(235 days)
The Alinity m CMV assay is an in vitro polymerase chain reaction (PCR) assay for use with the automated Alinity m System to quantitate cytomegalovirus (CMV) DNA in human EDTA plasma. The Alinity m CMV assay is intended for use as an aid in the management of Hematopoietic Stem Cell Transplant and Solid Organ Transplant patients who are undergoing anti-cytomegalovirus therapy. The Alinity m CMV assay can be used to assess virological response to anti-cytomegalovirus therapy.
The results from the Alinity m CMV test must be interpreted within the context of all relevant clinical and laboratory findings. The Alinity m CMV test is not intended as a screening test for the presence of CMV DNA in blood or blood products.
Alinity m CMV is an in vitro polymerase chain reaction (PCR) assay for the quantitation of CMV DNA in human EDTA plasma.
This device is similar to the predicate device originally approved (PMA P210022) with the exception that the subject device may use a new DNA Polymerase as an alternative to original DNA Polymerase in the reagent formulation of the assay. This formulation difference does not introduce any changes to sample processing, assay procedure, or data reduction.
Additional studies were initiated to support the formulation of the assay with alternative DNA Polymerase. Supplemental data from these studies were used with data previously obtained from the analytical and clinical testing studies submitted in P210022.
The steps of the Alinity m CMV consist of sample preparation, real-time PCR assembly, amplification/detection, result calculation, and reporting. All stages of the Alinity m CMV procedure are executed automatically by the Alinity m System. Manual dilutions may be performed for low-volume specimens to meet the minimum volume requirement.
The Alinity m System is designed to be a random-access analyzer that can perform the Alinity m CMV assay in parallel with other Alinity m assays on the same instrument.
Alinity m CMV requires three separate assay specific kits as follows:
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Alinity m CMV AMP Kit (List No. 09N46-095), consisting of 2 types of multi-well assay trays. The amplification trays (AMP TRAY 1) contain lyophilized, unit-dose PCR amplification/detection reagents and lyophilized, unit-dose IC in separate wells, and the activation trays (ACT TRAY 2) contain liquid unit-dose activation reagent. The intended storage condition for the Alinity m CMV AMP Kit is 2°C to 8°C.
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Alinity m CMV CTRL Kit (List No. 09N46-085), consisting of negative controls, low positive controls, and high positive controls, each supplied as liquid in single-use tubes. The intended storage condition for the Alinity m CMV CTRL Kit is –25°C to –15°C.
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Alinity m CMV CAL Kit (List No. 09N46-075), consisting of 2 calibrator levels, each supplied as liquid in single-use tubes. The intended storage condition for the Alinity m CMV CAL Kit is –25°C to –15°C.
CMV DNA from human plasma is extracted automatically on-board in the Alinity m System using the Alinity m Sample Prep Kit 2, Alinity m Lysis Solution, and Alinity m Diluent Solution. The Alinity m System employs magnetic microparticle technology to facilitate nucleic acid capture, wash, and elution. The resulting purified nucleic acids are then combined with liquid unit-dose Alinity m CMV activation reagent and lyophilized unit-dose Alinity m CMV amplification/detection reagents and transferred into a reaction vessel. Alinity m Vapor Barrier Solution is then added to the reaction vessel which is then transferred to an amplification/detection unit for PCR amplification, and real-time fluorescence detection of CMV targets.
At the beginning of the Alinity m CMV sample preparation process, a lyophilized unit-dose IC on the AMP Tray is rehydrated by the Alinity m System and delivered into each sample preparation reaction. The IC is then processed through the entire sample preparation and real-time PCR procedure along with the specimens, calibrators, and controls to demonstrate proper sample processing and validity.
The Alinity m CMV amplification/detection reagents consist of enzymes, primers, probes, and activation reagents that enable polymerization and detection.
A CMV calibration curve is required for determination of CMV DNA concentration. Two levels of calibrators are processed through sample preparation and PCR to generate the calibration curve. The concentration of CMV DNA in specimens and controls is then calculated from the stored calibration curve.
Assay controls are tested at or above an established minimum frequency to help ensure that instrument and reagent performance remains satisfactory. During each control event, a negative control, a low-positive control, and a high-positive control are processed through sample preparation and PCR procedures that are identical to those used for specimens.
The Alinity m CMV assay also utilizes the following:
- Alinity m CMV Application Specification File, (List No. 09N46-05B)
- Alinity m System and System Software (List No. 08N53)
- Alinity m Sample Prep Kit 2 (List No. 09N12-001)
- Alinity m Specimen Dilution Kit I (List No. 09N50-001)
- Alinity m System Solutions, (List No. 09N20):
- Alinity m Lysis Solution (List No. 09N20-001)
- Alinity m Diluent Solution (List No. 09N20-003)
- Alinity m Vapor Barrier Solution, (List No. 09N20-004)
- Alinity m Tubes and Caps (List No. 09N49):
- Alinity m LRV Tube (List No. 09N49-001)
- Alinity m Transport Tubes Pierceable Capped (List No. 09N49-010)
- Alinity m Transport Tube (List No. 09N49-011)
- Alinity m Pierceable Cap (List No. 09N49-012)
- Alinity m Aliquot Tube (List No. 09N49-013)
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided FDA 510(k) clearance letter for the Alinity m CMV assay:
The core of this submission is to demonstrate that a new formulation of the Alinity m CMV assay (using an "alternative DNA Polymerase") is substantially equivalent to the previously FDA-approved Alinity m CMV assay (using the "original DNA Polymerase"). Therefore, the acceptance criteria for the new formulation are implicitly that its performance characteristics (LoD, Linearity, Precision, Reproducibility, Method Comparison) are comparable to, and meet the established claims of, the original predicate device.
