NOFACT IX

K102908 · R2 Diagnostics, Inc. · GJT · Dec 19, 2011 · Hematology

Device Facts

• Record ID: K102908
• Device Name: NOFACT IX
• Applicant: R2 Diagnostics, Inc.
• Product Code: GJT · Hematology
• Decision Date: Dec 19, 2011
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 864.7290
• Device Class: Class 2
• Attributes: Pediatric

Intended Use

NoFact IX Deficient Plasma is a human plasma immunodepleted of Factor IX and intended for the quantitative determination of Factor IX activity in citrated plasma from patients suspected of FIX deficiency. FIX activity is based on the activated partial thromboplastin time. For in vitro diagnostic use.

Device Story

NoFact IX Deficient Plasma is a lyophilized, immunodepleted human plasma reagent used for in vitro diagnostic testing. It is intended for use in clinical laboratories to measure Factor IX activity in patient citrated plasma samples. The principle of operation involves mixing a diluted patient sample with the Factor IX deficient plasma and performing an activated partial thromboplastin time (APTT) test. The resulting clotting time is dependent on the concentration of Factor IX present in the patient sample. The device is used by laboratory technicians on automated coagulation analyzers. The output, provided as a percentage of Factor IX activity, assists clinicians in diagnosing and managing patients suspected of Factor IX deficiency.

Clinical Evidence

Bench testing only. Precision evaluated per CLSI EP5-A2 using three lots across 240-480 replicates; results showed within-device %CV of 7.2-7.8%. Method comparison study of 233 patient samples across three sites compared NoFact IX to the predicate using the Stago PTT-A FIX assay on an STA Compact analyzer, yielding a correlation coefficient (r) of 0.956 and r2 of 0.915.

Technological Characteristics

Lyophilized human plasma immunodepleted of Factor IX (<1% activity) with buffer and stabilizers. Clot-based assay principle using modified APTT. Designed for use on Diagnostica Stago STA Family analyzers. Reconstituted stability: 8 hours at 2-8°C, 4 hours at room temperature. Complies with CLSI guidelines for precision (EP5-A2), linearity (EP6-A), method comparison (EP9-A2), and stability (EP25-A).

Indications for Use

Indicated for quantitative determination of Factor IX activity in citrated plasma from patients suspected of Factor IX deficiency. Applicable to patients of all ages and genders.

Predicate Devices

• Stago IX Deficient Plasma (K933432)

Submission Summary (Full Text)

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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

A. 510(k) Number:
k102908

B. Purpose for Submission:
Clearance for new device

C. Measurand:
Factor IX activity

D. Type of Test:
Quantitative

E. Applicant:
r² Diagnostics, Inc

F. Proprietary and Established Names:
NoFact IX Deficient Plasma

G. Regulatory Information:
1. Regulation section:
21 CFR § 864.7290, Factor deficiency test
2. Classification:
Class II
3. Product code:
GJT, Plasma, Coagulation factor deficient
4. Panel:
81 Hematology

H. Intended Use:
1. Intended use(s):
NoFact IX Deficient Plasma is a human plasma immunodepleted of Factor IX and intended for the quantitative determination of Factor IX activity in citrated plasma from patients suspected of FIX deficiency. FIX activity is based on the activated partial thromboplastin time. For in vitro diagnostic use.
2. Indication(s) for use:
Same as Intended use
3. Special conditions for use statement(s):
For prescription use only
4. Special instrument requirements:
Diagnostica Stago STA Family analyzers

I. Device Description:
The r² NoFact IX Deficient plasma kit contains 10 x 1 mL vials of lyophilized human plasma artificially immunodepleted of Factor IX to contain less than 1% factor IX activity with buffer and stabilizers.

J. Substantial Equivalence Information:
1. Predicate device name(s):
STAGO Factor IX-Deficient Plasma
2. Predicate 510(k) number(s):
k933432
3. Comparison with predicate:

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| Similarities | | |
| --- | --- | --- |
| Item | Device: r² NoFACT IX Deficient Plasma (k102908) | Predicate: STAGO Factor IX-Deficient Plasma (k933432) |
| Intended Use | NoFact IX Deficient Plasma is a human plasma immunodepleted of Factor IX and intended for the quantitative determination of Factor IX activity in citrated plasma. | Same |
| Measurement Principle | Clot-based assay for Factor IX activity using a modified activated partial thromboplastin time (APTT) test and Factor IX deficient plasma. | Same |
| Format | Lyophilized plasma | Same |
| Analyte tested | Factor IX activity | Same |
| Differences | | |
| --- | --- | --- |
| Item | Device:r² NoFACT IX Deficient Plasma (k102908) | Predicate: STAGO Factor IX-Deficient Plasma (k933432) |
| Reconstituted Stability | 2-8°C: 8hrs
Room Temperature (18°-26°C): 4 hrs | 2-8°C: 8hrs
Room Temperature: not listed
On-board STA Compact® and STA-R®: 4hrs |
| Final Product Form | Kit contains 10 x 1 mL lyophilized vials | Kit containing 6 x 1 mL lyophilized vials |

## K. Standard/Guidance Document Referenced (if applicable):

CLSI EP5-A2, Evaluation of Precision Performance of Quantitative Measurement Methods; Approved Guidelines, Second Edition, 2004.

