← Product Code [LOJ](/submissions/IM/subpart-g%E2%80%94tumor-associated-antigen-immunological-test-systems/LOJ) · K071597

# DIMENSION VISTA (R) AFP FLEX(R) REAGENT CARTRIDGE, MODEL K6454, DIMENSION VISTA (R) LOCI 5 CALIBRATOR, MODEL KC600 (K071597)

_Dade Behring, Inc. · LOJ · Jun 4, 2008 · Immunology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/IM/subpart-g%E2%80%94tumor-associated-antigen-immunological-test-systems/LOJ/K071597

## Device Facts

- **Applicant:** Dade Behring, Inc.
- **Product Code:** [LOJ](/submissions/IM/subpart-g%E2%80%94tumor-associated-antigen-immunological-test-systems/LOJ.md)
- **Decision Date:** Jun 4, 2008
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 866.6010
- **Device Class:** Class 2
- **Review Panel:** Immunology

## Indications for Use

The AFP method is an in vitro diagnostic test for the quantitative measurement of alpha-fetoprotein in human serum on the Dimension Vista® system. Measurements of alpha-fetoprotein are used as an aid in managing non-seminomatous testicular cancer when used in conjunction with physical examination, histology/pathology, and other clinical evaluation procedures. For the calibration of Alpha-Fetoprotein (AFP) method on the Dimension Vista® System.

## Device Story

Dimension Vista AFP is a homogeneous, sandwich chemiluminescent immunoassay using LOCI technology. Input: human serum sample. Process: sample incubated with biotinylated anti-AFP monoclonal antibody and Chemibeads (coated with anti-AFP antibody and chemiluminescent dye); Sensibeads (coated with streptavidin and photosensitizer) added to form bead-pair immunocomplexes. Illumination at 680 nm triggers singlet oxygen diffusion from Sensibeads to Chemibeads, inducing chemiluminescence measured at 612 nm. Output: AFP concentration. Used in clinical laboratory settings by trained personnel. Results assist clinicians in managing non-seminomatous testicular cancer patients. LOCI 5 Calibrator is a multi-analyte liquid product used to calibrate the assay.

## Clinical Evidence

Clinical evaluation included 70 retrospective serial serum sample sets (244 sequential pairs) from men with non-seminomatous testicular cancer. Performance was assessed by comparing AFP concentration changes against physician-determined disease status (Active/Progressive, Responding, Stable, NED). The Reference Change Value (RCV) was 33.7% for the subject device vs 37.7% for the predicate. Sensitivity was 27.1% (95% CI: 16.4%-40.3%) and specificity was 87.0% (95% CI: 81.3%-91.5%). Overall agreement with the predicate was 97.5%.

## Technological Characteristics

Chemiluminescent immunoassay using LOCI™ technology. Reagents: synthetic beads (Chemibeads, Sensibeads) and biotinylated murine anti-AFP antibody. Energy source: 680 nm illumination; signal detection at 612 nm. System: Dimension Vista® automated analyzer. Standardization: WHO 72/225. Storage: 2 to 8°C.

## Regulatory Identification

A tumor-associated antigen immunological test system is a device that consists of reagents used to qualitatively or quantitatively measure, by immunochemical techniques, tumor-associated antigens in serum, plasma, urine, or other body fluids. This device is intended as an aid in monitoring patients for disease progress or response to therapy or for the detection of recurrent or residual disease.

## Special Controls

*Classification.* Class II (special controls). Tumor markers must comply with the following special controls: (1) A guidance document entitled “Guidance Document for the Submission of Tumor Associated Antigen Premarket Notifications (510(k)s) to FDA,” and (2) voluntary assay performance standards issued by the National Committee on Clinical Laboratory Standards.