1. Table of Acceptance Criteria and Reported Device Performance
Since this is a submission demonstrating equivalence to an already approved device, the acceptance criteria are not explicitly stated as pass/fail thresholds in this document, but rather as meeting or being comparable to the performance of the predicate device (P210022). The reported performance shows that the new formulation did meet these implicit criteria.
| Performance Characteristic | Acceptance Criteria (Implicit - based on predicate P210022) | Reported Device Performance (Alternative DNA Polymerase) |
|---|---|---|
| Limit of Detection (LoD) | Detection rate ≥ 95% at 30 IU/mL (similar to predicate) | 96.9% detection rate at 30 IU/mL (95% CI: 93.4%, 98.6%) |
| Linear Range | Linear across 30 IU/mL (1.48 Log IU/mL) to 100,000,000 IU/mL (8.00 Log IU/mL) (similar to predicate) | Linear across 30 IU/mL to 100,000,000 IU/mL (r = 0.999) |
| Precision | Within-lab SD: |
- ≤ 0.25 Log IU/mL for 500-100,000,000 IU/mL
- ≤ 0.50 Log IU/mL for 50-
§ 866.3180 Quantitative cytomegalovirus nucleic acid tests for transplant patient management.
(a)
Identification. A quantitative cytomegalovirus (CMV) nucleic acid test for transplant patient management is identified as a device intended for prescription use in the detection of CMV and as an aid in the management of transplant patients to measure CMV deoxyribonucleic acid (DNA) levels in human plasma and/or whole blood using specified specimen processing, amplification, and detection instrumentation. The test is intended for use as an aid in the management of transplant patients with active CMV infection or at risk for developing CMV infection. The test results are intended to be interpreted by qualified healthcare professionals in conjunction with other relevant clinical and laboratory findings.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The labeling required under § 809.10(b) of this chapter must include:
(i) A prominent statement that the device is not intended for use as a donor screening test for the presence of CMV DNA in blood or blood products.
(ii) Limitations, which must be updated to reflect current clinical practice. The limitations must include, but are not limited to, statements that indicate:
(A) Test results are to be interpreted by qualified licensed healthcare professionals in conjunction with clinical signs and symptoms and other relevant laboratory results;
(B) Negative test results do not preclude CMV infection or tissue invasive CMV disease, and that CMV test results must not be the sole basis for patient management decisions.
(iii) A detailed explanation of the interpretation of results and acceptance criteria must be provided and include specific warnings regarding the potential for variability in CMV viral load measurement when samples are measured by different devices. Warnings must include the following statement, where applicable: “Due to the potential for variability in CMV viral load measurements across different CMV assays, it is recommended that the same device be used for the quantitation of CMV viral load when managing CMV infection in individual patients.”
(iv) A detailed explanation of the principles of operation and procedures for assay performance.
(2) Design verification and validation must include the following:
(i) Detailed documentation of the device description, including all parts that make up the device, reagents required for use with the CMV assay but not provided, an explanation of the methodology, design of the primer/probe sequences, rationale for the selected gene target, and specifications for amplicon size, guanine-cytosine content, and degree of nucleic acid sequence conservation. The design and nature of all primary, secondary, and tertiary quantitation standards used for calibration must also be described.
(ii) A detailed description of the impact of any software, including software applications and hardware-based devices that incorporate software, on the device's function.
(iii) Documentation and characterization of all critical reagents (
e.g., determination of the identity, supplier, purity, and stability) and protocols for maintaining product integrity throughout its labeled shelf life.(iv) Stability data for reagents provided with the device and indicated specimen types, in addition to the basis for the stability acceptance criteria at all time points chosen across the spectrum of the device's indicated life cycle, which must include a time point at the end of shelf life.
(v) All stability protocols, including acceptance criteria.
(vi) Final lot release criteria, along with documentation of an appropriate justification that lots released at the extremes of the specifications will meet the claimed analytical and clinical performance characteristics as well as the stability claims.
(vii) Risk analysis and documentation demonstrating how risk control measures are implemented to address device system hazards, such as Failure Modes Effects Analysis and/or Hazard Analysis. This documentation must include a detailed description of a protocol (including all procedures and methods) for the continuous monitoring, identification, and handling of genetic mutations and/or novel CMV stains (
e.g., regular review of published literature and annual in silico analysis of target sequences to detect possible primer or probe mismatches). All results of this protocol, including any findings, must be documented.(viii) Analytical performance testing that includes:
(A) Detailed documentation of the following analytical performance studies: Limit of detection, upper and lower limits of quantitation, inclusivity, precision, reproducibility, interference, cross reactivity, carryover, quality control, specimen stability studies, and additional studies as applicable to specimen type and intended use for the device.
(B) Identification of the CMV strains selected for use in analytical studies, which must be representative of clinically relevant circulating strains.
(C) Inclusivity study results obtained with a variety of CMV genotypes as applicable to the specific assay target and supplemented by in silico analysis.
(D) Reproducibility studies that include the testing of three independent production lots.
(E) Documentation of calibration to a standardized reference material that FDA has determined is appropriate for the quantification of CMV DNA (
e.g., a recognized consensus standard).(F) Documentation of traceability performed each time a new lot of the standardized reference material to which the device is traceable is released, or when the field transitions to a new standardized reference material.
(ix) Clinical performance testing that includes:
(A) Detailed documentation of device performance data from either a method comparison study with a comparator that FDA has determined is appropriate, or results from a prospective clinical study demonstrating clinical validity of the device.
(B) Data from patient samples, with an acceptable number of the CMV positive samples containing an analyte concentration near the lower limit of quantitation and any clinically relevant decision points.
(C) The method comparison study must include predefined maximum acceptable differences between the test and comparator method across all primary outcome measures in the clinical study protocol.
(D) The final release test results for each lot used in the clinical study.