(260 days)
HemosIL Chromogenic Factor IX is an automated assay for the photometric, quantitative determination of factor IX activity in 3.2% citrated plasma on the ACL TOP® Family and ACL TOP Family 50 Series in the laboratory setting by a healthcare professional. HemosIL Chromogenic Factor IX is indicated for use on patients when identifying factor IX deficiency or measuring factor IX activity from patients on replacement therapy. For adult population only. For prescription use only.
Factor IX activity in a patient's plasma is determined using a chromogenic method, in which human factor IX is activated by human factor XIa, and, when formed, factor IXa activates human factor X in the presence of human factor VIII, calcium and phospholipid. The amount of factor Xa generated is proportionate to the factor IX activity and is determined from the hydrolysis of a chromogenic factor Xa substrate. Results are determined by comparing a chromogenic signal to a calibration curve.
Here's a breakdown of the acceptance criteria and the studies that demonstrate the device's performance, based on the provided FDA 510(k) summary for the HemosIL Chromogenic Factor IX:
1. Table of Acceptance Criteria and Reported Device Performance
The document doesn't explicitly list "acceptance criteria" in a separate table. However, it presents performance characteristics that implicitly serve as success metrics for the device's substantial equivalence. I've extrapolated these based on the study findings.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance | Study Performed |
|---|---|---|---|
| Precision (Within-run %CV) | Acceptable %CV for different Factor IX levels | ACL TOP Family: Normal Control (3.5%), Special Test Control (3.3%), Sample 1 (5.4%), Sample 2 (3.7%), Sample 3 (3.3%) ACL TOP Family 50 Series: Normal Control (2.7%), Special Test Control (2.5%), Sample 1 (3.3%), Sample 2 (3.1%), Sample 3 (3.4%) | Precision Study (EP05-A3) |
| Precision (Total %CV) | Acceptable %CV for different Factor IX levels | ACL TOP Family: Normal Control (5.6%), Special Test Control (5.1%), Sample 1 (7.3%), Sample 2 (5.1%), Sample 3 (5.2%) ACL TOP Family 50 Series: Normal Control (4.5%), Special Test Control (3.9%), Sample 1 (5.3%), Sample 2 (3.8%), Sample 3 (4.5%) Aggregated ACL TOP Family: Normal Control (5.8%), Special Test Control (5.3%), Sample 1 (8.4%), Sample 2 (5.4%), Sample 3 (5.8%) | Precision Study (EP05-A3) |
| Reproducibility (Total %CV) | Acceptable %CV across sites, runs, and days | Normal Control (8.3%), Special Test Control (5.6%), Sample 1 (21.1%), Sample 2 (7.1%), Sample 3 (5.1%), Sample 4 (6.1%), Sample 5 (6.8%), Concentrate Sample 1 (7.3%), Concentrate Sample 2 (4.9%), Concentrate Sample 3 (5.8%) | Reproducibility Study (EP05-A3) |
| Limit of Blank (LoB) | Low enough to distinguish from true zero | 0.1% | LoB, LoD, LoQ Studies (CLSI EP17-A2) |
| Limit of Detection (LoD) | Low enough to detect presence of analyte | 0.3% | LoB, LoD, LoQ Studies (CLSI EP17-A2) |
| Limit of Quantitation (LoQ) | Low enough for reliable quantitative measurement | 0.6% | LoB, LoD, LoQ Studies (CLSI EP17-A2) |
| Linear Range | Span the expected clinical range | 1.0 to 150% | Linearity Study (CLSI EP06, 2nd Ed.) |
| Interference | No significant interference from common substances | Hemoglobin (1000 mg/dL), Bilirubin (unconjugated/conjugated) (40 mg/dL), Triglycerides (1500 mg/dL), Unfractionated heparin (2.0 IU/mL), Low molecular weight heparin (2.0 IU/mL), Dabigatran (5.0 mg/L), Rivaroxaban (0.05 mg/L), Fondaparinux (1.02 mg/L), Lupus anticoagulant (dRVVT Screen/Confirm Ratio 1.8) | Interference Study (CLSI EP07, 3rd Ed.) |
| Normal Reference Interval | Established a suitable range for healthy individuals | 71.1 to 134.1% (0.7-1.3 IU/mL) | Normal Reference Interval Study (CLSI EP28-A3c) |
| Recovery of Factor IX Replacement Therapies | Acceptable recovery rates for various therapies | AlphaNine SD (90%), BeneFIX (93%), Rebinyn (112%), Idelvion (159%) | Recovery Study |
