The APTIMA Combo 2 Assay is a target amplification nucleic acid probe test that utilizes target capture for the in vitro qualitative detection and differentiation of ribosomal RNA (rRNA) from Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (GC) in clinician-collected endocervical, vaginal, and male urethral swab specimens, patientcollected vaginal swab specimens*, and female and male urine specimens. The assay is also intended for use with testing of gynecological specimens collected in the PreservCyt Solution and processed with the Cytyc ThinPrep 2000 System. The assay may be used to test specimens from symptomatic and asymptomatic individuals to aid in the diagnosis of gonococcal and/or chlamydial urogenital disease.

*Patient-collected vaginal swab specimens are an option for screening women when a pelvic exam is not otherwise indicated. The vaginal swab specimen collection kit is not for home use.

The GEN-PROBE® APTIMA® Specimen Transfer Kit is only for use with GEN-PROBE APTIMA assays for the detection of Chlamydia trachomatis and/or Neisseria gonorrhoeae. The GEN-PROBE APTIMA Specimen Transfer Kit allows for APTIMA Assay testing of gynecological specimens collected and processed by the Cytyc ThinPrep 2000 Processor according to the instructions provided.

Device Description

Clearance of this premarket notification extends the clinical performance claims of the commercially available GEN-PROBE APTIMA Combo 2 Assay to include PreservCyt liquid Pap specimens (collected and processed by the Cytyc ThinPrep 2000 Processor) as acceptable testing specimens. The ancillary kit formulated for this specific application is the GEN-PROBE APTIMA Specimen Transfer Kit. The components of the APTIMA Specimen Transfer Kit include: (1) a transport tube containing transport media with a penetrable cap and (2) specific instructions for use regarding decontamination and specimen processing procedures. The APTIMA Specimen Transfer Kit may only be used in conjunction with GEN-PROBE APTIMA Assays for the detection of Chlamydia trachomatis and/or Neisseria gonorrhoeae..

AI/ML Overview

The GEN-PROBE® APTIMA COMBO2® Assay performance has been evaluated through a multi-center clinical study.