## Predicate Devices

- Abbott AxSYM® AFP Method ([P820060](/device/P820060.md)/S019)
- Beckman Access AFP Calibrators on the Access® Immunoassay System ([K981354](/device/K981354.md))

## Submission Summary (Full Text)

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>
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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

A. 510(k) Number:
k071597

B. Purpose for Submission:
New device

C. Measurand:
Alpha-Fetoprotein (AFP)

D. Type of Test:
Quantitative, Chemiluminescence

E. Applicant:
Seimens Healthcare Diagnostics Inc. (formerly Dade Behring Inc.)

F. Proprietary and Established Names:
Dimension Vista® Alpha-Fetoprotein (AFP) reagent cartridge
Dimension Vista® LOCI 5 Calibrator

G. Regulatory Information:
1. Regulation section:
866.6010 Tumor-associated antigen immunological test system
862.1150 Calibrator
2. Classification:
Class II
3. Product code:
LOJ Kit, Test, Alpha-fetoprotein for testicular cancer
JIX Calibrator, Multi-analyte mixture
4. Panel:
Immunology (82)

H. Intended Use:
1. Intended use(s):
Dimension Vista® AFP Method: The AFP method is an in vitro diagnostic test for the quantitative measurement of alpha-fetoprotein in human serum on the Dimension Vista® system. Measurements of alpha-fetoprotein are used as an aid in managing non-seminomatous testicular cancer when used in conjunction with physical examination, histology/pathology and other clinical evaluation procedures.
Dimension Vista® LOCI 5 Calibrator: For the calibration of the Alpha-Fetoprotein (AFP) method on the Dimension Vista® System.
2. Indication(s) for use:
Same as above
3. Special conditions for use statement(s):
Prescription use only
4. Special instrument requirements:
Dimension Vista® System

I. Device Description:
The AFP method consists of two synthetic bead reagents and a biotinylated murine-

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anti-AFP antibody. The first bead reagent (Chemibeads) is coated with an anti-AFP monoclonal antibody and contains a chemiluminescent dye. The second bead reagent (Sensibeads) is coated with streptavidin and contains a photosensitizer dye. All are supplied in liquid format in a reagent cartridge.

The LOCI™ 5 Calibrator is a liquid multi-analyte product containing AFP from human cord serum. The kit consists of 10 vials, 2 each of 5 levels containing 2 mL per vial.

## J. Substantial Equivalence Information:

1. Predicate device name(s):
Abbott AxSYM® AFP Method
Beckman Access AFP Calibrators on the Access® Immunoassay System

2. Predicate 510(k) number(s):
P820060/S019
k981354

3. Comparison with predicate:
AFP Method

|  Similarities  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Intended Use | The AFP method is an in vitro diagnostic test for the quantitative measurement of alpha-fetoprotein in human serum on the Dimension Vista® System. | AxSYM AFP is a Microparticle Enzyme Immunoassay (MEIA) for the quantitative determination of alpha-fetoprotein (AFP) in human serum or plasma to aid in the management of patients with non-seminomatous testicular cancer.  |
|  Indications for Use | Measurements of alpha-fetoprotein are used as an aid in managing non-seminomatous testicular cancer when used in conjunction with physical examination, histology/pathology, and other clinical evaluation procedures | Same  |
|  Standardization | WHO 72/225 | Same  |
|  Capture antibody | Mouse monoclonal | Same  |
|  Storage | Store at 2 to 8°C | Same  |

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|  Differences  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Indications for Use | Not applicable | For the quantitative determination of alpha-fetoprotein (AFP) in amniotic fluid at 15 to 21 weeks gestation to aid in the detection of fetal open neural tube defects (NTD).  |
|  Methodology | Chemiluminescent immunoassay | Microparticle enzyme immunoassay  |
|  Measuring range | 0.5 to 1000 ng/mL | 0.4 to 350 ng/mL  |
|  Sample types | Serum | Serum, plasma and amniotic fluid  |
|  Sample size | 2 μL | 58 μL  |
|  Stability: Open | 7 days | 112 cumulative hours  |

Calibrator

|  Similarities  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Intended Use | For the calibration of Alpha-Fetoprotein (AFP) method on the Dimension Vista® system. | The Access AFP Calibrators are intended to calibrate the Access AFP assay for the quantitative determination of AFP levels in human serum, using the Access Immunoassay System.  |
|  Traceability | WHO reference preparation for human AFP (72/225) | Same  |
|  Composition | BSA-based matrix | Same  |
|  Preparation | Liquid, ready-to-use | Same  |
|  Storage | Store at 2 to 8°C | Store at 2 to 10°C  |
|  Differences  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Calibrator Levels | 5 target concentrations: 0, 8, 100, 500 and 1050 ng/mL | 6 target concentrations: 0, 2.5, 5, 25, 500 and 3000 ng/mL  |
|  Instrument | Dimension Vista system | Access Immunoassay systems  |

# K. Standard/Guidance Documents referenced (if applicable):

Guidance documents: "Bundling Multiple Devices of Multiple Indications in a Single

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Submission," "Guidance on Informed Consent for In Vitro Diagnostic Device Studies Using Leftover Human Specimens that are Not Individually Identifiable- Guidance for Sponsors, Institutional Review Boards, Clinical Investigators and FDA Staff." CLSI EP9-A2 Approved Guideline Method Comparison and Bias Estimation Using Patient Samples. CLSI EP17-A, Approved Guideline Protocols for Determination of Limits of Detection and Limits of Quantitation.

