PLAC TEST REAGENT KIT, MODELS 90107, 90112, 90115, 90116, 10-0112, 10-0113, 10-0115

K101853 · Diadexus, Inc. · NOE · Jan 3, 2011 · Immunology

Device Facts

• Record ID: K101853
• Device Name: PLAC TEST REAGENT KIT, MODELS 90107, 90112, 90115, 90116, 10-0112, 10-0113, 10-0115
• Applicant: Diadexus, Inc.
• Product Code: NOE · Immunology
• Decision Date: Jan 3, 2011
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.5600
• Device Class: Class 2

Intended Use

The PLAC® Test Reagent Kit is a turbidimetric immunoassay for the quantitative determination of Lp-PLA2 (lipoprotein-associated phospholipase A2) in human plasma or serum on automated clinical chemistry analyzers, to be used in conjunction with clinical evaluation and patient risk assessment as an aid in predicting risk for coronary heart disease, and ischemic stroke associated with atherosclerosis.

Device Story

The PLAC® Test Reagent Kit is an in vitro diagnostic assay for measuring Lp-PLA2 levels in human serum or plasma. It utilizes a turbidimetric immunoassay principle; reagents include a buffer solution and polymeric microparticles coated with two specific monoclonal antibodies (2C10 and 4B4). The device is designed for use on automated clinical chemistry analyzers in clinical laboratory settings. The system generates a standard curve using calibrators; sample concentrations are determined via spline curve fitting software. Healthcare providers use the resulting quantitative Lp-PLA2 values alongside clinical evaluation to assess patient risk for coronary heart disease and ischemic stroke associated with atherosclerosis. The device provides an automated alternative to the predicate ELISA method, offering faster processing on standard chemistry analyzers.

Clinical Evidence

Bench testing only. Performance was validated through method comparison against the predicate ELISA kit (n=742, slope 1.09, intercept -1.7, r=0.92). Imprecision studies were conducted with 40-80 replicates per sample; total assay CVs ranged from 1.4% to 5.3% across concentrations from 56.2 to 370.8 ng/mL.

Technological Characteristics

Turbidimetric immunoassay; utilizes polymeric microparticles coated with mouse monoclonal antibodies (2C10 and 4B4). Reagents include buffer solution and antibody-coated particles. Designed for use on automated clinical chemistry analyzers. Measures absorbance at 570 nm. Calibration uses a spline curve fit.

Indications for Use

Indicated for the quantitative determination of Lp-PLA2 in human plasma or serum to aid in predicting risk for coronary heart disease and ischemic stroke associated with atherosclerosis in patients undergoing clinical evaluation and risk assessment.

Regulatory Classification

Identification

A low-density lipoprotein immunological test system is a device that consists of the reagents used to measure by immunochemical techniques the low-density lipoprotein in serum and other body fluids. Measurement of low-density lipoprotein in serum may aid in the diagnosis of disorders of lipid (fat) metabolism and help to identify young persons at risk from cardiovascular diseases.

Predicate Devices

• PLAC® Test ELISA Kit (K062234)

Submission Summary (Full Text)

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### 510(k) Summary

KIDBS 3

#### 1.0 Submitted By:

Lynne McBride Director of Regulatory Affairs diaDexus 343 Oyster Point Blvd South San Francisco, California 94080 Telephone: [phone] Fax: [phone]

JAN - 3 2011

#### 2.0 Date Submitted

June 30, 2010

#### 3.0 Device Name(s):

PLAC® Test Reagent Kit

#### 4.0 Classification

Reagent:

866.5600 Low-density lipoprotein immunological test system NOE; test, system, immunoassay, lipoprotein-associated phospholipase a2

#### 5.0 Legally Marketed Device

| Predicate | Predicate<br>Manufacturer | Docket<br>Number |
|----------------------|---------------------------|------------------|
| PLAC® Test ELISA Kit | diaDexus | K062234 |

#### 6.0 Device Description

The PLAC® Test Reagent Kit consists of separately packaged reagents, calibrators and controls for the measurement of Lp-PLA2 in serum or plasma on automated clinical chemistry analyzers.