| Method Comparison (Overall Correlation with Predicate) | High correlation (r) and acceptable slope/intercept | r = 0.972, Slope = 1.015, Intercept = -0.920 | Multicenter Method Comparison Study (CLSI EP09c) |
| Method Comparison (Predicted Bias) | Acceptable bias at various Factor IX levels | 1%: -0.90 (-2.03 to -0.19 CI)5%: -0.84 (-1.89 to -0.17 CI)50%: -0.3% (-2.5% to 0.8% CI)100%: 0.6% (-1.4% to 2.2% CI) | Multicenter Method Comparison Study (CLSI EP09c) |
| System Comparison (ACL TOP Family 50 Series vs. ACL TOP Family systems) | High correlation (r) and acceptable slope/intercept | r = 0.998, Slope = 0.980, Intercept = 1.731 | Internal Method Comparison Study |
| In-Use Stability (Reagents) | Meets specified stability claims | Reagent A/B: 72 hrs at 2-8°C, 4 months at < -65°C, 8 hrs at 15°C (on instrument).Substrate: 1 month at 2-8°C, 12 months at ≤ -65°C, 24 hrs at 15°C (on instrument).Buffer: 12 months at 2-8°C.Diluted Buffer: 24 hrs on instrument. | In-Use Stability and Shelf-life Studies (CLSI EP25-A) |
| Shelf-life | Meets specified shelf-life claim | 28 Months at 2-8°C | In-Use Stability and Shelf-life Studies (CLSI EP25-A) |
| Sample Stability | Meets specified stability claims | Up to 8 hours at 15-25°C and up to 8 hours at 2-8°C | Sample Stability Study |
2. Sample Sizes Used for the Test Set and Data Provenance
- Precision Studies (Separate for ACL TOP Family and ACL TOP Family 50 Series):
- Sample Size: For each sample level (three patient sample pools, two control levels), there were 80 replicates (20 days * 2 runs/day * 2 replicates/run). So, 5 levels * 80 replicates = 400 measurements per instrument type for the representative reagent lot. For the aggregated data, this would be 3 reagent lots * 5 levels * 80 replicates = 1200 measurements.
- Data Provenance: Retrospective (clinical samples are often already collected). The documentation does not specify the country of origin, but it implies a laboratory setting.
- Reproducibility Study:
- Sample Size: 90 replicates per level (pooled three-site data). There were 10 levels (2 controls, 5 patient samples, 3 concentrate-spiked samples). So, 10 levels * 90 replicates = 900 measurements.
- Data Provenance: Retrospective (clinical samples) and prospective (concentrate-spiked samples). Conducted at two external sites and one internal site. Country of origin not specified, but likely US-based given FDA submission.
- LoB, LoD, LoQ Studies:
- Sample Size: Not explicitly stated as a number of distinct samples or runs, but performed using "three reagent lots" on "representative members" of both ACL TOP families.
- Data Provenance: Not specified, but generally involves laboratory-prepared samples.
- Linearity Study:
- Sample Size: Not explicitly stated as number of samples or points, but performed using "three reagent lots" on ACL TOP Family and "one reagent lot" on ACL TOP Family 50 Series. Typically, linearity studies involve multiple dilutions of a high concentration sample.
- Data Provenance: Not specified, likely laboratory-prepared samples.
- Interference Studies:
- Sample Size: Not explicitly stated as a number of distinct samples or runs, but used a "minimum of one reagent lot." Interference studies usually involve adding varying concentrations of potential interferents to samples with known analyte concentrations.
- Data Provenance: Not specified, likely laboratory-prepared or spiked samples.
- Normal Reference Interval Study:
- Sample Size: 120 plasma samples from "apparently healthy individuals."
- Data Provenance: Retrospective (plasma samples). Country of origin not specified.
- Recovery of Factor IX Replacement Therapies Study:
- Sample Size: Immunodepleted FIX deficient plasma was spiked with four factor IX replacement therapies at "seven to fourteen concentrations." So, 4 therapies * (7 to 14 concentrations) = between 28 and 56 samples tested.
- Data Provenance: Laboratory-prepared spiked samples using immunodepleted plasma.
