(145 days)
The Aptima Mycoplasma genitalium assay is an in vitro nucleic acid amplification test (NAAT) for the qualitative detection of ribosomal RNA (rRNA) from Mycoplasma genitalium on the fully automated Panther system. It is intended for use as an aid in the diagnosis of M. genitalium urogenital infections in male and female patients suspected of M. genitalium infection.
The assay may be used to test the following specimens: clinician-collected and selfcollected vaginal swabs (in a clinical setting), clinician-collected endocervical swabs, female and male urine, clinician-collected male urethral swabs, and self-collected penile meatal swabs (in a clinical setting).
For females, a vaginal swab is the preferred specimen type due to higher clinical sensitivity for detecting M. genitalium than other specimen types: however, female urine or clinician-collected endocervical swabs may be used as alternative specimens when vaginal swab specimens are not available. If female urine or clinician-collected endocervical swab specimens test negative, testing with a vaginal swab may be indicated, if M. genitalium infection is suspected.
The Aptima Mycoplasma genitalium Assay is a nucleic acid amplification test to qualitatively detect ribosomal RNA from Mycoplasma genitalium. The assay is performed using the Panther System and includes three main processing steps: target capture, transcription-mediated amplification (TMA), and detection by nucleic acid hybridization. The Aptima Mycoplasma genitalium Assay oligonucleotides are designed to specifically capture, amplify, and detect a highly conserved region of Mycoplasma genitalium and the internal control (IC).
The Aptima Mycoplasma genitalium Assay is provided as a 100-test kit. Following are the reagents and materials required to perform the assay on the Panther System:
Aptima Mycoplasma genitalium Assay Kit
- Amplification Reagent
- Enzyme Reagent
- Probe Reagent
- Internal Control Reagent
- Selection Reagent
- Target Capture Reagent
- Amplification Reconstitution Solution
- Enzyme Reconstitution Solution
- Probe Reconstitution Solution
Aptima Mycoplasma genitalium Calibrators Kit
- Negative Calibrator
- Positive Calibrator
Materials required but sold separately:
- Aptima Assay Fluids Kit
- Aptima Auto Detect Kit
- Aptima Multitest Swab Specimen Collection Kit
- Aptima Unisex Swab Specimen Collection Kit for Endocervical and Male Urethral Swab Specimens
- Aptima Urine Specimen Collection Kit
Aptima Mycoplasma genitalium Assay Study Summary
This document describes the acceptance criteria and a prospective, multi-center clinical study conducted to establish the clinical performance characteristics of the Aptima Mycoplasma genitalium Assay.
1. Acceptance Criteria and Reported Device Performance
The acceptance criteria for this device are not explicitly stated as quantitative thresholds in the provided text (e.g., "sensitivity must be >X%"). Instead, the document presents detailed performance characteristics obtained from various studies, which are implicitly considered acceptable for the de novo classification. The key performance metrics are summarized below:
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance (Specificity from PIS Study) |
|---|---|---|
| Sensitivity (Female Specimens) | High sensitivity desired across specimen types, with vaginal swabs as preferred. | Clinician-Collected Vaginal Swab: 92.0% (86.9-95.1%) |
| Patient-Collected Vaginal Swab: 98.9% (95.9-99.7%) | ||
| Endocervical Swab: 81.5% (75.1-86.6%) | ||
| Female Urine: 77.8% (71.1-83.3%) | ||
| Specificity (Female Specimens) | High specificity desired across specimen types. | Clinician-Collected Vaginal Swab: 98.0% (97.2-98.6%) |
| Patient-Collected Vaginal Swab: 98.5% (97.7-99.0%) | ||
| Endocervical Swab: 98.3% (97.5-98.8%) | ||
| Female Urine: 99.0% (98.3-99.4%) | ||
| Sensitivity (Male Specimens) | High sensitivity desired across specimen types. | Urethral Swab: 98.2% (94.8-99.4%) |
| Penile Meatal Swab: 88.4% (82.6-92.5%) | ||
| Male Urine: 90.9% (85.5-94.4%) | ||
| Specificity (Male Specimens) | High specificity desired across specimen types. | Urethral Swab: 99.6% (99.1-99.8%) |
| Penile Meatal Swab: 97.8% (96.9-98.5%) | ||
| Male Urine: 99.4% (98.8-99.7%) | ||
| Positive Percent Agreement (PPA) (Specimen-Specific) | High PPA desired across specimen types. | Clinician-Collected Vaginal Swab: 98.3% (95.2-99.4%) |
| Patient-Collected Vaginal Swab: 98.9% (95.9-99.7%) | ||
| Endocervical Swab: 97.0% (93.2-98.7%) | ||
| Female Urine: 94.2% (89.4-96.9%) | ||
| Urethral Swab: 98.2% (94.8-99.4%) | ||
| Penile Meatal Swab: 95.3% (91.0-97.6%) | ||
| Male Urine: 97.5% (93.9-99.0%) | ||
| Negative Percent Agreement (NPA) (Specimen-Specific) | High NPA desired across specimen types. | Clinician-Collected Vaginal Swab: 98.9% (98.3-99.3%) |
| Patient-Collected Vaginal Swab: 98.5% (97.7-99.0%) | ||
| Endocervical Swab: 99.6% (99.1-99.8%) | ||
| Female Urine: 99.4% (98.9-99.7%) | ||
| Urethral Swab: 99.6% (99.1-99.8%) | ||
| Penile Meatal Swab: 99.0% (98.3-99.4%) | ||
| Male Urine: 99.9% (99.5-100%) | ||
| Limit of Detection (LoD) | LoD should be low, indicating high analytical sensitivity. | Vaginal Swab: 0.04 - 0.10 GE/mL |
| Female Urine: 0.04 - 0.12 GE/mL | ||
| Penile Meatal Swab: 0.05 - 0.10 GE/mL | ||
| Male Urine: 0.03 - 0.16 GE/mL | ||
