HemosIL Liquid Anti-Xa is an automated chromogenic assay for in vitro diagnostic use by laboratory professionals in clinical laboratories. The assay provides quantitative results on 3.2% citrated human plasma for the following analytes based on the calibrators used:

· When used with HemosIL Heparin Calibrators:

Quantitative determination of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) activity on the ACL TOP Family and ACL TOP Family 50 Series.

· When used with HemosIL Apixaban Calibrators:

Quantitative determination of apixaban on the ACL TOP Family 50 Series through measurement of factor Xa activity, which is inversely proportional to the apixaban level. With HemosIL Apixaban Calibrators, the assay is intended to measure apixaban concentrations in patients on apixaban therapy in the following situations where measurement of apixaban levels could be useful to have as additional information:

Patients at risk for major bleeding
Patients experiencing a bleeding episode

· When used with HemosIL Rivaroxaban Calibrators:

Quantitative determination of rivaroxaban on the ACL TOP Family and ACL TOP Family 50 Series through measurement of factor Xa activity, which is inversely proportional to the rivaroxaban level. With HemosL Rivaroxaban Calibrators, the assay is intended to measure rivaroxaban concentrations in patients on rivaroxaban therapy in the following situations where measurement of rivaroxaban levels could be useful to have as additional information:

Patients at risk for major bleeding
Patients experiencing a bleeding episode

The assay is not a stand-alone test and the results should be used in conjunction with other clinical and laboratory findings. For use in adult population. For prescription use only.

Device Description

HemosIL Liquid Anti-Xa is a one stage chromogenic assay based on a synthetic chromogenic substrate and on Factor Xa inactivation. The assay provides quantitative rivaroxaban results on 3.2% citrated human plasma as follows: Rivaroxaban levels in patient plasma are measured automatically on ACL TOP Family and ACL TOP Family 50 Series when this assay is calibrated with HemosIL Rivaroxaban Calibrators. Rivaroxaban directly inhibits Factor Xa activity independent of the antithrombin present. The Factor Xa activity measured by the assay is exogenous. Factor Xa is neutralized directly by rivaroxaban. Residual Factor Xa is quantified with a synthetic chromogenic substrate. The paranitroaniline released is monitored kinetically at 405 nm and is inversely proportional to the rivaroxaban level in the sample.

When used with HemosIL Heparin Calibrators:
• Quantitative determination of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) activity on the ACL TOP Family and ACL TOP Family 50 Series.

When used with HemosIL Apixaban Calibrators:
• Quantitative determination of apixaban on the ACL TOP Family and ACL TOP Family 50 Series through measurement of factor Xa activity, which is inversely proportional to the apixaban level. With HemosIL Apixaban Calibrators, the assay is intended to measure apixaban concentrations in patients on apixaban therapy in the following situations where measurement of apixaban levels could be useful to have as additional information:

Patients at risk for major bleeding
Patients experiencing a bleeding episode

When used with HemosIL Rivaroxaban Calibrators:
• Quantitative determination of rivaroxaban on the ACL TOP Family and ACL TOP Family 50 Series through measurement of factor Xa activity, which is inversely proportional to the rivaroxaban level. With HemosIL Rivaroxaban Calibrators, the assay is intended to measure rivaroxaban concentrations in patients on rivaroxaban therapy in the following situations where measurement of rivaroxaban levels could be useful to have as additional information:

Patients at risk for major bleeding
Patients experiencing a bleeding episode

The assay is not a stand-alone test and the results should be used in conjunction with other clinical and laboratory findings.

For use in adult population. For prescription use only.

AI/ML Overview

This appears to be a 510(k) summary for a medical device called "HemosIL Liquid Anti-Xa," which is an in vitro diagnostic assay. The document details the device's technical specifications and performance studies to demonstrate substantial equivalence to a predicate device.

Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:

Important Note: The document focuses on demonstrating substantial equivalence for the HemosIL Liquid Anti-Xa assay for rivaroxaban measurement, comparing it to an existing HemosIL Liquid Anti-Xa device for apixaban measurement. Therefore, the "acceptance criteria" table below will reflect the performance characteristics the manufacturer is demonstrating for the new rivaroxaban application, and how its performance stacks up against those established for the predicate or against generally accepted analytical performance standards for such assays. It's not about a specific "AI" device as might be implied by some questions in the prompt, but rather a diagnostic assay.

1. Table of Acceptance Criteria and Reported Device Performance

The document doesn't explicitly state "acceptance criteria" in a separate section with specific numerical targets. Instead, it presents various performance study results (Precision, Reproducibility, LoB/LoD/LoQ, Linearity, Interferences, Stability, Method Comparison) which collectively demonstrate the device's analytical performance. The acceptance is implied by the successful completion of these studies and the presented data.

Here's a table summarizing the reported device performance for the HemosIL Liquid Anti-Xa for rivaroxaban measurement. The implicit acceptance criteria are that these performance characteristics are adequate for the intended use and comparable to or better than the predicate device/industry standards.

Performance Characteristic	Acceptance Criteria (Implicit/Industry Standard)	Reported Device Performance (HemosIL Liquid Anti-Xa for Rivaroxaban)
Precision	Low CV% (e.g., <5-10% for clinical assays)	ACL TOP Family:- Rivaroxaban Low Control: CV% (Total) 4.1%- Rivaroxaban High Control: CV% (Total) 2.4%- Samples 1-6: CV% (Total) 1.0% - 5.5%
		ACL TOP Family 50 Series:- Rivaroxaban Low Control: CV% (Total) 4.9%- Rivaroxaban High Control: CV% (Total) 2.4%- Samples 1-6: CV% (Total) 1.2% - 4.5%
Reproducibility	Low CV% across sites, days, runs, lots	Pooled 3 Site Data:- Rivaroxaban Low Control: CV% (Total) 4.1%- Rivaroxaban High Control: CV% (Total) 2.3%- Samples: CV% (Total) 3.9% - 9.8%
Limit of Blank (LoB)	As low as clinically relevant	2.4 ng/mL
Limit of Detection (LoD)	As low as clinically relevant	8 ng/mL
Limit of Quantitation (LoQ)	Clinical relevance for lower reportable limit	20 ng/mL (lower limit of linear range)
Linearity (Reportable Range)	Wide enough for clinical utility	20 to 1000 ng/mL
Interferences	Minimal impact from common interferents	No significant effect from Hemoglobin (600 mg/dL), Bilirubin (40 mg/dL), Triglycerides (921 mg/dL), Acetylsalicylic acid (3.00 mg/dL), Atorvastatin (0.075 mg/dL), Isosorbide dinitrate (0.600 mg/dL), Ticagrelor (0.188 mg/dL), Warfarin (7.50 mg/dL), Lupus anticoagulant (dRVVT Screen/Confirm Ratio 2.47). Note: Falsely elevated results post-andexanet alfa administration.
Stability (Open Vial)	Clinically practical	1 Month (2-8°C)
Stability (On-Board Instrument)	Clinically practical	4 Days (15-25°C)
Shelf-life	Adequate for manufacturing/distribution	30 Months (2-8°C)
Method Comparison (vs. LC-MS/MS)	Good correlation (r value close to 1) and low bias	Pooled Data (N=337):- r = 0.995- Slope = 0.971- Intercept = -0.697- Mean Bias = -2.8% (individual sites ranged from -8.7% to 2.0%)
Method Comparison (ACL TOP Family 50 Series vs. ACL TOP Family)	Good correlation	Rivaroxaban:- Slope = 0.972- Intercept = 0.810- r = 0.999

