K Number
K182779
Device Name
ARK EDDP Assay
Date Cleared
2018-11-21

(51 days)

Product Code
Regulation Number
862.3620
AI/MLSaMDIVD (In Vitro Diagnostic)TherapeuticDiagnosticis PCCP Authorized
Intended Use
The ARK EDDP Assay is an immunoassay intended for the qualitative and/or semiquantitative determination of EDDP in human urine at cutoff concentrations of 100 ng/mL and 300 ng/mL. The assay is intended for use in laboratories with automated clinical chemistry analyzers. This in vitro diagnostic device is for prescription use only. The semiquantitative mode is for the purpose of (1) enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method, such as Gas Chromatography/Mass Spectrometry (GC/MS) or Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS), or (2) permitting laboratories to establish quality control procedures. The ARK EDDP Assay provides only a preliminary analytical test result. A more specific alternative chemical method must be used in order to obtain a confirmed positive analytical result. Gas Chromatography/Mass Spectrometry (GC/MS) or Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS) is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug test result, particularly when the preliminary test result is positive.
Device Description
The ARK EDDP Assay is a homogeneous enzyme immunoassay technique used for the analysis of EDDP in human urine. The assay is based on competition between EDDP in the specimen and EDDP labeled with recombinant glucose-6-phosphate dehydrogenase (rG6PDH) for antibody binding sites. As the latter binds antibody, enzyme activity decreases. In the presence of EDDP from the specimen, enzyme activity increases and is directly related to the EDDP concentration. Active enzyme converts nicotinamide adenine dinucleotide (NAD) to NADH in the presence of glucose-6-phosphate (G6P), resulting in an absorbance change that is measured spectrophotometrically. Endogenous G6PDH does not interfere because the coenzyme NAD functions only with the bacterial enzyme used in the assay. The ARK EDDP Assay consists of reagents R1 anti-EDDP rabbit antibody with substrate and R2 EDDP derivative labeled with bacterial recombinant G6PDH enzyme.
More Information

Not Found

No
The device description and performance studies focus on a standard enzyme immunoassay technique and spectrophotometric measurement, with no mention of AI or ML algorithms for data analysis or interpretation.

No
This device is an in vitro diagnostic device used for the qualitative and semiquantitative determination of EDDP (a metabolite of methadone) in human urine, providing preliminary analytical test results for drug screening, not for therapeutic purposes.

Yes
The Intended Use section explicitly states, "This in vitro diagnostic device is for prescription use only." This clearly identifies it as a diagnostic device.

No

The device description clearly states it is a homogeneous enzyme immunoassay technique based on chemical reactions and uses reagents. This indicates a physical, in vitro diagnostic device, not a software-only device.

Yes, this device is an IVD (In Vitro Diagnostic).

Here's why:

  • Explicit Statement: The "Intended Use / Indications for Use" section clearly states: "This in vitro diagnostic device is for prescription use only."
  • Intended Use: The device is intended for the "qualitative and/or semiquantitative determination of EDDP in human urine." This is a diagnostic test performed on a biological sample (urine) outside of the body (in vitro).
  • Device Description: The description details a "homogeneous enzyme immunoassay technique used for the analysis of EDDP in human urine," which is a common method for in vitro diagnostic testing.
  • Care Setting: The intended users are "laboratories with automated clinical chemistry analyzers," which are typical settings for performing in vitro diagnostic tests.

N/A

Intended Use / Indications for Use

The ARK EDDP Assay is an immunoassay intended for the qualitative and/or semiquantitative determination of EDDP in human urine at cutoff concentrations of 100 ng/mL and 300 ng/mL. The assay is intended for use in laboratories with automated clinical chemistry analyzers. This in vitro diagnostic device is for prescription use only.

The semiquantitative mode is for the purpose of (1) enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method, such as Gas Chromatography/Mass Spectrometry (GC/MS) or Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS), or (2) permitting laboratories to establish quality control procedures.

The ARK EDDP Assay provides only a preliminary analytical test result. A more specific alternative chemical method must be used in order to obtain a confirmed positive analytical result. Gas Chromatography/Mass Spectrometry (GC/MS) or Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS) is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug test result, particularly when the preliminary test result is positive.

