(72 days)
Enzygnost F1+2 (monoclonal) is an enzyme immunoassay for the quantitative determination of human prothrombin F1+2 in plasma. Measurement of F1+2 is used as an aid in the diagnosis, monitoring, and evaluation of acquired or hereditary blood coagulation disorders. It is indicated as an aid in assessing risk of thrombosis and in monitoring efficacy of anticoagulant therapy.
The Enzygnost™ F1+2 Test Kit is an enzyme immunoassay based on the sandwich principle in microtiter format utilizing monoclonal mouse antibodies. During the first incubation, the F1+2 antigen in the sample binds to F1+2 antibodies attached to the microtiter plate. After washing, peroxidase-conjugated antibodies to human prothrombin are bound to a free F1+2 determinant in a second reaction. The excess enzyme-conjugated antibodies are removed by washing; the bound enzyme activity is then determined. The enzymatic reaction between hydrogen peroxide and chromogen is terminated by the addition of dilute sulfuric acid. The color intensity, which is proportional to the concentration of F1+2, is determined photometrically and quantified by means of a calibration curve based on the standards included in the kit.
Here's an analysis of the provided information, structured to answer your questions about acceptance criteria and the supporting study for the Enzygnost™ F1+2 (monoclonal) device:
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|---|
| Correlation to Predicate Device | High correlation coefficient (target usually > 0.9) | 0.96 |
| Slope (vs. predicate) | Slope close to 1 | 0.265 (This indicates a significant difference in scale or measurement between the two devices and is not close to 1. However, the FDA found substantial equivalence, suggesting this difference was acceptable in the context of the device's function or that a conversion factor is implied. It's important to note the discrepancy if interpreting solely on a "close to 1" metric.) |
| Intercept (vs. predicate) | Intercept close to 0 | -29.378 (Similar to the slope, this indicates a bias between the two devices. The FDA's acceptance suggests this was deemed acceptable.) |
| Within-Run Precision (CV) | Low coefficient of variation (typical <= 10%) | 3.6% - 5.5% |
| Day-to-Day Precision (CV) | Low coefficient of variation (typical <= 15%) | 4.4% - 11.2% |
Note on Acceptance Criteria: The provided document does not explicitly state numerical acceptance criteria for correlation, slope, or intercept. These are inferred based on typical industry expectations for substantial equivalence studies comparing new devices to predicate devices. The FDA's clearance (K042687) indicates that the presented performance met their criteria for substantial equivalence to the predicate device despite the slope and intercept values.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 190 patient samples.
- Data Provenance: The document does not specify the country of origin. The study was retrospective, as it involved "patient samples spanning the range of assay," implying pre-collected samples.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This type of information is generally not applicable to an in vitro diagnostic (IVD) device like the Enzygnost™ F1+2. The "ground truth" for this device is based on the quantitative measurement of a specific analyte (prothrombin fragment F1+2) using a laboratory method. The predicate device's results serve as the reference standard, rather than expert interpretation of images or clinical data. There are no "experts" establishing a ground truth in the way described for imaging or clinical decision support AI.
4. Adjudication Method for the Test Set
Not applicable. As described above, this is a quantitative measurement device, not one requiring expert adjudication of results. The comparison is statistical against a predicate device.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No. An MRMC study is relevant for devices that involve human interpretation, often in imaging. This device (Enzygnost™ F1+2) is an in vitro diagnostic test that provides a quantitative numerical output, not something a human "reads" in a subjective sense that would be improved by AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
Yes, in the context of an IVD. The performance metrics presented (correlation, precision) are for the device (the "algorithm") performing its function independently on samples. There is no human "in-the-loop" once the sample is loaded and the assay runs. The results are generated solely by the device.
7. The Type of Ground Truth Used
The "ground truth" for the test set was the results obtained from the predicate device, Enzygnost™ F1+2 micro test kit (K922934). This is a form of comparative reference standard or established assay performance.
8. The Sample Size for the Training Set
The document does not explicitly mention a "training set" like one would describe for an AI/ML model. For an IVD like this, calibration curves are established using standards provided within the kit. The document mentions "a calibration curve based on the standards included in the kit." The number of samples used to establish these internal calibration standards is not specified but would be part of the manufacturer's internal validation, not typically detailed in 510(k) summaries unless specifically relevant to a new method of calibration.
9. How the Ground Truth for the Training Set Was Established
For IVD devices, the "ground truth" for training (i.e., calibration) is typically established using:
- Certified Reference Materials: Substances with a precisely known concentration of the analyte.
- Primary Calibrators: Highly pure substances with accurately assigned values.
- Traceability to Reference Measurement Procedures: Ensuring the calibration is linked to higher-order reference methods.
The document states, "quantified by means of a calibration cure based on the standards included in the kit," implying that the ground truth for calibration is based on these manufacturer-supplied, value-assigned standards, which are themselves derived from rigorous analytical methods. This is an internal manufacturing and quality control process rather than an external expert consensus panel.
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DEC 1 0 2004 Summary of Safety and Effectiveness Information
This summary of 510(k) safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.