2. Sample Sizes and Data Provenance

Precision Study:
- Sample Size: n=80 per instrument/lot for each sample level, tested over 20 days (2 runs/day, 2 replicates/run). 6 citrated plasma samples + Rivaroxaban Controls.
- Data Provenance: Not explicitly stated (e.g., country of origin, prospective/retrospective). Implied to be internal laboratory studies.
Reproducibility Study:
- Sample Size: 270 replicates per level (Rivaroxaban Controls and 5 citrated plasma samples). Each material tested in triplicate, twice a day for 5 days.
- Data Provenance: Conducted at 3 sites. No specific country of origin or retrospective/prospective status is given, but "multicenter" implies multiple distinct lab settings.
LoB, LoD, LoQ Studies:
- Sample Size: Not explicitly stated but implied to be sufficient to meet CLSI EP17-A2 guidelines.
- Data Provenance: Not explicitly stated, implied to be internal laboratory studies.
Linearity Studies:
- Sample Size: Each rivaroxaban level tested in quadruplicate for Analytical Measuring Interval (13 concentrations) and Extended Measuring Interval (9 concentrations).
- Data Provenance: Not explicitly stated, implied to be internal laboratory studies.
Interference Studies:
- Sample Size: Not explicitly stated but implied to be sufficient to meet CLSI EP07 guidelines.
- Data Provenance: Not explicitly stated, implied to be internal laboratory studies.
In-Use Stability and Shelf-life Studies:
- Sample Size: Not explicitly stated.
- Data Provenance: Not explicitly stated, implied to be internal laboratory studies.
Method Comparison (HemosIL Liquid Anti-Xa vs. LC-MS/MS):
- Sample Size: 337 samples.
- Data Provenance: Multicenter study (3 laboratory sites). Samples were from patients treated with rivaroxaban, including 12 from bleeding patients and 261 from patients at risk of major bleeding. This indicates retrospective clinical samples where the rivaroxaban levels were already established or patients were undergoing treatment. No country of origin is specified.

3. Number of Experts used to Establish Ground Truth for Test Set and Qualifications

N/A for this type of diagnostic assay. The "ground truth" for the method comparison study was established using a gold standard analytical method (LC-MS/MS), not by human experts interpreting images or clinical cases.

4. Adjudication Method for the Test Set

N/A. This is a quantitative diagnostic assay. The comparison is against a reference analytical method (LC-MS/MS), not subjective human interpretations requiring adjudication.

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

No, this is not applicable. An MRMC study is relevant for imaging or diagnostic tools where human interpretation is a primary component of the diagnostic process (e.g., radiologists reading scans). This device is an automated, chromogenic assay delivering quantitative results.

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

Yes, in essence, the entire performance evaluation (Precision, Reproducibility, LoB/LoD/LoQ, Linearity, Interferences, Stability) is a "standalone" evaluation of the assay's analytical performance. The method comparison study also evaluates the assay (algorithm + reagents + instrument) against a reference method. Human involvement is limited to performing the tests and interpreting the instrument's numerical output, not making a subjective diagnosis based on qualitative assay results.

7. The Type of Ground Truth Used

For Analytical Performance Studies (Precision, Reproducibility, LoB/LoD/LoQ, Linearity, Interferences, Stability): The "ground truth" is established through carefully prepared samples with known concentrations (e.g., calibrators, controls, spiked samples) or by evaluating the assay's intrinsic performance characteristics against statistical and analytical chemistry standards (e.g., CLSI guidelines).
For Method Comparison Study: The ground truth was established using LC-MS/MS (Liquid Chromatography–Mass Spectrometry/Mass Spectrometry), which is considered a highly accurate and precise reference method for drug concentration measurement in biological samples.

8. The Sample Size for the Training Set

N/A. This is an assay based on established chromogenic chemistry, not a machine learning or AI model that requires a "training set" in the computational sense. The device's calibration curves are established using calibrators with known concentrations, which are analogous to a very small "training set" in terms of how the system learns to relate absorbance to concentration, but it's not a large-scale data training as seen with AI.

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

N/A. As above, there is no "training set" in the AI/ML context. The assay's performance relies on its chemical and enzymatic principles, and its calibration is set using commercially supplied or manufactured calibrators with assigned values based on internal reference methods.

Summary

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Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: a symbol on the left and the FDA name and title on the right. The symbol on the left is a stylized representation of a human figure, while the text on the right reads "FDA U.S. FOOD & DRUG ADMINISTRATION" in blue letters.