Product codes (comma separated list FDA assigned to the subject device)

DJR

Device Description

The ARK EDDP Assay is a homogeneous enzyme immunoassay technique used for the analysis of EDDP in human urine. The assay is based on competition between EDDP in the specimen and EDDP labeled with recombinant glucose-6-phosphate dehydrogenase (rG6PDH) for antibody binding sites. As the latter binds antibody, enzyme activity decreases. In the presence of EDDP from the specimen, enzyme activity increases and is directly related to the EDDP concentration. Active enzyme converts nicotinamide adenine dinucleotide (NAD) to NADH in the presence of glucose-6-phosphate (G6P), resulting in an absorbance change that is measured spectrophotometrically. Endogenous G6PDH does not interfere because the coenzyme NAD functions only with the bacterial enzyme used in the assay.

The ARK EDDP Assay consists of reagents R1 anti-EDDP rabbit antibody with substrate and R2 EDDP derivative labeled with bacterial recombinant G6PDH enzyme.

Mentions image processing

Not Found

Mentions AI, DNN, or ML

Not Found

Input Imaging Modality

Not Found

Anatomical Site

human urine

Indicated Patient Age Range

Not Found

Intended User / Care Setting

laboratories with automated clinical chemistry analyzers. This in vitro diagnostic device is for prescription use only.

Description of the training set, sample size, data source, and annotation protocol

Not Found

Description of the test set, sample size, data source, and annotation protocol

Not Found

Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)

Precision studies were performed using CLSI EP05-A3 as a guideline. Drug-free, negative human urine was supplemented with EDDP (0.0 to 200.0 ng/mL for the 100 ng/mL cutoff and 0.0 to 600.0 for the 300 ng/mL cutoff). Each level was assayed in quadruplicate twice a day for 20 days (N=160) and evaluated qualitatively and semiquantitatively.

Analytical Recovery: Recovery across the assay range was assessed using the semiquantitative mode. Drug-free, negative human urine was supplemented with EDDP (1100.0 ng/mL) and dilutions were made proportionally with drug-free human urine. EDDP concentrations ranged from 50.0 to 1000.0 ng/mL. At each level, percentage recovery was calculated based on the mean concentration (N=6) compared to the expected concentration.

Analytical Specificity/Cross-reactivity: Structurally related compounds were evaluated.

Interference: High concentrations of structurally unrelated compounds and endogenous substances were added to urine spiked with EDDP (± 25% of the cutoff concentration) and tested.

Specific Gravity: Urine samples with specific gravity values ranging from 1.002 to 1.030 were tested in the presence of two levels of EDDP (± 25% of the cutoff concentration).

pH: Urine samples with pH values from 3.0 to 11.0 were tested in the presence of two levels of EDDP (± 25% of the cutoff concentration).

Method Comparison: A total of one hundred nine (109) unaltered clinical human urine specimens were analyzed for EDDP at two cutoff levels with the ARK EDDP Assay in both qualitative and semiquantitative modes. Results were compared to GC/MS, performed by a licensed reference laboratory.

Key results from the method comparison show:
For 100 ng/mL Cutoff:

  • 40 samples that were 150 ng/mL by GC/MS were Positive by ARK Immunoassay.

For 300 ng/mL Cutoff:

  • 49 samples that were 450 ng/mL by GC/MS were Positive by ARK Immunoassay.

Calibration Curve Stability: A stored calibration curve was effective up to at least 15 days based on supporting data.

Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)

Not explicitly stated as Sensitivity, Specificity, PPV, NPV tables, but qualitative precision results indicate the proportion of negative and positive results around the cutoff concentrations. For instance, at the 100 ng/mL cutoff, 100.0 ng/mL samples yielded 123 Negative and 37 Positive results qualitatively. At +25% cutoff (125.0 ng/mL), 160/160 were Positive. At -25% cutoff (75.0 ng/mL), 160/160 were Negative. Similar breakdowns are provided for the 300 ng/mL cutoff.

Predicate Device(s): If the device was cleared using the 510(k) pathway, identify the Predicate Device(s) K/DEN number used to claim substantial equivalence and list them here in a comma separated list exactly as they appear in the text. List the primary predicate first in the list.