- Multicenter Method Comparison Study:
- Sample Size: 344 samples in total (N for each site: 105, 105, 104, 30). These samples were from "patients with von Willebrand disease, patients with hemophilia A and B and patients on factor IX replacement therapy."
- Data Provenance: Retrospective patient samples. Conducted at four sites (three external and one internal). Country of origin not specified, but multi-center suggests potentially diverse data.
- Internal Method Comparison Study (ACL TOP Family 50 Series vs. ACL TOP Family):
- Sample Size: 126 samples.
- Data Provenance: Not explicitly stated, but likely patient samples or a mix. Internal study suggests data from the manufacturer's own facilities.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not mention the use of experts to establish a "ground truth" for the test sets in the typical sense of subjective interpretation (e.g., radiologists, pathologists). This device is an in vitro diagnostic (IVD) assay designed for quantitative determination of Factor IX activity.
For IVDs, the "ground truth" is generally established by:
- Reference Methods: Such as the predicate device (HemosIL Factor IX deficient plasma) in the method comparison study, or established laboratory methods for determining analyte concentrations.
- Known Concentrations: In studies like linearity, LoB/LoD/LoQ, interference, and recovery, samples are often prepared with known concentrations of the analyte or interferent.
- Clinical Diagnosis: For studies involving patient samples, the "ground truth" for the patient's condition (e.g., Factor IX deficiency, hemophilia A/B) would be based on established clinical diagnostic criteria, which involve a healthcare professional's assessment, not a single 'expert' review of the test results themselves.
Therefore, the concept of "number of experts" and their "qualifications" for ground truth establishment, as often seen in imaging or pathology AI, is not directly applicable here.
4. Adjudication Method for the Test Set
Since this is an IVD device for quantitative measurement, there is no mention of an adjudication method (like 2+1 or 3+1 consensus) for establishing ground truth. The "ground truth" for quantitative assays is typically based on:
- Reference measurements: The results from the predicate device or a recognized reference method.
- Prepared concentrations: Samples with precisely known concentrations.
- Statistical analysis: Agreement between the device and the reference, or the consistency of results over time/across sites.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
No, an MRMC comparative effectiveness study was not done. This device is an in vitro diagnostic (IVD) assay, not an imaging or diagnostic AI tool that assists human readers (e.g., radiologists, pathologists). It provides a quantitative measurement of Factor IX activity directly. It does not involve human interpretation that could be "assisted" by AI in the way an imaging algorithm would.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, the performance studies described are essentially "standalone" algorithm performance. The HemosIL Chromogenic Factor IX assay is an automated photometric assay. The precision, reproducibility, linearity, LoB/LoD/LoQ, interference, normal reference interval, and recovery studies assess the device's analytical performance on its own without human interpretation in the results generation. While a healthcare professional operates the instrument and interprets the final numerical result in the context of a patient's condition, the device's output itself is a direct quantitative value. The method comparison studies also evaluate the standalone output of the new device against a predicate device.
7. The Type of Ground Truth Used
The ground truth for the various studies primarily involved:
- Reference Method Comparison: The predicate device, HemosIL Factor IX deficient plasma (K031829), which uses an activated partial thromboplastin time (APTT) assay. This serves as the comparative "ground truth" in the method comparison studies.
- Known Concentrations/Spiked Samples: For studies like LoB/LoD/LoQ, linearity, interference, and recovery of Factor IX replacement therapies, ground truth was established by preparing samples with precisely known concentrations of Factor IX or interferents, or by spiking immunodepleted plasma with known amounts of Factor IX concentrates.
- Clinically Characterized Samples: For studies involving patient samples (e.g., method comparison, normal reference interval), the samples were sourced from "patients with von Willebrand disease, patients with hemophilia A and B and patients on factor IX replacement therapy" or "apparently healthy individuals." The "ground truth" for their clinical status would have been based on established clinical diagnostic criteria and patient outcomes/history, not specifically pathology or ad-hoc expert consensus on the test results themselves.
8. The Sample Size for the Training Set
The document does not explicitly describe a "training set" in the context of machine learning or AI algorithm development. This is a traditional IVD assay, not an AI/ML-based device that would typically undergo a distinct training phase with a dedicated dataset. The development and optimization of such assays rely on chemical/biological principles, reagent formulations, and analytical validation rather than iterative learning from data.
