The Tacrolimus Assay Kit is used for quantitative determination of the tacrolimus concentration in human whole blood on the Beckman Coulter AU480. It is to be used as an aid in the management of liver and kidney allograft patients receiving tacrolimus therapy.

For In Vitro Diagnostic Use.

Device Description

The Tacrolimus Assay Kit utilizes the latex-enhanced competitive immunoturbidimetry method for quantitative determination of the tacrolimus concentration in human whole blood. The assay consists of reagents, sample extract and calibrator.

AI/ML Overview

The provided text describes the acceptance criteria and a study demonstrating the substantial equivalence of the "Tacrolimus Assay Kit" (candidate device) to a predicate device, the ARCHITECT Tacrolimus Assay.

Here's an analysis of the requested information:

1. A table of acceptance criteria and the reported device performance

The document does not explicitly list "acceptance criteria" in a structured table with direct performance targets. Instead, it states that "Analytical studies were performed to evaluate the precision, linearity, assay reportable range, recovery, specificity, and accuracy of the candidate device." The conclusion then states that these tests demonstrate "substantial equivalence." This implies that the performance in these areas met thresholds considered acceptable for substantial equivalence to the predicate device.

However, a key difference between the candidate and predicate device is the "Measuring Range." This could be considered a performance characteristic with an implicit acceptance criterion that the range should be clinically relevant and comparable to other devices.

Performance Characteristic	Acceptance Criteria (Implicit from Predicate & Substantial Equivalence Claim)	Reported Device Performance (Tacrolimus Assay Kit)
Measuring Range	Comparable to predicate device (2 - 30 ng/mL)	1.5 - 30 ng/mL (Slightly wider lower limit)
Precision	Demonstrated substantial equivalence	Evaluated, results demonstrate substantial equivalence
Linearity	Demonstrated substantial equivalence	Evaluated, results demonstrate substantial equivalence
Assay Reportable Range	Demonstrated substantial equivalence	Evaluated, results demonstrate substantial equivalence
Recovery	Demonstrated substantial equivalence	Evaluated, results demonstrate substantial equivalence
Specificity	Demonstrated substantial equivalence	Evaluated, results demonstrate substantial equivalence
Accuracy	Demonstrated substantial equivalence	Evaluated, results demonstrate substantial equivalence

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

The document does not provide details on the sample size used for the analytical studies (precision, linearity, etc.), nor does it specify the data provenance (country of origin, retrospective/prospective). It simply states that "Analytical studies were performed."

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

This question is not applicable to this type of device (Tacrolimus Assay Kit). The "ground truth" for an in-vitro diagnostic test like this is established through reference methods or highly accurate analytical techniques, not through expert consensus on images or clinical assessments.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

This question is not applicable. Adjudication methods like 2+1 or 3+1 are typically used for establishing ground truth in studies involving human interpretation (e.g., radiology studies). For an in-vitro diagnostic assay, the "adjudication" would involve rigorous laboratory protocols, quality control, and comparison to established reference materials or methods, not human adjudication between experts.

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

This question is not applicable. The device is a Tacrolimus Assay Kit, an in-vitro diagnostic test, not an AI-assisted diagnostic tool that would involve human readers interpreting images or data.

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

This question is not applicable in the context of "algorithm only" as typically understood for AI/CAD devices. However, the performance assessment described (precision, linearity, accuracy, etc.) is essentially "standalone" in the sense that it evaluates the kit's performance on its own, independent of human interpretation or intervention beyond standard laboratory procedures for running the assay. It's a laboratory test, not an AI algorithm.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

For in-vitro diagnostic assays, "ground truth" is typically established by:

Reference materials/standards: Samples with known concentrations of tacrolimus, often certified.
Reference methods: Highly accurate and validated laboratory methods (e.g., mass spectrometry) used to determine the true concentration in patient samples.
Split-sample comparison: Comparing results from the candidate device to a legally marketed predicate or other established method using the same patient samples.

The document implicitly refers to these by stating the studies evaluated "precision, linearity, assay reportable range, recovery, specificity, and accuracy." Accuracy, for instance, would be assessed against known values from reference methods or materials.

8. The sample size for the training set

This question is not applicable. The device is an in-vitro diagnostic assay based on a chemical/immunological reaction, not a machine learning model that requires a "training set" in the conventional sense.

9. How the ground truth for the training set was established

This question is not applicable, as there is no "training set" for this type of device.

Summary

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January 27, 2023

Shanghai Genext Medical Technology Co., Ltd. % Giselle Zhang Regulatory Consultant Emergo Global Consulting, LLC 2500 Bee Cave Road, Building 1, Suite 300 Austin, TX 78746

Re: K203833

Trade/Device Name: Tacrolimus Assay Kit Regulation Number: 21 CFR 862.1678 Regulation Name: Tacrolimus Test System Regulatory Class: Class II Product Code: MLM Dated: August 19, 2022 Received: August 19, 2022

Dear Giselle Zhang:

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,

Paula Caposino -S	Digitally signed by Paula Caposino -S
	Date: 2023.01.27
	15:31:02 -05'00'

Paula Caposino, Ph.D. Acting Deputy Director Division of Chemistry and Toxicology 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) K203833

Device Name Tacrolimus Assay Kit

Indications for Use (Describe)

For In Vitro Diagnostic Use.