K151395

Reference Device(s): Identify the Reference Device(s) K/DEN number and list them here in a comma separated list exactly as they appear in the text.

Not Found

Predetermined Change Control Plan (PCCP) - All Relevant Information for the subject device only (e.g. presence / absence, what scope was granted / cleared under the PCCP, any restrictions, etc).

Not Found

§ 862.3620 Methadone test system.

(a)
Identification. A methadone test system is a device intended to measure methadone, an addictive narcotic pain-relieving drug, in serum and urine. Measurements obtained by this device are used in the diagnosis and treatment of methadone use or overdose and to determine compliance with regulations in methadone maintenance treatment.(b)
Classification. Class II (special controls). A methadone test system is not exempt if it is intended for any use other than employment or insurance testing or is intended for Federal drug testing programs. The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9, provided the test system is intended for employment and insurance testing and includes a statement in the labeling that the device is intended solely for use in employment and insurance testing, and does not include devices intended for Federal drug testing programs (e.g., programs run by the Substance Abuse and Mental Health Services Administration (SAMHSA), the Department of Transportation (DOT), and the U.S. military).

0

Image /page/0/Picture/0 description: The image contains the logos of the Department of Health & Human Services and the Food and Drug Administration (FDA). The Department of Health & Human Services logo is on the left, and the FDA logo is on the right. The FDA logo is a blue square with the letters "FDA" in white, followed by the words "U.S. FOOD & DRUG ADMINISTRATION" in blue.

November 21, 2018

ARK Diagnostics, Inc. Cherry Mun Manager, Quality and Regulatory Affairs 48089 Fremont Boulevard Fremont, California 94538

Re: K182779

Trade/Device Name: ARK EDDP Assay Regulation Number: 21 CFR 862.3620 Regulation Name: Methadone test system Regulatory Class: Class II Product Code: DJR Dated: September 28, 2018 Received: October 1, 2018

Dear Cherry Mun:

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 requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part

1

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/CombinationProducts/GuidanceRegulatoryInformation/ucm597488.htm); 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 http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). 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 (http://www.fda.gov/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

for Courtnev H. Lias. Ph.D. Director Division of Chemistry and Toxicology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health

Enclosure

2

Form Approved: OMB No. 0910-0120
Expiration Date: 06/30/2020
See PRA Statement below.

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

Indications for Use

510(k) Number (if known)K182779
Device NameARK EDDP Assay

Indications for Use (Describe)

The ARK EDDP Assay is an immunoassay intended for the qualitative and/or semiquantitative determination of EDDP in
human urine at cutoff concentrations of 100 ng/mL and 300 ng/mL. The assay is intended for use in laboratories with
automated clinical chemistry analyzers. This in vitro diagnostic device is for prescription use only.

The semiquantitative mode is for the purpose of (1) enabling laboratories to determine an appropriate dilution of the
specimen for confirmation by a confirmatory method, such as Gas Chromatography/Mass Spectrometry (GC/MS) or
Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS), or (2) permitting laboratories to establish quality
control procedures.

The ARK EDDP Assay provides only a preliminary analytical test result. A more specific alternative chemical method
must be used in order to obtain a confirmed positive analytical result. Gas Chromatography/Mass Spectrometry (GC/MS)
or Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS) is the preferred confirmatory method. Clinical
consideration and professional judgment should be exercised with any drug test result, particularly when the preliminary
test result is positive.

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)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

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DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

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and review the collection of information. Send comments regarding this burden estimate or any other aspect
of this information collection, including suggestions for reducing this burden, to:

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information unless it displays a currently valid OMB number."

FORM FDA 3881 (7/17)Page 1 of 1
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노-남 10 レ-৮ ခုနှစ် ချောင်းများ မြို့နယ်ရှိ ရွာများ BotU

3

510(k) SUMMARY

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

The assigned 510(k) number is K182779.