9. How the Ground Truth for the Training Set was Established
As there's no explicit "training set" described for an AI/ML algorithm, this question is not directly applicable. The "ground truth" for the various performance studies (as described in point 7) was established through reference methods, known concentrations, and clinical characterization of patient samples for validation, not for training a model.
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Image /page/0/Picture/0 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: the Department of Health & Human Services logo on the left and the FDA acronym along with the full name of the agency on the right. The FDA part of the logo is in blue, with the acronym in a square and the full name, "U.S. Food & Drug Administration," written out next to it.
December 13, 2023
Instrumentation Laboratory Company Carol Marble Senior Director of Regulatory Affairs 180 Hartwell Road Bedford, Massachusetts 01730
Re: K230852
Trade/Device Name: HemosIL Chromogenic Factor IX Regulation Number: 21 CFR 864.7290 Regulation Name: Factor deficiency test Regulatory Class: Class II Product Code: GGP Dated: March 27, 2023 Received: March 28, 2023
Dear Carol Marble:
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 (the 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 available 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.
Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).
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Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review. the OS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).
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 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safetyreporting-combination-products); 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 Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). 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 (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
Min Wu-S
Min Wu, Ph.D. Branch Chief Division of Immunology and Hematology Devices OHT7: Office of In Vitro Diagnostics Office of Product Evaluation and Quality Center for Devices and Radiological Health
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Indications for Use
510(k) Number (if known) K230852
Device Name HemosIL Chromogenic Factor IX
Indications for Use (Describe)
HemosIL Chromogenic Factor IX is an automated assay for the photometric, quantitative determination of factor IX activity in 3.2% citrated plasma on the ACL TOP® Family and ACL TOP Family 50 Series in the laboratory setting by a healthcare professional. HemosIL Chromogenic Factor IX is indicated for use on patients when identifying factor IX deficiency or measuring factor IX activity from patients on replacement therapy. For adult population only. For prescription use only.
| 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) |
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werfen
510(k) Summary
This 510(k) Summary of Safety and Effectiveness is being submitted in accordance with the requirements of the Safe Medical Device Act of 1990 and 21 CFR 807.92.
| Submitter's Information | Instrumentation Laboratory (IL) Company180 Hartwell RoadBedford, MA 01730, USA |
|---|---|
| Contact Person | Carol Marble, Senior Director of Regulatory AffairsPhone: 781-861-4467Fax: 781-861-4207Email: cmarble@werfen.com |
| Preparation Date | December 12, 2023 |
| Device Trade Name | HemosIL Chromogenic Factor IX |
| Regulatory Information | Regulation No. 21 CFR 864.7290Regulation Description Factor deficiency testClassification Class IIProduct Code GGPClassification Panel Hematology (81) |
| Predicate Device | K031829 HemosIL Factor IX deficient plasma |
| Device Description | Factor IX activity in a patient's plasma is determined using a chromogenic method, inwhich human factor IX is activated by human factor XIa, and, when formed, factorIXa activates human factor X in the presence of human factor VIII, calcium andphospholipid. The amount of factor Xa generated is proportionate to the factor IXactivity and is determined from the hydrolysis of a chromogenic factor Xa substrate.Results are determined by comparing a chromogenic signal to a calibration curve. |
| Intended Use /Indications for Use | HemosIL Chromogenic Factor IX is an automated assay for the photometric,quantitative determination of factor IX activity in 3.2% citrated plasma on the ACLTOP Family and ACL TOP Family 50 Series in the laboratory setting by a healthcareprofessional. HemosIL Chromogenic Factor IX is indicated for use on patients whenidentifying factor IX deficiency or measuring factor IX activity from patients onreplacement therapy. For adult population only. For prescription use only. |