## L. Test Principle:

The AFP method is a homogeneous, sandwich chemiluminescent immunoassay based in  $\mathrm{LOCI}^{\mathrm{TM}}$  technology. The  $\mathrm{LOCI}^{\mathrm{TM}}$  reagents include two synthetic bead reagents and a biotinylated anti-AFP monoclonal antibody fragment. The first bead reagent (Chemibeads) is coated with an anti-AFP monoclonal antibody and contains chemiluminescent dye. The second bead reagent (Sensibeads) is coated with streptavidin and contains a photosensitizer dye. Sample is incubated with biotinylated antibody and Chemibeads to form bead-AFP-biotinylated antibody sandwiches. Sensibeads are added and bind to the biotin to form bead-pair immunocomplexes. Illumination of the complex at  $680~\mathrm{nm}$  generates singlet oxygen from Sensibeads which diffused into the Chemibeads, triggering a chemiluminescent reaction. The resulting signal is measured at  $612~\mathrm{nm}$  and is a direct function of the AFP concentration in the sample.

The  $LOCI^{\mathrm{TM}}5$  Calibrator is a liquid multi-analyte product containing AFP from human cord serum.

## M. Performance Characteristics (if/when applicable):

### 1. Analytical performance:

#### a. Precision/Reproducibility:

The reproducibility testing was conducted in accordance with the CLSI/NCCLS Approved Guideline for User Evaluation of Precision Performance of Clinical Chemistry Devices EP5-A2. Samples (pooled serum, pooled plasma, and controls) were measured in duplicate, two times per day over 20 days. Repeatability, between-run, between day, and within-lab were determined by the analysis of variance method. The repeatability and within-lab data are presented below. Imprecision was less than  $2.3\%$  CV.

|  Sample | Mean (ng/mL) | Repeatability |   | Within Lab  |   |
| --- | --- | --- | --- | --- | --- |
|   |   |  SD (ng/mL) | %CV | SD (ng/mL) | %CV  |
|  Serum Pool* | 0.92 | 0.01 | 1.3 | 0.02 | 1.9  |
|  Liquimmune ® Control Level 1 | 12.8 | 0.1 | 1.1 | 0.2 | 1.8  |
|  Level 2 | 75.6 | 0.7 | 0.9 | 1.2 | 1.6  |
|  Level 3 | 139.3 | 1.7 | 1.2 | 2.6 | 1.8  |
|  Plasma Pool | 249 | 2.9 | 1.2 | 5.1 | 2.0  |
|  Serum Pool | 496.2 | 7.0 | 1.4 | 10.9 | 2.2  |
|  Serum Pool | 772.5 | 9.4 | 1.2 | 17.9 | 2.3  |
|  Serum Pool | 832.5 | 12.7 | 1.5 | 16.4 | 2.0  |

*5-day protocol was employed for this sample.

Between-Lot reproducibility was also evaluated using 4 different samples (2

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sera and 2 quality control materials) representing the range of the assay 12 ng/mL to 891 ng/mL) on two different AFP Flex® reagent lots (with two different calibrator lots). The %CV was less than 2.0%

b. Linearity/assay reportable range:

Linearity of the reportable range (1.7 to 1014 ng/mL) and for the low end of the assay range (1.6 to 178.2 ng/mL) was evaluated by comparing observed vs. expected values using a series of equally spaced sample pools that were prepared by a sequential mixing of a high spiked serum equivalent and low serum equivalent of known concentrations. Linear regression analysis demonstrated the following results:

|  Range (ng/mL) | Slope (95% CI) | Intercept ng/mL (95% CI) | Correlation Coefficient | n  |
| --- | --- | --- | --- | --- |
|  1.7 to 1014 | 1.00 (0.98-1.01) | 3.24 (-5.98 to 12.46) | 1.000 | 7  |
|  1.6 to 178.2 | 1.00 (0.99-1.01) | -0.24 (1.74 – 1.25) | 1.000 | 5  |

Spiking recovery: A spiking recovery study was performed by adding known amounts of AFP (WHO 72/225) to a human serum pool with baseline AFP values of 1.5 ng/mL. The sample concentrations were measured and the percent recovery ranged from 97.8% to 101.7% with a mean recovery of 100%.

