(28 days)
The Aptima® CMV Quant Assay is an in vitro nucleic acid amplification test for the quantitation of human cytomegalovirus (CMV) DNA in human EDTA plasma on the fully automated Panther® system.
The Aptima CMV Quant Assay is intended for use to aid in the management of solid-organ transplant patients and hematopoietic stem cell transplant patients receiving anti-CMV therapy, serial DNA measurements can be used to assess viral response to treatment. The results from Aptima CMV Quant assay must be interpreted within the context of all relevant clinical and laboratory findings.
The Aptima CMV Quant Assay is not intended for use as a screening assay for the presence of CMV in blood or blood products.
The Aptima CMV Quant Assay is an in vitro nucleic acid amplification test that uses real-time transcription mediated amplification (TMA) technology on the Panther Fusion system to quantify CMV DNA, genotypes 1, 2, 3, and 4. The primer design targets the highly conserved UL56 gene to ensure accurate quantitation of the CMV DNA. The assay is standardized to the WHO International Standard for human cytomegalovirus. The Aptima CMV Quant Assay is intended for use to aid in the management of solid-organ transplant patients and hematopoietic stem cell transplant patients.
The addition of a protocol to treat specific plasma samples with proteinase K in the assay package insert will allow the retesting of those samples to obtain a valid result.
The provided text describes a 510(k) premarket notification for the "Aptima CMV Quant Assay" and specifically details an update to the assay's package insert to include a protocol for retesting plasma samples that initially yield an "ML2 flag" invalid result. This retesting involves a manual pretreatment with proteinase K. The information provided is for a diagnostic assay, not an AI/ML-based device. Therefore, many of the requested elements pertaining to AI/ML development, such as training sets, ground truth establishment for AI/ML, expert consensus for imaging, MRMC studies, and effect sizes of AI assistance, are not applicable.
However, I can extract information related to the acceptance criteria and the study that proves the device (specifically, the proteinase K pretreatment protocol) meets the acceptance criteria within the context of a diagnostic assay's performance and validation.
Acceptance Criteria and Study for the Proteinase K Pretreatment Protocol
The primary acceptance criterion for this change is to demonstrate that the proteinase K pretreatment protocol effectively resolves the "ML2 flag" invalid results and does not negatively impact the accuracy of the CMV quantification.
1. Table of Acceptance Criteria and the Reported Device Performance:
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Reduction/Elimination of ML2 Flag Invalid Results: The protocol should effectively enable valid results for samples initially flagged with ML2. | The prevalence of specimens invalidated with ML2 flags at the NIH decreased from 0.87% (on testing 1039 plasma specimens without proteinase K treatment) to 0% (on testing 4098 specimens with proteinase K treatment) when the proteinase K protocol was used. |
| Maintenance of Accuracy: The proteinase K pretreatment should not negatively impact the accuracy of CMV quantification. | The NIH also demonstrated that using proteinase K for pretreatment of specimens did not impact the accuracy of CMV quantification in the Aptima Assay (as referenced by Youn et al. 2024). The Hologic risk assessment concluded that the benefits outweigh the risks and the "assay performance characteristics including accuracy are maintained with incorporation of this modification." |
| Feasibility and Safety of Protocol Implementation: The protocol should be practical for use in clinical laboratories and not introduce new safety concerns for the assay. | The protocol is described with clear steps (temperature, volume, timing). The risk assessment stated that "the benefits provided by the updates to the Hologic specimen handling workflow at customer sites outweigh the risks." |
2. Sample Size Used for the Test Set and the Data Provenance:
- Test Set Sample Sizes:
- Without Proteinase K: 1039 plasma specimens
- With Proteinase K: 4098 plasma specimens
- Data Provenance: The plasma specimens were collected from the transplant patient population by the National Institute of Health (NIH). This suggests a retrospective analysis of archived samples or a prospective study conducted at the NIH. The location is the USA.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications:
- Not applicable as this is a quantitative diagnostic assay for DNA detection, not an image-based AI/ML device requiring expert interpretation of images for ground truth. The "ground truth" here is the actual CMV DNA concentration, which the assay is designed to measure.
4. Adjudication Method for the Test Set:
- Not applicable for a quantitative diagnostic assay. The performance is assessed against the ability to produce a valid quantitative result for CMV DNA and maintain accuracy, not against human consensus.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done:
- No, this is not an MRMC study. MRMC studies are typically performed for visual diagnostic aids (e.g., medical imaging AI) to compare human reader performance with and without AI assistance. This device is a direct quantitative assay.