1. Table of Acceptance Criteria and Reported Device Performance

Performance Metric	Acceptance Criteria	Reported Device Performance (Overall) - Chlamydia trachomatis	Reported Device Performance (Overall) - Neisseria gonorrhoeae
Clinical Sensitivity	Not explicitly stated in the provided document, but typically expected to be high for a diagnostic assay. Implied by the study's aim to demonstrate equivalent performance to reference NAATs.	96.7% (87/90) with 95% CI (90.6-99.3)	92.3% (12/13) with 95% CI (64.0-99.8)
Clinical Specificity	Not explicitly stated in the provided document, but typically expected to be high for a diagnostic assay. Implied by the study's aim to demonstrate equivalent performance to reference NAATs.	99.2% (1545/1557) with 95% CI (98.7-99.6)	99.8% (1630/1633) with 95% CI (99.5-100)
Prevalence	Prevalence of C. trachomatis and N. gonorrhoeae in the study population. Not an acceptance criterion in itself, but a characteristic of the test population. The prevalence rates in the study (CT: 3.2% to 14.0%, GC: 0% to 5.0%) were considered appropriate.	C. trachomatis only: 5.6% (93/1647)	N. gonorrhoeae only: 0.6% (10/1647)
Analytical Sensitivity (Limit of Detection)	1 Inclusion-Forming Unit (IFU) per assay (9.75 IFU/mL PreservCyt liquid Pap) for C. trachomatis; 50 cells/assay (488 cells/mL PreservCyt liquid Pap) for N. gonorrhoeae.	All 15 C. trachomatis serovars tested positive at less than 1 IFU/assay.	All N. gonorrhoeae strains tested positive at less than 50 cells/assay.
Analytical Specificity	Not explicitly stated as a numerical criterion, but the expectation is no cross-reactivity with a panel of common related and unrelated organisms.	All 50 culture isolates (47 Neisseria strains, Chlamydia psittaci, Chlamydia pneumoniae) produced negative results.	All 50 culture isolates (47 Neisseria strains, Chlamydia psittaci, Chlamydia pneumoniae) produced negative results.
Interference	No interference observed from common cervical specimen substances.	No interference was observed with any of the tested substances (10% blood, contraceptive jelly, spermicide, moisturizer, hemorrhoidal anesthetic, body oil, powder, anti-fungal cream, vaginal lubricants, feminine spray, and leukocytes).	No interference was observed with any of the tested substances (10% blood, contraceptive jelly, spermicide, moisturizer, hemorrhoidal anesthetic, body oil, powder, anti-fungal cream, vaginal lubricants, feminine spray, and leukocytes).
Recovery	Not explicitly stated, but the expectation is that co-existing common bacteria do not interfere with detection.	The addition of Escherichia coli, Gardnerella vaginalis, Lactobacillus acidophilus, Bacteroides ureolyticus, and Staphylococcus epidermidis did not interfere with detection.	The addition of Escherichia coli, Gardnerella vaginalis, Lactobacillus acidophilus, Bacteroides ureolyticus, and Staphylococcus epidermidis did not interfere with detection.
Stability	PreservCyt liquid Pap samples should demonstrate stable detection of C. trachomatis and N. gonorrhoeae under recommended shipping and storage conditions.	All tested conditions were positive for both C. trachomatis and N. gonorrhoeae at all specified times and temperatures (30℃ for 7 days, 4℃, 10℃, 30℃, and -20℃ for up to 106 days).	All tested conditions were positive for both C. trachomatis and N. gonorrhoeae at all specified times and temperatures (30℃ for 7 days, 4℃, 10℃, 30℃, and -20℃ for up to 106 days).
Precision (Reproducibility)	Not explicitly stated as a numerical criterion, but consistent results across sites, operators, and runs are expected.	Summarized in a table (refer to document Section {7}), showing varying Coefficients of Variation (CV%) for inter-site, inter-operator, inter-run, and intra-run for spiked samples. Specificity ranged from 97.7% to 100%.	Summarized in a table (refer to document Section {7}), showing varying Coefficients of Variation (CV%) for inter-site, inter-operator, inter-run, and intra-run for spiked samples. Specificity ranged from 99.0% to 100%.

2. Sample size used for the test set and the data provenance:

Test Set Sample Size: 1,647 female subjects (1,288 asymptomatic, 359 symptomatic).
Data Provenance: Prospective multi-center clinical study conducted in the United States (as implied by the FDA submission and the company's US address). The study involved subjects attending OB/GYN, family planning, public health, women's, and STD clinics.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

The document does not explicitly state the number or qualifications of experts used to establish the ground truth. Instead, the ground truth was established by a patient infected status algorithm based on the results of two commercially-available reference NAATs performed on endocervical swab specimens. This implies that the ground truth was determined by laboratory testing protocols rather than direct expert consensus on each individual case.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:

Adjudication Method: "None" in the sense of expert human adjudication. The ground truth for the "patient infected status" was based on concordant positive results from two reference NAATs (APTIMA Combo 2 Assay and APTIMA CT Assay for C. trachomatis; APTIMA Combo 2 Assay and APTIMA GC Assay for N. gonorrhoeae). If the two reference NAATs disagreed or were negative, the patient was designated as non-infected. This is a form of algorithmic adjudication rather than human expert adjudication.

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, a multi-reader multi-case (MRMC) comparative effectiveness study was NOT done. This study evaluates a laboratory diagnostic assay (APTIMA Combo 2 Assay) and does not involve human readers interpreting images or data to be assisted by AI. Therefore, the concept of "human readers improve with AI vs without AI assistance" does not apply here.

6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done:

Yes, this was effectively a standalone performance study for the device. The APTIMA Combo 2 Assay, as a nucleic acid amplification test, functions as an algorithm-only device (an in vitro diagnostic test kit that produces a qualitative result based on amplification and detection of rRNA). Its performance was evaluated against a defined ground truth without direct human interpretation in a diagnostic loop that would affect its result. The assay generates a direct qualitative result (positive/negative) which is then used by clinicians for diagnosis.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

Algorithm-based Patient Infected Status (Reference NAATs):
- For C. trachomatis: A patient was considered infected if both the APTIMA Combo 2 Assay and the APTIMA CT Assay (both performed on endocervical swabs) returned positive results.
- For N. gonorrhoeae: A patient was considered infected if both the APTIMA Combo 2 Assay and the APTIMA GC Assay (both performed on endocervical swabs) returned positive results.
- A non-infected patient was established if the results from the two reference NAATs disagreed or were negative. This is effectively a composite reference standard based on other validated diagnostic tests.