June 23, 2023

Instrumentation Laboratory Co. Carol Marble Senior Regulatory Affairs Director 180 Hartwell Road Bedford, Massachusetts 01730

Re: K223187

Trade/Device Name: HemosIL Liquid Anti-Xa Regulation Number: 21 CFR 864.7295 Regulation Name: Heparin And Direct Oral Factor Xa Inhibitor Drug Test System Regulatory Class: Class II Product Code: QLU Dated: Mav 23, 2023 Received: May 24, 2023

Dear Carol Marble:

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. 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 located 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.

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

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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 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-

542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 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 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,

Image /page/1/Picture/6 description: The image contains the text "Min Wu -S". The text is written in a simple, sans-serif font. The letters are black against a white background. The text appears to be a name or a title.

Min Wu, Ph. D. Branch Chief Division of Immunology and Hematology Devices OHT7: Office of In Vitro Diagnostics Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K223187

Device Name HemosIL Liquid Anti-Xa

Indications for Use (Describe)

· When used with HemosIL Heparin Calibrators:

Quantitative determination of unfractionated heparin (UFH) and low molecular weight heparin (LMWH) activity on the ACL TOP Family and ACL TOP Family 50 Series.

· When used with HemosIL Apixaban Calibrators:

Patients at risk for major bleeding
Patients experiencing a bleeding episode

· When used with HemosIL Rivaroxaban Calibrators:

Patients at risk for major bleeding
Patients experiencing a bleeding episode

The assay is not a stand-alone test and the results should be used in conjunction with other clinical and laboratory findings. For use in adult population. For prescription use only.

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)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

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510(k) Summary

This 510(k) Summary of Safety and Effectiveness is being submitted in accordance with the requirements of the Safe Medical Device Act of 1990 and 21 CFR 807.92.

Submitter'sInformation	Instrumentation Laboratory (IL) Co.180 Hartwell RoadBedford, MA 01730, USA
Contact Person	Carol Marble, Senior Regulatory Affairs DirectorPhone: 781-861-4467Fax: 781-861-4207Email: cmarble@werfen.com
Preparation Date	June 22, 2023
Device Trade Name	HemosIL Liquid Anti-Xa
RegulatoryInformation	Regulation No.	21 CFR 864.7295
	Regulation Description	Anti-Factor Xa Activity Test System
	Classification	Class II
	Product Code	QLU
	Classification Panel	Hematology (81)
Predicate Device Nos.	DEN190032 K213464	Predicate Device Name	HemosIL Liquid Anti-Xa
Device Description	HemosIL Liquid Anti-Xa is a one stage chromogenic assay based on a syntheticchromogenic substrate and on Factor Xa inactivation. The assay providesquantitative rivaroxaban results on 3.2% citrated human plasma as follows:Rivaroxaban levels in patient plasma are measured automatically on ACL TOPFamily and ACL TOP Family 50 Series when this assay is calibrated withHemosIL Rivaroxaban Calibrators.Rivaroxaban directly inhibits Factor Xa activity independent of the antithrombinpresent. The Factor Xa activity measured by the assay is exogenous. Factor Xais neutralized directly by rivaroxaban.Residual Factor Xa is quantified with a synthetic chromogenic substrate. Theparanitroaniline released is monitored kinetically at 405 nm and is inverselyproportional to the rivaroxaban level in the sample.