6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done:
- Yes, in a sense. The study validates the protocol (which includes a manual pretreatment step) and its effect on the automated assay system's ability to produce a valid result. The "performance" refers to the assay's output after the sample preparation, not an AI algorithm's independent decision. The core assay itself operates in a "standalone" fashion once the sample is loaded onto the Panther system.
7. The type of ground truth used:
- The implicit ground truth is the actual CMV DNA concentration in patient samples (or spiked controls used in accuracy assessments), as determined by a reference method or known concentrations. The study's focus, however, is on resolving an assay technical issue (ML2 flag) and demonstrating that the resolution method maintains the accuracy of CMV quantification. The reference to the NIH demonstrating that "using proteinase K for pretreatment of specimens did not impact the accuracy of CMV quantification" confirms that accurate quantitation (the ground truth outcome) was assessed.
8. The Sample Size for the Training Set:
- Not applicable. This is not an AI/ML device that requires a training set in the conventional sense. The "training" for such an assay would be its initial development and optimization, which isn't described in terms of a specific "training set" size for this modification. The data provided refers to validation/test sets for the new protocol.
9. How the ground truth for the training set was established:
- Not applicable, as it's not an AI/ML device with a training set for model development.
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January 17, 2025
Image /page/0/Picture/1 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo, which consists of the letters "FDA" in a blue square, followed by the words "U.S. FOOD & DRUG" in blue, with the word "ADMINISTRATION" underneath.
Hologic, Inc. Maria Jose Cortes-Mateos Regulatory Affairs Specialist III 10210 Genetic Center Dr. San Diego, California 92121
Re: K243935
Trade/Device Name: Aptima CMV Quant Assay Regulation Number: 21 CFR 866.3180 Regulation Name: Quantitative Cytomegalovirus Nucleic Acid Tests For Transplant Patient Management Regulatory Class: Class II Product Code: PAB Dated: December 19, 2024 Received: December 20, 2024
Dear Maria Jose Cortes-Mateos:
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 (the 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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
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Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).
Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30. Design controls; 21 CFR 820.90. Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).
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 Part 801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safetyreporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.
All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-device-advicecomprehensive-regulatory-assistance/unique-device-identification-system-udi-system.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See
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the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
MARIA I. GARCIA -S
Maria Garcia, Ph.D. Assistant Director Division of Microbiology Devices OHT7: Office of In Vitro Diagnostics Office of Product Evaluation and Quality Center for Devices and Radiological Health
Enclosure
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DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration
Indications for Use
Form Approved: OMB No. 0910-0120 Expiration Date: 07/31/2026 See PRA Statement below.
Submission Number (if known)
Device Name
Aptima CMV Quant Assay
Indications for Use (Describe)
The Aptima® CMV Quant Assay is an in vitro nucleic acid amplification test for the quantitation of human cytomegalovirus (CMV) DNA in human EDTA plasma on the fully automated Panther® system.
The Aptima CMV Quant Assay is intended for use to aid in the management of solid-organ transplant patients and hematopoietic stem cell transplant patients receiving anti-CMV therapy, serial DNA measurements can be used to assess viral response to treatment. The results from Aptima CMV Quant assay must be interpreted within the context of all relevant clinical and laboratory findings.
The Aptima CMV Quant Assay is not intended for use as a screening assay for the presence of CMV in blood or blood products.
Type of Use (Select one or both, as applicable)
X Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
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Image /page/4/Picture/2 description: The image shows the logo for Hologic. The logo is in blue and consists of the word "HOLOGIC" in large, bold letters. Below the word, there are several vertical lines of varying lengths, followed by the text "The Science of Sure".
510(k) SUMMARY
Aptima CMV Quant Assay
I. SUBMITTER
Hologic, Inc.
10210 Genetic Center Drive San Diego, CA 92121
| Contact Person: | Maria Jose Cortes-Mateos, Ph.D., RACRegulatory Affairs Specialist IIIMaria-Jose.Cortes-Mateos@hologic.comPhone: (858) 410-8713 |
|---|---|
| ----------------- | -------------------------------------------------------------------------------------------------------------------------------------------- |
Date Prepared: December 17, 2024
II. DEVICE
| Proprietary Name: | Aptima CMV Quant Assay |
|---|---|
| Classification Name: | Quantitative cytomegalovirus nucleic acid tests fortransplant patient management. |
| Regulation Number: | 21 CFR 866.3180 |
| Regulatory Class: | Class II |
| Product Code: | PAB |
III. PREDICATE DEVICE
The predicate device is the Aptima CMV Quant Assay (P210029; approved May 9, 2022), marketed as a 100-test kit configuration.
