VITAMIN D TEST SYSTEM NICHOLS ADVANTAGE 25-HYDROXYVITAMIN D

K012367 · Nichols Institute Diagnostics · JIT · Oct 9, 2001 · Clinical Chemistry

Device Facts

• Record ID: K012367
• Device Name: VITAMIN D TEST SYSTEM NICHOLS ADVANTAGE 25-HYDROXYVITAMIN D
• Applicant: Nichols Institute Diagnostics
• Product Code: JIT · Clinical Chemistry
• Decision Date: Oct 9, 2001
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1150
• Device Class: Class 2

Intended Use

The Nichols Advantage® 25-Hydroxyvitamin D assay is for use only on the Nichols Advantage® Specialty System. The Nichols Advantage 25-Hydroxyvitamin D assay is intended for the quantitative determination of 25-hydroxyvitamin D (25-OH-D) and other hydroxylated metabolites of vitamin D in serum or plasma to be used as an aid in the assessment of vitamin D sufficiency in an adult population. Assay results should be used in conjunction with other clinical data to assist the clinician in making individual patient management decisions.

Device Story

The Nichols Advantage 25-OH-D is an automated, hands-free immunoassay for use on the Nichols Advantage Specialty System. It utilizes 20 uL of serum or plasma as input. The device employs a competitive ligand binding technique using human vitamin D binding protein and acridinium-ester labeled anti-DBP, with 25-OH-D3 magnetic particles as the solid phase. The system performs automated incubation (two 21-minute steps at 37°C) without requiring manual extraction. The device outputs quantitative 25-OH-D concentrations (ng/mL). It is intended for clinical laboratory use to assist physicians in assessing vitamin D sufficiency and managing patient care. By providing automated, high-precision quantification of vitamin D levels, the device aids in the diagnosis and monitoring of vitamin D deficiency and insufficiency, particularly in patients with conditions like chronic renal insufficiency.

Clinical Evidence

Clinical evaluation included a method comparison study (n=111) against the DiaSorin RIA kit, showing an overall agreement of 93.9% using a 20 ng/mL cutoff. A separate clinical study (n=100) of patients with chronic renal insufficiency demonstrated the assay's ability to recognize vitamin D deficiency and insufficiency, with results consistent with biochemical markers of disordered calcium mineral ion metabolism. Performance metrics included Passing & Bablok slope of 1.1, Pearson correlation r=0.84, and within-run precision (CV) of 3.0-4.5%.

Technological Characteristics

Automated immunoassay system. Materials: 25-OH-D3 magnetic particles, human vitamin D binding protein, acridinium-ester labeled anti-DBP. Sensing principle: Competitive ligand binding. Sample volume: 20 uL serum/plasma. Incubation: 21 min @ 37°C (displacement) + 21 min @ 37°C (assay). Reportable range: 7-120 ng/mL. Connectivity: Integrated with Nichols Advantage Specialty System.

Indications for Use

Indicated for quantitative determination of 25-hydroxyvitamin D and metabolites in serum or plasma to aid in assessing vitamin D sufficiency in adult populations.

Regulatory Classification

Identification

A calibrator is a device intended for medical purposes for use in a test system to establish points of reference that are used in the determination of values in the measurement of substances in human specimens. (See also § 862.2 in this part.)

Special Controls

*Classification.* Class II (special controls). 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.

Predicate Devices

• DiaSorin 25-Hydroxyvitamin D 125I RIA kit

Submission Summary (Full Text)

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#### 510(k) Summary 12.0

This summary of safety and effectiveness is being submitted in accordance with the requirements of SMDA 1990 and 21 CFR 807.92.

# 1. Name of Manufacturer, Contact Person and Date Summary Prepared:

Nichols Institute Diagnostics 33051 Calle Aviador San Juan Capistrano, CA 92675 Phone: [phone] FAX: [phone] Contact Person: Jimmy Wong, Manager of Clinical and Technical Affairs Date Prepared: September 20, 2001

#### 2. Device Name:

| Trade/Proprietary Name: | Nichols Advantage® 25-Hydroxyvitamin D |
|-------------------------|----------------------------------------|
| Common Name: | 25-OH-D Immunoassay |
| Classification Name: | Vitamin D test system |

- Classification: Class II ട്.
Regulation Number: 862.1825 Product Code: MRG. Clinical Chemistry

- DiaSorin 25-Hydroxyvitamin D 1251 RIA kit 4. Predicate Device:
#### Device Description: 5.

The Nichols Advantage 25-OH-D (NA 25-OH-D) contains sufficient reagents for 100 tests. The NA 25-OH-D is an automated 25-OH-D assay for use only on the Nichols Advantage Immunoassay System.