8. The sample size for the training set:

The document does not explicitly describe a separate training set for the APTIMA Combo 2 Assay in the context of this submission. The product being submitted for clearance is an existing assay (APTIMA Combo 2 Assay (K003395)) and the clearance sought is an extension of its clinical performance claims to include PreservCyt liquid Pap specimens.
The non-clinical (analytical) studies (Limit of Detection, Specificity, Interference, Recovery, Stability, Precision) likely involved internal development and optimization, which could be considered an implicit "training" or development phase. However, a distinct "training set" in the machine learning sense is not mentioned. The clinical study described is solely for validation/testing of the assay's performance with the new specimen type.

9. How the ground truth for the training set was established:

As a distinct training set is not explicitly mentioned for this 510(k) submission, the method for establishing its ground truth is also not detailed. The ground truth for the non-clinical (analytical) studies typically involved controlled laboratory experiments using known concentrations of organisms and interference substances, with results verified by standard laboratory methods.

Summary

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AUG 9 - 2005

Summary of Safety and Effectiveness

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: K043224

GEN-PROBE® APTIMA COMBO2® Assay GEN-PROBE® APTIMA® Specimen Transfer Kit

Sponsor/Contact Information

Submitted By: Gen-Probe Incorporated 10210 Genetic Center Drive San Diego, California 92121 Phone: (858) 410-8000

Company Contact: Alan Maderazo, Ph.D., RAC Sr. Regulatory Affairs Specialist Phone: (858) 410-8332 Fax: (858) 410-8139 e-mail: alanma@gen-probe.com

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General Information

Trade Name:	GEN-PROBE® APTIMA COMBO2® Assay
Common or Usual Name:	Ribosomal RNA (rRNA) target-amplified nucleic acid probtest for the in vitro diagnostic detection of Chlamydiatrachomatis and/or Neisseria gonorrhoeae
Classification Names:	DNA Probe, Nucleic Acid Amplification, ChlamydiaDNA Reagents, Neisseria

APTIMA Combo 2 Assay

DNA Probe, Nucleic Acid Amplification, Chlamydia Device Description Medical Specialty Microbiology Product Code MKZ Device Class l Regulation number 866.3120

Device Description	DNA Reagents, Neisseria
Medical Specialty	Microbiology
Product Code	LSL
Device Class	2
Regulation number	866.3390

Substantially Equivalent Devices:

APTIMA Combo 2 Assay (K003395)

Roche COBAS AMPLICOR™ CT/NG Test (P950039/S008)

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Device Description

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Intended Use

AC2 Assay package insert:

*Patient-collected vaginal swab specimens are an option for screening women when a pelvic exam is not otherwise indicated. The vaginal swab specimen collection kit is not for home use.

Ancillary Kit package insert:

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APTIMA Combo 2 Assay

A complete description of the APTIMA Combo 2 Assay is provided in the commercialized package insert.

Summary of Non-Clinical (Analytical Laboratory) Performance Data

Limit of Detection (Analytical Sensitivity)

Chlamydia trachomatis analytical sensitivity (limits of detection) was determined by directly comparing dilutions of C. trachomatis organisms in cell culture and in the assay. The analytical sensitivity claim for the assay is one Inclusion-Forming Unit (IFU) per assay (9.75 IFU/mL PreservCyt liquid Pap) for all 15 C. trachomatis serovars. However, dilutions of less than 1 IFU/assay of all serovars tested positive in the APTIMA Combo 2 Assay.

Neisseria gonorrhoeae analytical sensitivity was determined by directly comparing dilutions of 20 different clinical isolates in culture and in the APTIMA Combo 2 Assay. The analytical sensitivity claim for the assay is 50 cells/assay (488 cells/mL PreservCyt liquid Pap). However, all strains tested were positive at less than 50 cells/assay.