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DEVICE DESCRIPTION IV.
The Aptima CMV Quant Assay is an in vitro nucleic acid amplification test that uses real-time transcription mediated amplification (TMA) technology on the Panther Fusion system to quantify CMV DNA, genotypes 1, 2, 3, and 4. The primer design targets the highly conserved UL56 gene to ensure accurate quantitation of the CMV DNA. The assay is standardized to the WHO International Standard for human cytomegalovirus. The Aptima CMV Quant Assay is intended for use to aid in the management of solid-organ transplant patients and hematopoietic stem cell transplant patients.
The addition of a protocol to treat specific plasma samples with proteinase K in the assay package insert will allow the retesting of those samples to obtain a valid result.
Principles of the Procedure
The Aptima CMV Quant Assay is an in vitro nucleic acid amplification test that uses real-time transcription mediated amplification (TMA) technology on the Panther system* to quantify CMV DNA, genotypes 1, 2, 3, and 4. The primer design targets the highly conserved UL56 gene to ensure accurate quantitation of the CMV DNA. The assay is standardized to the 1st WHO International Standard for human cytomegalovirus (NIBSC code: 09/162).
The Aptima CMV Quant Assay involves three main steps, which take place in a single tube on the Panther system: target capture, target amplification by TMA, and detection of the amplification products (amplicon) by the fluorescently labeled probes (torches).
During target capture, viral DNA is isolated from specimens. The specimen is treated with a detergent to solubilize the viral envelope, denature proteins, and release viral genomic DNA. Capture oligonucleotides hybridize to highly conserved regions of CMV DNA, if present, in the test specimen. The hybridized target is then captured onto magnetic microparticles that are separated from the specimen in a magnetic field. Wash steps remove extraneous components from the reaction tube.
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Target amplification occurs via TMA, which is a transcription-mediated nucleic acid amplification method that utilizes two enzymes, Moloney murine leukemia virus (MMLV) reverse transcriptase and T7 RNA polymerase. The reverse transcriptase is used to generate a DNA copy (containing a promoter sequence for T7 RNA polymerase) of the target sequence. T7 RNA polymerase produces multiple copies of RNA amplicon from the DNA copy template.
Detection is achieved using single-stranded nucleic acid torches that are present during the amplification of the target and that hybridize specifically to the amplicon in real time. Each torch has a fluorophore and a quencher. When the torch is not hybridized to the amplicon, the quencher is in close proximity of the fluorophore and suppresses the fluorescence. When the torch binds to the amplicon, the quencher is moved farther away from the fluorophore, which will emit a signal at a specific wavelength when excited by a light source. As more torches hybridize to amplicon, a higher fluorescent signal is generated. The time taken for the fluorescent signal to reach a specified threshold is proportional to the starting CMV concentration. Each reaction has an internal calibrator/internal control (IC) that controls for variations in specimen processing, amplification, and detection. The concentration of a sample is determined by the Panther system software using the CMV and IC signals for each reaction and comparing them to calibration information.
Assay results are converted from copies/mL to IU/mL using a conversion factor equation embedded in the Panther software.
Assay Components
The Aptima CMV Quant Assay provides enough reagents to run 100 tests. The assay kit contains 4 boxes: Box 1, Main Assay Kit Reagents: Box 2, Target Enhancer Reagent (TER): Box 3, Calibrator Kit; and Box 4, Controls Kit. All these components are required for sample processing.
Box 1, Main Assay Reagents, and Box 2, TER, are master lot related and cannot be ordered separately. They are provided in different boxes due to the different reagent storage temperature conditions. Box 3 contains the Calibrator Kit, and Box 4 contains the Controls Kit when
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provided as part of the master kit. These two kits may also be procured separately if customers need additional calibrators or controls. A listing of the components that are required to perform the Aptima CMV Quant Assay is detailed in Table 1. The ancillary reagents are listed in Table 2.