807.92 (a)(1): Name:ARK Diagnostics, Inc.
Address:48089 Fremont Blvd
Fremont, CA 94538 USA
Owner Operator Number:10027663
Establishment Registration:3005755244
Phone:(510) 270-6270
FAX:(510) 270-6298
Contact:Cherry Mun – (510) 270-6288
Manager of Quality and Regulatory Affairs

Date Prepared: November 19th, 2018

807.92 (a)(2): Device Name – Trade Name, Common Name, and Classification

Trade Name:ARK™ EDDP Assay
Common Name:Homogeneous Enzyme Immunoassay, Methadone Test System

Classification:

Product CodeClassificationRegulation SectionPanel
DJRClass II21 CFR 862.3620
Methadone Test SystemToxicology
(91)

807.92 (a)(3): Identification of the Legally Marketed Predicate Device

Immunalysis EDDP Specific Urine Enzyme Immunoassay (K151395)

4

807.92 (a)(4): Device Description

The ARK EDDP Assay is a homogeneous enzyme immunoassay technique used for the analysis of EDDP in human urine. The assay is based on competition between EDDP in the specimen and EDDP labeled with recombinant glucose-6-phosphate dehydrogenase (rG6PDH) for antibody binding sites. As the latter binds antibody, enzyme activity decreases. In the presence of EDDP from the specimen, enzyme activity increases and is directly related to the EDDP concentration. Active enzyme converts nicotinamide adenine dinucleotide (NAD) to NADH in the presence of glucose-6-phosphate (G6P), resulting in an absorbance change that is measured spectrophotometrically. Endogenous G6PDH does not interfere because the coenzyme NAD functions only with the bacterial enzyme used in the assay.

The ARK EDDP Assay consists of reagents R1 anti-EDDP rabbit antibody with substrate and R2 EDDP derivative labeled with bacterial recombinant G6PDH enzyme.

807.92 (a)(5): Intended Use / Indications for Use

ARK EDDP Assay

The ARK EDDP Assay is an immunoassay intended for the qualitative and/or semiquantitative determination of EDDP in human urine at cutoff concentrations of 100 ng/mL and 300 ng/mL. The assay is intended for use in laboratories with automated clinical chemistry analyzers. This in vitro diagnostic device is for prescription use only.

The semiquantitative mode is for the purpose of (1) enabling laboratories to determine an appropriate dilution of the specimen for confirmation by a confirmatory method, such as Gas Chromatography/Mass Spectrometry (GC/MS) or Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS), or (2) permitting laboratories to establish quality control procedures.

The ARK EDDP Assay provides only a preliminary analytical test result. A more specific alternative chemical method must be used in order to obtain a confirmed positive analytical result. Gas Chromatography/Mass Spectrometry (GC/MS) or Liquid Chromatography/tandem Mass Spectrometry (LC-MS/MS) is the preferred confirmatory method. Clinical consideration and professional judgment should be exercised with any drug test result, particularly when the preliminary test result is positive.

5

807.92 (a)(6): Technological Similarities and Differences to the Predicate

SUBSTANTIAL EQUIVALENCE COMPARATIVE TABLE

Comparison between the Immunalysis EDDP Specific Urine Enzyme Immunoassay and the ARK™ EDDP Assay

| Characteristic | Predicate Device
Immunalysis EDDP Specific Urine
Enzyme Immunoassay (K151395) | Candidate Device
ARKTM EDDP Assay |
|-----------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------|
| Similarities | | |
| Test System | Homogenous enzyme immunoassay
(EIA) | Same |
| Intended Use | For the qualitative and semiquantitative
determination of EDDP in human urine;
For in vitro diagnostic use | Same |
| Sample Matrix | Human urine | Same |
| User Environment | Clinical laboratories; Prescription use
only | Same |
| Mass Spectrometry
Confirmation | Required to confirm preliminary positive
analytical results | Same |
| Platform Required | Automated clinical chemistry analyzer | Same |
| Reagents Form | Liquid - Ready to use | Same |
| Reagent Materials | Two (2) reagent system:
Antibody/substrate reagent (antibodies to
EDDP) and enzyme labeled conjugate
(EDDP derivative labeled with enzyme)
Sodium azide preservative | Same |
| Storage | 2-8°C until expiration date | Same |
| Measured Analyte | EDDP | Same |
| Detection | Absorbance change measured
spectrophotometrically at 340 nm | Same |
| Characteristic | Predicate Device
Immunalysis EDDP Specific Urine
Enzyme Immunoassay (K151395) | Candidate Device
ARKTM EDDP Assay |
| Differences | | |
| Cutoff Levels | 100 ng/mL, 300 ng/mL and 1000 ng/mL | 100 ng/mL and 300 ng/mL |

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807.92 (b)(1) and 807.92 (b)(2): Brief Description of Nonclinical and Clinical Data

The following performance characteristics were obtained on the Beckman Coulter AU680® automated clinical chemistry analyzer.

