(315 days)
The AspirinWorks® Test Kit is an enzyme-linked immunoassay (ELISA) to determine levels of 11-Dehydro Thromboxane B2 (11dhTxB2) in human urine, which aids in the qualitative detection of aspirin effect in apparently healthy individuals post ingestion. For professional use only. The AspirinWorks® Test Kit is intended for use in clinical (hospital and reference) laboratories.
An ELISA for the detection of urinary 11-Dehydro Thromboxane B2 (11dhTxB2). Goat anti-mouse IgG polyclonal antibody (Jackson ImmunoResearch Laboratories, Inc, West Grove, PA) is coated onto 96microwell plates. Reference, control, and patient samples are diluted in a Tris-based sample diluent (pH 9.0) and added to the microwells. An 11dhTxB2 tracer (11dhTxB2 linked to alkaline phosphatase, (AP); Cayman Chemical Company, Ann Arbor, MI) is then added to all wells except assay blanks, followed by the addition of an anti-11dhTxB2 murine monoclonal antibody (Cayman Chemical Company) to all wells except assay blanks. The maximum binding wells (Bo) contain sample diluent, tracer, and monoclonal antibody, but no unlabeled 11dhTxB2. The plate is then covered with the plastic sheet provided in the kit, and incubated at room temperature on a rotary shaker at 300-600 pm for two hours. The AP-Tracer and unlabeled 11dhTxB2 from the reference curve/controls/samples compete for binding to the anti-11dhTxB2 monoclonal antibody, which is bound to the plate by the goat anti-mouse polyclonal antibody. After incubation, the reaction solution is removed from the wells followed by five washes with TBS/Tween 20. The pNPP substrate is then added and the plate is covered and incubated with shaking for 30 minutes. The reaction is stopped by the addition of Stop Solution (0.1M EDTA) to the wells, and the plate is read at 405-420 mm. Results are compared to the reference curve and expressed in pg/ml. Patient results are then normalized using the creatinine concentration of the sample, as measured by a separate assay.
The Corgenix AspirinWorks® Test Kit is an enzyme-linked immunoassay (ELISA) designed to measure levels of 11-Dehydro Thromboxane B2 (11dhTxB2) in human urine. This measurement aids in the qualitative detection of aspirin effect in apparently healthy individuals post ingestion.
1. Acceptance Criteria and Reported Device Performance:
The document implicitly defines acceptance criteria through the reported performance that demonstrates the device's ability to detect aspirin effect consistently with established literature. While explicit numerical acceptance criteria for sensitivity/specificity against a definitive gold standard are not provided, the "cutoff" value and the agreement with published aspirin non-responsiveness rates serve as the basis for acceptance.
| Criterion | Reported Device Performance |
|---|---|
| Cut-off for aspirin effect | Established at ≤1500 pg 11dhTxB2/mg creatinine. |
| Detection of aspirin-naive individuals | 180/204 (88.2%) of samples from individuals not taking aspirin were above the cutoff value (>1500 pg 11dhTxB2/mg creatinine), indicating a lack of aspirin effect (as expected). |
| Detection of aspirin non-responsiveness | - 7/163 (4.3%) of 81 mg/day aspirin users indicated a lack of aspirin effect (>1500 pg 11dhTxB2/mg creatinine).- 4/38 (10.5%) of the 325 mg/day aspirin users indicated a lack of aspirin effect.- In total, 11/201 (5.5%) of all aspirin users tested indicated a lack of aspirin effect.- These percentages are reported as "consistent with those in published literature for aspirin non-responsiveness or lack of aspirin effect." |
| Detection Range (Non-clinical) | 300 - 4000 pg/mL |
| Precision (Non-clinical) | Intra- and inter-assay precision %CV's are all <20%. |
| Recovery (Non-clinical) | Recovery across the range of detection is within 10% of expected values. |
| Interference (Non-clinical) | No interference was caused by physiologically excessive concentrations of materials likely to be found in human urine. |
| Linearity (Non-clinical) | Linearity testing at different sample dilutions confirmed that matrix effects do not affect measured levels of 11dhTxB2. |
2. Sample size used for the test set and the data provenance:
- Test Set Sample Sizes:
- Aspirin-naive individuals: 204 samples.
- Aspirin users (81 mg/day): 163 samples.
- Aspirin users (325 mg/day): 38 samples.
- Total aspirin users: 201 samples.