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	HemosIL Liquid Anti-Xa is an automated chromogenic assay for in vitrodiagnostic use by laboratory professionals in clinical laboratories. The assayprovides quantitative results on 3.2% citrated human plasma for the followinganalytes based on the calibrators used:
	When used with HemosIL Heparin Calibrators:• Quantitative determination of unfractionated heparin (UFH) and lowmolecular weight heparin (LMWH) activity on the ACL TOP Family andACL TOP Family 50 Series.
	When used with HemosIL Apixaban Calibrators:• Quantitative determination of apixaban on the ACL TOP Family and ACLTOP Family 50 Series through measurement of factor Xa activity, which isinversely proportional to the apixaban level. With HemosIL ApixabanCalibrators, the assay is intended to measure apixaban concentrations inpatients on apixaban therapy in the following situations where measurementof apixaban levels could be useful to have as additional information:- Patients at risk for major bleeding- Patients experiencing a bleeding episode
Intended Use /Indications for Use
	When used with HemosIL Rivaroxaban Calibrators:• Quantitative determination of rivaroxaban on the ACL TOP Family and ACLTOP Family 50 Series through measurement of factor Xa activity, which isinversely proportional to the rivaroxaban level. With HemosIL RivaroxabanCalibrators, the assay is intended to measure rivaroxaban concentrations inpatients on rivaroxaban therapy in the following situations wheremeasurement of rivaroxaban levels could be useful to have as additionalinformation:- Patients at risk for major bleeding- Patients experiencing a bleeding episode
	The assay is not a stand-alone test and the results should be used in conjunctionwith other clinical and laboratory findings.
	For use in adult population. For prescription use only.
Item	Predicate Device	Subject Device
Trade Name andMeasurand	HemosIL Liquid Anti-Xafor apixaban measurement	HemosIL Liquid Anti-Xafor rivaroxaban measurement
Manufacturer	Instrumentation Laboratory Co.	Same
Intended Use /Indications for Use	See updated intended use / indications for use on previous page.
Similarities
Item	Predicate Device	Subject Device
Trade Name andMeasurand	HemosIL Liquid Anti-Xafor apixaban measurement	HemosIL Liquid Anti-Xafor rivaroxaban measurement
Regulation No.	21 CFR 864.7295	Same
RegulationDescription	Anti-Factor Xa Activity Test System	Same
Classification	Class II	Same
Product Code	QLU	Same
Review Panel	Hematology (81)	Same
Technical Method	The test detects residual factor Xa usinga chromogenic substrate. The signal oroptical density is compared to a drug-specific calibration curve and results arereported as nanograms per milliliter(ng/mL).	Same
Sample Type	3.2% citrated human plasma	Same
Measurement	Quantitative	Same
Testing Methodology	Chromogenic	Same
Reporting Unit	ng/mL	Same
Similarities (Cont.)
Item	Predicate Device	Subject Device
Composition	The HemosIL Anti-Xa kit includes the following components:• Factor Xa reagent: Liquid preparation containing purified bovine Factor Xa (approximately 5.5 nkat/mL), Tris-Buffer, EDTA, dextran sulfate, sodium chloride and bovine serum albumin.• Chromogenic substrate: liquid chromogenic substrate S-2732 (approximately 1.2 mg/mL) and bulking agent.	Same
Instrumentation	ACL TOP Family (K160276)ACL TOP Family 50 Series (K150877)	Same
On-board Stability	4 days	Same
Open Reagent Stability	1 month	Same
Differences
Item	Predicate Device	Subject Device
Measurand	apixaban	rivaroxaban
Limit ofDetection	9 ng/mL for apixaban	8 ng/mL for rivaroxaban
Linearity	20 to 1000 ng/mL for apixaban	20 to 1000 ng/mL for rivaroxaban
Kit SizeConfigurations	4 mL Kit Vial Size (Only 1 Size):Factor Xa reagent (Cat. No.0020302612): 5 x 2.5 mL vial of aliquid preparation containingpurified bovine Factor Xa(approximately 5.5 nkat/mL), Tris-Buffer, EDTA, dextran sulfate,sodium chloride and bovine serumalbumin. Chromogenic substrate (Cat. No.0020302622): 5 x 3 mL vial ofliquid chromogenic substrate S-2732 (approximately 1.2 mg/mL)and bulking agent.	4 mL Kit Vial Size (Size 1):Factor Xa reagent (Cat. No. 0020302612): 5x 2.5 mL vial of a liquid preparationcontaining purified bovine Factor Xa(approximately 5.5 nkat/mL), Tris-Buffer,EDTA, dextran sulfate, sodium chloride andbovine serum albumin. Chromogenic substrate (Cat. No.0020302622): 5 x 3 mL vial of liquidchromogenic substrate S-2732(approximately 1.2 mg/mL) and bulkingagent. 10 mL Kit Vial Size (Size 2):Factor Xa reagent (Cat. No. 0020303610): 5x 5 mL vial of a liquid preparation containingpurified bovine Factor Xa (approximately 5.5nkat/mL), Tris-Buffer, EDTA, dextransulfate, sodium chloride and bovine serumalbumin. Chromogenic substrate (Cat. No.0020303620): 5 x 6 mL vial of liquidchromogenic substrate S-2732(approximately 1.2 mg/mL) and bulkingagent
Calibrators(SoldSeparately)	HemosIL Apixaban CalibratorsTarget Levels: 0 and ~500 ng/mL	HemosIL Rivaroxaban CalibratorsTarget Levels: 0 and ~500 ng/mL
Controls(SoldSeparately)	HemosIL Apixaban ControlsTarget Levels: ~75 and ~300 ng/mL	HemosIL Rivaroxaban ControlsTarget Levels: ~80 and ~300 ng/mL

