IDS-iSYS Ostase BAP

{0} FDA U.S. FOOD & DRUG ADMINISTRATION # 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY ## I Background Information: A 510(k) Number K200475 B Applicant Immunodiagnostic Systems Ltd. C Proprietary and Established Names IDS-iSYS Ostase® BAP D Regulatory Information | Product Code(s) | Classification | Regulation Section | Panel | | --- | --- | --- | --- | | CIN | Class II | 21 CFR 862.1050 - Alkaline Phosphatase Or Isoenzymes Test System | CH - Clinical Chemistry | ## II Submission/Device Overview: A Purpose for Submission: New Device B Measurand: Bone-specific alkaline phosphatase (BAP) C Type of Test: Quantitative Enzymatic immunoassay (EIA) Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993-0002 www.fda.gov {1} III Intended Use/Indications for Use: A Intended Use(s): See Indications for Use below. B Indication(s) for Use: The IDS-iSYS Ostase® BAP assay is an in vitro diagnostic device intended for the quantitative determination of bone-specific alkaline phosphatase (BAP), an indicator of osteoblastic activity, in human serum on the IDS system. Results are to be used in conjunction with other clinical and laboratory data to aid the clinician in the management of postmenopausal osteoporosis and Paget’s disease. C Special Conditions for Use Statement(s): Rx - For Prescription Use Only D Special Instrument Requirements: IDS iSYS Multi-Discipline Automated System (k091849) IV Device/System Characteristics: A Device Description: The device is a bone alkaline phosphatase assay that consists of a reagent cartridge and one set of calibrators (CAL A & CAL B). The reagent cartridge contains: MPM1 (Magnetic particles coated with streptavidin in a phosphate buffer with sodium azide as preservative (<0.09%), (1 x 2.6 mL)); Ab-BIOT Monoclonal anti-BAP labelled with biotin, in buffer containing horse serum with bovine and mouse proteins and sodium azide as a preservative (<0.09%), (1 x 10.5 mL)) and SUBS (p-nitrophenyl phosphate in a stabilizing buffer containing preservatives (1 x 40 mL)). B Principle of Operation: The IDS-iSYS Ostase® BAP assay is a quantitative enzyme immunoassay. The serum sample is incubated for 15 min in the presence of an antibody linked to biotin, magnetic particles coated to streptavidin are added and incubated for another 15 min. The BAP/antibody-biotin complex binds to the magnetic particles. These magnetic particles are captured with magnets and washed by the washing buffer used into the IDS system. After that, the magnetic particles containing BAP bound to the antibody are incubated in the presence of p-nitrophenyl phosphate (pNPP) and the absorbance is measured during a short time (300 sec) to obtain the kinetic constant in milli optical density / min at 405 nm. The signal is directly proportional to the amount of BAP present in the original sample. K200475 - Page 2 of 10 {2} V Substantial Equivalence Information: A Predicate Device Name(s): Tandem-MP Ostase Immunoenzymetric Assay B Predicate 510(k) Number(s): k972666 C Comparison with Predicate(s): | Device & Predicate Device(s): | K200475 | K972666 | | --- | --- | --- | | Device Trade Name | IDS-iSYS Ostase® BAP | Tandem-MP Ostase Immunoenzymetric Assay | | General Device Characteristic Similarities | | | | Intended Use/Indications For Use | For quantitative determination of Bone Alkaline Phosphatase concentration, an indicator of osteoblastic activity, in human serum. To be used as an aid in the management of postmenopausal osteoporosis and Paget’s disease. | Same | | Sample Type | Human Serum | Same | | Sample Volume | 50 μL | Same | | Analyte | Bone Alkaline Phosphatase | Same | | General Device Characteristic Differences | | | | Instrument platform | Automated analyzer | Manual microplate assay | | Range of assay | 3 - 70 μg/L | 0.7 - 90 μg/L | VI Standards/Guidance Documents Referenced: CLSI EP05-A3- Evaluation of Precision of Quantitative Measurement Procedures CLSI EP06-A- Evaluation of the Linearity of Quantitative Measurement Procedures: A Statistical Approach CLSI EP17-A2- Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures K200475 - Page 3 of 10 {3} CLSI EP28-A3c- Defining, Establishing, And Verifying Reference Intervals in the Clinical Laboratory CLSI EP25-A- Evaluation of Stability of In Vitro Diagnostics Reagents ## VII Performance Characteristics (if/when applicable): ## A Analytical Performance: ### 1. Precision/Reproducibility: This study was designed based