) demonstrates rigorous characterization of the assay's fundamental properties.

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

As a dedicated "training set" is not explicitly mentioned, the establishment of ground truth specifically for it cannot be detailed. However, for the analytical studies (non-clinical performance), ground truth was established by:
- Known concentrations of Neisseria gonorrhoeae CFU/test for analytical sensitivity and precision studies.
- Known organisms (bacteria, fungi, protozoa, viruses) at specified genomic DNA concentrations for analytical specificity studies. These would have been characterized externally (e.g., from American Type Culture Collection) to confirm their identity.

Summary

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DEC - 1 1999

K974503

510(k) Summary

Roche AMPLICOR® CT/NG Test for Neisseria gonorrhoeae

This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.

The assigned 510(k) number is: K974503

Intended Use:

The AMPLICOR® CT/NG Test for Neisseria gonorrhoeae is a qualitative in vitro test for the detection of Neisseria gonorrhoeae in clinical specimens. The test utilizes polymerase chain reaction (PCR) for the multiplex nucleic acid amplification of Neisseria gonorrhoeae and Chlamvdia trachomatis DNA in endocervical and male urethral swab specimens and in male and female urine specimens from symptomatic and asymptomatic patients, and target-specific probe hybridization capture for the detection of the amplified Neisseria gonorrhoeae DNA.

Description of the Device:

Similarities and Differences to Predicate Device:

The AMPLICOR CT/NG Test for Neisseria gonorrhoeae is substantially equivalent to other commercially available in vitro diagnostic devices for the detection of Neisseria gonorrhoeae in urogenital swab and urine specimens. These methods include biochemical and immunologic assays for specific identification of N. gonorrhoeae on selective culture medium, and tests for specific nucleic acid in patient specimens. Isolation of N. gonorrhoeae on selective culture medium with confirmation by acid production from carbohydrates, rapid enzyme tests, serologic assays, and tests for

November 23, 1999 Roche Molecular Systems P.O. Box 9002 Pleasanton CA 94566-0900

Contact: James F. Kelly Tel. 925-730-8180 FAX 925-730-8128

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specific nucleic acid are generally considered to be the international gold standard methods for detection. A commonality among all of these devices is that the unique biochemical properties of the target organism are all encoded in the DNA of the organism, essentially reducing each device to a test for genetic (i.e., phenotypic or genotypic) characteristics of the organism.

The AMPLICOR CT/NG Test for Neisseria gonorrhoeae detects a conserved sequence of 201 nucleotides within the M·NgoPII putative cytosine DNA methyltransferase gene of the N. gonorrhoeae bacterial chromosome while culture-based methods identify isolated organisms according to their biochemical or immunologic properties. The clinical performance of the AMPLICOR CT/NG Test for Neisseria gonorrhoeae has been shown to be substantially equivalent to culture methods.

The AMPLICOR CT/NG Test for Neisseria gonorrhoeae allows the automated multiplex amplification of Neisseria gonorrhoeae, Chlamydia trachomatis and an Internal Control that is used to detect the presence of PCR inhibitors. All of these tests use similar detection reactions that are based on the absorbance measurement of a chromophore that is produced by the oxidation of 3.3'.5.5'-tetramethybenzidine by hydrogen peroxide in the presence of horseradish peroxidase.

Non-Clinical Performance:

The analytical sensitivity (limit of detection) of the AMPLICOR CT/NG Test for Neisseria gonorrhoeae is 5 colony forming units (CFU) per test for each of 15 isolates tested for CTM and urine specimens. The AMPLICOR CT/NG Test for N. gonorrhoeae gave positive results for all strains tested at 20. 10, and 5 CFU/test. At 1 CFU/test, the test gave positive results for at least one replicate for all 15 strains, and positive results for all three replicates for 14 of the 15 strains at 2 CFU/test.

The analytical specificity of the AMPLICOR CT/NG Test for Neisseria gonorrhoeae was tested against 132 bacteria, 6 fungi, 1 protozoan and 11 virus isolates that are commonly isolated from the urogenital tract. Isolates were added to CTM and normal human urine at approximately 10 copies of genomic DNA per test. CTM and urine samples were processed and tested using the standard AMPLICOR CT/NG Test procedure. Multiple isolates of Neisseria subflava and Neisseria cinerea obtained from the American Type Culture Collection were tested. Four of the Neisseria subflava and one Neisseria cinerea isolate gave false positive test results. All of the remaining organisms gave negative results with the AMPLICOR CT/NG Test for Neisseria gonorrhoeae.