Analytical Specificity

The Chlamydia and Neisseria species were used to evaluate the analytical specificity of the AC2 Assay. A total of 50 culture isolates were tested in the PreservCyt liquid Pap media. These isolates included 47 Neisseria strains and two species of Chlamydia (two strains of Chlamydia psittaci and one strain of Chlamydia pneumoniae). All organisms except C. psittaci and C. pneuomoniae were tested at greater than 1.0 X 106 cells/assay in the mixed solution (PreservCyt/STM). For C. psittaci, two isolates were tested - VR601 at a concentration of 7.91 x 104 cells/assay, and VR629 at a concentration of 1 x 10 CELDss/0.2 mL. For C. pneumoniae (VR1360), the tested concentration was 3.95 x 10

Gen-Probe Incorporated

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cells/assay. The list of organisms tested and their corresponding AC2 Assay results are provided in the Table below

ORGANISM	ORGANISM
Chlamydia psittaci	Neisseria cinerea (4)
Chlamydia psittaci	Neisseria dentrificans
Chlamydia pneumoniae	Neisseria lactamica (9)
Neisseria elongate (3)	N. meningitidis Serogroup A
Neisseria flava	N. meningitidis Serogroup B
Neisseria mucosa	N. meningitidis Serogroup C (4)
Neisseria mucosa	N. meningitidis Serogroup D
Neisseria perflava	N. meningitidis Serogroup Y
Neisseria sicca	N. meningitidis Serogroup W135
Neisseria sicca	Neisseria polysaccharea
Neisseria subflava(14)

Analytical Specificity - PreservCyt liquid Pap Specimen Study

(n) = number of strains tested

All organisms tested produced a negative result in the APTIMA Combo 2 Assay.

Interference Studies

The following substances commonly present in cervical specimens that were tested in the assay. 10% blood, contraceptive jelly, spermicide, moisturizer, hemorrhoidal anesthetic, body oil, powder, anti-fungal cream, vaginal lubricants, feminine spray, and leukocytes (1 x 106 cells/mL).

All were tested for potential assay interference in the absence and presence of C. trachomatis and N. gonorrhoeae at the estimated rRNA equivalent of one C. trachomatis IFU/assay (5 fg/assay) and 50 N. gonorrhoeae cell/assay (250 fg/assay). The rRNA equivalents were calculated based on the genome size and estimated DNA:RNA ratio/cell of each organism. No interference was observed with any of the tested substances.

Recovery

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Escherichia coli, Gardnerella vaginalis, Lactobacillus acidophilus, Bacteroides ureolyticus and Staphylococcus epidermidis (1 x 10° cells/assay) were added to samples containing the rRNA equivalent of approximately 1 C. trachomatis IFU (5 fg) and 50 N. gonorrhoeae cells (250 fg). These additions did not interfere with the amplification and detection of C. trachomatis or N. gonorrhoeae rRNA using the AC2 Assay.

PreservCyt Liquid Pap Specimen Stability Studies

Data to support the recommended shipping and storage conditions for PreservCyt liquid Pap samples were generated with pooled negative PreservCyt liquid Pap samples. Four pooled samples were spiked with C. trachomatis and N. gonorrhoeae at final concentrations of 10 IFU and 100 CFU per reaction, respectively. The PreservCyt liquid Pap samples were placed at 30℃ for 7 days, after which 1 mL of the sample was added to an APTIMA Transfer Tube. The spiked samples were held at 4℃, 10℃ and 30℃. Samples stored at 4℃ and 10℃ were tested in duplicate at days 0, 6, 13, 26, 30 and 36. Samples stored at 30℃ were tested in duplicate at days 0, 5, 8, 14 and 17. Four spiked PreservCyt Iiquid Pap sample pools were added to APTIMA Transfer Tubes and placed at 30℃ for 14 days before being stored at -20℃. The -20℃ samples were tested in duplicate after 0, 30, 60, 90 and 106 days of storage. All test conditions were positive for both C. trachomatis and N. gonorrhoeae at all times and temperatures.

