Thrombonostika F1.2 is an enzymed-linked immunosorbent assay for the quantitative determination of prothrombin activation fragment 1.2 (F1.2) in human plasma. It is indicated as an aid to both assess the risk of thrombosis and monitor the efficacy of anticoagulant therapy.

Device Description

Thrombonostika F1.2 is a two-stage enzymed-linked immunosorbent assay for the prothrombin activation peptide F.12. The high specificity of the solid-phase anti-F1.2 monoclonal antibody allows quantitation of nanomolar F1.2 in the presence of micromolar prothrombin that is typically found in plasma. Rabbit polyclonal antibodies to the calcium-dependent conformer of prothrombin (i.e., the amino terminal region present on both prothrombin and F1.2 ) coupled to horseradish peroxidase (HRP) serves as the conjugate with tetramethylbenzidine (TMB) used as the substrate.

In the first stage, test sample or calibrator is incubated with a monoclonal F1.2-specific antibody (murine) coated on a microelisa well. F1.2 binds to the solid-phase antibody. Following an incubation, unbound proteins (including prothrombin) are aspirated and the well washed with buffer. In the second stage, conjugate (rabbit) labeled with HRP is added. The enzyme-labeled antibody is bound to the solid-phase F1.2 complex. Following a wash and incubation with TMB substrate, blue color is produced that turns yellow hen the reaction is stopped with stop solution. Within limits, the amount of prothrombin fragment 1.2 is proportional to the color development.

AI/ML Overview

Here is a summary of the acceptance criteria and study information for the Thrombonostika F1.2 device, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The provided document describes a modification to an existing device, Thrombonostika F1.2 (K911434). The study focuses on demonstrating substantial equivalence of the modified device to the original. Explicit, pre-defined quantitative "acceptance criteria" for each performance metric are not clearly stated in the document as separate, distinct criteria. Instead, the results themselves demonstrate that the modified device performs comparably to or within expected ranges of the original or ideal performance.

Therefore, the "acceptance criteria" are inferred from the demonstrated performance that leads to the conclusion of substantial equivalence.

Performance Metric	Acceptance Criteria (Inferred)	Reported Device Performance
Equivalence to Original Device (Comparison Data without 0.25 nM calibrator vs. with 0.25 nM calibrator)	High correlation (R² approaching 1), slope near 1, intercept near 0, demonstrating agreement with original device values.	Without 0.25 nM calibrator: Coefficient of determination (R²) = 0.998. Estimated slope = 1.001. Estimated intercept = 0.001. 240 out of 268 test results (90%) fell in the 0.0-1.0 nM range.
Equivalence to Original Device (Comparison Data (fresh patient samples) current vs. modified version)	High correlation (R² approaching 1), slope near 1, intercept near 0, demonstrating agreement between current and modified versions.	Current vs. Modified Version: Coefficient of determination (R²) = 0.9999. Estimated slope = 0.987. Estimated intercept = 0.036.
Sensitivity	Minimum detectable F1.2 level, ideally low to detect small concentrations.	Minimum F1.2 level distinguishable from Calibrator A is 0.1 nM.
Accuracy	Mean recovery within an acceptable range (e.g., 80-120%), indicating accurate measurement across different concentrations.	Mean recovery of 113.5% (SD=13%) was obtained when purified F1.2 (0.5-20 nM) was added to 16 plasma samples from 5 donors. (The document does not explicitly state a pre-defined acceptance range for recovery, but 113.5% with SD 13% is presented as an acceptable outcome for accuracy).
Precision	Low intra-assay and total coefficients of variation (CV) and standard deviations (SD) for various F1.2 levels and kit lots, demonstrating reproducibility.	Estimates of total and intra-assay precision were calculated for each of three kit lots by assaying multiple replicates of Level I and Level II Controls on multiple plates and occasions. (Specific CV and SD values are not provided in the summary but are stated to have been calculated and considered in the conclusion of safety and effectiveness).

2. Sample Size Used for the Test Set and Data Provenance

Comparison Data (without 0.25 nM calibrator vs. with 0.25 nM calibrator): 268 test results. Data provenance is not explicitly stated (e.g., country of origin) but is implied to be from laboratory testing to compare versions of the device. The nature (retrospective/prospective) is not specified.
Comparison Data (51 fresh patient samples): 51 fresh patient samples. Data provenance is implied to be from actual patient samples, likely retrospective or a small prospective collection for this specific comparison.
Accuracy: 16 plasma samples from 5 different donors. Data provenance is laboratory-controlled, using added (spiked) purified F1.2.
Precision: "Multiple replicates" of Level I and Level II Controls on "multiple plates and occasions" for "three kit lots." Specific numbers of replicates are not given in the summary, but it implies extensive internal testing. Provenance is laboratory testing.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

Not applicable. This is an in-vitro diagnostic (IVD) assay measuring a biomarker. The "ground truth" is established through the analytical measurement process itself using calibrators and controls, rather than expert interpretation of images or clinical cases.