Dilution recovery: A dilution recovery study was performed by diluting 2 plasma and 3 serum samples with AFP values from 93.2 ng/mL to 761.9 ng/mL with Reagent grade water. The samples were diluted 1:2, 1:5, 1:10 and 1:20 and assayed for recovery. The recoveries ranged from 98.0% to 112.3% with a mean of 104.2%.

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|  Sample | Dilution | Observed (ng/mL) | Expected (ng/mL) | Observed (IU/mL) | Expected (IU/mL) | Recovery %  |
| --- | --- | --- | --- | --- | --- | --- |
|  Plasma 1 | - | 93.2 |  | 77.0 |  |   |
|   |  1:2 | 45.8 | 46.6 | 37.8 | 38.5 | 98.2  |
|   |  1:5 | 18.3 | 18.6 | 15.1 | 15.4 | 98.3  |
|   |  1:10 | 9.3 | 9.3 | 7.7 | 7.7 | 99.4  |
|   |  1:20 | 4.6 | 4.7 | 3.8 | 3.8 | 98.0  |
|   |  Mean |  |  |  |  | 98.5  |
|  Plasma 2 | - | 270.2 |  | 223.2 |  |   |
|   |  1:2 | 137.6 | 135.1 | 113.7 | 111.6 | 101.8  |
|   |  1:5 | 57.0 | 54.0 | 47.1 | 44.6 | 105.5  |
|   |  1:10 | 28.2 | 27.0 | 23.3 | 22.3 | 104.4  |
|   |  1:20 | 13.7 | 13.5 | 11.3 | 11.2 | 101.3  |
|   |  Mean |  |  |  |  | 103.3  |
|  Serum 1 | - | 464.8 |  | 383.9 |  |   |
|   |  1:2 | 243.7 | 232.4 | 201.3 | 192.0 | 104.9  |
|   |  1:5 | 101.8 | 93.0 | 84.1 | 76.8 | 109.5  |
|   |  1:10 | 50.2 | 46.5 | 41.5 | 38.4 | 108.0  |
|   |  1:20 | 25.1 | 23.2 | 20.7 | 19.2 | 107.8  |
|   |  Mean |  |  |  |  | 107.5  |
|  Serum 2 | - | 373.7 |  | 308.7 |  |   |
|   |  1:2 | 187.1 | 186.9 | 154.5 | 154.4 | 100.1  |
|   |  1:5 | 78.0 | 74.7 | 64.4 | 61.7 | 104.4  |
|   |  1:10 | 38.0 | 37.4 | 31.4 | 30.9 | 101.6  |
|   |  1:20 | 19.2 | 18.7 | 15.8 | 15.4 | 102.6  |
|   |  Mean |  |  |  |  | 102.2  |
|  Serum 3 | - | 761.9 | 761.9 | 629.4 |  |   |
|   |  1:2 | 398.0 | 381.0 | 328.8 | 314.7 | 104.5  |
|   |  1:5 | 168.5 | 152.4 | 139.2 | 125.9 | 110.6  |
|   |  1:10 | 84.6 | 76.2 | 69.9 | 62.9 | 111.1  |
|   |  1:20 | 42.8 | 38.1 | 35.3 | 31.5 | 112.3  |
|   |  Mean |  |  |  |  | 109.6  |

All Samples Mean Recovery (%) 104.2

Antigen Excess (Hook Effect): The effect of antigen excess was evaluated using a serum sample above the assay range. No effect was seen up to 2877 IU/mL. Samples above this level are reported as exceeding assay range (>600 IU/mL).

c. Traceability, Stability, Expected values (controls, calibrators, or methods): The AFP calibrators are traceable to WHO reference preparation for human AFP (72/225).

Stability claims in the IFU were supported by stability protocols and data. Specimen stability claims were supported by protocols employing freeze-thaw and stress testing up to 7 days or stored at -20°C for 30 days.

d. Detection limit:

The Limit of Blank (LoB) and the Limit of Detection (LoD) were evaluated according to CLSI EP17-A "Protocols for Determination of Limits of Detection and Limits of Quantitation." The data supports the claim of 0.5 ng/mL.