#### Intended Use: 6.

The Nichols Advantage® 25-Hydroxyvitamin D assay is intended for the quantitative determination of 25-hydrxoyvitamin D (25-OH-D) and other hydroxylated metabolites of vitamin D in serum or plasma to be used as an aid in the assessment of vitamin D sufficiency. Assay results should be used in conjunction with other clinical data to assist the clinician in making individual patient management decisions.

### 7. Comparison to Predicate Device:

The Nichols Advantage 25-OH-D (Y) is substantially equivalent to the DiaSorin 25-Hydroxvyitamin D 125] RIA kit (X). N=99 samples were used in a split sample method comparison study following the NCCLS EP9-A quidelines. For n=80 samples within the reportable ranges of each method, the Passing & Bablok method comparison demonstrates: Y=1.1(X) - 0.6 (95% cf slope: 0.94 to 1.27; 95% cf intercept: -4.6 to 2.1), and a Pearson correlation r=0.84 (95%cf: 0.76-0.89). For the entire n=99 samples, relative agreement using a cut-off of 20 ng/mL or greater was 91%, and the relative agreement for values less than 20 ng/mL was 98%, with an overall agreement of 94%.

### 8. Clinical Study

Patients (n=100) with a diagnosis of chronic renal insufficiency were evaluated with the NA 25-OH-D. Using a cutoff of 20 ng/mL, the results demonstrate the assay recognizes vitamin D deficiency and vitamin D insufficiency, consistent with biochemical measures of disordered calcium mineral ion metabolism. As renal failure becomes progressive worse, the frequency of low 25-0H-D levels increases as do biochemical measures of worsening indices of calcium mineral ion metabolism.

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### 9. Similarities:

- Intended use for each assay is identical. .
- Both assays use 25-OH-D3 in their standards, and both report values using the same units: ● ng/mL.
- Both assay use the competitive ligand binding technique. .
- Both assays are capable of using serum, EDTA and heparinized plasma as samples. .

## 10. Differences:

The following differences pertain to differences in immunoassay technology and do not affect the intended uses of the NA 25-OH-D assay.

| Feature | Nichols 25-OH-D | DiaSorin 25-OH-D |
|---------------------------------------|---------------------------------------------------------------------------------------|--------------------------------------------------------------------------------|
| Sample Size: | 20 uL serum or plasma | 50 ul serum or plasma |
| Solid Phase/Precipitating<br>Complex: | 25-OH-D3 magnetic particles | Donkey anti-goat + normal goat<br>serum + PEG precipitating<br>complex. |
| Label: | Acridinium-ester labeled Anti-DBP | $^{125}I$ analog o f 25-OH-D3 |
| Binder/Antibody: | Human vitamin D binding protein | Goat anti-25-OH-D |
| Technology | Automated, hands free set-up<br>No extraction is required. | Manual procedure<br>Separate extraction is required. |
| Incubation steps and temperature: | 21 minutes @ 37°C (25-OH-D<br>displacement)+ 21 minutes @<br>37°C (assay incubation). | 90 minutes @ 20-25°C + 20<br>minutes @ 20-25°C + 20 minutes<br>centrifugation. |
| Reportable Range | 7-120 ng/mL | 5.0-100 ng/mL |

### 11. Comparison of Performance Characteristics

| Feature | Nichols 25-OH-D | DiaSorin 25-OH-D |
|----------------------------|------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------|
| Sensitivity | Analytical: 4 ng/mL<br>Functional: 7 ng/mL | Analytical: ≤ 1.5 ng/mL<br>Functional: 2.5 ng/mL (optional std.) |
| Within-Run Precision (%CV) | 3.0-4.5% | 8.6-12.5% |
| Total Precision (%CV) | 6.4-14.5% | 8.2-11.0% |
| Recovery | 90-99% | 92-119% |
| Linearity | 80-109% | 96-110% |
| Specificity @ 50% B/Bo | Vitamin D2 = 1.6%<br>Vitamin D3 = 1.2%<br>25-OH-D2 = 100%<br>25-OH-D3 = 100%<br>24,25(OH)2D3 = 100%<br>25-26-OH2D3 = 39%<br>1,25(OH)2D3 = 1.1% | Vitamin D2 = 0.8%<br>Vitamin D3 = 0.8%<br>25-OH-D2 = 100%<br>25-OH-D3 = 100%<br>24,25(OH)2D3 = 100%<br>25-26-OH2D3 = 100%<br>1,25(OH)2D3 = 11.0% |

Conclusions: These data, which were provided to FDA, demonstrate safety and effectiveness of the Nichols Advantage 25-Hydroxyvitamin D for the intended in vitro diagnostic use. Furthermore, based on performance characteristics, the Nichols Advantage 25-OH-D assay is substantially equivalent to the predicate method.