1. Manufacturer's Name, Address, Telephone, and Contact Person, Date of Preparation:
| Manufacturer: | Dade Behring Marburg GmbHEmil-von-Behring Str. 76Marburg/Germany |
|---|---|
| Contact Information: | Dade Behring Inc.Glasgow SiteP.O. Box 6101Newark, Delaware 19714Attn: Donna WolfTel: 302-631-0384 |
| Preparation date: | September 27, 2004 |
| 2. Name of Product: | Enzygnost™ F1+2 (monoclonal) |
| 3. FDA Classification Name: | Fibrinogen/Fibrin degradation products assay |
| 4. Predicate Device: | Enzygnost™ F1+2 micro test kit (K922934) |
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Device Description: The Enzygnost™ F1+2 Test Kit is an enzyme immunoassay based on the sandwich principle in microtiter format utilizing monoclonal mouse antibodies. During the first incubation, the F1+2 antigen in the sample binds to F1+2 antibodies attached to the microtitrotionship After washing, peroxidase-conjugated antibodies to human prothrombin are bound to a firee F1+2 determinant in a second reaction. The excess enzyme-conjugated antibodies are removed by washing; the bound enzyme activity is then determined. The enzymatic reaction between hydrogen peroxide and chromogen is terminated by the addition of dilute sulfuric acid. The color intensity, which is proportional to the concentration of F1+2, is determined photometrically and quantified by means of a calibration cure based on the standards included in the kit.
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Intended Use: For the quantitative determination of the human prothrombin fragment F1+2 in plasma as an aid in diagnosing, monitoring and evaluating blood coagulation disorders involving changes in coagulation system activity.
7. Comparison to Predicate Device:
Conclusion: Split sample comparison between the Enzygnost™ F1+2 (monoclonal) and the Enzygnost™ F1+2 micro test kit (K922934) gave a correlation coefficient of 0.96, slope of 0.265, and an intercept of -29.378 when tested with 190 patient samples spanning the range of assay.
In a precision study using samples ranging from 38 - 646 pmol/L, the resulting coefficients of variation were 3.6%- 5.5% within run, and 4.4% - 11.2% day to day.
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DEPARTMENT OF HEALTH & HUMAN SERVICES
Image /page/1/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized eagle with three stripes forming its body and wing. The eagle is positioned to the right of a circular arrangement of text that reads "DEPARTMENT OF HEALTH & HUMAN SERVICES USA".
Public Health Service
DEC 1 0 2004
Food and Drug Administration 2098 Gaither Road Rockville MD 20850
Ms. Donna A. Wolf Regulatory Affairs and Compliance Manager Dade Behring Inc. P.O. Box 6101 Newark, DE 19714
K042687 Re:
Trade/Device Name: Enzygnost™ F1+2 (monoclonal) Regulation Number: 21 CFR 864.7320 Regulation Name: Fibrinogen/fibrin degradation products assay Regulatory Class: Class II Product Code: MIF Dated: November 17, 2004 Received: November 18, 2004
Dear Ms. Wolf:
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 (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. 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.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in Title 21, Code of Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.
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 Parts 801 and 809); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820). This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.
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If you desire specific information about the application of labeling requirements to your device, or questions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (301) 594-3084. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.
Sincerely yours,
Robert L. Becker Jr.
Robert L. Becker, Jr., M.D., Ph.D. Director Division of Immunology and Hematology Devices Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health
Enclosure
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Dade Behring Inc. Enzygnost™ F1+2 (monoclonal) Test Kit
November 17, 2004
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Indications for Use Statement
Device Name: Enzygnost™ F1+2 (monoclonal)
Indications for Use:
Enzygnost F1+2 (monoclonal) is an enzyme immunoassay for the quantitative determination of human prothrombin F1+2 in plasma. Measurement of F1+2 is used as an aid in the diagnosis, monitoring, and evaluation of acquired or hereditary blood coagulation disorders. It is indicated as an aid in assessing risk of thrombosis and in monitoring efficacy of anticoagulant therapy.
| Prescription Use (Part 21 CFR 801 Subpart D) | ✓ | AND/OR | Over-The-Counter Use (21 CFR 801) | |
|---|---|---|---|---|
| ---------------------------------------------- | --- | -------- | ----------------------------------- | -- |
(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of In Vitro Diagnostic Devices (OIVD)
Division Sign-Off
Office of In Vitro Diagnostic Device Evaluation and Safety
| 510(k) | K042687 |
|---|---|
| -------- | --------- |
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§ 864.7320 Fibrinogen/fibrin degradation products assay.
(a)
Identification. A fibrinogen/fibrin degradation products assay is a device used to detect and measure fibrinogen degradation products and fibrin degradation products (protein fragments produced by the enzymatic action of plasmin on fibrinogen and fibrin) as an aid in detecting the presence and degree of intravascular coagulation and fibrinolysis (the dissolution of the fibrin in a blood clot) and in monitoring therapy for disseminated intravascular coagulation (nonlocalized clotting in the blood vessels).(b)
Classification. Class II (performance standards).