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Substantial Equivalence Discussion

Following is a description of the similarities and differences between the predicate device, the currently marketed HemosIL Liquid Anti-Xa for apixaban measurement under DEN190032, with modified on-board instrument stability claims under K213464, compared to the subject device with the expanded intended use for rivaroxaban measurement.

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Performance Summary

Precision

Within-run and total precision was assessed in accordance with CLSI EP05-A3 for 20 days, with 2 runs per day and 2 replicates per run for each sample level (n=80/instrument/lot), using 3 lots of HemosIL Liquid Anti-Xa on representative members of the ACL TOP Family and ACL TOP Family 50 Series. To span the assay range, 6 citrated plasma samples were tested, as well as HemosIL Rivaroxaban Controls.

ACL TOP Family	Mean (ng/mL)	CV% (Within-run)	CV% (Total)
Rivaroxaban Low Control	77.2	3.3	4.1
Rivaroxaban High Control	284.0	1.4	2.4
Sample 1	49.3	3.9	5.5
Sample 2	762.1	1.4	2.5
Sample 3	904.0	1.3	2.8
Sample 4	125.0	1.3	1.6
Sample 5	32.0	4.1	5.2
Sample 6	428.0	0.9	1.0

The tables below include data for representative systems each with 1 reagent lot.

ACL TOP Family 50 Series	Mean (ng/mL)	CV% (Within-run)	CV% (Total)
Rivaroxaban Low Control	80.9	2.5	4.9
Rivaroxaban High Control	283.9	1.4	2.4
Sample 1	51.0	2.7	3.2
Sample 2	798.7	1.6	1.6
Sample 3	943.7	1.1	1.2
Sample 4	130.4	1.0	1.5
Sample 5	33.0	3.4	4.5
Sample 6	445.0	1.2	1.2

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Reproducibility

Reproducibility studies were conducted at 3 stes using (1 operator per site) on 3 different ACL TOP Family systems (1 system per site), using 3 lots of HemosIL Liquid Anti-Xa and 1 lot of HemosIL Rivans (Low and High). Five citrated plasma samples were also tested across the 3 sites. Each material was tested in triplicate, twice a day for 5 days, for a total of 30 replicates per level.

The pooled 3 site data is presented below.

Pooled 3 Site Data
Level	Mean(ng/mL)	N	Repeatability(Within-Run)		Between-Run		Between-Day		Between-Site		Between-Lot		Reproducibility(Total)
			SD	%CV	SD	%CV	SD	%CV	SD	%CV	SD	%CV	SD	%CV
Rivaroxaban Low Control	72.6	270	2.28	3.1%	1.03	1.4%	0.00	0.0%	1.44	2.0%	0.80	1.1%	3.00	4.1%
Rivaroxaban High Control	281	270	4.58	1.6%	4.10	1.5%	0.00	0.0%	2.15	0.8%	0.17	0.1%	6.51	2.3%
Sample 1	45.0	270	2.55	5.7%	0.88	2.0%	0.56	1.3%	3.38	7.5%	0.66	1.5%	4.41	9.8%
Sample 2	750	270	19.68	2.6%	1.44	0.2%	6.30	0.8%	22.12	3.0%	5.26	0.7%	30.76	4.1%
Sample 3	939	270	25.49	2.7%	3.43	0.4%	7.41	0.8%	22.98	2.4%	8.83	0.9%	36.36	3.9%
Sample 4	51.8	270	2.46	4.7%	1.30	2.5%	0.84	1.6%	1.55	3.0%	0.83	1.6%	3.39	6.5%
Sample 5	118	270	3.71	3.1%	4.29	3.6%	2.76	2.3%	5.71	4.8%	1.64	1.4%	8.67	7.3%