The precision of the AMPLICOR CT/NG Test for Neisseria gonorrhoeae was determined for a panel of culture transport media specimens containing 0, 12.5, 37.5 and 62.5 Neisseria gonorrhoeae CFU/test; and urine specimens containing 0, 10, 30 and 50 Neisseria gonorrhoeae CFU/test. Three independent operators at three different geographical sites tested the panel in duplicate once a day for three days.. The results of this study are presented in Tables 1 and 2.

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	N. gonorrhoeae Spiked CTM (CFU/test)
	0	12.5	37.5	62.5
Number of Replicates	72	36	36	36
No. Correct Results (%)*	72 (100)	36 (100)	36 (100)	33 (100)
No. Equivocal A450 0.2-1.999	0	0	0	3
No. Equivocal A450 2.0-3.499	0	14	16	16
Median A450	0.056	4.000	4.000	2.889
Minimum A450	0.044	2.208	2.054	1.634
Maximum A450	0.177	4.000	4.000	4.000

Table 1 AMPLICOR CT/NG Test for Neisseria gonorrhoeae CTM Reproducibility Study Results

Specimens with initial equivocal results 0.2-1.999 were considered non-reportable, and were excluded from the calculations of % correct results. Specimens with equivocal results 2.0-3.499 were considered positive in the calculations.

Table 2
AMPLICOR CT/NG Test for Neisseria gonorrhoeaeUrine Reproducibility Study Results

	N. gonorrhoeae Spiked Urine (CFU/test)
	0	10	30	50
Number of Replicates	72	36	36	36
No. Correct Results (%)*	(100)	27 (90.0)†	(100)	(100)
No. Equivocal A450 0.2-1.999	0	6	7	4
No. Equivocal A450 2.0-3.499	0	12	5	7
Median A450	0.055	2.754	4.000	4.000
Minimum A450	0.047	1.097§	1.535	1.395
Maximum A450	0.106	4.000	4.000	4.000

Specimens with initial equivocal results 0.2-1.999 were considered non-reportable, and were excluded from the calculations of % correct results. Specimens with equivocal results 2.0-3.499 were considered positive in the calculations.

One sample gave negative results in three of six initial replicates at one site The sample was repeat tested in duplicate at the site and correct results were obtained for all replicates % Correct results based on 27 correct results out of 30 tests.

§ Minimum absorbance excluding the three initial negative tests.

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Clinical Performance

The AMPLICOR CT/NG Test for Neisseria gonorrhoeae was evaluated in a clinical study conducted at six geographically diverse sites. The clinical performance of the test was evaluated by comparing the results of the 5374 swab and urine specimens to the Neisseria gonorrhoeae culture results. Specimens with discrepant results were also tested by an alternate primer (16S rRNA) PCR test. Analyses were also performed including and excluding the use of the Internal Control result. The alternate primer PCR test results were not used to calculate the clinical performance characteristics of the test and are reported for information purposes only.

When the Internal Control result was used in the analysis, specimens with repeatedly negative Internal Control test results were excluded because the results were not interpretable. Of the 5374 specimens collected and tested in the AMPLICOR CT/NG Test clinical study, 33 were repeatedly inhibitory. Therefore, a total of 5341 specimens were used in the analyses when the Internal Control result was used. Table 3 shows the results from the clinical study.

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Table 3 Clinical Performance of AMPLICOR CT/NG Test for Neisseria gonorrhoeae Including and Excluding the Internal Control