PLAC® Test Reagent Kit

- R1 Buffer solution with protein stabilizers
- R2 Suspension of polymeric microparticles coated with mouse monoclonal antibodies specific to Lp-PLA2 (2C10 and 4B4). .

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The PLAC® Test Reagent Kit is based on turbidimetric immunoassay technology utilizing two Lp-PLA3-specific monoclonal antibodies (2C10 and 4B4) coated to polymeric microparticles. A set of Lp-PLA2 calibrators is used to plot a standard curve of absorbance (y-axis) versus Lp-PLA2 concentration in ng/mL (x-axis) from which the Lp-PLA2 concentration in the test sample can be determined. The concentration of Lp-PLA, in each sample and control is then interpolated from the standard curve using a spline curve fit with appropriate calibration curve fitting software. The kit expiration date and storage conditions are indicated on the package.

### 7.0 Intended Use

### REAGENT KIT

The PLAC® Test Reagent Kit is a turbidimetric immunoassay for the quantitative determination of Lp-PLA2 (lipoprotein-associated phospholipase A2) in human plasma or serum on automated clinical chemistry analyzers, to be used in conjunction with clinical evaluation and patient risk assessment as an aid in predicting risk for coronary heart disease, and ischemic stroke associated with atherosclerosis.

### 8.0 Similarities and Differences to the Predicate

| | Similarities | |
|-------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Item | Predicate - k062234 PLAC Test ELISA Kit | Modified - PLAC Test Reagent Kit |
| Product Intended<br>Use/Indications | The diaDexus PLAC® Test ELISA Kit is an<br>enzyme immunoassay for the quantitative<br>determination of Lp-PLA2 (lipoprotein-<br>associated phospholipase A2) in human plasma<br>and serum, to be used in conjunction with<br>clinical evaluation and patient risk assessment<br>as an aid in predicting risk for coronary heart<br>disease, and ischemic stroke associated with<br>atherosclerosis. | The PLAC® Test Reagent Kit is a<br>turbidimetric immunoassay for the<br>quantitative determination of Lp-PLA2<br>(lipoprotein-associated phospholipase A2)<br>in human plasma or serum on automated<br>clinical chemistry analyzers, to be used in<br>conjunction with clinical evaluation and<br>patient risk assessment as an aid in<br>predicting risk for coronary heart disease,<br>and ischemic stroke associated with<br>atherosclerosis. |
| Key Reagent<br>Components | Anti-PLA2 (2C10) and anti-PLA2 (4B4) | same |
| Calibrators Matrix | Recombinant Lp-PLA2 antigen in a protein<br>stabilizing diluent | Same |
| Control Matrix | Recombinant Lp-PLA2 antigen in a protein<br>stabilizing diluent | same |
| Controls Levels | 2 | same |

# Similarities

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| Differences | | |
|--------------------------|---------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------|
| Item | Predicate - k062234 PLAC ELISA Kit | Modified - PLAC Test Reagent Kit |
| Measuring range | 0-1000 ng/mL | 25 to 500 ng/mL |
| Methodology | Dual monoclonal antibody sandwich ELISA read<br>at 450 nm on a microwell plate reader | Immuno- Turbidimetric assay read at 570<br>nm on clinical chemistry analyzers |
| Reagent<br>Configuration | Anti-Lp-PLA₂ mAb (2C10) coated stripwellsWash bufferEnzyme conjugate anti-Lp-PLA₂ mAb (4B4)-HRPTMB substrateStop solution | Two reagent system<br>R1- Buffer solution with protein stabilzers<br>R2- antibody coated microparticles (mAbs 2C10 and 4B4) |
| Kit Configuration | Reagent, calibrators and controls all in one kit | Reagent, calibrators and controls in<br>separate kits. |
| Calibrator Levels | 6 levels - 0,50,100, 250, 500, 1000 ng/ml | 5 levels - 0, 50, 100, 250, 500 ng/ml |
| Reference Range | Median value is 235 ng/ml per population<br>studied in 2006 | Median value is 152 ng/mL per population<br>studied in 2010 |
| Samples Types | Serum, EDTA, Heparin | Serum, K₂EDTA |

### 9.0 Summary of Performance Data

The data in the Premarket Notification on safety and effectiveness supports a finding of substantial equivalence to chemistry test systems already in commercial distribution. Assay equivalence is demonstrated through method comparison and imprecision studies.