CLSI EP6-A, Evaluation of the Linearity of Quantitative Measurement Procedures: A statistical Approach; Approved Guidelines, 2003.

CLSI EP9-A2 Method Comparison and Bias Estimation Using Patient Samples; Approved Guideline, Second Edition, 2002.

CLSI EP25-A, Evaluation of Stability of In Vitro Diagnostic Reagents; Approved Guideline, 2009.

CLSI H21-A5, Collection, Transport and Processing of Blood Samples for Testing Plasma-based Coagulation Assays and Molecular Hemostasis Assays; Approved Guideline-Fifth Edition, 2008.

## L. Test Principle:

The assay determines the functional activity of Factor IX by measuring the degree of prolongation of activated partial thromboplastin time in the presence of a contact activator, thromboplastin, phospholipids and calcium ions. Factor IX activity is correlated with the prolongation of the clotting time of the Factor IX deficient plasma when added to diluted patient plasma. The APTT clotting time of this mixture is inversely proportional to factor IX concentration (% activity) in the patient plasma.

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M. Performance Characteristics (if/when applicable):

1. Analytical performance:

a. Precision/Reproducibility:

Studies for within-run, lot-to-lot and within-device precision were performed on low % activity factor IX pooled plasma for 10 days along with normal and high controls for 20 days. The controls and low % activity pooled plasma were tested with 3 lots of Stago PTT-A reagent and 3 lots of NoFACT IX deficient plasma on the Stago STA Compact analyzer. Testing was conducted twice a day with two replicates per run for each sample. The acceptance criteria for within-run and lot-to-lot %CV is &lt;10% and for within device %CV is &lt;15%. The overall results of the study met the acceptance criteria as follows:

| Sample Type | Mean FVIII activity % | % CV Lot-to-Lot | NoFact VIII Lot# | % CV Between - day | % CV Within-run | % CV Within-Device |
| --- | --- | --- | --- | --- | --- | --- |
| System N (Normal Control Plasma) | 109% | 1.1% | 1 | 3.2 | 5.3 | 6.6 |
| | | | 2 | 4.4 | 4.4 | 7.0 |
| | | | 3 | 2.6 | 5.4 | 7.6 |
| System P (Abnormal Control Plasma) | 43% | 2.9% | 1 | 4.4 | 5.2 | 7.3 |
| | | | 2 | 4.0 | 4.1 | 7.2 |
| | | | 3 | 3.5 | 4.4 | 6.7 |

b. Linearity/assay reportable range:

Linearity studies were performed using the Stago PTT-A reagent on the STA Compact analyzer. The assays were calibrated using the Stago Unicalibrator. A series of 11 dilutions was conducted from reconstituted ISTH SSC approved plasma and diluted with the assay diluent and was tested at concentrations ranging from 0.8 to 188% activity. Duplicate measurements of each dilution were obtained with each of 3 lots of NoFACT IX. The Factor IX dilutions were run in duplicate for each NoFACT VIII Deficient Plasma lot and the average activities were plotted against their assigned values. The acceptance criteria were as follows: slope of 0.8-1.2, intercept &lt;6.0 and r &gt;0.9. The calculated slope, intercept, and correlation coefficient are provided in the following table:

| NoFact IX Deficient Plasma | Slope | Intercept | r-value |
| --- | --- | --- | --- |
| Lot 1 | 1.212 | -0.57 | 0.9998 |
| Lot 2 | 1.084 | 1.168 | 0.9959 |
| Lot 3 | 1.066 | 0.815 | 0.9979 |

The results of the study were within acceptable limits.

c. Traceability, Stability, Expected values (controls, calibrators, or methods): Real-time Stability:

Three lots of NoFACT IX Deficient Plasma were tested with Stago System N and P control plasmas for factor IX recovery for real-time stability. The lots were tested on the Stago STA Compact using Stago PTT-A, Stago System N

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and P control plasmas, and Stago Unicalibrator. The NoFact IX plasma was stored, reconstituted and tested from 0 months through 33 months at specific time intervals. Factor IX recovery of all three lots was acceptable based on the established reference range of each control. Results for the accelerated stability study, which projects a 2.4 year shelf life, support a 2-year shelf life claim of NoFact IX Deficient Plasma when stored at 2-8 °C. Ongoing real-time stability testing will be used to update the shelf life.