4. Adjudication Method for the Test Set

Not applicable. As an IVD assay, adjudication by multiple experts is not relevant to establishing the ground truth for F1.2 concentration measurements. The assay itself provides a quantitative measurement.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done

No, an MRMC comparative effectiveness study was not performed. This type of study is relevant for diagnostic imaging or interpretation tasks where human readers are involved. This device is an in-vitro diagnostic assay.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done

Yes, the studies described are standalone performance evaluations of the assay itself. The Thrombonostika F1.2 is an ELISA kit, and its performance metrics (sensitivity, accuracy, precision, comparative analysis) measure the device's analytical capability independently. There is no human-in-the-loop component in the performance evaluation of the assay's output itself, although human operators perform the assay.

7. The Type of Ground Truth Used

The ground truth for this device's performance evaluation relies on:

Quantifiable concentrations: Established by known values of calibrators and spiked samples with purified F1.2 (for accuracy).
Reference measurements: Comparison to the performance of the original, legally marketed Thrombonostika F1.2 device (K911434) and analysis of fresh patient samples using both current and modified versions.
Statistical analysis: Based on standard laboratory practices for determining analytical performance parameters like R², slope, intercept, sensitivity, and precision using replicates and controls.

8. The Sample Size for the Training Set

The document does not explicitly mention a "training set" in the context of an algorithm or statistical model. For an ELISA kit, the development and optimization process (analogous to "training") would involve extensive internal testing to establish reagent concentrations, incubation times, wash steps, etc. However, specific sample sizes for such development phases are not detailed in this 510(k) summary. The presented data represents the validation (test) phase.

9. How the Ground Truth for the Training Set was Established

As noted above, there isn't a "training set" in the sense of a dataset used to train an AI algorithm. For an IVD, the "ground truth" during development (training analog) would be established through:

Known concentrations of F1.2: Using highly purified F1.2 and calibrated standards.
Reference methods: Comparing experimental results to established, validated methods for F1.2 measurement or related coagulation markers during development.
Clinical correlation: Indirectly, by ensuring the assay provides values that align with expected physiological states (e.g., elevated in thrombotic risk groups, depressed in anticoagulated patients), although this is more for clinical utility than analytical ground truth for individual measurements.

Summary

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K964934

MAR 1188 1997 11 1997

and the contraction of the comments of the comments of the comments of

510(k) Summary 9.0

and the comments of the comments of the comments of

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510(k) SUMMARY

THROMBONOSTIKA F1.2

This summary of safety and effectiveness information is being submitted in accordance with the requirements of SMDA 1990 and the final rule under 21 CFR 807.92 published December 14, 1994.

(a) (1) The submitter's name, address, telephone number, a contact person, and the date the summary was prepared;

Organon Teknika Corporation Submitter's Name: 100 Akzo Avenue, Durham, North Carolina 27712, USA Submitter's Address: (919) 620-2373 Submitter's Telephone: Ron Sanyal, M. Pharm, CQE, RAC Submitter's Contact: Date 510(k) Summmary Prepared: December 6, 1996

The name of the device, including the trade or proprietary name if applicable, the common or (a) (2) usual name, and the classification name, if known;

Trade/Proprietary Name:	Thrombonostika F1.2
Common/ Usual Name:	ELISA for Prothrombin Fragment 1.2
Classification Name:	Prothrombin Activation Fragment 1.2 (F1.2)

An identification of the legally marketed device to which the submitter claims substantial (a) (3) equivalence.

Device Equivalent to: Thrombonostika F1.2 (K911434)

(a) (4) A description of the device(System)

Prothrombin fragment1.2 (F1.2) is a polypeptide released from prothrombin during its activation to thrombin. When formed, thrombin can convert fibrin which in turn can incorporate into thrombus. Because thrombin has many natural inhibitors and substrates, thrombin formation need not be coincident with fibrin formation. However, as more prothrombin activation occurs, the amount of thrombin available to form fibrin and potentially thrombi also increases. Conversely, when less prothrombin activation occurs (as may happen during anticoagulation), less thrombin is available to form fibrin and possible thrombi.

F1.2 levels reflect the extent of prothrombin activation in plasma and have been demonstrated to correlate with the thrombotic risk associated with certain patient populations. Mean F1.2 levels are elevated in those that are elderly, have inherited thrombophilia, or have deep vein thrombosis (DVT); these are all conditions with an increased risk of thrombosis. Mean F1.2 levels are depressed in those receiving oral anticoagulant therapy, or

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heparin infusion; these are conditions with decreased thrombotic risk. Monitoring of F1.2 levels will provide additional information for assessing thrombotic risk and monitoring efficacy of anticoagulant therapy.

(a) (5) A statement of the intended use of the device.

Thrombonostika F1.2 is an enzymed-linked immunosorbent assay for the Device Intended Use: quantitative determination of prothrombin activation fragment 1.2 (F1.2) in human plasma. It is indicated as an aid to both assess the risk of thrombosis and monitor the efficacy of anticoagulant therapy.