Precision

Precision studies were performed using CLSI EP05-A3 as a guideline. Drug-free, negative human urine was supplemented with EDDP (0.0 to 200.0 ng/mL for the 100 ng/mL cutoff and 0.0 to 600.0 for the 300 ng/mL cutoff). Each level was assayed in quadruplicate twice a day for 20 days (N=160) and evaluated qualitatively and semiquantitatively. Results are summarized in the tables below.

| Human Urine
(ng/mL) | Relative %
Cutoff | # of Results | Qualitative
Precision Results |
|------------------------|----------------------|--------------|----------------------------------|
| 0.0 | -100 | 160 | 160 Negative |
| 25.0 | -75 | 160 | 160 Negative |
| 50.0 | -50 | 160 | 160 Negative |
| 75.0 | -25 | 160 | 160 Negative |
| 100.0 | Cutoff | 160 | 123 Negative;
37 Positive |
| 125.0 | +25 | 160 | 160 Positive |
| 150.0 | +50 | 160 | 160 Positive |
| 175.0 | +75 | 160 | 160 Positive |
| 200.0 | +100 | 160 | 160 Positive |

Qualitative Precision - 100 ng/mL Cutoff

Semiquantitative Precision – 100 ng/mL Cutoff

| Human Urine
(ng/mL) | Relative %
Cutoff | # of Results | Mean
(ng/mL) | Semiquantitative
Precision Results |
|------------------------|----------------------|--------------|-----------------|---------------------------------------|
| 0.0 | -100 | 160 | 0.3 | 160 Negative |
| 25.0 | -75 | 160 | 22.6 | 160 Negative |
| 50.0 | -50 | 160 | 47.7 | 160 Negative |
| 75.0 | -25 | 160 | 72.2 | 160 Negative |
| 100.0 | Cutoff | 160 | 98.1 | 114 Negative;
46 Positive |
| 125.0 | +25 | 160 | 125.3 | 160 Positive |
| 150.0 | +50 | 160 | 145.1 | 160 Positive |
| 175.0 | +75 | 160 | 169.4 | 160 Positive |
| 200.0 | +100 | 160 | 190.7 | 160 Positive |

7

Qualitative Precision – 300 ng/mL Cutoff

| Human Urine
(ng/mL) | Relative %
Cutoff | # of Results | Qualitative
Precision Results |
|------------------------|----------------------|--------------|----------------------------------|
| 0.0 | -100 | 160 | 160 Negative |
| 75.0 | -75 | 160 | 160 Negative |
| 150.0 | -50 | 160 | 160 Negative |
| 225.0 | -25 | 160 | 160 Negative |
| 300.0 | Cutoff | 160 | 57 Negative;
103 Positive |
| 375.0 | +25 | 160 | 160 Positive |
| 450.0 | +50 | 160 | 160 Positive |
| 525.0 | +75 | 160 | 160 Positive |
| 600.0 | +100 | 160 | 160 Positive |

Semiquantitative Precision – 300 ng/mL Cutoff

| Human Urine
(ng/mL) | Relative %
Cutoff | # of Results | Mean
(ng/mL) | Semiquantitative
Precision Results |
|------------------------|----------------------|--------------|-----------------|---------------------------------------|
| 0.0 | -100 | 160 | 0.3 | 160 Negative |
| 75.0 | -75 | 160 | 72.2 | 160 Negative |
| 150.0 | -50 | 160 | 145.1 | 160 Negative |
| 225.0 | -25 | 160 | 205.9 | 160 Negative |
| 300.0 | Cutoff | 160 | 298.8 | 85 Negative;
75 Positive |
| 375.0 | +25 | 160 | 381.4 | 160 Positive |
| 450.0 | +50 | 160 | 461.0 | 160 Positive |
| 525.0 | +75 | 160 | 539.8 | 160 Positive |
| 600.0 | +100 | 160 | 620.0 | 160 Positive |