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e. Analytical specificity:

i. Interference Studies: Interference testing was performed according to CLSI Approved Guideline for Interference Testing in Clinical Chemistry EP7-A2, to determine the effect of various substances on the Dimension Vista® AFP assay at two concentrations of AFP (~9.0 ng/mL and ~230 ng/mL). The following interferents were tested for their effect on test samples and compared to a control sample without interferent; bias exceeding 10% is considered interference: bilirubin (conjugated and unconjugated, 60 mg/dL), hemoglobin (1000 mg/dL), Intralipid 3000 mg/dL, total protein (12 g/dL) and rheumatoid factor (500 IU/mL). Acceptance criteria were met. Additionally, 41 potentially interfering drugs were also assayed on serum samples containing 10 ng/mL AFP and shown to exhibit minimal interference (<10%).

ii. Interference by chemotherapeutic reagents: Interference by common chemotherapeutic reagents was evaluated on two AFP concentrations (10 ng/mL and 250 ng/mL). The results are shown below. The acceptance criteria (bias <10%) were met.

|  Substance | Test Concentration | Bias (%) at 10 ng/mL | Bias (%) at 250 ng/mL  |
| --- | --- | --- | --- |
|  Bleomycin | 3.3 mg/dL | -0.3 | -0.6  |
|  Cisplatin | 8.8 mg/dL | 0.6 | 0.6  |
|  Cyclophosphamide | 327.9 mg/dL | -2.3 | -3.1  |
|  Doxorubicin | 16.5 mg/dL | -1.2 | -2.3  |
|  Etopside | 22.0 mg/dL | 0.1 | 0.1  |
|  5-Fluorouracil | 130.9 mg/dL | 0.1 | 0.9  |
|  Ifosfamide | 261.8 mg/dL | -2.3 | -3.4  |
|  Mesna | 84.0 mg/dL | -5.0 | -6.0  |
|  Methotrexate | 450.5 mg/dL | 2.5 | 5.5  |
|  Mitomycin C | 6.0 mg/dL | -0.4 | -0.9  |
|  Paclitaxel | 38.2 mg/dL | 1.2 | 0.0  |
|  Vinblastine | 4.0 mg/dL | 0.4 | -0.9  |
|  Vincristine | 0.44 mg/dL | 0.7 | -2.7  |

iii. HAMA: Interference by human anti-murine antibodies was evaluated using three heterophilic human plasma samples containing HAMA and two AFP concentrations (10 and 250 ng/mL). The percent bias was calculated and shown to be less than -4.8%.

iv. Cross Reactivity: The following substances were evaluated for cross-reactivity with the AFP method when present in serum in the amounts indicated. Systematic inaccuracies (bias) due to these substances are less than 10% at an AFP concentration of 10 ng/mL and 240 ng/mL.

|  Substance | Concentration  |
| --- | --- |
|  α_{1}-glycoprotein | 2.0 mg/mL [2.0 g/L]  |
|  α- globulin | 32 mg/mL [32 g/L]  |
|  Chorionic gonadotropin | 1000 mIU/mL [IU/L]  |

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f. Assay cut-off: Not applicable.

2. Comparison studies:

a. Method comparison with predicate device:

A split sample method comparison study was performed according to CLSI document EP9-A2; “Guideline for Method Comparison and Bias Estimation using Patient Samples.” A total of 317 serum samples spanning the assay range (0.97 to 881 ng/mL) were evaluated on both the Dimension® Vista and the Abbott AxSYM® AFP methods. A similar comparison using 84 samples (range 1.6 – 842.9 ng/mL) was performed between the Dimension Vista® AFP Method and the ADVIA Centaur® AFP method. Passing-Bablok non-parametric linear regression of singlicate measurements yielded the following statistics:

|  Comparative Method | Slope (95% CI) | Intercept ng/mL (95% CI) | Correlation Coefficient | n  |
| --- | --- | --- | --- | --- |
|  AxSYM® AFP | 0.93 (0.912-0.938) | 0.093 (0.042-0.146) | 0.995 | 317  |
|  ADVIA Centaur® AFP | 0.97 | -0.6 | 0.997 | 84  |

b. Matrix comparison: Serum is the sample type used.