Precision

Reproducibility was established with a 12-member panel generated by spiking PreservCyt Solution with 0 to 2000 fg/assay of C. trachomatis and 0 to 5,000 fg/assay of N. gonorrhoeae rRNA and aliquotting 1mL into the APTIMA Specimen Transfer Kit collection tube. Two (2) operators at each of the three sites performed one run per day on each of three days, totaling three valid runs per operator. The results of the precision study are summarized in the table below. Reproducibility when testing PreservCyt liquid Pap clinical specimens containing target organism has not been determined.

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		Inter-Site		Inter-Operator		Inter-Run		Intra-Run
Agrmt(%)	Mean RLU(x1000)	SD(x1000)	CV(%)	SD(x1000)	CV(%)	SD(x1000)	CV(%)	SD(x1000)	CV(%)
97.5	9.7	6.4	N/A	4.7	N/A	3.4	N/A	31.6	N/A
96.3	1296	0.0	0.0	0.0	0.0	54.8	4.2	146	11.3
100	1140	101	8.9	2.4	0.2	79.8	7.0	54.1	4.7
100	2345	94.7	4.0	37.9	1.6	78.0	3.3	79.6	3.4
100	953	161	16.9	90.7	9.5	0.0	0.0	114	12.0
100	971	22.8	2.4	85.0	8.8	71.7	7.4	58.3	6.0
100	2294	153	6.7	0.0	0.0	88.9	3.9	114	5.0
98.1	1911	348	18.2	39.7	2.1	130	6.8	139	7.3
100	2136	98.8	4.6	166	7.8	130	6.1	113	5.3
96.3	2044	360	17.6	26.9	1.3	169	8.3	138	6.7

TIMA Combo 2 Assay Precision Study - PreservCyt Solutio

W/A = not applicable for negative panel members
Agnnt = Agreement, CV = Coefficient of variation, RLU = Relative Light Units, SD = Standard deviation

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PreservCyt Liquid Pap Specimen Clinical Study Results

A prospective multi-center clinical study was conducted to evaluate the use of the PreservCyt Solution (a component of the ThinPrep 2000 System) as an alternative medium for gynecological specimens for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae. One thousand six hundred forty-seven (1,647) symptomatic and asymptomatic female subjects attending OB/GYN, family planning, public health, women's and STD clinics were evaluated in the clinical study. Of the 1,647 evaluable subjects, 1,288 were asymptomatic subjects and 359 were symptomatic subjects. Subjects were enrolled from sites with CT prevalence that ranged from 3.2 to 14.0% and GC prevalence that ranged from 0 to 5.0%. Two specimens were collected from each eligible subject: one PreservCyt Solution specimen and one endocervical swab. PreservCyt Solution specimens were processed in accordance with the ThinPrep 2000 Processor Operator's Manual and APTIMA Specimen Transfer Kit Package Insert. After processing the PreservCyt Solution specimen with the ThinPrep 2000 Processor, the specimen was transferred into the APTIMA Specimen Transfer Kit for testing with the APTIMA Combo 2 Assay. The PreservCyt liquid Pap specimens and endocervical swab specimens were tested with the APTIMA Combo 2 Assay.

Sensitivity and specificity for PreservCyt liquid Pap specimens were calculated by comparing results to a patient infected status algorithm. In the algorithm, the designation of a subject as being infected or non-infected with C. trachomatis or N.gonorrhoeae was based on endocervical swab specimen results from two commercially-available NAATs. For C. trachomatis, the reference NAATs included the APTIMA Combo 2 Assay and the APTIMA CT Assay. For N. gonorrhoeae, the reference NAATs included the APTIMA Combo 2 Assay and the APTIMA GC Assay. Positive results from both reference NAATs were required to establish an infected patient. A non-infected patient was established if the results from the two reference NAATs disagreed or were negative.

Sensitivity and specificity for C. trachomatis in PreservCyt liquid Pap specimens tested in the APTIMA Combo 2 Assay, by symptom status and overall, is presented in Table 1. For

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C. trachomatis, overall sensitivity was 96.7% (87/90). In symptomatic and asymptomatic subjects, sensitivity was 96.7% (29/30) and 96.7% (58/60), respectively. Overall specificity for C. trachomatis PreservCyt liquid Pap specimens was 99.2% (1545/1557). In symptomatic and asymptomatic subjects, specificity was 98.5% (324/329) and 99.4% (1221/1228), respectively. Table 2 shows the APTIMA Combo 2 Assay sensitivity and specificity values for C. trachomatis in PreservCyt liquid Pap specimens by clinical site and overall. For C. trachomatis, the sensitivity ranged from 92.9% to 100%. The specificity ranged from 97.7% to 100%.

