(174 days)
The CEP 12 SpectrumOrange Direct Labeled Chromosome Enumeration DNA Probe Kit is designed to be an adjunct to standard cytogenetic analysis for in vitro diagnostic use in identifying and enumerating chromosome 12 via fluorescence in situ hybridization (FISH) in interphase nuclei of cells obtained from peripheral blood lymphocytes in patients with chronic lymphocytic leukemia (CLL). Results from the CEP 12 SpectrumOrange Direct Labeled Chromosome Enumeration DNA Probe Kit are intended for use in conjunction with standard cytogenetics and for further assessing the trisomy 12 status in normal and abnormal tissue specimens characterized by standard cytogenetics, in patients with and/or without clinical symptoms of CLL. It is not intended to be a stand alone assay for test reporting.
The CEP 12 SpectumOrange DNA Probe is a SpectumOrange fluorescent labeled DNA probe specific for the centromeric region of chronosome 12. This assey is designed IDN provide a rapid and reliable method for the desertion and quantification of chromosome 12 In interphase nuclei by fluorescence in situ hybridization (FISH).
Here's a breakdown of the acceptance criteria and study information for the CEP 12 SpectrumOrange DNA Probe Kit, based on the provided text:
Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Metric | Acceptance Standard | Reported Device Performance |
|---|---|---|---|
| Hybridization Efficiency | Percentage of cells with no hybridization signal | ≤ 2% (realistic standard) | Average of 0.43% (S.D.=1.48%) on 402 peripheral blood specimens. |
| Analytical Sensitivity | Limit of Detection (LOD) | 4.0% (estimated) | 0% specimen estimated with mean 1.72%. Slight overlap with 5% specimen (upper 95% CI for 0% was 3.86%, lower 95% CI for 5% was 2.93%). |
| Analytical Specificity | Cross-hybridization to other loci | No cross-hybridization to other chromosomes | No cross-hybridization observed in any of the 56 metaphase spreads examined. Hybridization was limited to chromosome 12 centromere. |
| Reproducibility | Intra-assay variation (CV) for 0% specimen | Not explicitly stated as a numerical acceptance criterion, but implicitly expected low CV. | CV of 63.1% for 0% specimen (Mean=1.72%, SD=1.09%, N=22). |
| Intra-assay variation (CV) for 5% specimen | Not explicitly stated as a numerical acceptance criterion. | CV of 20.4% for 5% specimen (Mean=4.87%, SD=0.99%, N=23). | |
| Intra-assay variation (CV) for 10% specimen | Not explicitly stated as a numerical acceptance criterion. | CV of 19.4% for 10% specimen (Mean=9.19%, SD=1.78%, N=23). | |
| Intra-assay variation (CV) for 13% specimen | Not explicitly stated as a numerical acceptance criterion. | CV of 13.3% for 13% specimen (Mean=12.07%, SD=1.61%, N=24). | |
| Inter-site/inter-observer variation | Expected to be acceptable reflecting visual enumeration | "significant site-to-site and observer-to-observer variations were observed, reflecting the subjectivity of the visual enumeration process." | |
| Clinical Sensitivity | Relative Sensitivity | Not explicitly stated as a numerical acceptance criterion, but expected high. | 100% (95% CI 91.2% to 100%) compared to standard cytogenetics. |
| Clinical Specificity | Relative Specificity | Not explicitly stated as a numerical acceptance criterion, but expected high. | 91.47% (95% CI 86.66% to 96.22%) compared to standard cytogenetics. |
Study Details
2. Sample Size Used for the Test Set and Data Provenance:
- Pivotal Study (Hybridization Efficiency): 402 peripheral blood specimens.
- Analytical Specificity: 56 metaphase spreads.
- Reproducibility Study:
- 0% specimen: 22 replicates
- 5% specimen: 23 replicates
- 10% specimen: 23 replicates
- 13% specimen: 24 replicates
- Provenance: Hematologically derived human cells (mixtures with known percentages of trisomy 12).
- Clinical Specimens (Methods Comparison):
- Total 402 peripheral blood specimens from patients with B-cell chronic lymphocytic leukemia (B-CLL).
- Provenance: Multi-center study; specimens from three sites (Site 1: 97 specimens, Site 2: 205 specimens, Site 3: 100 specimens). One site (from the United Kingdom) provided 157 specimens.
- Retrospective/Prospective: Not explicitly stated, but the collection of "peripheral blood specimens... from a total of 402 patients" suggests they were likely retrospective, selected for the study.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- Analytical Specificity: Examination "sequentially by G-banding" followed by FISH. This implies cytogeneticists, but the number and specific qualifications are not detailed.
- Reproducibility Study: "Known percentages of trisomy 12" in the cell mixtures suggests a predefined truth, likely established by advanced cytogenetic techniques, but no "experts" are explicitly described for this part of ground truth establishment.
- Clinical Specimens (Methods Comparison): Standard cytogenetic analysis was used as the comparator (ground truth). Each site followed "its own in-house protocol for standard cytogenetic analysis." This implies trained cytogeneticists performed the standard cytogenetic analysis and interpretation due to the nature of G-banding and karyotyping. The number of experts per site is not specified, nor are their detailed qualifications (e.g., years of experience).
4. Adjudication Method for the Test Set:
The document does not explicitly describe a formal adjudication method (e.g., 2+1, 3+1) for the interpretation of either the FISH results or the standard cytogenetic results. For clinical specimens, it notes that "inter-site and observer-to-observer variations were observed" in the reproducibility study, suggesting independent assessments without a specific adjudication process mentioned for discrepancies in the broader clinical study.
5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study:
No, an MRMC comparative effectiveness study, in the sense of evaluating how much human readers improve with AI vs. without AI assistance, was not performed. This study compares a device (FISH probe) to a standard clinical method (cytogenetics), which are both human-interpreted methods, not an AI system.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study:
Yes, the analytical sensitivity, specificity, and reproducibility studies for the CEP 12 SpectrumOrange DNA Probe Kit essentially represent standalone performance where the probe kit itself is being evaluated. The reading of the FISH signals is a human-in-the-loop step, but the performance metrics (hybridization efficiency, LOD, cross-hybridization) are inherent to the probe and its interaction with the biological sample.
7. Type of Ground Truth Used:
- Analytical Specificity: G-banding (a traditional cytogenetic technique for chromosome identification).
- Reproducibility: "Known percentages of trisomy 12" in cell mixtures, implying a highly characterized true state.
- Clinical Specimens (Methods Comparison): Standard cytogenetic analysis (G-banded karyotyping).
8. Sample Size for the Training Set:
The document does not mention a training set or machine learning/AI algorithms that would require one. This submission is for a DNA probe kit, not an AI-powered diagnostic device.
9. How the Ground Truth for the Training Set Was Established:
Not applicable, as there is no training set mentioned.
§ 866.6040 Gene expression profiling test system for breast cancer prognosis.
(a)
Identification. A gene expression profiling test system for breast cancer prognosis is a device that measures the ribonucleic acid (RNA) expression level of multiple genes and combines this information to yield a signature (pattern or classifier or index) to aid in prognosis of previously diagnosed breast cancer.(b)
Classification. Class II (special controls). The special control is FDA's guidance document entitled “Class II Special Controls Guidance Document: Gene Expression Profiling Test System for Breast Cancer Prognosis.” See § 866.1(e) for the availability of this guidance document.