**Reconstituted stability at Room Temperature and 2-8°C:**

Two lots of NoFact IX Deficient Plasma were reconstituted according to the package insert. The Stago PTT-A and NoFact IX deficient plasma assay was used to test the System N and P controls for factor IX recovery. The recovered FIX activity values at the time of reconstitution were considered the "zero hour" baseline. The reconstituted vials were stored at 0, 2, 6, 8 and 24 hours at 2-8°C and 0, 4, 6 and 8 hours at room temperature. At the time periods after reconstitution, vials from both sets of temperatures were run and the recovery at that time point was determined. These recoveries were compared to the baseline recovery by calculating the % shift in value: (baseline value - time point value) divided by (baseline value). The acceptance criterion is a shift of ≤10% compared to the zero hour baseline. The overall results meet the acceptance criteria with study results at room temperature of &lt;8.1% and 2-8°C at &lt;7.5%. Stability data supports the reconstituted stability claim of 8 hours at 2-8°C and 4 hours at room temperature.

**d. Detection limit:**

Not applicable

**e. Analytical specificity:**

Interference studies were conducted using pooled normal plasma (PNP) spiked with the interferents at predetermined maximum concentrations to create a stock preparation. The stock preparation was serially diluted 12 times with PNP in which each dilution was tested for factor IX activity on the STA Compact using Stago PTT-A and NoFACT IX. The % difference between the spiked dilutions to baseline (PNP) was accessed with an overall % difference &lt;6%, which met the acceptance criteria difference of &lt;10%.

Maximum Concentration results are as follows:

| Interferents | Maximum Concentration |
| --- | --- |
| Hemolysis | 500 mg/dL |
| Icterus | 20 mg/dL |
| Lipemia | 2000 mg/dL (triglycerides) |
| Low Molecular Weight Heparin | 5 anti-Xa units/mL |
| Direct Thrombin Inhibitor | 20 ug/mL |
| Unfractionated Heparin | 2.0 Units/mL |

**f. Assay cut-off:**

Not applicable

**2. Comparison studies:**

**a. Method comparison with predicate device:**

NoFact IX Deficient Plasma was compared to the predicate STA IX Deficient plasma using the Stago PTT-A with factor IX deficient plasma assay on the

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STA Compact measuring the factor IX % activity range from 6% to 220%. A total of 233 (124 normal/109 abnormal) donors and patient samples, were analyzed over three laboratory sites. The clinical distribution of the samples is detailed in the tables below:

Table 1:
| Gender | Sample size (n) | Age | Sample size (n) |
| --- | --- | --- | --- |
| Male | 147 | <21 yrs | 22 |
| Female | 86 | 21-60 yrs | 193 |
| | | >60 yrs | 18 |

Table 2:
| | Site 1 | Site 2 | Site 3 |
| --- | --- | --- | --- |
| Total (n): | 100 | 80 | 53 |
| Normal donors: | 45 | 44 | 44 |
| Abnormal: | 55 | 36 | 9 |
| - Hemophilia | 50 | 28 | 7 |
| - Sepsis | 2 | 2 | 1 |
| - VWD | 3 | 4 | - |
| - Surgery | - | 2 | - |
| - Other | - | - | 1 |

Citrated plasma samples were tested in parallel with the Stago PTT-A assay using the STA FIX and NoFact IX deficient plasma. The acceptance criteria for the study were: slope between 0.8-1.2, and correlation coefficient (r) &gt;0.90. Data analysis for the overall study is as follows:

Table 3:
| All Sites (n = 233) | |
| --- | --- |
| Slope (95% CI) | 0.858 (0.824-0.892) |
| Intercept (95% CI) | 5.729 (2.175-9.238) |
| Correlation coefficient (r) | 0.956 |

b. Matrix comparison:

Fresh vs. Frozen (Thawed) -Testing was performed on the Stago Compact using Stago PTT-A assay and NoFact IX Deficient Plasma. A total of 18 (9 normal &amp; 9 abnormal) samples were tested. The samples were split, tested fresh and then frozen at 20°C and 80°C for 1-3 days and later thawed and re-tested. A linear regression was conducted from the test results from the samples thawed from -20°C and -80°C. The acceptance criterion is r &gt;0.90. The slope, intercept and correlation coefficient (r) at -20°C were 1.065, -0.02 and 0.994 respectively. The slope, intercept, and correlation coefficient (r) for

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the -80°C results were 0.995, -0.02, and 0.997 respectively. The study results met the acceptance criterion.

3. Clinical studies:
a. Clinical Sensitivity: Not applicable
b. Clinical specificity: Not applicable
c. Other clinical supportive data (when a. and b. are not applicable): Not applicable

4. Clinical cut-off: Not applicable

5. Expected values/Reference range: To verify the normal range for factor IX activity, a total of 109 normal samples were tested for factor IX activity using Stago PTT-A assay and NoFact IX deficient plasma on the Stago Compact. The data was used to calculate a 2SD distribution for the normal range activity for factor IX. The results verified the cited literature normal range of 78%-184%.

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.