Sensitivity and specificity for N. gonorrhoeae in PreservCyt liquid Pap specimens tested in the APTIMA Combo 2 Assay, by symptom status and overall, is presented in Table 3. For N. gonorrhoeae, overall sensitivity was 92.3% (12/13). In symptomatic and asymptomatic subjects, sensitivity was 100% (7/7) and 83.3% (5/6), respectively. Overall specificity for N. gonorrhoeae PreservCyt liquid Pap specimens was 99.8% (1630/1633). symptomatic and asymptomatic subjects, specificity was 100% (352/352) and 99.8% (1278/1281), respectively. Table 4 shows the APTIMA Combo 2 Assay sensitivity and specificity values for N. gonorrhoeae in PreservCyt liquid Pap specimens by clinical site and overall. For N. gonorrhoeae, the sensitivity ranged from 80.0% to 100%. Specificity ranged from 99.0% to 100%.

The distribution of cervical sampling devices used in this clinical study according to clinical site is summarized in the table below.

Cervical sampling devices

Cervical sampling device used	Clinical Collection Site						Total
	1	2	3	4	5	6
Spatula/Cytobrush	0	124	475	287	57	364	1307
Broom-Type Device	100	0	0	0	240	0	340

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		AC2 ES+ and ACT ES+			AC2 ES+ and ACT ES-			Sensitivity (95% CI)
	AC2/CTThinPrep Result	Positive	Negative	Total	Positive	Negative	Total
Asympt	Positive	58	1	60	0	1	2	96.7% (88.5-99.6)	99.4% (98.8-99.8)
	Negative	2	1	3	6	12	1208
	Total	60	2	12	1214
Sympt	Positive	29	0	29	0	3	3	96.7% (82.8-99.9)	98.5% (96.5-99.5)
	Negative	1	3	4	5	4	317
	Total	30	3	332	4	322
All	Positive	87	1	88	0	1	1	96.7% (90.6-99.3)	99.2% (98.7-99.6)
	Negative	3	4	7	11	16	1525
	Total	90	5	16	1536
AC2 ES+ = Positive endocervical swab specimen APTIMA Combo 2 Assay result

ACE BS - - Positive endocervical swab specimen APTIMA Cosmo 2 rossil
ACT ES+ = Negative endocervical swab specimen APTIMA CT Assalt
ACT ES+ = Positive endocervical swab speci

Endocervical Swab Specimen, Negative == RESULTS

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Site	AC2/CTThinPrep Result	AC2 ES+andACT ES+	AC2 ES+andACT ES-	AC2 ES-andACT ES+	AC2 ES-andACT ES-	Prev(%)	Sensitivity (95% CI) (%)	Specificity (95% CI) (%)	PPV(%)	NPV(%)
1	Positive	14	0	0	2	14.0	100% (76.8 - 100)	97.7% (91.9 - 99.7)	87.5	100
	Negative	0	0	1	83
	Total	14	0	1	85
2	Positive	4	0	0	0	3.2	100% (39.8 - 100)	100% (97.0 - 100)	100	100
	Negative	0	0	2	118
	Total	4	0	2	118
3	Positive	29	0	0	2	6.5	93.5% (78.6 - 99.2)	99.5% (98.4 - 99.9)	93.5	99.5
	Negative	2	0	2	440
	Total	31	0	2	442
4	Positive	8	1	0	4	2.8	100% (63.1 - 100)	98.2% (95.9 - 99.4)	61.5	100
	Negative	0	2	1	271
	Total	8	3	1	275
5	Positive	13	0	0	2	4.7	92.9% (66.1 - 99.8)	99.3% (97.5 - 99.9)	86.7	99.6
	Negative	1	1	4	276
	Total	14	1	4	278
6	Positive	19	0	0	1	5.2	100% (82.4 - 100)	99.7% (98.4 - 100)	95.0	100
	Negative	0	1	6	337
	Total	19	1	6	338
All	Positive	87	1	0	11	5.5	96.7% (90.6 - 99.3)	99.2% (98.7 - 99.6)	87.9	99.8
	Negative	3	4	16	1525
	Total	90	5	16	1536