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| Comparison to Predicate Device | ||
|---|---|---|
| Item | Predicate Device (K031829) | Subject Device |
| Proprietary andEstablished Name | HemosIL Factor IX deficient plasma | HemosIL Chromogenic Factor IX |
| Legal Manufacturer | Instrumentation Laboratory Co. | Same |
| Similarities | ||
| Measurand | Factor IX activity | Same |
| Measurement | Quantitative | Same |
| Regulation No. | 21 CFR 864.7290 | Same |
| RegulationDescription | Factor deficiency test | Same |
| Classification | Class II | Same |
| Product Code | Classification Product Code:GJTSubsequent Product Code:GGP | GGP |
| Review Panel | Hematology (81) | Same |
| Intended Use /Indications for Use | HemosIL Factor IX deficient plasma ishuman plasma immunodepleted of factorIX for the quantitative determination offactor IX activity in citrated plasma, basedon activated partial thromboplastin time(APTT) assay, on IL Coagulation Systems. | HemosIL Chromogenic Factor IX is anautomated assay for the photometric,quantitative determination of factor IXactivity in 3.2% citrated plasma on the ACLTOP Family and ACL TOP Family 50Series in the laboratory setting by ahealthcare professional. HemosILChromogenic Factor IX is indicated for useon patients when identifying factor IXdeficiency or measuring factor IX activityfrom patients on replacement therapy. Foradult population only. For prescription useonly. |
| Sample Type | Citrated plasma | Same |
| Type of Test | Quantitative | Same |
| Reporting Units | % Activity, U/mL and/or sec | % Activity and/or IU/mL |
| Instruments | ACL Elite/Elite ProACL TOP FamilyACL TOP Family 50 Series | ACL TOP FamilyACL TOP Family 50 Series |
| Controls(Sold Separately) | HemosIL Normal Control AssayedHemosIL Special Test Control Level 2 | Same |
| Calibrator(Sold Separately) | HemosIL Calibration Plasma | Same |
| Linear Range | 1.0-150% | Same |
| Differences | ||
| Item | Predicate Device (K031829) | Subject Device |
| Test Principle | Factor IX activity in a patient's plasma isdetermined by performing a modifiedactivated partial thromboplastin time test(APTT). Patient plasma is diluted and addedto a plasma deficient in factor IX. Correctionof the clotting time of the deficient plasma isproportional to the concentration (% activity)of that factor in the patient plasma,interpolated from a calibration curve. | Factor IX activity in a patient's plasma isdetermined using a chromogenic method, inwhich human factor IX is activated by humanfactor XIa, and, when formed, factor IXaactivates human factor X in the presence ofhuman factor VIII, calcium and phospholipid.The amount of factor Xa generated isproportionate to the factor IX activity and isdetermined from the hydrolysis of achromogenic factor Xa substrate. Results aredetermined by comparing a chromogenic signalto a calibration curve. |
| Methodology | Functional clotting assay | Chromogenic assay |
| Kit Components | Factor IX deficient plasma: Lyophilizedhuman plasma that has been artificiallydepleted of factor IX containing buffer andstabilizers. The residual factor IX activity isless than or equal to 1% whereas all othercoagulation factors have normal levels. | Reagent A: Lyophilized preparation containing human factor VIII, human factorX, bovine factor V, bovine serum albumin and a fibrin polymerization inhibitor. Reagent B: Lyophilized preparation containing human factor XIa, human factorII, bovine serum albumin, calcium chloride and phospholipids. Substrate: Solution containing 2.5 mmol/L chromogenic factor Xa substrate (Z-D-Arg-Gly-Arg-pNA), a thrombin inhibitor and preservative. Buffer: Stock solution of buffer containing a heparin antagonist, bovine serum albuminand preservative. Diluted Buffer Barcode Labeled Vials:Empty vials with linear barcode labels for Diluted Buffer (to be prepared). |
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Performance Summary
Precision
Within-run (repeatability) and total (within-device) precision were assessed in accordance with EP05-A3 for 20 days, with two runs per day and two replicates per run for each sample level (n=80) for three reagent lots on representative members of the ACL TOP Family. To span the assay range, three patient sample pools were tested, as well as two control levels. The tables below show data for one representative reagent lot on one instrument and also aggregated data for the three reagent lots on one instrument.