| Precision/Reproducibility | Low variability across different conditions (instruments, operators, lots, days, runs). | %CV for S/CO: 5.58% - 16.21% (total variability for positive samples) |
| % Agreement: 100% for all negative panel members, 100% for positive panel members in reproducibility study. | ||
| Analytical Reactivity (Inclusivity) | Ability to detect various Mycoplasma genitalium strains. | 9 Mycoplasma genitalium strains detected at ≥95% positivity, with most at low GE/mL concentrations. |
| Analytical Specificity (Cross-reactivity) | No false positives with common genitourinary flora and related microorganisms. | No false positive test results with any of 56 tested microorganisms. In silico analysis showed no significant interactions. |
| Microbial Interference | No, or minimal, interference from other microorganisms. | No microbial interference observed, except with Mycoplasma pneumoniae (a limitation noted in the package insert). |
| Interfering Substances | No interference from common gynecological/feminine hygiene products, bodily fluids. | No interference observed with listed interfering substances at specified concentrations, except with mucus at 0.3% w/v (a limitation noted in the package insert). |
| Carryover Contamination | No carryover from high positive to negative samples. | No carryover observed in checkerboard study. |
2. Sample Size and Data Provenance (Clinical Study)
- Sample Size (Test Set):
- Subjects: 3300 evaluable subjects (1737 women, 1563 men).
- Specimens with Valid Aptima Results: 11,774.
- Specimens with Valid PIS Results (used for Sensitivity/Specificity): 11,557.
- Specimens with Specimen-Specific Composite Comparator Results (used for PPA/NPA): 11,665.
- Data Provenance: Prospective, multi-center clinical study conducted at 21 US sites. Testing was performed at three sites.
3. Number of Experts and Qualifications for Ground Truth (Clinical Study)
The ground truth ("patient infected status" - PIS) was established using a "composite comparator algorithm comprised of three validated transcription mediated amplification (TMA) based assays for Mycoplasma genitalium." The document specifies that these comparator TMA assays were developed by Hologic (the applicant), as shown in section "O. Other Supportive Instrument Performance Characteristics Data Not Covered In The "Performance Characteristics" Section above: Comparator TMA Assays validation."
Therefore, the ground truth was not established by human experts but by a composite of validated laboratory tests.
4. Adjudication Method (Clinical Study)
The PIS was determined using a composite comparator algorithm of three validated TMA assays.
- Method: Two of the three comparator TMA assays had to be positive or negative to establish the infected or not-infected PIS, respectively.
- Tie-breaker: The third TMA assay was run as a tie-breaker if the results of the first two TMA assays were discordant.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly described. This study evaluated the performance of a diagnostic device (the Aptima Mycoplasma genitalium Assay) against a composite reference standard (PIS), not the comparative effectiveness of human readers with or without AI assistance.
6. Standalone Performance Study
Yes, the study described is a standalone (algorithm only without human-in-the-loop performance) study. The Aptima Mycoplasma genitalium Assay is an in vitro diagnostic device (NAAT) whose performance characteristics (sensitivity, specificity, PPA, NPA) were directly evaluated against a composite reference standard. There is no indication of human interpretation or assistance being part of the device's output or the evaluation process.
7. Type of Ground Truth Used (Clinical Study)
The type of ground truth used was a composite comparator algorithm (laboratory-based), also referred to as "patient infected status (PIS)." This PIS was determined by the concordance of three validated transcription-mediated amplification (TMA) assays for Mycoplasma genitalium.
8. Sample Size for the Training Set
The document does not specify the sample size for a "training set." This is an in vitro diagnostic assay, and while it involves design and development, the primary clinical evaluation described is a prospective validation study. The analytical performance evaluations (e.g., LoD, inclusivity, cross-reactivity) involve testing various samples, but these are generally considered part of the verification and validation of the assay, not a distinct "training set" in the machine learning sense. The clinical study is a test set evaluation.
9. How the Ground Truth for the Training Set Was Established
As noted above, a distinct "training set" with independent ground truth establishment is not described in the context of this diagnostic assay's evaluation. The analytical studies establishing LoD, inclusivity, and specificity use characterized samples (e.g., spiked samples with known concentrations of M. genitalium or other microorganisms), which serve as their own form of "ground truth" for those specific analytical characteristics.
§ 866.3393 Device to detect nucleic acids from non-viral microorganism(s) causing sexually transmitted infections and associated resistance marker(s).
(a)
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.(b)
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.