Table 1 - Reagents Required to Perform the Aptima CMV Quant Assay, 100 test kit
| Box | Description | Components Description |
|---|---|---|
| BOX 1 | Aptima CMV QuantMain Assay Reagents Kit(2°C to 8°C) | Amplification Reagent |
| Enzyme Reagent | ||
| Promoter Reagent | ||
| Amplification Reconstitution Solution | ||
| Enzyme Reconstitution Solution | ||
| Promoter Reconstitution Solution | ||
| Target Capture Reagent (TCR) | ||
| BOX 2 | Aptima CMV QuantTarget Enhancer Reagent(15°C to 30°C) | Target Enhancer Reagent (TER) |
| BOX 3 | Aptima CMV QuantCalibrator Kit(-15°C to -35°C) | Positive Calibrator |
| BOX 4 | Aptima CMV QuantControls Kit(-15°C to -35°C) | Negative Control |
| Low Positive Control | ||
| High Positive Control |
Table 2 - Ancillary Reagents
| Aptima Assay Fluids Kit |
|---|
| Proteinase K (RNA grade), 20 mg/mL, DNase-Free, RNase-Free |
| (Thermo Fisher Scientific) |
Instrumentation
The Aptima CMV Quant Assay has been designed for and validated on the Panther/Panther Fusion system. The Panther/Panther Fusion system is an integrated hardware and software system that together with the Aptima CMV Quant Assay fully automates all the steps necessary to perform the assay from sample preparation through amplification of nucleic acid, detection, data reduction, and amplicon inactivation.
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Note: Retesting plasma samples with an ML2 flag will require manual addition of proteinase K reagent to the plasma specimen prior to loading the sample onto the Panther/Panther Fusion System for testing. The processing steps are fully automated as indicated above.
INDICATIONS FOR USE V.
The Aptima® CMV Quant Assay is an in vitro nucleic acid amplification test for the quantitation of human cytomegalovirus (CMV) DNA in human EDTA plasma on the fully automated Panther system.
The Aptima CMV Quant Assay is intended for use to aid in the management of solid-organ transplant patients and hematopoietic stem cell transplant patients receiving anti-CMV therapy, serial DNA measurements can be used to assess viral response to treatment. The results from Aptima CMV Quant Assay must be interpreted within the context of all relevant clinical and laboratory findings.
The Aptima CMV Quant Assay is not intended for use as a screening assay for the presence of CMV in blood or blood products.
VI. COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE
Table 3 displays the updates made to the assay's package insert to include the protocol for retesting plasma samples with an associated ML2 flag. This protocol involves the manual pretreatment of plasma specimens with ML2 flag invalid results associated with ML2 flags with proteinase K reagent prior to testing on Panther/Panther Fusion System.
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| Table 3 - Comparison of Predicate and Subject Device |
|---|
| ------------------------------------------------------ |
| Feature | Aptima CMV Quant Assay | Aptima CMV Quant Assay(including proteinase K protocol) | Predicate andSubject DeviceComparison |
|---|---|---|---|
| Intended Use | The Aptima® CMV Quant Assay is an invitro nucleic acid amplification test for thequantitation of human cytomegalovirus(CMV) DNA in human EDTA plasma on thefully automated Panther system. | The Aptima® CMV Quant Assay is an in vitronucleic acid amplification test for thequantitation of human cytomegalovirus (CMV)DNA in human EDTA plasma on the fullyautomated Panther system. | Same |
| The Aptima CMV Quant Assay is intendedfor use to aid in the management of solid-organ transplant patients and hematopoieticstem cell transplant patients. In patientsreceiving anti-CMV therapy, serial DNAmeasurements can be used to assess viralresponse to treatment. The results fromAptima CMV Quant Assay must beinterpreted within the context of all relevantclinical and laboratory findings. | The Aptima CMV Quant Assay is intended foruse to aid in the management of solid-organtransplant patients and hematopoietic stem celltransplant patients. In patients receiving anti-CMV therapy, serial DNA measurements canbe used to assess viral response to treatment.The results from Aptima CMV QuantAssay must be interpreted within thecontext of all relevant clinical andlaboratory findings. | ||
| Aptima CMV Quant Assay is not intended foruse as a screening assay for the presence ofCMV in blood or blood products. | The Aptima CMV Quant Assay is notintended for use as a screening assay for thepresence of CMV in blood or blood products. | ||
