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510(k) Data Aggregation
(115 days)
OSTEX INTL., INC.
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(125 days)
OSTEX INTL., INC.
Osteomark® NTx Serum EIA provides a quantitative measure of cross-linked Ntelopeptides of type I collagen (NTx) in serum as an indicator of human bone resorption. Serum NTx level is used to aid in predicting skeletal response (bone mineral density) to antiresorptive therapy and in monitoring bone resorption changes following initiation of antiresorptive therapy. Prior to initiating antiresorptive therapy, serum NTx level is used to determine the probability for a decrease in bone mineral density after one year in postmenopausal women treated with hormonal antiresorptive therapy relative to those treated with calcium supplement.
The Osteomark NTx Serum EIA is a competitive-inhibition enzyme-linked immunosorbent assay (ELISA/EIA) for quantitative determination of NTx present in human serum. NTx is adsorbed to a 96-well microplate: Diluted samples are added to the microplate wells, followed by a horseradish peroxidase labeled monoclonal antibody. NTx in the specimen competes with the NTx epitope on the microtiter plate for antibody binding sites. Following a wash step, the amount of labeled antibody bound is measured by colorimetric generation of a peroxide substrate. NTx concentration is determined spectrophotometrically and calculated using a standard calibration curve. Assay values are reported in nanomoles Bone Collagen Equivalents per liter (nM BCE).
The Osteomark NTx Serum EIA is a competitive-inhibition enzyme-linked immunosorbent assay (ELISA/EIA) designed for the quantitative determination of NTx in human serum. This assay is used to predict skeletal response to antiresorptive therapy and to monitor changes in bone resorption after therapy initiation. It also helps determine the probability of bone mineral density decrease in postmenopausal women on hormonal antiresorptive therapy versus those on calcium supplements.
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Intra-assay variability | Not explicitly stated as "acceptance criteria," but the study established this metric. | 2.6% (measured by testing four human serum specimens distributed throughout the calibration range) |
| Inter-assay variability | Not explicitly stated as "acceptance criteria," but the study established this metric. | 6.9% (measured by testing eight human serum specimens distributed throughout the calibration range) |
| Total assay precision (Level I Serum Control) | Not explicitly stated as "acceptance criteria," but the study established this metric. | 13.99% Coefficient of Variation |
| Total assay precision (Level II Serum Control) | Not explicitly stated as "acceptance criteria," but the study established this metric. | 11.92% Coefficient of Variation |
| Antigen Recovery | Not explicitly stated as "acceptance criteria," but the study established this metric. | 100% average recovery (across the assay range) |
| Dilutional Linearity | Not explicitly stated as "acceptance criteria," but the study established this metric. | 98% average linearity |
| Prediction of BMD decrease (high baseline NTx, no HRT) | Not explicitly stated as "acceptance criteria," but implicitly shown as a significant risk factor. | A high baseline NTx (≥18.1 nM BCE) indicated a 6 times higher risk of BMD loss if not treated with HRT. |
| Monitoring response to HRT | Not explicitly stated as "acceptance criteria," but implicitly shown as a significant decrease in NTx levels. | Mean values fell significantly after 3 months of HRT (from 15.9 nM BCE to 12.2 nM BCE, a -22.9% decrease). |
| Monitoring response to Bisphosphonate | Not explicitly stated as "acceptance criteria," but implicitly shown as a significant decrease in NTx levels. | Mean values after 6 months of alendronate treatment (11.0 nM BCE) were significantly lower than baseline (16.1 nM BCE). |
| Correlation with greater BMD gain | Not explicitly stated as "acceptance criteria," but implicitly shown as a significant correlation. | Subjects with highest baseline NTx (≥16.6 nM BCE) had the greatest gain in PA spine BMD (5.76%) with alendronate. |
2. Sample Size Used for the Test Set and Data Provenance
The document describes several studies:
- Reference Range Studies:
- Premenopausal Women: N = 257 (multi-center, cross-sectional study at five regional sites). The country of origin is not specified but implied to be the US given the FDA submission. This was a prospective study to determine reference ranges.
- Men: N = 176 (multi-center, cross-sectional study at three regional sites). The country of origin is not specified but implied to be the US. This was a prospective study to determine reference ranges.
- Intra-subject Variability Studies:
- Postmenopausal Women: n=271 (short-term), n=261 (long-term). Provenance not specified. Retrospective/Prospective not specified for this specific study, but the overall context suggests prospective data collection in clinical settings.
- Men: n=32 (short-term), n=27 (long-term). Provenance not specified. Retrospective/Prospective not specified for this specific study.
- Assay Reproducibility and Precision Studies:
- Intra-assay variability: Four human serum specimens. Provenance not specified. Not directly tied to a clinical population, but rather assay samples.