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### 10.5 Comparison to a Predicate Device

Method comparison was made against the DiaSorin 25-Hydroxyvitamin D 125RIA kit. Both the predicate device and the subject device were performed exactly as described by their respective manufacturer's directional inserts. The NCCLS Method Comparison (EP9A) procedures were followed. There were n=111 total samples assayed, each in duplicate. The samples were assayed over 3 days in 3 different runs, and guality control samples for each run were within their respective ranges. Of the 111 paired samples, 80 were within the reportable ranges of each method and demonstrated acceptable levels of imprecision. We used 4 standard deviations to delete outliers for reasons of imprecision. Twelve samples demonstrated unacceptable levels of imprecision (>4 sd) and were deleted. Nineteen samples were below the reportable range (<7 ng/mL) with the subject device, and of these, 4 were below the reportable range with the DiaSorin assay (<5 ng/mL). Tabulated data showing the above three groups are located in Appendix 6.

Method comparison statistical analysis was performed with the 80 samples that demonstrated acceptable levels of imprecision. The 80 samples with good precision and the 19 samples that were below the reportable ranges were combined to determine overall concordance using McNemars test. Below is a chart summarizing the levels of imprecision observed in the 80 samples with acceptable levels of imprecision. These data demonstrate that the Nichols Advantage 25-OH-D assay has better within-run precision.

| N=80 paired samples | Nichols Advantage<br>25-OH-D | DiaSorin 25-OH-D |
|---------------------|------------------------------|------------------|
| Ave. CV | 4.7% | 10.6% |
| Median CV | 3.3% | 9.1% |
| Minimum CV | 0.1% | 0% |
| Maximum CV | 25.4% | 35.0% |

NCCLS method comparison analysis was performed on the 80 paired samples. The range of results, the Deming method comparison analysis, the Passing and Bablok method comparison, the Pearson correlation, and the NCCLS bias

41

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analysis are summarized in the chart below. These data, and a scatterplot of the entire method comparison are located in Appendix 6.

| | Nichols Advantage | DiaSorin 25-OH-D (X) |
|------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------|
| | 25-OH-D (Y) | |
| Range | 7.0-69.5 ng/mL | 5.9-88.8 ng/mL |
| Deming Method<br>Comparison: | Y=0.99(X) + 0.7<br>95% confidence slope: 0.85 to 1.14<br>95% confidence intercept: -3.8 to 5.2 | |
| Passing and Bablok Method<br>Comparison: | Y=1.1(X) – 0.6<br>95% confidence slope: 0.94 to 1.27<br>95% confidence intercept: -4.6 to 2.1 | |
| Pearson correlation | R=0.84<br>95% confidence: 0.76 to 0.89 | |
| Bias | Ave. bias: 0.6 ng/mL<br>95% confidence of ave. bias: -1.4 to 2.5 ng/mL<br>95% confidence of agreement:<br>lower limit: -16.5 ng/mL (-19.7 to -13.2)<br>upper limit: 17.6 ng/mL (14.4 to 20.9) | |

Either the Passing and Bablok analysis or the Deming analysis could have been used for describing the method comparison. Because the Passing and Bablok analysis is not dependent upon a constant level of imprecision for the two methods, we think this analysis accurately reflects the comparison between the two methods. The average bias was small, only +0.6 ng/mL, but the upper and lower limits of the bias was large (-16.5 ng/mL to 17.6 ng/mL). The large bias we observed could be due to several reasons. The bias could have been influenced by the larger imprecision we observed with the DiaSorin, and because the crossreactivity of each assay is slightly different for vitamin D sterols. The issue of crossreactivity differences and differences in technology were previously discussed in the Crossreactivity section of this 510k.

Pearson correlation was not ideal because the range of observed results could have been higher. Several high samples were deleted due to poor imprecision obtained using the DiaSorin assay. Here are two examples:

- 1. Nichols: 101.1, 98.1 vs. DiaSorin: 44.3, 70.8
- 2. Nichols: 103.8, 100.9 vs. DiaSorin: 89.9, 47.1

We think the Pearson's correlation coefficient would have been higher if those samples were included in the analysis, since the range of results would be

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higher. Obtaining samples with high 25-OH-D levels is difficult because levels approaching 100 ng/mL or higher only come from individuals who are ingesting large quantities of vitamin D or are taking pharmacologic doses of vitamin D. Our method comparison study shows good agreement between methods across the reportable ranges, but potentially with large bias for values above approximately 20 ng/mL. The concordance chart below further illustrates this bias.