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Limit of Blank (LoB), Limit of Detection (LoD) and Limit of Quantitation (LoQ)

LoB, LoD and LoQ studies for rivaroxaban were performed in accordance with CLSI EP17-A2, using 3 lots of HemosIL Liquid Anti-Xa on a representative ACL TOP Family model and a representative ACL TOP Family 50 Series model. The following maximum limits were determined:

Limit of Blank (LoB)	Limit of Detection (LoD)	Limit of Quantitation (LoQ)
2.4 ng/mL	8 ng/mL	20 ng/mL*

*Note: The reportable value for the LoQ will be 20 ng/mL as the lower limit of the linear range.

Linearity

Linearity studies for rivaroxaban were performed in accordance with CLSI EP06, 2nd Edition, using 3 lots of HemosIL Liquid Anti-Xa on a representative ACL TOP Family model and a representative ACL TOP Family 50 Series model.

Analytical Measuring Interval (AMI): The AMI was performed over the range of 18-550 ng/mL for 13 . rivaroxaban concentrations. Each rivaroxaban level was tested in quadruplicate on both instrument models with each reagent lot.
Extended Measuring Interval (EMI): The EMI was performed over the range of 425-1100 ng/mL for 9 ● rivaroxaban concentrations. Each rivaroxaban level was tested in quadruplicate on both instrument models with each reagent lot.

The studies support a reportable linear range for rivaroxaban on the ACL TOP Family 50 Series of 20 to 1000 ng/mL.

Interferences and Limitations

Interference studies for rivaroxaban were performed in accordance with CLSI EP07, 34 Edition, using 1 lot of HemosIL Liquid Anti-Xa on a representative ACL TOP Family model. The studies support that rivaroxaban results on the ACL TOP Family and ACL TOP Family 50 Series are not affected by the following interferents up to:

Hemoglobin	600 mg/dL
Bilirubin (unconjugated)	40 mg/dL
Bilirubin (conjugated)	40 mg/dL
Triglycerides	921 mg/dL
Acetylsalicylic acid	3.00 mg/dL
Atorvastatin	0.075 mg/dL
Isosorbide dinitrate	0.600 mg/dL
Ticagrelor	0.188 mg/dL
Warfarin	7.50 mg/dL
Lupus anticoagulant	dRVVT Screen/Confirm Ratio 2.47

Rivaroxaban results may be falsely elevated in samples tested post-andexanet alfa administration.

The assay is not intended for the monitoring and dosage adjustment of rivaroxaban.

Administer a reversal agent based on current clinical guidance, and take into consideration other clinical and laboratory findings including the Factor Xa inhibitor dose and time since last dose. For additional information, refer to current clinical guidance and reversal agent prescribing information.

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In-Use Stability and Shelf-life

In-use stability and shelf-life studies for rivaroxaban were performed in accordance with CLSI EP25-A, using multiple lots of HemosIL Liquid Anti-Xa on a representative ACL TOP Family model. The studies support the following rivaroxaban claims on the ACL TOP Family and ACL TOP Family 50 Series:

Study Type	Storage Condition	Claim
Open Vial	2-8°C	1 Month
On-Board Instrument	15-25°C	4 Days
Shelf-life	2-8°C	30 Months

Method Comparison

A multicenter study was performed in accordance with CLSI EP09c, 3rd Edition, at 3 laboratory sites comparing Liquid Anti-Xa for the measurement of rivaroxaban oon the ACL TOP HemosIL Family to LC-MS/MS. Samples were from patients treated with rivaroxaban, including 12 samples from bleeding patients and 261 samples from patients at risk of major bleeding. A summary of the individual site and pooled 3-site results on 337 samples is shown below.