on CLSI EP05-A3 “Evaluation of Precision Performance of Quantitative Measurement Methods”. Ten samples that were individual or pooled serum samples containing endogenous levels of BAP were tested. The samples were assayed in duplicate, twice per day for 20 days on 3 instruments in one laboratory using 3 lots of reagents (n=240 replicates per sample). Results from 3 combined lots: | Sample | N | Mean Conc. (μg/L) | Repeatability | | Within Laboratory | | | --- | --- | --- | --- | --- | --- | --- | | | | | SD (μg/L) | %CV | SD (μg/L) | %CV | | Sample 1 | 240 | 6.2 | 0.2 | 2.8% | 0.4 | 5.9% | | Sample 2 | 240 | 8.7 | 0.1 | 1.7% | 0.5 | 6.2% | | Sample 3 | 240 | 11.7 | 0.3 | 2.5% | 0.8 | 6.6% | | Sample 4 | 240 | 12.5 | 0.3 | 2.4% | 0.9 | 7.1% | | Sample 5 | 240 | 18.4 | 0.4 | 2.4% | 1.3 | 6.8% | | Sample 6 | 240 | 20.6 | 0.5 | 2.5% | 1.5 | 7.2% | | Sample 7 | 240 | 45.5 | 1.0 | 2.3% | 1.4 | 3.0% | | Sample 8 | 240 | 53.2 | 1.1 | 2.1% | 1.8 | 3.4% | | Sample 9 | 240 | 54.7 | 0.9 | 1.7% | 2.1 | 3.9% | | Sample 10 | 240 | 59.8 | 1.1 | 1.9% | 2.3 | 3.8% | Results from one representative lot (Lot #3): | Sample | N | Mean Conc. (μg/L) | Repeatability | | Within Laboratory | | | --- | --- | --- | --- | --- | --- | --- | | | | | SD (μg/L) | %CV | SD (μg/L) | %CV | | Sample 1 | 80 | 6.1 | 0.2 | 2.5% | 0.2 | 2.8% | | Sample 2 | 80 | 8.4 | 0.1 | 1.6% | 0.2 | 2.8% | | Sample 3 | 80 | 11.4 | 0.2 | 2.0% | 0.4 | 3.9% | | Sample 4 | 80 | 12.1 | 0.3 | 2.2% | 0.5 | 4.5% | | Sample 5 | 80 | 18.0 | 0.4 | 2.4% | 0.8 | 4.5% | | Sample 6 | 80 | 19.8 | 0.5 | 2.5% | 0.9 | 4.6% | | Sample 7 | 80 | 45.1 | 1.2 | 2.7% | 1.6 | 3.5% | | Sample 8 | 80 | 52.4 | 1.0 | 1.9% | 1.9 | 3.5% | | Sample 9 | 80 | 54.3 | 0.9 | 1.7% | 1.6 | 2.9% | | Sample 10 | 80 | 58.6 | 1.1 | 1.8% | 1.5 | 2.5% | K200475 - Page 4 of 10 {4} K200475 - Page 5 of 10 2. Linearity: Linearity was evaluated based on CLSI EP06-A guideline. A high human serum sample (70.4 µg/L) and a low human serum sample (2.7 µg/L) were intermixed in different proportions to create 11 evenly spaced dilutions. The results of this study support the claimed reportable range of 3 to 70 µg/L. The linear regression of observed versus the expected concentrations is: $$ y = 0.98 x - 0.9 \, \mathrm{ng/mL}, \, R^2 = 1.00 $$ Dilution Recovery: To validate the labeling instructions that patient samples with BAP levels above the claimed measuring range can be manually diluted 1:2, 4 unique serum samples and 1 contrived sample were tested. The samples were then diluted 1:2 with the IDS-iSYS Diluent B (IS-10B) and assayed for recovery and compared to the expected concentration (as determined by the predicate device). The dilution study results support the sponsor's labeling claims that samples with BAP concentrations above 70 µg/L may be diluted manually to obtain results up to 140 µg/L. | | Expected Conc. µg/L | Observed Conc. µg/L | % Difference | Sample composition | | --- | --- | --- | --- | --- | | Sample 1 | 78.0 | 75.4 | -3% | Native | | Sample 2 | 94.6 | 89.0 | -6% | Native | | Sample 3 | 122.9 | 113.5 | -8% | Contrived* | | Sample 4 | 131.5 | 139.6 | 6% | Native | | Sample 5 | 136.7 | 134.5 | -2% | Native | * Serum sample spiked with a high concentration BAP material prepared from Stock Standard (BAP Antigen) 3. Analytical Specificity/Interference: Potential interference from common endogenous substances was evaluated in accordance with CLSI EP07-A2. To determine interference, two serum samples containing two different concentrations of BAP were spiked with the potential interferent. Control samples (blank) were spiked with a volume of phosphate buffer saline (PBS) (0 ng/mL) or relevant diluent equal to that of the spiked interferent. The differences observed between the mean spiked and control sample values (determined as the mean of 26 replicates) were examined and assessed according to acceptance criteria. Significant interference was defined as greater than 10% difference between spiked and control samples. The following compounds were tested and found not to interfere significantly with the test: {5} | Potential Interfering Substance | Highest concentration tested that demonstrated no significant interference | | --- | --- | | Acetaminophen | 20 mg/dL | | Alendronate | 5 mg/dL | | Bilirubin (Conjugated) | 40 mg/dL | | Bilirubin (Unconjugated) | 40 mg/dL | | Calcium Chloride | 20 mg/dL | | Cholesterol | 325 mg/dL | | Estradiol | 400 μg/mL | | Etidronate | 90 mg/dL | | Haemoglobin | 300 mg/dL | | HAMA | 4000 ng/mL | | Ibuprofen | 40 mg/dL | | Pamidronate | 18 mg/dL | | Progesterone | 25 mg/dL | | PTH 1-34 | 20 μg/dL | | PTH 1-84 | 11.8 μg/dL | | Raloxifene | 20 μg/mL | | Red Blood Cells | 0.3% | | Risedronate | 50 μg/mL | | Salicylic Acid (Asprin) | 50 mg/dL | | Salmon Calcitonin | 112 IU/dL | | Total Protein | 12 g/dL | | Triglycerides | 667 mg/dL | | 25-hydroxyvitamin D | 125 ng/mL | Biotin interference was tested up to 3500 ng/mL in serum samples at low and high concentrations of BAP. Significant interference was defined as greater than 10% difference between spiked and un-spiked samples. The results are summarized in the tables below: % Bias for samples containing various concentrations of Biotin: | | Biotin Concentration (ng/mL) | | | | | | | | | | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | | 250 | 300 | 350 | 400 | 450 | 500 | 750 | 1500 | 2500 | 3500 | | Sample 1 (Low BAP) | 0% | 0% | 1% | -8% | -7% | -3% | -35% | -91% | -93% | -95% | | Sample 2 (High BAP) | NA | NA | NA | -10% | -11% | -13% | NA | NA | NA | NA | NA = not tested K200475 - Page 6 of 10 {6} Rheumatoid Factor (Rf) interference was tested by recovery. A sample with known high levels of rheumatoid factor was spiked into a low and high concentration BAP base sample. The expected BAP concentration of the Rf sample was calculated through dilution series in an undetectable BAP matrix buffer. Lower dilution of Rf sample was included to ensure no interference from the Rf on the value when calculating back to its neat concentration. Significant interference was defined as greater than 10% difference between spiked and un-spiked samples. Rf interference was calculated as below: $$ \% \text{ Interference} = \frac{\text{Observed concentration}}{(\text{Expected conc. from base sample} + \text{Expected conc. from Rf sample})} $$ The results are summarized in the following table: | Highest concentration tested that demonstrated no significant interference: | % Interference | | | | --- | --- | --- | --- | | | | Low sample | High sample | | Rheumatoid Factor (RF) | 1200 IU/mL | 98% | 103% | The cholesterol interference was assessed by recovery where a sample with known cholesterol levels was spiked with 10% and 20% of a high BAP calibrator level. Significant interference was defined as > ±10% recovery. The Total Cholesterol interference was calculated as below: Recovery value = Observed mean spiked value – Observed mean un-spiked value $$ \% \text{ Recovery} = \frac{[\text{Recovery value} / \text{Expected Recovery value (Analyte added})] \times 100}{} $$ The highest cholesterol concentration tested that demonstrated no significant interference was 325 mg/dL. ## Cross-reactivity Studies were conducted according to CLSI EP07-A2 to evaluate the potential cross-reactivity of the assay with placental, intestinal and liver ALP. These exogenous cross-reactants were prepared using a concentrated stock material in matrix containing undetectable BAP and were tested by spiking into serum samples. The % cross-reactivity was calculated based on following equation: $$ \% \text{ cross reactivity} = \frac{(\text{Mean concentration of spiked sample} - \text{mean concentration of un-spiked sample}) \times 100}{\% \text{ Spiked concentration}} $$ Cross reactivity results: | Cross-Reactant | Spiked Concentration | % Cross Reactivity | | --- | --- | --- | | Liver ALP | 750 μg/L | 0.1% | | Placental ALP | 90 U/L | 0.5% | | Intestinal ALP | 500 μg/L | 0.0% | K200475 - Page 7 of 10 {7} K200475 - Page 8 of 10 4. Assay Reportable Range: The reportable range of the assay is 3 to 70 µg/L, and up to 140 µg/L for diluted samples. Any value that reads below 3 µg/L is reported as “< 3 µg/L”. Please see the Linearity and Method Comparison sections and LoQ for details. 5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods): The IDS-iSYS Ostase® BAP kit calibrators are traceable to the predicate device via in house secondary standards (IRs). The sponsor's traceability scheme was reviewed and found acceptable. 