## Methods Comparison Data

| Predicate<br>Method | Slope | Intercept | R | n | Acceptance Criteria | Modified<br>Product |
|-------------------------|-------|-----------|------|-----|-----------------------------------------------------|---------------------------|
| PLAC® Test<br>ELISA Kit | 1.09 | -1.7 | 0.92 | 742 | Slope 0.9 to 1.1<br>Intercept ≤ 50 ng/mL<br>r ≥0.90 | PLAC® Test<br>Reagent Kit |

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# Imprecision Testing

| Samples | Mean Concentration<br>Lp-PLA2 (ng/mL) | Intra-assay<br>%CV n=40 | Inter-assay<br>%CV n=40 | Total Assay<br>%CV n=80 |
|------------------|---------------------------------------|-------------------------|-------------------------|-------------------------|
| Serum 1 | 56.2 | 2.5% | 4.6% | 5.3% |
| Serum 2 | 250.1 | 1.0% | 2.7% | 2.9% |
| Buffer Control 1 | 191.2 | 0.7% | 0.9% | 1.4% |
| Buffer Control 2 | 370.8 | 1.0% | 0.7% | 1.6% |

This summary of safety and effectiveness is being submitted in accordance with the requirements of the Safe Medical Device Act of 1990 and the implementing regulation 21 CFR 807.92.

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Image /page/4/Picture/2 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized eagle with three wings, representing service, science, and protection. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular pattern around the eagle.

Food & Drug Administration 10903 New Hampshire Avenue Building 66 Silver Spring, MD 20993

diaDexus, Inc. c/o Nina Peled, PhD Regulatory Affairs Consultant 343 Oyster Point Blvd South San Francisco, CA 94080

JAN 0 3 2011

Re: ' k101853 PLAC® Test Reagent Kit Trade/Device Name: Regulation Number: 21 CFR 866.5600 Regulation Name: Low-density lipoprotein immunological test system Regulatory Class: Class II Product Code: NOE Dated: November 23, 2010 Received: November 24, 2010

Dear Dr. Peled,

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 predicate device results in a classification for your device and thus, permits your device to proceed to the market.

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If you desire specific advice for your device on our labeling regulation (21 CFR Parts 801 and 809), please contact the Office of In Viro Diagnostic Device Evaluation and Safety at [phone]. 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 the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

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 [phone] or [phone] or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours,

CJC.

Courmey Harper, Ph.D. Director Division of Chemistry and Toxicology Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

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JAN - 3 2011

# Indications for Use Form

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Device Name:

Indications for Use:

The PLAC® Test Reagent Kit is a turbidimetric immunoassay for the quantitative determination of Lp-PLA2 (lipoprotein-associated phospholipase A₂) in human serum or plasma on automated clinical chemistry analyzers, to be used in conjunction with clinical evaluation and patient risk assessment as an aid in predicting risk for coronary heart disease, and ischemic stroke associated with atherosclerosis.

| Prescription Use <span style="text-decoration: underline;">X</span> (Part 21 CFR 801 Subpart D) | AND/OR | Over-The-Counter Use (21 CFR 801 Subpart C) |
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(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE OF NEEDED)

Concurrence of CDRH, Office of In Vitro Diagnostic Devices (OIVD)

Carol C. Benson

Division Sign-Off Office of In Vitro Diagnostic Device Evaluation and Safety

510(k) K101853