ACE ES - Tostive endocervical swab specimen APTIMA Combro 2 Assay result
ACT ES+ = Negative endocervical swab specimen AFTIMA CT Assay result
ACT ES+ = Positive endocervical

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Table 3: GC Sensitivity and Specificity: AC2 Assay PreservCyt Specimens vs. Patient Infected Status	AC2/GCThinPrep Result	AC2 ES+andAGC ES+	AC2 ES+andAGC ES-	AC2 ES-andAGC ES-	Sensitivity (95% CI)	Specificity (95% CI)
Asympt	Positive	5	0	3	83.3% (35.9 - 99.6)	99.8% (99.3 - 100)
	Negative	1	5	1273
	Total	6	5	1276
Sympt	Positive	7	0	0	100% (59.0 - 100)	100% (99.0-100)
	Negative	0	0	352
	Total	7	0	352
All	Positive	12	0	3	92.3% (64.0 - 99.8)	99.8% (99.5 - 100)
	Negative	1	5	1625
	Total	13	5	1628

2 ES+= Positive endocervical swab specimen Al
C2
MA Combo 2 Assay resu
ES-=Negative endocervical swab specimen APTIMA Combo 2 Assay resu

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Site	AC2/GCThinPrep Result	AC2 ES+andAGC ES+	AC2 ES-andAGC ES+	AC2 ES-andAGC ES-	Prev(%)	Sensitivity (95% CI)	Specificity (95% CI)	PPV(%)	NPV(%)
1	Positive	5	0	0	5.0	100% (47.8 - 100)	100% (96.2 - 100)	100	100
	Negative	0	0	95
	Total	5	0	95
2	Positive	1	0	0	0.8	100% (2.5 - 100)	100% (97.0 - 100)	100	100
	Negative	0	0	123
	Total	1	0	123
3	Positive	4	0	0	1.1	80.0% (28.4 - 99.5)	100% (99.2 - 100)	100	99.8
	Negative	1	0	470
	Total	5	0	470
4	Positive	1	0	0	0.3	100% (2.5 - 100)	100% (98.7 - 100)	100	100
	Negative	0	3	283
	Total	1	3	283
5	Positive	0	0	3	0.0	N/A	99.0% (97.1 - 99.8)	0.0	100
	Negative	0	0	294
	Total	0	0	297
6	Positive	1	0	0	0.3	100% (2.5 - 100)	100% (99.0 - 100)	100	100
	Negative	0	2	360
	Total	1	2	360
All	Positive	12	0	3	0.8	92.3% (64.0 - 99.8)	99.8% (99.5 - 100)	80.0	99.9
	Negative	1	5	1625
	Total	13	5	1628

Total	13	0	5	1028
AC2 ES+= Positive endocervical swab specimen APTIMA Combo 2 Assay result
AC2 ES-= Negative endocervical swab specimen APTIMA Combo 2 Assay result
AGC ES+= Positive endocervical swab specimen APTIMA GC Assay result
AGC ES-= Negative endocervical swab specimen APTIMA GC Assay result
N/A = not applicable

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Prevalence

The prevalence of C. trachomatis and/or N. gonorrhoeae disease in patient populations depends on risk factors such as age, gender, the presence of symptoms, the type of clinic, and the test method. A summary of the prevalence of three C. trachomatis and N. gonorrhoeae disease outcomes as determined by the APTIMA Combo 2 Assay is shown in Table 5 by clinical site and overall. The CT and GC prevalence were calculated using the APTIMA Combo 2 Assay results of PreservCyt liquid Pap specimen

Table 5: Prevalence of C. trachomatis and/or N. gonorrhoeae Disease as Determined by the APTIMA Combo 2 Assay Results by Clinical Site