Type of Use (Select one or both, as applicable)

☑ Prescription Use (Part 21 CFR 801 Subpart D)
☐ Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary

Submission Number: K203833

The following information is provided in accordance with 21 CFR 807.92:

Submitter Information

Company:	Shanghai Genext Medical TechnologyCo., Ltd.
Address:	Rml101, 11th Floor, Bldg 2,Pujiang Hi-Tech Plaza, No.2388Chenhang Road, Minhang District,Shanghai, China
Contact Name:	Kimmy Zong
Contact Title:	RA Associate Director
Tel:	+ 86-13918832180
Fax:	N/A
Email:	wenwen.zong@genext.com.cn
Regulatory Correspondent	Giselle Zhang
Email:	LST.AUS.ProjectManagement@ul.com
Date Summary Prepared:	January 24, 2023

Name of the Device

Device Trade Name:	Tacrolimus Assay Kit
Common Name:	Tacrolimus Assay Kit
Classification Name:	Toxicology
Review Panel	Clinical Chemistry (TX)
Regulation Number:	862.1678
Classification:	II
Product Code:	MLM

Intended Use:

Indications for Use:

For In Vitro Diagnostic Use.

Reagent:

Reagent 1 (R1): FK506-protein complex, stored in MES buffer; Preservative: sodium azide. .
Reagent 2(R2): Latex particles sensitized by anti-FK506 monoclonal antibody, 4-(2-. hydroxyerhyl) piperazine-1-erhaesulfonic acid; Preservative: sodium azide.

Pretreatment Reagent:

Sample extractant: Containing methanol and inorganic salt protein denaturant. ●
Calibrator:
Calibrator: Bovine whole blood solution containing different concentrations of FK506 (the . calibration target list please see the following table); preservative.: sodium azide.

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The calibrators yield the following concentrations: ●

Calibrator name	Target value (ng/mL)
Calibrator A	0.0
Calibrator B	3.0
Calibrator C	6.0
Calibrator D	10.0
Calibrator E	20.0
Calibrator F	30.0

Special Conditions for use statement(s):

For prescription use only. ●
Special Instrument Requirements:
Beckman Coulter AU480. ●

Device Description

Test Principle

The kit is based on the principle of latex-enhanced competitive immunoturbidimetry method; The sample should be pretreated, and the protein-bound tacrolimus in the whole blood should be extracted for detection before the tacrolimus concentration is determined in the detection process. FK506 in the sample competes with FK506 in the FK506- protein complex in the reagent to bind the anti-FK506 antibody on the surface of the sensitized latex particles. The higher the concentration of FK506 in the sample, the greater the degree to which the latex surface antibody is bound by it, and the lower the latex aggregation extent induced by FK506- protein complex. The turbidity of the reaction system is negatively correlated with the concentration of FK506 in the sample. Therefore, a calibration curve can be established and the concentration of the whole blood sample FK506 can be calculated by measuring the absorbance at 546 nm.

Substantial Equivalence Information

Predicate Device Identification: ARCHITECT TACROLIMUS: MODEL IL 77 (K070820)

Comparison with Predicate:

Device & PredicateDevice(s):	Candidate DeviceK203833	Predicate DeviceK070820
Device Trade Name	Tacrolimus Assay Kit	ARCHITECTTacrolimus Assay
General DeviceCharacteristic Similarities
Intended Use/IndicationsFor Use	Same	For the quantitativedetermination oftacrolimus in humanwhole blood.
Sample pre-treatment	Same	Manual

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General DeviceCharacteristic Differences	Candidate DeviceK203833	Candidate DeviceK070820
Measuring Range	1.5 - 30 ng/mL	2 - 30 ng/mL
Methodology	Particle-enhancedturbidimetric inhibitionimmunoassay(PETINIA)	Chemiluminescentmicroparticleimmunoassay
Analyzer platform	Beckman CoulterAU480 analyzer	ARCHITECT i System.

Summary of Testing:

Analytical studies were performed to evaluate the precision, linearity, assay reportable range, recovery, specificity, and accuracy of the candidate device.

Conclusion:

Tacrolimus Assay Kit has the same indications for use as the predicate device. Any minor differences in the technological characteristics of the subject device when compared to the predicate device have been evaluated through performance testing which demonstrates that the Tacrolimus Assay Kit is substantially equivalent.

Regulation Number and Section

§ 862.1678 Tacrolimus test system.

(a)
Identification. A tacrolimus test system is a device intended to quantitatively determine tacrolimus concentrations as an aid in the management of transplant patients receiving therapy with this drug. This generic type of device includes immunoassays and chromatographic assays for tacrolimus.(b)
Classification. Class II (special controls). The special control is “Class II Special Controls Guidance Document: Cyclosporine and Tacrolimus Assays; Guidance for Industry and FDA.” See § 862.1(d) for the availability of this guidance document.