3. Clinical studies:

a. Clinical Sensitivity and Specificity: Not applicable.

b. Other clinical supportive data (when a .is not applicable):

A clinical evaluation was performed to assess the Dimension Vista® AFP method for the purpose of obtaining FDA premarket clearance for monitoring patients with non-seminomatous testicular cancer. Seventy (74) retrospective serial serum sample sets (with a minimum of 3 blood draws for each patient) with clinical data from men with testicular cancer were tested. Inclusion and exclusion criteria for the samples were provided. Four patients were excluded from statistical analysis when it was determined they did not meet the inclusion criteria for non-seminomatous testicular cancer. Samples were selected for age (range 1.1 year old to 53.7 years old; average age 30.8 years old), ethnicity (specimens from African Americans were not evaluated in this study), and stage of disease (stage I through IV).

A longitudinal analysis of serial draws from 70 patients was performed. All patients were categorized as Active/Progressive, Responding, Stable, or No Evidence of Disease (NED). Disease progression was determined by the patient physician based on either or all of the following:

- Physical examination of clinical signs and symptoms, including results of laboratory tests.

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- Radiographic findings used in the assessment of cancer status (CAT Scans, MRI, X-rays, or ultrasound images.
- Surgical procedures including needle aspirations and Orchiectomy.

The Reference Change Value (RCV) was used to determine if a significant change in AFP occurred. For this calculation, the RCV for each assay (the Dimension Vista AFP method and predicate) was derived by taking into account the published biological variation for AFP and the total imprecision of the assay. The formula for this calculation is  $RCV = 2^{1/2} * Z * (CV_A^2 + CV_I^2)^{1/2}$ , where  $Z$  is the z-score,  $CV_A$  is the analytical variation, and  $CV_I$  is the biological variation (Fraser, Callum G. Biological Variation: From Principles to Practice, Washington, DC: AACC Press, 2001). The within-subject biological variation (12%) was obtained from the literature (Trapé J, Botarges JM, Porta F, Ricós C, Badal JM, Salinas R, Sala M, Roca A. Reference change value for alpha-fetoprotein and its application in early detection of hepatocellular carcinoma in patients with hepatic disease. Clin Chem 2003;49:1209-1211). The RCV for the Vista AFP method was calculated to be 33.7% and that of the predicate to be 37.7%.

# Per Visit analysis:

Changes in AFP concentrations and in disease status were analyzed on a per visit basis. Patients were categorized as Active/Progressive, Responding, Stable or No Evidence of Disease (NED) by the attending physician based on the clinical information. All 70 patients were analyzed to determine the change of disease status per sequential pair  $(n = 244)$ . The table below shows the distribution of results when compared to the disease status:

|   | Change in Disease State  |   |   |   |   |
| --- | --- | --- | --- | --- | --- |
|  Change in AFP | Responding n (%) | Stable n (%) | No Evidence of Disease n (%) | Progression n(%) | Total  |
|  >33.7% increase | 5 (2.1%) | 10 (4.1%) | 9 (3.7%) | 16 (6.6%) | 40 (16.5%)  |
|  No significant Change | 4 (1.6%) | 13 (5.3%) | 94 (38.5%) | 22 (9.0%) | 133 (54.4%)  |
|  >33.7% decrease | 16 (6.6%) | 24 (9.8%) | 10 (4.1%) | 21 (8.6%) | 71 (29.1%)  |
|  Total | 25 (10.3%) | 47 (19.2%) | 113 (46.3%) | 59 (24.2%) | 244 (100.0%)  |

The following two tables show per visit clinical performance results for the Dimension Vista AFP test and predicate device analyzed as "Progression" and "No Progression" with "No Progression" consisting of responding, stable, and no evidence of disease:

Vista AFP Value vs. Disease Progression

|   | Progression | No-Progression | Total  |
| --- | --- | --- | --- |
|  >33.7% increase | 16 | 24 | 40  |
|  ≤33.7% increase | 43 | 161 | 204  |
|  Total | 59 | 185 | 244  |

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|   | Estimate | Exact 95% Confidence Interval  |
| --- | --- | --- |
|  Accuracy | 72.5% | (66.5 % - 77.8%)  |
|  Sensitivity | 27.1% | (16.4 % - 40.3%)  |
|  Specificity | 87.0% | (81.3% - 91.5%)  |