| Representative Reagent Lot on ACL TOP Family Instrument | |||||
|---|---|---|---|---|---|
| Material | Mean(%) | Within-run | Total | ||
| SD | %CV | SD | %CV | ||
| Normal Control Assayed | 111.7 | 3.9 | 3.5 | 6.3 | 5.6 |
| Special Test Control Level 2 | 33.3 | 1.1 | 3.3 | 1.7 | 5.1 |
| Sample 1 (Pool) | 4.3 | 0.2 | 5.4 | 0.3 | 7.3 |
| Sample 2 (Pool) | 65.7 | 2.5 | 3.7 | 3.4 | 5.1 |
| Sample 3 (Pool) | 102.7 | 3.4 | 3.3 | 5.3 | 5.2 |
| Aggregated Data (Reagent Lots 1, 2 and 3) | |||||
| Material | Mean(%) | Total(Within-Laboratory) | |||
| SD | %CV | ||||
| Normal Control Assayed | 110.6 | 6.4 | 5.8 | ||
| Special Test Control Level 2 | 33.0 | 1.8 | 5.3 | ||
| Sample 1 (Pool) | 4.2 | 0.4 | 8.4 | ||
| Sample 2 (Pool) | 65.3 | 3.5 | 5.4 | ||
| Sample 3 (Pool) | 101.8 | 5.9 | 5.8 |
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Further, within-run (repeatability) and total (within-device) precision were assessed in accordance with EP05-A3 for 20 days, with two runs per day and two replicates per run for each sample level (n=80) for one reagent lot on representative members of the ACL TOP Family 50 Series. To span the assay range, three patient sample pools were tested, as well as two control levels. The table below shows data for one instrument.
| Representative Reagent Lot on ACL TOP Family 50 Series Instrument | |||||
|---|---|---|---|---|---|
| Material | Mean(%) | Within-run | Total | ||
| SD | %CV | SD | %CV | ||
| Normal Control Assayed | 111.9 | 3.0 | 2.7 | 5.0 | 4.5 |
| Special Test Control Level 2 | 33.5 | 0.8 | 2.5 | 1.3 | 3.9 |
| Sample 1 (Pool) | 4.1 | 0.1 | 3.3 | 0.2 | 5.3 |
| Sample 2 (Pool) | 66.4 | 2.1 | 3.1 | 2.5 | 3.8 |
| Sample 3 (Pool) | 103.5 | 3.5 | 3.4 | 4.6 | 4.5 |
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Reproducibility
Reproducibility studies were conducted in accordance with EP05-A3 at two external site using different operators (one operator per site) on three different ACL TOP Family 30 Series members (one instrument per site), using three reagent lots of Hemostl. Chromogenic Pactor IX with each site total a with each site total a different reagent lot. The same five patient pools and chree sites, as well as three patient sample pools spilled with a factor IX concentate. Each material was tested in triplicate, twice a day for five atotal of 30 replicates per level. The table belows the pooled three-site data for all reagent lots.
| Pooled Three-Site Data | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Level | Mean (%) | N | Repeatability (Within-Run) | Between-Run | Between-Day | Between-Site | Reproducibility (Total) | |||||
| SD | %CV | SD | %CV | SD | %CV | SD | %CV | SD | %CV | |||
| Normal Control Assayed | 108.9 | 90 | 5.5 | 5.0 | 4.4 | 4.0 | 3.7 | 3.4 | 4.3 | 3.9 | 9.0 | 8.3 |
| Special Test Control Level 2 | 30.7 | 90 | 1.2 | 3.9 | 0.5 | 1.6 | 1.0 | 3.3 | 0.5 | 1.5 | 1.7 | 5.6 |
| Sample 1 (Pool) | 1.3 | 90 | 0.2 | 15.2 | 0.0 | 0.0 | 0.2 | 12.7 | 0.1 | 7.1 | 0.3 | 21.1 |
| Sample 2 (Pool) | 4.0 | 90 | 0.2 | 5.3 | 0.0 | 0.0 | 0.1 | 3.3 | 0.1 | 3.3 | 0.3 | 7.1 |
| Sample 3 (Pool) | 33.6 | 90 | 1.2 | 3.6 | 0.9 | 2.7 | 0.7 | 2.1 | 0.4 | 1.2 | 1.7 | 5.1 |
| Sample 4 (Pool) | 73.9 | 90 | 3.0 | 4.1 | 1.4 | 1.9 | 3.1 | 4.2 | 0.0 | 0.0 | 4.5 | 6.1 |
| Sample 5 (Pool) | 109.7 | 90 | 4.9 | 4.5 | 1.7 | 1.5 | 5.4 | 4.9 | 0.0 | 0.0 | 7.5 | 6.8 |
| Concentrate Sample 1 (Pool) | 3.7 | 90 | 0.2 | 6.2 | 0.0 | 0.0 | 0.1 | 1.7 | 0.1 | 3.4 | 0.3 | 7.3 |
| Concentrate Sample 2 (Pool) | 30.1 | 90 | 1.1 | 3.6 | 0.1 | 0.3 | 0.9 | 3.1 | 0.4 | 1.3 | 1.5 | 4.9 |
| Concentrate Sample 3 (Pool) | 98.8 | 90 | 3.8 | 3.8 | 1.5 | 1.5 | 4.1 | 4.1 | 0.3 | 0.3 | 5.8 | 5.8 |
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Limit of Blank (LoB), Limit of Detection (LoD) and Limit of Quantitation (LoQ)
LoB, LoD and LoQ studies were performed in accordance with CLSI EP17-A2, using three reagent lots of HemosIL Chromogenic Factor IX on representative members of the ACL TOP Family and ACL TOP Family 50 Series.