Concordance chart showing number of sample results falling within the specified ranges. The concordance chart include the 19 samples below the reportable range, and the 80 samples used in the method comparisons.

| Adv.<br>25-OH-D<br>(ng/mL) | 0-10 | 10.1-20 | 20.1-30 | 30.1-40 | 40.1-50 | 50.1-60 | 60.1-80 | ≥80.1 |
|----------------------------|------|---------|---------|---------|---------|---------|---------|-------|
| 0-10 | 18 | 7 | | | | | | |
| 10.1-20 | 4 | 16 | 4 | 1 | | | | |
| 20.1-30 | | | 13 | 1 | | | | |
| 30.1-40 | | | 11 | 5 | 5 | 1 | 1 | |
| 40.1-50 | | 1 | 2 | 3 | 1 | | | |
| 50.1-60 | | | | | | 1 | | 1 |
| 60.1-80 | | | | | | | 1 | 1 |
| >80.1 | | | | | | | | |

DiaSorin 25-OH-D (no/ml )

Using a cutoff of 20 ng/mL or higher, the relative agreement between methods were calculated.

Relative agreement at 20 ng/mL or less: [45/(45+1)] x 100 = 97.8% Relative agreement at 20 ng/mL and higher: [48/(5+48)] x 100 = 90.6% Overall agreement using 20 ng/mL as the cutoff: [45+48/99] x 100 = 93.9%

Using a cutoff of 20 ng/mL as the lower limit for vitamin D sufficiency, the subject device demonstrates a relative agreement of 90.6% with the DiaSorin assay at 20 ng/mL and higher. This demonstrates that the subject device is substantially equivalent to the DiaSorin kit in detecting absence of low 25-OH-D levels for determining vitamin D sufficiency. For values below 20 ng/mL, the subject device demonstrates a relative agreement of 97.8% with the DiaSorin kit in identifying low 25-OH-D levels. The overall agreement was 93.9%.

In conclusion, these results in addition to the previous clinical study that evaluates levels of 25-OH-D in patients who are at great risk for vitamin D insufficiency and vitamin D deficiency demonstrate that this device is safe and effective for its intended use.

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Image /page/5/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized eagle or bird symbol, composed of three curved lines, representing the department's mission. The bird is encircled by the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA". The text is arranged in a circular fashion around the bird symbol.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

OCT - 92001

Mr. Jimmy Wong Manager. Clinical and Technical Affairs Nichols institute Diagnostics 33051 Calle Aviador San Juan Capistrano, CA 92675

Re: k012367

> Trade/Device Name: Nichols Advantage 25-Hydroxyvitamin D Regulation Number: 21 CFR 862.1825 Regulation Name: Vitamin D test system Regulatory Class: Class II Product Code: JIT, MRG Regulatory Class: Class I, reserved Product Code: JJX Dated: September 26, 2001 Received: September 27, 2001

Dear Mr. Wong:

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 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 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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Page 2 -

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed nouncation. The I Drice results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFF Part 801 and 1 IT you desire specific acrice for your dotic devices), please contact the Office of Compliance at additionally 607.10 for in Nue and successions on the promotion and advertising of your device, [phone]. Additionally, for quest [phone]. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Information on your responsionals and Consumer Assistance at its toll-free number [phone] or Manufacturers International and Constant Constitution w.fda.gov/cdrh/dsma/dsmamain.html".

Sincerely yours,

Steven Sutman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory-Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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#### 2.0 Indications For Use Statement

| INDICATIONS FOR USE STATEMENT |
|-------------------------------|
|-------------------------------|

| 510(k) Number: | K012367 |
|----------------|---------|
|----------------|---------|

Nichols Advantage 25-Hydroxyvitamin D Device Name:

Indications for Use Statement: The Nichols Advantage® 25-Hydroxyvitamin D assay is for use only on the Nichols Advantage® Specialty System. The Nichols Advantage 25-Hydroxyvitamin D assay is intended for the quantitative determination of 25-hydroxyvitamin D (25-OH-D) and other hydroxylated metabolites of vitamin D in serum or plasma to be used as an aid in the assessment of vitamin D sufficiency in an adult population. Assay results should be used in conjunction with other clinical data to assist the clinician in making individual patient management decisions.

(Please Do Not Write Below This Line - Continue On Another Page If Needed)

# Concurrence of CDRH, Office of Device Evaluation (ODE)

**Prescription Use**
(Per 21 CFR 801.109)

Or 510(k) Number

Over -The-Counter Use (Optional Format 1-2-96)