8

Analytical Recovery

Recovery across the assay range was assessed using the semiquantitative mode. Drug-free, negative human urine was supplemented with EDDP (1100.0 ng/mL) and dilutions were made proportionally with drug-free human urine. EDDP concentrations ranged from 50.0 to 1000.0 ng/mL. At each level, percentage recovery was calculated based on the mean concentration (N=6) compared to the expected concentration. Results are summarized in the table below.

| Theoretical
Concentration
(ng/mL) | Mean
Concentration
(ng/mL) | Recovery
(%) |
|-----------------------------------------|----------------------------------|-----------------|
| 50.0 | 47.6 | 95.1 |
| 75.0 | 72.1 | 96.1 |
| 100.0 | 97.1 | 97.1 |
| 200.0 | 189.1 | 94.6 |
| 300.0 | 286.6 | 95.5 |
| 400.0 | 414.5 | 103.6 |
| 500.0 | 506.6 | 101.3 |
| 600.0 | 647.4 | 107.9 |
| 700.0 | 722.7 | 103.2 |
| 800.0 | 800.6 | 100.1 |
| 900.0 | 880.8 | 97.9 |
| 1000.0 | 955.8 | 95.6 |

9

Analytical Specificity

All compounds tested were added to drug-free, negative human urine and tested with the ARK EDDP Assay in both qualitative and semiquantitative modes.

The cross-reactivity of the following structurally related compounds was evaluated by spiking these compounds into drug-free, negative human urine to determine the minimum concentration that would give a positive result approximately equivalent to the 100 ng/mL and 300 ng/mL EDDP cutoffs. These concentrations were used to determine the percent cross-reactivity according to the formula:

% Cross-reactivity = (Cutoff concentration / Lowest concentration of cross-reactant causing a positive result) X 100

For compounds that did not produce a positive result, the highest concentration tested was used to calculate percent cross-reactivity.

| Compound | Concentration
Tested
(ng/mL) | Semiquantitative
Mode Result
(Positive/Negative) | Qualitative Mode
Result
(Positive/Negative) | Cross-reactivity
(%) |
|-----------------|------------------------------------|--------------------------------------------------------|---------------------------------------------------|-------------------------|
| EDDP | 100 | Positive | Positive | 100 |
| Methadone | 2,000,000 | Negative | Negative | 150 ng/mL
by GC/MS) |
|------------------------------|----------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------|
| Negative | 40 | 5 | 0 | 0 |
| Positive | 0 | 0 | 4 | 60 |

Method Comparison – 300 ng/mL Cutoff

| ARK
Immunoassay
Result | Low Negative
Less than
50% below
the Cutoff
( 450 ng/mL
by GC/MS) |
|------------------------------|-----------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------|
| Negative | 49 | 4 | 0 | 0 |
| Positive | 0 | 1* | 3 | 52 |

*Discordant Result

| Sample ID Number | ARK Immunoassay
Result | EDDP
(ng/mL by GC/MS) |
|------------------|---------------------------|--------------------------|
| 51 | Positive | 294 |

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Traceability and Value Assignment

ARK EDDP Calibrators and Controls are prepared by volumetric dilution of high purity EDDP (certified solution traceable to HPLC) into non-sterile, processed human urine free of EDDP. Testing is performed with the ARK EDDP Assay on the Beckman Coulter AU680 automated clinical chemistry analyzer, calibrated with the ARK EDDP Calibrator.

Calibration Curve Stability

A stored calibration curve was effective up to at least 15 days based on supporting data. Calibration curve stability may depend on individual laboratory performance.

807.92 (b)(3): Conclusions from Nonclinical Testing

As summarized above, the ARK EDDP Assay is substantially equivalent to the legally marketed predicate device, Immunalysis EDDP Specific Urine Enzyme Immunoassay (K151395).