(265 days)
The Verigene® CYP2C19 Nucleic Acid Test (CYP2C19 Test), performed using the sample-to-result Verigene System, is a qualitative multiplexed in vitro diagnostic test for the simultaneous detection and identification of an individual's CYP450 2C19 genotype in genomic deoxyribonucleic acid (DNA) obtained from EDTA-anticoagulated whole blood samples. The Verigene CYP2C19 Nucleic Acid Test (CYP2C19 Test) is indicated for use in clinical laboratories upon prescription by the attending physician as an aid to clinicians in determining therapeutic strategy for therapeutics that are metabolized by the CYP450 2C19 gene product, specifically *2, *3, and *17. The Verigene CYP2C19 Nucleic Acid Test (CYP2C19 Test) is not indicated to be used to predict drug response or non-response.
The Verigene® System is comprised of test consumables and shared instrumentation. All Verigene tests are formatted in self-contained test-specific Verigene Test Cartridges which serve to analyze a nucleic acid sample that is presented to them. Nucleic acids are prepared directly from a whole blood specimen using magnetic glass particles and input automatically into a Test Cartridge inside the Verigene Processor SP. Test progress is tracked and directed by the Verigene Reader instrument, which serves as a central control unit for each Verigene System. Genomic DNA is extracted from the white blood cells in a whole blood specimen, fragmented and denatured. This fragmented, single-stranded genomic DNA hybridizes to complementary sequence-specific DNA oligonucleotides, known as capture oligonucleotides, arrayed on the surface of a substrate (glass slide). A second DNA oligonucleotide is then hybridized to the captured genomic DNA that was captured initially. This oligonucleotide is known as a mediator oligonucleotide containing two sequence domain is complementary to the genomic DNA target and a second domain is complementary to a common oligonucleotide attached to a signal generating gold nanoparticle probe. After washing away any DNA not affixed to the captures, the probe is exposed to the captured mediator/target compound where it hybridizes to any captured mediators. Presence of the gold nanoparticle probes at a particular location on the substrate is assessed optically. The Verigene CYP2C19 Nucleic Acid Test is designed to detect and genotype the CYP450 2C19 *2, *3 and *17 alleles. The test report lists the alleles and provides which genotype was detected in the specimen. The CYP2C19 Test algorithm automatically calculates each of the allele results using a preset normalized ratio of the signal of wild type capture locations on the microarray to the mutant capture locations on the microarray.
This submission focuses on the analytical and clinical performance of the Verigene® CYP2C19 Nucleic Acid Test. Here's a breakdown based on your request:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Acceptance Criteria (Implicit/Explicit) | Reported Device Performance |
|---|---|---|
| Analytical Sensitivity / Limit of Detection (LOD) | Initial call rate > 90% and 100% accuracy vs. BDS for detected genotypes within specified sample volume range. | Initial call rate > 90% and 100% accuracy vs. BDS for all tested genotypes between 800µL - 1200µL sample input volume. |
| Interference | Consistent detection and 100% accuracy vs. BDS in presence of elevated interfering substances. | All genotypes detected consistently with 100% accuracy vs. BDS in the presence of albumin, bilirubin (conjugated and unconjugated), triglycerides, and cholesterol. |
| Specimen Stability | No degradation (e.g., no decrease in extracted DNA concentration/purity, high daily call rate, 100% genotype accuracy) for designated storage conditions. | No signs of degradation, daily call rate > 97%, and 100% genotype accuracy observed for 10 days at refrigerated storage (2 to 8°C). |
| Carry-over / Cross-contamination | 100% genotyping accuracy and no evidence of carry-over/cross-contamination. | 100% genotyping accuracy and no evidence of carry-over/cross-contamination (initial call rates > 93%) during sequential testing of different genotypes. |
| Precision | High percent agreement compared to bi-directional sequencing, with a high initial and final call rate. | Initial Call Rate: 97.7% (375/384). Final Call Rate: 100% (384/384). Agreement vs. BDS: 100% (384/384). |
| Reproducibility | High percent agreement compared to bi-directional sequencing, with a high initial and final call rate across multiple sites. | Initial Call Rate: 96.9% (465/480). Final Call Rate: 99.6% (478/480). Agreement vs. BDS: 99.6% (478/480). |
| Method Comparison | High percent agreement compared to bi-directional sequencing, with high initial and final call rates. | Initial Call Rate: 94.8% (635/670). Final Call Rate: 99.9% (669/670). Agreement vs. BDS: 99.6% (667/670). |
2. Sample Size Used for the Test Set and Data Provenance
The document describes several test sets used for different studies:
- Analytical Sensitivity / LOD: 7 individual whole blood samples, each with a different genotype. Tested in replicates of 40 (total 280 tests). The data provenance is not specified, but it refers to "individual whole blood samples," suggesting clinical samples. The study appears to be prospective in nature, designed specifically for this validation.