The following maximum limits were determined:
| Limit of Blank (LoB) | Limit of Detection (LoD) | Limit of Quantitation (LoQ) |
|---|---|---|
| 0.1% | 0.3% | 0.6% |
Linearity
Linearity studies were performed in accordance with CLSI EP06, 2nd Edition, using three reagent lots of HemosIL Chromogenic Factor IX on a representative member of the ACL TOP Family and one reagent lot on a representative member of the ACL TOP Family 50 Series. The studies support a reportable linear range on the ACL TOP Family and ACL TOP Family 50 Series of 1.0 to 150%.
Interferences and Limitations
Interference studies were performed in accordance with CLSI EP07, 3dd Edition (where applicable), using a minimum of one reagent lot of HemosIL Chromogenic Factor IX on a representative member of the ACL TOP Family or ACL TOP Family 50 Series model. The studies support that results on the ACL TOP Family and ACL TOP Family 50 Series are not affected by the following interferents up to:
| Hemoglobin | 1000 mg/dL |
|---|---|
| Bilirubin (unconjugated) | 40 mg/dL |
| Bilirubin (conjugated) | 40 mg/dL |
| Triglycerides | 1500 mg/dL |
| Unfractionated heparin | 2.0 IU/mL |
| Low molecular weight heparin | 2.0 IU/mL |
| Dabigatran | 5.0 mg/L |
| Rivaroxaban | 0.05 mg/L |
| Fondaparinux | 1.02 mg/L |
| Lupus anticoagulant | dRVVT Screen/Confirm Ratio 1.8 |
Note: Warfarin inhibits vitamin K dependent coagulation factors and interferes with the quantification of factor IX activity.
Due to different methodologies used to assign potency for factor IX replacement therapies, differences between factor IX recovery may exist. For recommendations on monitoring factor IX replacement therapy, refer to current guidance and factor IX replacement therapy prescribing information.
To avoid discrepancies that have been reported, consider performing both a chromogenic and one stage factor IX clotting assay for the laboratory investigation of patients being assessed due to the clinical suspicion of hemophilia B. Results of this test should always be interpreted in conjunction with the patient's medical history, clinical presentation and other findings.
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Normal Reference Interval
A normal reference interval study was performed in accordance with CLSI EP28-A3c on one reagent lot of HemosIL Chromogenic Factor IX with a representative ACL TOP Family instrument. A population of 120 plasma samples from apparently healthy individuals were tested. The nonparametric 95% reference interval with two-sided 90% confidence intervals was calculated as 71.1 to 134.1% (0.7-1.3 IU/mL).
Due to many variables which may affect the results (including the population age), each laboratory should determine its own normal range.
Recovery of Factor IX Replacement Therapies
A recovery study was performed using one reagent lot of HemosIL Chromogenic Factor IX on a representative member of the ACL TOP Family. Immunodepleted FIX deficient plasma was spiked with four factor IX replacement therapies at seven to fourteen concentrations, ranging from 0.5 to 200% and percent recovery was determined. HemosIL Chromogenic Factor IX accurately evaluated the potency of factor IX concentrates including AlphaNine SD, BeneFIX, and Rebinyn.
| Product | Mean Percent Recovery (%) |
|---|---|
| AlphaNine SD | 90 |
| BeneFIX | 93 |
| Rebinyn | 112 |
| Idelvion* | 159 |
- Per the manufacturer's recommendations, a one stage clotting assay is recommended for measurement of Idelvion and results may vary based on the APTT reagent in use.