Site	PreservCyt liquid Pap Specimens% Prevalence (# positive/# tested)
	CT+/GC+	CT+/GC-	CT-/GC+
1	3.0(3/100)	13.0(13/100)	2.0(2/100)
2	0(0/124)	3.2(4/124)	0.8(1/124)
3	0.4(2/475)	6.1(29/475)	0.4(2/475)
4	0.4(1/287)	4.2(12/287)	0(0/287)
5	0(0/297)	5.1(15/297)	1.0(3/297)
6	0(0/364)	5.5(20/364)	0.6(2/364)
All	0.4(6/1647)	5.6(93/1647)	0.6(10/1647)

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Conclusions from the Clinical Data

The non clinical and clinical study results support the use of PreservCyt liquid Pap specimens collected and processed by the Cytyc ThinPrep 2000 Processor in the GEN-PROBE APTIMA Combo 2 Assay for the detection of C. trachomatis and/or N. gonorrhoeae. The GEN-PROBE APTIMA Specimen Transfer Kit provides the necessary materials and instructions to allow for the testing of PreservCyt liquid Pap specimens in the AC2 Assay. Use of this ancillary kit broadens the application of the AC2 Assay as a diagnostic tool to provide information that measurably contributes to a diagnosis of C. trachomatis and/or N. gonorrhoeae infection.

The results of the clinical study demonstrate reasonable evidence that when the AC2 Assay and the APTIMA Specimen Transfer Kit are labeled as proposed, the AC2 Assay continues to be safe and effective for its stated intended use.

Contraindications and Cautions

There are no contraindications or cautions.

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Image /page/16/Picture/1 description: The image shows a logo with a circular border containing the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA". Inside the circle is a stylized graphic of an eagle or bird-like figure, represented by three curved lines that suggest wings or feathers. The logo is simple and monochromatic, with a focus on the text and the abstract bird symbol.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

AUG 9 - 2005

Alan Maderazo, Ph.D. RAC Sr. Regulatory Affairs Specialist Gen-Probe Incorporated 10210 Genetic Center Drive San Diego, CA 92121-1589

Re: K043224

Trade/Device Name: GEN-PROBE® APTIMA® Combo 2 Assay Regulation Number: 21 CFR 866.3390 Regulation Name: Neisseria spp. direct serological test reagents Regulatory Class: Class II Product Code: LSL, MKZ Dated: August 2, 2005 Received: August 4, 2005

Dear Dr. Maderazo:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in Title 21, Code of Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820).

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Page 2 -

This letter will allow you to begin marketing your device as described in your Section 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 information about the application of labeling requirements to your device, or questions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (240)276-0484. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html

Sincerely yours,

Sales, a Form

Sally A. Hojvat, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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CDRH Special Sheet - Device Indications for Use

510(k) Number (if known): K043224

Device Name: GEN-PROBE® APTIMA® Combo 2 Assay

Indications For Use:

AC2 Assay package insert:

The APTIMA Combo 2 Assay is a target amplification nucleic acid probe test that utilizes target capture for the in vitro qualitative detection and differentiation of ribosomal RNA (rRNA) from Chlamydia trachomatis (CT) and/or Neisseria gonorrhoeae (GC) in clinician-collected endocervical, and male urethral swab specimens, patient-collected vaginal swab specimens , and female and male urine specimens. The assay is also intended for use with testing of gynecological specimens collected in the PreservCyt Solution and processed with the Cytyc ThinPrep 2000 System. The assay may be used to test specimens from symptomatic and asymptomatic individuals to aid in the diagnosis of gonococcal and/or chlamydial urogenital disease.

*Patient-collected vaginal swab specimens are an option for screening women when a pelvic exam is not otherwise indicated. The vaginal swab specimen collection kit is not for home use.

Ancillary Kit package insert:

Prescription Use _____________________________________________________________________________________________________________________________________________________________ (Part 21 CFR 801 Subpart D)

AND/OR

Over-The-Counter Use _ (21 CFR 807 Subpart C)

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

Concurrence of CDRH, Office of In Vitro Diagnostic Devices (OIVD)

	Division Sign-Off
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Office of In Vitro Diagnostic Device Evaluation and Safety

Gen-Probe Incorporated
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510(k)	K043224
Confidential

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).