Predicate AFP Value vs. Disease Progression

|   | Progression | No-Progression | Total  |
| --- | --- | --- | --- |
|  >37.7% increase | 16 | 18 | 34  |
|  ≤37.7% increase | 43 | 167 | 210  |
|  Total | 59 | 185 | 244  |
|   |  | Estimate | Exact 95% Confidence Interval  |
|  Accuracy |  | 75.0% | (69.2 % - 80.0%)  |
|  Sensitivity |  | 27.1% | (16.4 % - 40.3%)  |
|  Specificity |  | 90.3% | (85.1% - 94.1%)  |

Per Patient analysis:

Within each patient's series, disease status was classified as "Progression" and "No Progression" with "No Progression" consisting of responding, stable, and no evidence of disease, and computed on a per patient basis according to the theory presented in, "Analysis of repeated markers used to predict progression of cancer", by B. Emir, S. Wieand, John Q.S., and S. Cha, Statistics in Medicine, 17, 2563-2578 (1998).

Efficacy is demonstrated when the sum of sensitivity and specificity is greater than one. Non-parametric estimates for the 95% confidence intervals were derived using a bootstrap resampling technique with 2000 iterations. For the Dimension Vista AFP method, the bootstrap 95% CI was between 1.0062 and 1.2861 for the sum of Sensitivity and Specificity, and for the comparative method the bootstrap 95% CI for the sum of Sensitivity and Specificity was between 1.0444 and 1.3166.

Concordance between Dimension Vista AFP and predicate:

All specimens were analyzed for percent agreement between the two assays using their RCVs. Results are shown below:

Vista AFP Concordance to Comparative Method (on a per visit basis)

|   | >37.7% increase | ≤37.7% increase | Total  |
| --- | --- | --- | --- |
|  >33.7% increase | 34 | 6 | 40  |
|  ≤33.7% increase | 0 | 204 | 204  |
|  Total | 34 | 210 | 244  |
|   |  |  | 95% Confidence Interval  |
|  % Overall agreement |   | 97.5% | (94.7% - (99.1%)  |
|  % Positive agreement |   | 100% | (89.7% - 100%)  |
|  % Negative agreement |   | 97.1% | (93.9% - 98.9%)  |

4. Clinical cut-off:

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Not applicable

5. Expected values/Reference range:
The distribution of AFP values determined in 803 specimens from normal individuals and patients with nonmalignant or malignant disease was evaluated. In this study 97.4% of the healthy subjects had AFP levels less than 8.0 ng/mL.

Distribution of AFP values (%)

|   | Number of Subjects | 0-8.0 ng/mL [0-6.6 IU/mL] | 8.1-20.0 ng/mL [6.7-16.5 IU/mL] | 20.1-500 ng/mL [16.6-413 IU/mL] | 500.1-1000 ng/mL [413-826 IU/mL] | > 1000 ng/mL > 826 IU/mL]  |
| --- | --- | --- | --- | --- | --- | --- |
|  Healthy Subjects  |   |   |   |   |   |   |
|  Males 18 -61 years | 231 | 97.4 | 2.6 | 0 | 0 | 0  |
|  Carcinoma  |   |   |   |   |   |   |
|  Testicular  |   |   |   |   |   |   |
|  Seminoma | 10 | 100 | 0 | 0 | 0 | 0  |
|  Hepatocellular | 123 | 44.7 | 7.3 | 20.3 | 7.3 | 20.3  |
|  Pancreatic | 35 | 91.4 | 8.6 | 0 | 0 | 0  |
|  Other GI Cancers² | 164 | 91.5 | 6.1 | 1.8 | 0 | 0.6  |
|  Nonmalignant Disease  |   |   |   |   |   |   |
|  Liver Cirrhosis | 122 | 50.8 | 16.4 | 27.0 | 2.5 | 3.3  |
|  Hepatitis | 118 | 90.7 | 8.5 | 0.8 | 0 | 0  |

N. Proposed Labeling:
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.

O. Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

---

**Source:** [https://fda.innolitics.com/submissions/IM/subpart-g%E2%80%94tumor-associated-antigen-immunological-test-systems/LOJ/K071597](https://fda.innolitics.com/submissions/IM/subpart-g%E2%80%94tumor-associated-antigen-immunological-test-systems/LOJ/K071597)

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