Sex	Specimen	Symptom	TP	TN	FP	FN	No.Inhib.	%RepeatedlyInhibitory	Total	Sensitivity(95% CI)	Specificity(95% CI)	16S+/FP2
Female	CTM	Asymptomatic	49(49)	1032(1038)	12(12)	1(1)	6	0.58%	1100(1100)	98.0%(89.3-99.9)(98.0%)(89.3-99.9)	98.9%(98.2-99.5)(98.9%)(98.2-99.5)	4/12(4/12)
		Symptomatic	69(68)	1034(1048)	16(16)	4(6)	15	1.42%	1138(1138)	94.5%(86.6-98.5)(91.9%)(85.7-98.1)	98.5%(97.7-99.2)(98.5%)(97.8-99.2)	10/16(10/16)
	Total for Females			118(117)	2066(2086)	28(28)	5(7)	21	1.00%	2238(2238)	95.9%(90.8-98.7)(94.4%)(90.3-98.4)	98.7%(98.2-99.2)(98.7%)(98.2-99.2)
	CTM	Symptomatic	340(340)	858(860)	38(38)	5(5)	2	0.23%	1243(1243)	98.6%(96.6-99.5)(98.6%)(96.6-99.5)	95.8%3(94.4-97.1)(95.8%)(94.5-97.1)	21/38(21/38)
Male	URINE	Asymptomatic	8(8)	672(674)	4(4)	3(3)	2	0.30%	689(689)	72.7%(39.0-94.0)(72.7%)(39.0-94.0)	99.4%(98.5-99.8)(99.4%)(98.5-99.8)	2/4(2/4)
		Symptomatic	308(296)	847(848)	25(24)	16(36)	8	0.92%	1204(1204)	95.1%4(92.7-97.4)(89.2%)(85.8-92.5)	97.1%(96.0-98.2)(97.2%)(96.2-98.3)	15/25(14/24)
	Total for Males			656(644)	2377(2382)	67(66)	24(44)	12	0.50%	3136(3136)	96.5%(95.1-97.9)(93.6%)(91.8-95.4)	97.3%(96.6-97.9)(97.3%)(96.7-97.9)

Numbers in parenthesis show the performance results when the Internal Control was not used

2 Number of apparent false positive AMPLICOR test results that were positive by alternate primer pair PCR/Total number of apparent AMPLICOR false positive results.

3 For site #6, specificity was 89.5% (95% C1 86.0 – 93.0) for CTM specimens (n = 412) at this site were frozen prior to AMPLICOR CT/NG testing. At all other sites for specimens not frozen prior to AMPLICOR CT/NG testing (n = 733) specificity was 99.1% (95% CI 97.9 – 99.7).

4 For site #6 sensitivity was 79.6% (95% Cl 68.3 - 90.9) for AMPLICOR CT/NG testing frozen urine specimens (n = 161) and 96.2% (95% Cl 87.0 - 99.5) for AMPLICOR testing fresh urine specimens (n = 209). At all other sites sensitivity was 98.1% (95% Cl 95.1 - 99.5) for both fresh (n = 778) or frozen (n = 56) specimens.

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Image /page/5/Picture/1 description: The image shows the seal of the Department of Health & Human Services - USA. The seal is circular, with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the top half of the circle. In the center of the seal is a stylized image of three human profiles facing to the right, with a flowing design above them.

DEC - 1 1999

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

James F. Kelly, Ph.D. Regulatory Affairs Manager Roche Molecular Systems, Inc. 4300 Hacienda Drive Pleasanton, California 94566-0900

K974503 Re:

Trade Name: AMPLICOR® CT/NG Test for Neisseria gonorrhoeae Regulatory Class: II Product Code: LSL Dated: September 23, 1999 Received: September 27, 1999

Dear Dr. Kelly:

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 (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). 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 Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply 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"

Sincerely yours,

Steven Butman

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): K974503

Device Name: AMPLICOR CT/NG Test for Neisseria gonorrhoeae

Indications For Use:

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

Good luck

Concurrence of CDRH, Office of Device Evaluation (ODE)

vision of Clinical Laboratory Dev K974502 510(k) Number.

Prescription Use (Per 21 CFR 801.109)

Over-The-Counter Use

(Optional Format 1-2-96)

Regulation Number and Section

§ 866.3390

Neisseria spp. direct serological test reagents.(a)
Identification. Neisseria spp. direct serological test reagents are devices that consist of antigens and antisera used in serological tests to identifyNeisseria spp. from cultured isolates. Additionally, some of these reagents consist ofNeisseria spp. antisera conjugated with a fluorescent dye (immunofluorescent reagents) which may be used to detect the presence ofNeisseria spp. directly from clinical specimens. The identification aids in the diagnosis of disease caused by bacteria belonging to the genusNeisseria, such as epidemic cerebrospinal meningitis, meningococcal disease, and gonorrhea, and also provides epidemiological information on diseases caused by these microorganisms. The device does not include products for the detection of gonorrhea in humans by indirect methods, such as detection of antibodies or of oxidase produced by gonococcal organisms.(b)
Classification. Class II (performance standards).