- Data Provenance: The studies are described as "clinical studies" and "non-clinical studies." No specific country of origin is mentioned, but the submission is to the FDA, suggesting compliance with US regulatory standards. The studies appear to be prospective, where samples were collected and tested to evaluate the device's performance in detecting aspirin effect or lack thereof.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
The document does not explicitly state the number of experts used or their qualifications for establishing ground truth for the clinical studies. The classification of individuals as "not taking aspirin" or "taking various doses of aspirin" likely served as the primary categorisation for ground truth regarding aspirin exposure. The ground truth for "aspirin effect" was established by the AspirinWorks Test Kit measurement itself, with the clinical studies validating that the obtained results (e.g., non-responsiveness rates) are consistent with existing "published literature" on aspirin non-responsiveness.
4. Adjudication method for the test set:
Not applicable. The study involved a comparison of device measurements against defined categories (aspirin user vs. non-user) and consistency with published literature, rather than expert adjudication of individual case results for a diagnostic decision.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
Not applicable. This is an ELISA-based diagnostic kit, not an AI-assisted diagnostic imaging or interpretation device that would involve human readers.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done:
Yes, the studies evaluate the standalone performance of the AspirinWorks® Test Kit. The device, an ELISA kit, operates as a standalone diagnostic tool to measure 11dhTxB2 levels. The results are interpreted against a predetermined cutoff (≤1500 pg 11dhTxB2/mg creatinine) to indicate an aspirin effect. There is no mention of a human-in-the-loop component in the interpretation of the 11dhTxB2 measurement itself.
7. The type of ground truth used:
The ground truth for the clinical studies was based on:
- Stated aspirin usage: Patients were categorized as "individuals not taking aspirin" or "individuals taking various doses of aspirin."
- Consistency with outcomes/published literature: The observed rates of "lack of aspirin effect" (i.e., aspirin non-responsiveness) in the aspirin-taking groups were compared to and found to be "consistent with those in published literature for aspirin non-responsiveness or lack of aspirin effect." This implies that the accepted understanding of aspirin's physiological effect and its variability was used as a reference.
8. The sample size for the training set:
The document does not explicitly describe a separate "training set" in the context of machine learning or algorithm development. For an ELISA kit, development typically involves analytical validation (precision, accuracy, range, linearity, interference) and then clinical validation. The "clinical studies" mentioned (with 204 aspirin-naive and 201 aspirin-user samples) likely served as the primary dataset for establishing the clinical performance and cutoff value, which in some contexts could be viewed as a development/validation set.
9. How the ground truth for the training set was established:
As no explicit "training set" is described for algorithm development in the AI sense, this question is not fully applicable. However, for the development and establishment of the device's performance characteristics and cutoff:
- The "cutoff for aspirin effect at ≤1500 pg 11dhTxB2/mg creatinine" was "established" through the "two different clinical studies." This suggests an empirical derivation from the collected clinical data, likely aiming to optimize the correlation between urinary 11dhTxB2 levels measured by the kit and observed aspirin status, while also ensuring consistency with published literature on aspirin non-responsiveness. The ground truth for these studies was the patient's self-reported or clinically determined aspirin usage status.
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Image /page/0/Picture/0 description: The image shows the word "corgenix" in a simple, sans-serif font. The "o" in "corgenix" is replaced by a solid black circle. There is a small dot above the "i" in "corgenix".
MAY 2 9 2007
510(K) Summary [As required by 21 CFR 807.92(c)]
Kimberly Hassler
Submitter's Name and Address: Corgenix, Inc. 11575 Main Street Broomfield, CO 80020
Director of Quality and Regulatory Affairs Phone: 303.457.4345 x130 303.457.4519 Fax: Email: khassler@corgenix.com
Contact Name/Information:
Date Summary Prepared: Device Proprietary Name: Regulation Name: Proposed Classification: Proposed Product Code: Predicate Device:
July 17, 2006, Revised on April 3, 2007 AspirinWorks® Test Kit (11-Dehydro Thromboxane B2) Automated platelet aggregation system 21 CFR 864,5700 1020KW VerifyNow™ Aspirin Assay (K042423)
Device Description:
An ELISA for the detection of urinary 11-Dehydro Thromboxane B2 (11dhTxB2). Goat anti-mouse IgG polyclonal antibody (Jackson ImmunoResearch Laboratories, Inc, West Grove, PA) is coated onto 96microwell plates. Reference, control, and patient samples are diluted in a Tris-based sample diluent (pH 9.0) and added to the microwells. An 11dhTxB2 tracer (11dhTxB2 linked to alkaline phosphatase, (AP); Cayman Chemical Company, Ann Arbor, MI) is then added to all wells except assay blanks, followed by the addition of an anti-11dhTxB2 murine monoclonal antibody (Cayman Chemical Company) to all wells except assay blanks. The maximum binding wells (Bo) contain sample diluent, tracer, and monoclonal antibody, but no unlabeled 11dhTxB2. The plate is then covered with the plastic sheet provided in the kit, and incubated at room temperature on a rotary shaker at 300-600 pm for two hours. The AP-Tracer and unlabeled 11dhTxB2 from the reference curve/controls/samples compete for binding to the anti-11dhTxB2 monoclonal antibody, which is bound to the plate by the goat anti-mouse polyclonal antibody. After incubation, the reaction solution is removed from the wells followed by five washes with TBS/Tween 20. The pNPP substrate is then added and the plate is covered and incubated with shaking for 30 minutes. The reaction is stopped by the addition of Stop Solution (0.1M EDTA) to the wells, and the plate is read at 405-420 mm. Results are compared to the reference curve and expressed in pg/ml. Patient results are then normalized using the creatinine concentration of the sample, as measured by a separate assay.