In-Use Stability and Shelf-life
In-use stability and shelf-life studies were performed in accordance with CLSI EP25-A, using three reagent lots of HemosIL Chromogenic Factor IX on a representative ACL TOP Family model. The studies support the following labeled claims on the ACL TOP Family and ACL TOP Family 50 Series:
- . Reagent A: Stability after reconstitution: 72 hours at 2-8℃ in the closed original vial or 4 months at < - 65°C or 8 hours at 15°C on the ACL TOP Family and ACL TOP Family 50 Series. Frozen reagent may be thawed once and gently mixed before use. Do not refreeze.
- Reagent B: Stability after reconstitution: 72 hours at 2-8℃ in the closed original vial or 4 months at . < - 65°C or 8 hours at 15°C on the ACL TOP Family and ACL TOP Family 50 Series. Frozen reagent may be thawed once and gently mixed before use. Do not refreeze.
- Substrate: Opened reagent is stable 1 month at 2-8°C in the closed original vial or 12 months at ≤ -65°C or 24 hours ● at 15°C on the ACL TOP Family and ACL TOP Family 50 Series. Frozen reagent may be thawed once and gently mixed before use. Do not refreeze.
- Buffer: Opened reagent is stable 12 months at 2-8℃.
- Diluted Buffer: Stability after dilution: 24 hours on the ACL TOP Family and ACL TOP Family 50 Series.
- Shelf-life: 28 Months at 2-8°C
Sample Stability
A sample stability study was performed using one reagent lot of HemosIL Chromogenic Factor IX on a representative ACL TOP Family model or ACL TOP Family 50 Series model. The study supports the following labeled claims on the ACL TOP Family and ACL TOP Family 50 Series:
- Specimens are stable up to 8 hours at 15-25°C and up to 8 hours at 2-8°C. ●
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Multicenter Method Comparison
A multicenter method comparison study was conducted at four sites (three external and one internal) in accordance with CLSI EP09c to compare the accuracy of the HemosIL Chromogenic Factor IX assay relative to the predicate device, HemosIL Factor deficient plasma, on representative members of the ACL TOP Family and ACL TOP Family 50 Series, using samples from patients with von Willebrand disease, patients with hemophilia A and B and patients on factor IX replacement therapy.
| N | r | Slope | Intercept | |||
|---|---|---|---|---|---|---|
| Value | 95% CI | Value | 95% CI | |||
| Site 1 | 105 | 0.927 | 1.023 | 0.977 1.101 | -0.411 | -2.867 1.049 |
| Site 2 | 105 | 0.978 | 0.960 | 0.922 0.995 | -1.977 | -3.298 -0.490 |
| Site 3 | 104 | 0.984 | 1.072 | 1.041 1.105 | -3.161 | -4.713 -1.629 |
| Site 4 | 30 | 0.984 | 1.024 | 0.952 1.110 | 0.592 | -0.818 8.478 |
| Overall | 344 | 0.972 | 1.015 | 0.994 1.037 | -0.920 | -2.064 -0.185 |
The following results were obtained:
| Factor IX (%) | Predicted Bias | Lower CI | Upper CI |
|---|---|---|---|
| 1 | $-0.90$ | $-2.03$ | $-0.19$ |
| 5 | $-0.84$ | $-1.89$ | $-0.17$ |
| 50 | $-0.3%$ | $-2.5%$ | $0.8%$ |
| 100 | $0.6%$ | $-1.4%$ | $2.2%$ |
In the table above, the 1 and 5% results are presented in absolute measured units and the 50 and 100% results are Note: presented in relative units.
An internal method comparison study was performed comparing the performance of the ACL TOP Family 50 Series to the ACL TOP Family using representative systems from both families.
| System | N | Slope | Intercept | r | Reference Method |
|---|---|---|---|---|---|
| ACL TOP Family 50 Series | 126 | 0.980 | 1.731 | 0.998 | ACL TOP Family |
Conclusion
The performance testing results demonstrate that HemosIL Chromogenic Factor IX is substantially equivalent to the predicate device, HemosIL Factor IX deficient plasma (K031829), and that the assay is safe and effective for its labeled intended use.
§ 864.7290 Factor deficiency test.
(a)
Identification. A factor deficiency test is a device used to diagnose specific coagulation defects, to monitor certain types of therapy, to detect coagulation inhibitors, and to detect a carrier state (a person carrying both a recessive gene for a coagulation factor deficiency such as hemophilia and the corresponding normal gene).(b)
Classification. Class II (performance standards).