| OrganismsDetected | Human cytomegalovirus (CMV) | Human cytomegalovirus (CMV) | Same |
| Test Quantity | 100 Tests | 100 Tests | Same |
| PatientPopulation | Solid-organ transplant and hematopoietic stemcell transplant patients | Solid-organ transplant and hematopoietic stemcell transplant patients | Same |
| SpecimenTypes | Plasma | Plasma | Same |
| Feature | Aptima CMV Quant Assay | Aptima CMV Quant Assay(including proteinase K protocol) | Predicate andSubject DeviceComparison |
| Analyte | CMV DNA, genotypes 1, 2, 3, and 4 | CMV DNA, genotypes 1, 2, 3, and 4 | Same |
| TechnologyPrinciple ofOperation | Real-time Transcription Mediated Amplification (TMA) | Real-time Transcription Mediated Amplification (TMA) | Same |
| UserComplexity | High | High | Same |
| Platform | Panther/Panther Fusion system | Panther/Panther Fusion system | Same |
| PlatformSoftware | Panther/Panther Fusion system software | Panther/Panther Fusion system software | Same |
| AssaySoftware | Aptima CMV Quant Assay software | Aptima CMV Quant Assay software | Same. |
| Warnings andPrecautions –Assay Related | N/A | O. In case of an invalid result with ML2 flag,do not retest the neat specimen with the AptimaCMV Quant Assay. Refer to Panther SystemTest Procedure , step F, in this package insertfor instructions to treat the plasma specimenwith proteinase K prior to retesting.Note: For ML2 flag, refer to the appropriatePanther/Panther Fusion System Operator'sManual for Mag Wash Clean Instructions.P. Avoid contact of proteinase K with theAptima CMV Quant Assay reagents andreagent preparation area. The performance ofthe assay may be affected if the reagents comein contact with proteinase K. Change gloves ifthey come in contact with proteinase K. | Section added toindicate how tohandle sampleswith an ML2 flagand proper use ofthe proteinase Kreagent. |
| Feature | Aptima CMV Quant Assay | Aptima CMV Quant Assay(including proteinase K protocol) | Predicate andSubject DeviceComparison |
| SamplesOnboard thePantherSystem | Samples may be left on the Panther systemuncapped for up to 8 hours. Samples may beremoved from the Panther system and testedas long as the total time onboard does notexceed 8 hours prior to the pipetting of thesample by the Panther system. | Samples may be left on the Panther systemuncapped for up to 8 hours, excludingspecimens treated with proteinase K thatneed to be tested immediately afterproteinase K treatment. Samples may beremoved from the Panther system and tested aslong as the total time onboard does not exceed 8hours prior to the pipetting of the sample by thePanther system. | Added aclarification totest samplestreated withproteinase Kimmediately aftertreatment. |
| MaterialsRequired butAvailableSeparately | Panther® System | Cat. No.303095Panther® SystemPanther Fusion SystemPRD-04172Panther System Continuous Fluids and Waste(Panther Plus)PRD-06067Proteinase K (RNA grade), 20 mg/mL,DNase-Free, RNase-Free25530-049(Thermo Fisher Scientific)Thermo FisherScientific | The catalognumbers of thePanther/PantherFusion systemwere added.The proteinase Kcatalog numberwas added. |
| OptionalMaterials | Aptima Specimen Aliquot Tubes (SATs) (100pack)503762 | Aptima Specimen Aliquot Tubes (SATs) (100pack)FAB-18184 | The SATs catalognumber wasupdated |
| Feature | Aptima CMV Quant Assay | Aptima CMV Quant Assay(including proteinase K protocol) | Predicate andSubject DeviceComparison |
| Processing ofCMV plasmaspecimen withan ML2 flagfor retesting | N/A | F. Processing of CMV plasma specimen with anML2 flag for retesting1. Allow the specimens to reach 15°C to 30°Cprior to processing.2. Transfer 1000 µL of patient specimen into alabeled secondary tube.3. Add 50 µL of proteinase K to aliquotedplasma specimen.4. Cap the labeled secondary tube.5. Vortex for 15 seconds.6. Incubate for 10 minutes at 65°C.7. Cool down for 1 minute at room temperature(15°C to 30°C).8. Briefly centrifuge the specimen to gather alldroplets at the bottom of the tube before testingon the Panther system.See System Preparation, Step G.2 below, forinformation about loading the rack andremoving the caps.Note: After a specimen is treated withproteinase K, it should be tested immediately. | The proteinase Kprotocol has beenadded to allowthe retesting ofsamples with anML2 flag (Step F) |
| QualityControl | N/A | In case of an invalid result with ML2 flag, donot retest the neat specimen with the AptimaCMV Quant Assay. Refer to Panther SystemTest Procedure, step F, in this package insertfor instructions to treat the plasma specimenwith proteinase K prior to retesting. | Text was added toindicate how tohandle sampleswith a ML2 flagand Mag Washcleaninginstructions. |