Intended Use:
The AspirinWorks® Test Kit is an enzyme-linked immunoassay (ELISA) to determine levels of 11-Dehydro Thromboxane B2 (11dhTxB2) in human urine, which aids in the qualitative detection of aspirin effect in apparently healthy individuals post ingestion. For professional use only.
Technological Characteristics of the Device Compared to Predicate Device:
The AspirinWorks Test Kit was compared to the Accumetrics® VerifyNow™ Aspirin Assay (K042423) as the predicate device. The AspirinWorks Test Kit is a competitive enzyme-linked immunoassay (ELISA) that detects 11dhTxB2 in urine. It is run in 96-well microtiter plates that have been coated with goat anti-nouse antibodies. To these wells samples, controls, or reference solution is added, followed by an 11dhTxB2alkaline phosphatase-linked tracer, and a monoclonal antibody specific for 11dhTxB2. During the two-hour incubation, the 11dhTxB2 monoclonal antibody forms a complex with either endogenous 11dhTxB2 or the 11dhTxB2 tracer, and this complex is bound to the plate by the antibodies. After washing, a substrate is added for 30 minutes, the reaction is terminated by addition of a stopping solution, and optical density at 405-420 nm is measured. The concentration of I l dhTxB2 is indirectly proportional to the amount
11575 MAIN STREET, SUITE 400 · BROOMFIELD, CO · 80020 U.S.A. PHONE: 303.457.4345 FAX: 303.453-4519 www.corgenix.com
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of yellow color measured at 405-420 mm. 11dhTxB2 is a metabolite of thromboxane A2 (TxA2), which is a potent inducer of platelet aggregation. Because TxAs has a short half-life, the more stable urinary 11dhTxB2 metabolite is used as a direct measure of concentrations of TxA2 and therefore platelet aggregation.
The Accumetrics VerifyNow Assay is a turbidimetric-based optical detection system which measures platelet-induced aggregation. The system uses the agonist arachidonic acid to induce platelet response and is based on the ability of TxAx-activated platelets to bind fibrinogen-coated beads. Light transmittance increases as activated platelets bind and aggregate the beads, and the instrument measures this change in optical signal caused by aggregation. The optical signal is measured as aspirin resistance units, or ARU (an arbitrarily assigned unit), and the normal response to aspirin results in ARU values of <550.
The manual AspirinWorks Test Kit measures urinary 11dhTxB2, while the automated Accumetrics VerifyNow Aspirin Assay is a turbidimetric-based optical detection system which measures platelet-induced aggregation in whole blood. The two devices have similar intended uses in that they both measure aspirin effect. The AspirinWorks kit detects a metabolite of TxA2, a direct inducer of platelet aggregation, while the Accumetrics kit measures ex vivo platelet aggregation caused by TxA2 by artificially inducing aggregation and measuring an optical signal. Ultimately, both are analyzing aspirin's effect through the reduction of TxA2 production or the resulting inhibition of platelet aggregation. Despite the differences between kits (manual vs. automated, urine vs. whole blood, ELISA vs. platelet aggregation turbidometry), no new issues of safety or effectiveness are raised as shown by the performance characteristics and predicate comparison between the two devices. Thus, the Accumetrics VerifyNow Aspirin Assay is a good predicate device for which to compare the AspirinWorks Test Kit. In addition, the AspirinWorks Test Kit minimizes the influence of preanalytical variables that may affect the Accumetrics device.