6. Detection Limit: The limit of blank (LoB), limit of detection (LoD) and limit of quantitation (LoQ) were determined with following CLSI EP17-A2 guideline. To establish the limit of blank (LoB), each blank sample was measured in duplicate, for a total of five measurements in a five-day period. A total of 60 replicates per lot was used to establish the LoB, where each kit lot was tested on a different instrument. A total of 3 kits lots were tested. Data was analyzed using the parametric statistical method. The LoB was calculated as 0.3 µg/L. The LoD was determined using ten (10) samples with very low BAP concentrations. LoD samples were prepared by diluting human serum with calibrator buffer matrix to achieve 10 sample levels. Each LoD sample was measured in duplicate, for a total of five measurements in a five-day period. Each kit lot was tested on a different instrument. A total of 3 kit lots were tested where 94 replicates, 100 replicates and 100 replicates were tested in Lot 1, Lot2 and Lot 3 respectively. Data was analyzed using the parametric statistical method. The LoD was calculated as 0.4 µg/L. The LoQ was established using ten (10) samples with low BAP concentration ranging from approximately 0.2 µg/L to approximately 0.6 µg/L. Samples were prepared by diluting one human serum sample with calibrator buffer matrix to achieve 10 sample levels. Each LoQ sample was measured in duplicate, for a total of five measurements in a five-day period. Each kit lot was tested on a different instrument. A total of 3 kit lots were tested where 96 replicates, 100 replicates and 100 replicates were used in Lot 1, Lot 2 and Lot 3 respectively. The LoQ was defined based on a precision profile as the concentration where the within-laboratory %CV is 20%. The LoQ was calculated as 0.5 µg/L. | Sensitivity | BAP Concentration (μg/L) | | --- | --- | | LoB (Limit of Blank) | 0.3 | | LoD (Limit of Detection) | 0.4 | | LoQ (Limit of Quantitation) | 0.5 | {8} Any value that reads below $3\ \mu\mathrm{g}/\mathrm{L}$ is reported as $< 3\ \mu\mathrm{g}/\mathrm{L}$. 7. Assay Cut-Off: Not Applicable. B Comparison Studies: 1. Method Comparison with Predicate Device: A total of 160 serum samples were measured by the predicate and candidate methods. For the predicate device, the mean of duplicates was calculated and reported for each sample as per the predicate’s instructions for use. For the candidate device, duplicate analysis was performed and the first singlicate result was used for analysis. Ten samples were excluded from analysis because either samples were above or below the candidate measuring range, and or predicate measuring range, or samples were tested in singlicate in the predicate device. A total of 150 samples were included in the final analysis. Of these, 19 (13%) were contrived (diluted in the undetectable BAP buffer matrix or spiked with BAP High Concentrated material) to ensure the full measuring range was covered. The BAP concentrations ranged from 2.5 to $66.0\ \mu\mathrm{g}/\mathrm{L}$, as measured by the predicate device. Passing-Bablok regression analysis was performed on the data, giving following results: | N | Slope | 95% CI | Intercept (μg/L) | 95% CI | Corr. Coefficient (r) | | --- | --- | --- | --- | --- | --- | | 150 | 0.99 | 0.97 to 1.02 | 0.17 | -0.1 to 0.5 | 0.99 | 2. Matrix Comparison: Not Applicable. The assay is intended for use only with serum samples. C Clinical Studies: 1. Clinical Sensitivity: Not Applicable 2. Clinical Specificity: Not Applicable 3. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable): Not Applicable D Clinical Cut-Off: Not Applicable K200475 - Page 9 of 10 {9} E Expected Values/Reference Range: The BAP concentration was measured in serum samples collected from 419 apparently healthy donors from the United States using the IDS Ostase® BAP assay. The study population included 140 males (35 to 75 years of age), 140 pre-menopausal women (35 to 45 years of age) and 139 post-menopausal women (55 to 75 years of age). The observed ranges (2.5th to 97.5th percentile) were established following CLSI guideline C28-A3c, "How to Define and Determine Reference Intervals in the Clinical Laboratory". Results are summarized in the below table: | Population | n | Age (years) | | BAP Concentration (μg/L) | | | | | --- | --- | --- | --- | --- | --- | --- | --- | | | | Median | Min.-Max | Mean | Median | SD | Observed Range | | Males | 140 | 49 | 35 to 75 | 13.7 | 13.0 | 4.1 | 7.9 to 23.5 | | Pre-menopausal | 140 | 39 | 35 to 45 | 11.5 | 11.1 | 3.9 | 5.9 to 20.5 | | Post-menopausal | 139 | 58 | 55 to 75 | 15.7 | 14.3 | 6.7 | 7.9 to 34.2 | VIII Proposed Labeling: The labeling does support the finding of substantial equivalence for this device. IX Conclusion: The submitted information in this premarket notification is substantially equivalent. K200475 - Page 10 of 10