| Feature | Aptima CMV Quant Assay | Aptima CMV Quant Assay(including proteinase K protocol) | Predicate andSubject DeviceComparison |
| Note: For ML2 flag, refer to the appropriatePanther/Panther Fusion System Operator'sManual for Mag Wash Clean Instructions. | |||
| Interpretationof Results | The Panther system automatically determinesthe concentration of CMV DNA forspecimensand controls by comparing the results to acalibration curve. CMV DNA concentrationsare reported in IU/mL and log10 IU/mL. | The Panther system automatically determinesthe concentration of CMV DNA for specimensand controls by comparing the results to acalibration curve. CMV DNA concentrationsare reported in IU/mL and log10 IU/mL. | Same |
| Bibliography | N/A | 21. Youn J-H, Walker L, Carlson S, Soutar C,Frank K, Zelazny A, Das S. Mitigation of errorson an FDA-approved platform forcytomegalovirus viral load assay. J ClinMicrobiol. 2024 Jul 16;62(7) | Addition of areference |
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PERFORMANCE DATA VI.
Plasma samples containing abnormally high presence of globulin proteins can coagulate on exposure to alkaline shock (addition of the Target Enhancer Reagent, a component of the assay kit) during the nucleic acid extraction step of the assay, forming a gel in the assay tube. This gel clogs the aspirators in the magnetic wash station on the Panther Fusion system, during the wash steps for nucleic acid purification, causing the instrument sensors to invalidate the results of the sample and report it with a ML2 flag. Pre-treatment of the invalidated ML2 specimens with proteinase K reagent enables generation of valid results for these specimens by digesting the proteins and preventing the formation of gels when the sample is exposed to alkaline shock.
The validated proteinase K protocol has been incorporated into the assay's package insert as follows:
Processing of CMV plasma specimen with an ML2 flag for retesting:
-
- Allow the specimens to reach 15℃ to 30℃ prior to processing.
-
- Transfer 1000 uL of patient specimen into a labeled secondary tube.
-
- Add 50 µL of proteinase K to aliquoted plasma specimen.
-
- Cap the labeled secondary tube.
-
- Vortex for 15 seconds.
-
- Incubate for 10 minutes at 65°C.
-
- Cool down for 1 minute at room temperature (15°C to 30°C).
-
- Briefly centrifuge the specimen to gather all droplets at the bottom of the tube before testing on the Panther system.
- Note: After a specimen is treated with proteinase K, it should be tested immediately.
This protocol was validated using plasma specimens collected from the transplant patient population by the National Institute of Health (NIH). The prevalence of specimens invalidated with ML2 flags at the NIH decreased from 0.87% (on testing 1039 plasma specimens without proteinase K treatment) to 0% (on testing 4098 specimens with proteinase K treatment). The NIH also demonstrated that using proteinase K for pretreatment of specimens did not impact the
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accuracy of CMV quantification in the Aptima Assay (Youn J-H, Walker L, Carlson S, Soutar C, Frank K, Zelazny A, Das S. Mitigation of errors on an FDA-approved platform for cytomegalovirus viral load assay. J Clin Microbiol. 2024 Jul 16;62(7). The Hologic risk assessment to evaluate the impact of changing the specimen handling workflow to incorporate proteinase K pretreatment of specimens prior to performing the Aptima CMV Quant Assay concluded that the benefits provided by the updates to the Hologic specimen handling workflow at customer sites outweigh the risks.
Using this protocol will enable clinical laboratories to generate a valid result on the Panther/Panther Fusion system for plasma specimens that initially reported an invalid result with ML2 flag.
CONCLUSIONS VII.
Implementation of pre-treatment of plasma specimens with proteinase K prior to testing in the Aptima CMV Quant Assay enables clinical laboratories to generate a valid retest result, for plasma specimens that initially reported invalid results with ML2 flag. Prompt generation of valid retest results minimizes delays in patient treatment decisions.
This protocol does not negatively impact the safety and effectiveness of the Aptima CMV Quant Assay because the assay performance characteristics including accuracy are maintained with incorporation of this modification.
§ 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.