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A summary of the technological characteristics of the new device in comparision to those of the (a) (6) predicate device.

The technological characteristics of the new device in comparison to those of the device [Thrombonostika F1.2 (K911434)] are given in the table 1 below.

TABLE 1

PARAMETERS	ORGNON TEKNIKATHROMBONOSTIKA F1.2(ORIGINAL)	ORGANON TEKNIKATHROMBONOSTIKA F1.2(MODIFIED)
CATEGORY	Enzyme-linked ImmunosorbentAssay (ELISA)	Enzyme-linked ImmunosorbentAssay (ELISA)
INTENDED USE	Thrombonostika F1.2 is anenzymed-linked immunosorbentassay for the quantitativedetermination of prothrombinactivation fragment 1.2 (F1.2) inhuman plasma. It is indicated asan aid to both assess the risk ofthrombosis and monitor theefficacy of anticoagulant therapy.	Thrombonostika F1.2 is anenzymed-linked immunosorbentassay for the quantitativedetermination of prothrombinactivation fragment 1.2 (F1.2) inhuman plasma. It is indicated asan aid to both assess the risk ofthrombosis and monitor theefficacy of anticoagulant therapy.
SAMPLE	Human Plasma	Human Plasma
SENSITIVITY	0.1 nM	0.1 nM
CONTROLS	Level I Control-Lyophilizedhuman plasma containing a lowF1.2 levelLevel II Control-Lyophilizedhuman plasma containing a highF1.2 level	Level I Control-Lyophilizedhuman plasma containing a lowF1.2 levelLevel II Control-Lyophilizedhuman plasma containing a highF1.2 level
MONOCLONAL ANTIBODY	Murine	Murine
CONJUGATE	Rabbit polyclonal antibodies tothe calcium-dependent conformerof prothrombin (i.e., the aminoterminal region present on bothprothrombin and F1.2 ) coupledto horseradish peroxidase (HRP)serves as the conjugate	Rabbit polyclonal antibodies tothe calcium-dependent conformerof prothrombin (i.e., the aminoterminal region present on bothprothrombin and F1.2 ) coupledto horseradish peroxidase (HRP)serves as the conjugate
CALIBRATORS	0, 0.25, 1.0, 3.0, 6.0, 10 nMLabeled with target values	0, 1.0, 3.0, 6.0, 10.0 nMLabeled with assayed values
SUBSTRATE	TMB (Tetramethylbenzidine)	TMB (Tetramethylbenzidine)

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(b) (1) A brief discussion of the nonclinical tests submitted, reference, or relied on in the premarket notification submission for a determination of substantial equivalency.

Not Applicable

A brief discussion of the clinical tests submitted, reference, or relied on in the premarket (b)(2) notification submission for a determination of substantial equivalency.

Comparison Data:

The coefficient of determination ( R2 ) from regressing F1.2 values obtained without the 0.25 nM calibrator on the corresponding values obtained originally with the 0.25 nM calibrator is 0.998, with an estimated slope and intercept of 1.001and 0.001, respectively. These data and the estimated regression line are shown in Figure 1.0. Two hundred forty (240) of the 268 test results fall in the 0.0-1.0 nM range.

An additional 51 samples fresh patient samples were analyzed by the current version of the test and compared to results from modified version. The coefficient of determination obtained from regressing F1.2 values without the 0.25 nM calibrator on values obtained with the calibrator is 0.9999. The slope and the intercept of the regression line 0.987 and 0.036, respectively. These data and the estimated regression line are shown in Figure 2.0.

Sensitivity

The minimum F1.2 level distinguishable from Calibrator A is 0.1 nM. This minimum detection limit is the F1.2 value corresponding to the mean absorbance plus two standard deviations for at least 16 replicates of Calibrator A.

Accuracy

A mean recovery of 113.5% (SD=13%) was obtained when purified F1.2, at levels between 0.5-20 nM, was added to 16 plasma samples from 5 different donors

Precision

Estimates of total and intra-assay precision were calculated for each of three kit lots by assaying multiple replicates of the Level I and Level II Controls on multiple plates and occasions. Intra-assay precision was estimated using analysis of variance. Total precision includes both interassay and intra-assay precision. Shown for each control and kit lot are the total number of tests (N), the mean F1.2 level (MEAN) in nM units, the total standard deviation (SD TOTAL) of all tests, the overall coefficient of variation (CV TOTAL), the intra-assay standard deviation (SD INTRA), and the intra-assay coefficient of variation (CV INTRA)

The conclusion drawn from the nonclinical and clinical tests that demonstrate that the device is (b) (3) as safe, as effective, and performed as well or better than the legally marketed device identified in (a) (3).

In concusion, the Thrombonostika F 1.2 (Modified) has sucessfully met all aspects of non clinical and clinical testing and have demonstrated that the device is safe and effective and has performed well and is substantially equivalent to the legally marketed device [Thrombonostika F1.2 (K911434)].

Regulation Number and Section

§ 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).