Summary of Non-Clinical and Clinical Studies:
Two different clinical studies were employed for the evaluation of the AspirinWorks Test Kit. Results from these studies established a cutoff for aspirin effect at ≤1500 pg 11dhTxB2/mg creatinine. Further analysis revealed that 180/204 (88.2%) of samples from individuals not taking aspirin were above the cutoff value. Analysis of samples from individuals taking various doses of aspirin revealed that 7/163 (4.3%) of 81 mg/day aspirin users indicated a lack of aspirin effect (>1500 pg 11dhTxBy/mg creatinine) and 4/38 (10.5%) of the 325 mg/day aspirin users indicated a lack of aspirin effect. In total, 11/201 (5.5%) of all aspirin users tested indicated a lack of aspirin effect. These percentages are consistent with those in published literature for aspirin non-responsiveness or lack of aspirin effect.
Non-clinical studies show a detection range for the AspirinWorks Test Kit of 300 - 4000 pg/mL, while intraand inter-assay precision %CV's are all <20%. Recovery across the range of detection is within 10% of expected values, and no interference was caused by physiologically excessive concentrations of materials likely to be found in human urine. Finally, linearity testing at different sample dilutions confirmed that matrix effects do not affect measured levels of 11dhTxB2.
The clinical and non-clinical studies demonstrate that the AspirinWorks Test Kit is a safe and effective method of determining levels of urinary 11dhTxB2 as an aid in the assessment of aspirin effect in apparently healthy individuals.
Kimberly Hinkle
Kimberly Hassler Director of Quality and Regulatory Affairs 2007-04 - 054
Date
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Indications for Use Statement
510(k) Number: _______________________________________________________________________________________________________________________________________________________________
Device Name: AspirinWorks® Test Kit (11-Dehydro Thromboxane B2)
Indications for Use:
The AspirinWorks® Test Kit is an enzyme-linked immunoassay (ELISA) to determine levels of 11-Dehydro Thromboxane B2 (11dhTxB2) in human urine, which aids in the qualitative detection of aspirin effect in apparently healthy individuals post ingestion. For professional use only.
The AspirinWorks® Test Kit is intended for use in clinical (hospital and reference) laboratories.
Prescription Use __ لا __ الا (Part 21 CFR 801 Subpart D) AND/OR
Over-The-Counter Use_ (21 CFR 801 Subpart C)
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NECESSARY) Concurrence of CDRH, Office of Device Evaluation (ODE)
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Food and Drug Administration 2098 Gaither Road Rockville MD 20850
MAY 2 9 2007
Kimberly N. Hassler Corgenix, Inc. 11575 Main Street, Suite 400 Broomfield, Colorado 80020
Re: K062025/S2
: Trade/Device Name: AspirinWorks® Test Kit (11-Dehydro Thromboxane B2) Regulation Number: 21 CFR 864.5700 Regulation Name: Automated platelet aggregation system Regulatory Class: Class II Product Code: OBW Dated: April 3, 2007 Received: April 4, 2007
Dear Ms. Hassler:
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
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Page 2 - Kimberly N. Hassler
predicate device results in a classification for your device and thus, permits your device to proceed to the market.
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 (240) 276-0450. 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 (240) 276-3150, or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.
Sincerely yours,
Robert L. Beattie, f
Robert L. Becker, Jr., MD, PhD Director Division of Immunology and Hematology Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health
Enclosure
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Indications for Use Statement
510(k) Number: K062025
Device Name: AspirinWorks® Test Kit (11-Dehydro Thromboxane B2)
Indications for Use:
The AspirinWorks® Test Kit is an enzyme-linked immunoassay (ELISA) to determine levels of 11-Dehydro Thromboxane B2 (11dhTxB2) in human urine, which aids in the qualitative detection of aspirin effect in apparently healthy individuals post ingestion. For professional use only.
The AspirinWorks® Test Kit is intended for use in clinical (hospital and reference) laboratories.
Prescription Use V (Part 21 CFR 801 Subpart D) AND/OR
Over-The-Counter Use (21 CFR 801 Subpart C)
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NECESSARY) Concurrence of CDRH, Office of Device Evaluation (ODE)
Josephine Bautista
Division Sign-Off
Office of In Vitro Diagnostic Device Evaluation and Safety
510(k) K062025
§ 864.5700 Automated platelet aggregation system.
(a)
Identification. An automated platelet aggregation system is a device used to determine changes in platelet shape and platelet aggregation following the addition of an aggregating reagent to a platelet-rich plasma.(b)
Classification. Class II (performance standards).