- Interference Testing: 5 individual whole blood samples, each with a different genotype. Tested in 30 replicates per specimen for each interfering substance (total 150 tests per substance, with 5 substances and a control, leading to 900 measurements in Table 2). Data provenance is not specified, but it refers to "EDTA-anticoagulated whole blood samples," suggesting clinical samples. This study appears to be prospective.
- Specimen Stability Study: 35 EDTA whole blood samples. Tested once at 5, 10, 12, and 15 day time points (total 140 tests). Data provenance is not specified (e.g., "freshly-collected whole blood samples"). This study appears to be prospective.
- Carry-over / Cross-contamination: Whole blood specimens containing different genotypes. Tested sequentially on ten Verigene instruments, repeated in triplicate (total number of samples not explicitly stated, but includes "*1/*2, followed by *1/*1, then *1/*17, then *1/*1" repeated in triplicate). Data provenance is not specified. This study appears to be prospective.
- Precision Study: 8 unique whole blood specimens. Each tested in duplicate twice daily by two operators over 12 non-consecutive days at one site (48 replicates per specimen, total 384 data points). Data provenance is not specified. This study appears to be prospective.
- Reproducibility Study: The same 8-member panel of specimens as the Precision Study. Tested in duplicate twice daily by two operators over 5 non-consecutive days at three sites (60 replicates per specimen, total 480 data points). Data provenance is not specified. This study appears to be prospective.
- Method Comparison Study: 670 unique human whole blood samples, collected in EDTA. Data provenance is not specified, but the samples are "human whole blood samples," implying clinical origin. The study appears to be prospective, specifically for method comparison.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The ground truth for all performance studies (Analytical Sensitivity, Interference, Precision, Reproducibility, Method Comparison) was established by bi-directional sequencing (BDS). This is a laboratory method, not reliant on human experts for interpretation in the same way imaging studies might be. Therefore, the concept of "number of experts" and their "qualifications" for ground truth establishment is not applicable here.
4. Adjudication Method for the Test Set
Not applicable for this type of laboratory test. The ground truth (bi-directional sequencing) is considered definitive. When the device produced "No Calls" initially, these samples were re-tested, and if successful, contributed to the "Final Call Rate." In the Reproducibility study, the two final "No Call" results were considered discordant. For the Method Comparison study, one sample with an initial and final no-call on the Verigene test had a BDS result of *1/*2, indicating this was a definite discrepancy.
5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was done
No, an MRMC comparative effectiveness study was not conducted. This device is a molecular diagnostic test that provides a genotype result, not an imaging device requiring human reader interpretation.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, the performance studies detailed (Analytical Sensitivity, Interference, Stability, Carry-over, Precision, Reproducibility, Method Comparison) represent the standalone performance of the Verigene® CYP2C19 Nucleic Acid Test. The system is described as "sample-to-result" with "automated DNA extraction" and the "Test algorithm automatically calculates each of the allele results." This indicates minimal human intervention in the final result generation once the sample is loaded.
7. The Type of Ground Truth Used
The primary ground truth used for all performance evaluations was bi-directional sequencing (BDS). This is a highly accurate molecular method for determining specific DNA sequences, considered the gold standard for genotyping.
8. The Sample Size for the Training Set
The document does not specify a separate training set or its sample size. This is common for diagnostic tests like this, especially when the underlying technology (genotyping microarray and algorithm) is based on established scientific principles rather than a machine learning model that requires explicit training data in the context of regulatory submissions. The algorithm's parameters are likely "preset" based on scientific design and internal development/optimization rather than a distinct, large-scale training dataset as seen with AI/ML systems.
9. How the Ground Truth for the Training Set was Established
Since no explicit "training set" is described in the context of this 510(k) summary, the method for establishing its ground truth is also not provided. The device's "preset normalized ratio of the signal of wild type capture locations on the microarray to the mutant capture locations on the microarray" implies that the underlying genetic science and expected signal profiles for specific alleles dictate the algorithm's basis, rather than being "trained" on a dataset in the AI/ML sense.
§ 862.3360 Drug metabolizing enzyme genotyping system.
(a)
Identification. A drug metabolizing enzyme genotyping system is a device intended for use in testing deoxyribonucleic acid (DNA) extracted from clinical samples to identify the presence or absence of human genotypic markers encoding a drug metabolizing enzyme. This device is used as an aid in determining treatment choice and individualizing treatment dose for therapeutics that are metabolized primarily by the specific enzyme about which the system provides genotypic information.(b)
Classification. Class II (special controls). The special control is FDA's guidance document entitled “Class II Special Controls Guidance Document: Drug Metabolizing Enzyme Genotyping Test System.” See § 862.1(d) for the availability of this guidance document.