	N	r	Slope		Intercept			Mean Bias
			Value	95% CI	Value	95% CI
Site 1	111	0.995	0.947	0.927 0.966	-3.872	-5.922	-1.822	-8.7%
Site 2	107	0.995	0.981	0.944 1.019	2.374	-2.750	7.497	2.0%
Site 3	119	0.995	0.994	0.962 1.025	-1.376	-5.114	2.362	-1.6%
Pooled	337	0.995	0.971	0.953 0.990	-0.697	-3.087	1.692	-2.8%

An internal method comparison study was performed comparing the performance of the ACL TOP Family 50 Series to the ACL TOP Family using representative systems from both families. Representative results are shown below.

System	Analyte	Slope	Intercept	r	Comparator method
ACL TOP Family 50 Series	Rivaroxaban	0.972	0.810	0.999	ACL TOP Family

Conclusion

HemosIL Liquid Anti-Xa for rivaroxaban measurement is substantially equivalent to the legally marketed predicate device, HemosIL Liquid Anti-Xa, FDA marketing authorized under DEN190032 for apixaban measurement and FDA cleared under K213464 with modified on-board instrument stability claims.

Regulation Number and Section

§ 864.7295 Heparin and direct oral factor Xa inhibitor drug test system.

(a)
Identification. A heparin and direct oral factor Xa inhibitor drug test system is intended for the detection of heparin and direct oral factor Xa inhibitors in human specimens collected from patients taking heparin or direct oral factor Xa inhibitors. This device is intended to aid in the management of therapy in conjunction with other clinical and laboratory findings.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Design verification and validation must include the following:
(i) Detailed documentation of analytical device performance studies and results demonstrating acceptable analytical performance with a sufficient number of specimens tested in order to obtain unbiased estimates of analytical performance. This documentation shall include the following as appropriate to the technology, specimen types tested, and intended use of the device:
(A) Studies and results for that demonstrate device precision including repeatability and reproducibility, using quality controls and clinical samples, when appropriate. Precision studies must assess specimens for each indicated drug at concentrations throughout the measuring range of the device including near clinically relevant levels, as appropriate. The study must evaluate different sources of variability including, as appropriate, between-run, between-operator, between-lot, between-instrument, between-day, and between-site;
(B) Studies and results that demonstrate that the device is free from clinically significant interference, from endogenous and exogenous interferents associated with the target population(s), and interferents that are specific for, or related to, the technology or methodology of the device;
(C) Data to demonstrate appropriate specimen stability for the intended sample matrices under the intended conditions for specimen collection, handling, and storage described in the device labeling;
(D) Studies and results that demonstrate the linear range, limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ), as applicable to the technology of the device; and
(E) For any devices intended for use for near patient testing, studies and results that demonstrate the robustness of the device in the hands of the intended user, including the entire testing procedure, pre-analytical specimen processing steps, and results interpretation.
(ii) Detailed documentation of clinical performance testing in which the performance is analyzed relative to a comparator that FDA has determined is appropriate. Specimens must be representative of the intended use population(s) and must cover the full range of the device output and any clinically relevant decision points as appropriate.
(2) The labeling required under § 809.10(b) of this chapter must include:
(i) Identification of any known interferents, including all endogenous, exogenous, technology-specific, and patient population-specific interferents, specific to the test outputs. The information must include the concentration(s) or level(s) of the interferent at which clinically significant interference was found to occur, and the concentration range or levels at which interference was not found to occur;
(ii) A prominent statement that the device is not intended for use in monitoring patients taking heparin or direct oral factor Xa inhibitors; and
(iii) Limiting statements indicating, as applicable:
(A) That the device should only be used in conjunction with information available from clinical evaluations and other diagnostic procedures; and
(B) That the device is not specific to the direct oral factor Xa inhibitor that has been evaluated and may detect the presence of other direct factor Xa inhibitors that have not been evaluated.