- Inter-assay variability: Eight human serum specimens. Provenance not specified. Not directly tied to a clinical population, but rather assay samples.
- Total assay precision: Level I Serum Control and Level II Serum Control tested at four clinical laboratories. Provenance not specified. These are control materials, not patient samples.
- Antigen Recovery: Nine serum specimens. Provenance not specified. These are assay samples.
- Dilutional Linearity: Five serum specimens. Provenance not specified. These are assay samples.
- Clinical Studies (HRT):
- Postmenopausal Women treated with HRT: The study enrolled a cohort of postmenopausal women. The baseline NTx mean was 15.9 nM BCE. Post-treatment mean was 12.2 nM BCE. While a specific N for the HRT group is not provided in this summary, the context suggests a clinical trial. The study results (Reference 4) indicate the source is likely from U.S. clinical trials. This was a prospective clinical trial.
- Clinical Studies (Bisphosphonate):
- Postmenopausal Women treated with Bisphosphonate: The study was conducted at a regional specialty hospital in the northeast United States. The study was randomized and double-blind. N is not explicitly stated in the summary, but it involved women randomized to either placebo or alendronate. This was a prospective clinical trial.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Those Experts
The document does not describe the use of human "experts" to establish ground truth for the device performance studies in the traditional sense of a diagnostic interpretation.
For the clinical efficacy studies (HRT and Bisphosphonate), the "ground truth" was clinical outcomes:
- Bone Mineral Density (BMD) changes: Measured by objective methods (e.g., DEXA scans) over time. This is an objective clinical measurement, not expert consensus on an image or test result.
- Response to therapy: Defined by changes in NTx levels and subsequent changes in BMD.
4. Adjudication Method for the Test Set
Not applicable. The reported studies evaluate the analytical performance of the assay and its correlation with clinical outcomes (BMD changes), not the interpretation of results by human readers requiring adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. The Osteomark NTx Serum EIA is an in-vitro diagnostic assay for quantitative measurement. It does not involve human readers interpreting images or data where AI assistance would be relevant for a MRMC study.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
Yes, implicitly. The performance characteristics (variability, recovery, linearity) and the clinical utility of the assay itself (e.g., "Osteomark NTx Serum EIA mean baseline values... fell significantly after 3 months of therapy") are reported as standalone performance of the diagnostic kit. There is no human-in-the-loop component for the assay's execution or the interpretation of the numerical NTx values for these studies. The physician uses the derived NTx value in clinical management.
7. Type of Ground Truth Used
- Analytical Performance: The ground truth for analytical performance (variability, recovery, linearity) is based on established laboratory analytical methods and expected theoretical values for spiked samples or diluted controls.
- Clinical Studies: The ground truth for the clinical studies (HRT and Bisphosphonate) is outcomes data and objective clinical measurements:
- Bone Mineral Density (BMD) assessed after one year.
- Changes in NTx levels post-therapy. This is an outcome of the intervention, not an externally established ground truth for the device itself.
8. Sample Size for the Training Set
The document describes the device performance validation and clinical studies. There is no description of a "training set" in the context of machine learning (AI) for this diagnostic assay. The terms "training set" and "test set" are not applicable in the typical AI sense to this type of in-vitro diagnostic device. Instead, the studies cited relate to establishing reference ranges and validating analytical and clinical performance.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as no "training set" in the AI sense is described. The analytical and clinical performance data were established through direct laboratory measurements and clinical trial outcomes, respectively, as outlined above.
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(49 days)
OSTEX INTL., INC.
Osteomark is a urinary assay that provides a quantitative measure of the excretion of cross-linked N-telopeptides of type I collagen (NTx) as an indicator of human bone resorption. Elevated levels of urinary NTx indicate elevated human bone resorption. Measurement of NTx is intended for use in:
A. Predicting skeletal response (bone mineral density) to hormonal antiresorptive therapy in postmenopausal women.
B. Therapeutic monitoring of:
-
- antiresorptive therapies in postmenopausal women
-
- antiresorptive therapies in individuals diagnosed with osteoporosis
-
- antiresorptive therapies in individuals diagnosed with Paget's disease of bone
- estrogen-suppressing therapies
C. Assessing the relative risk for loss of spinal bone mass after one year if not treated with hormonal antiresorptive therapy
Osteomark is a competitive enzyme-linked immunosorbent assay (ELISA) which utilizes a horseradish peroxidase labeled monoclonal antibody directed against the cross-linked N-telopeptides (NTx) present in urine specimens. An Osteomark® kit is comprised of the following reagents:
Antigen Coated 96-Well Plate Calibrators: 1 nM BCE 30 nM BCE 100 nM BCE 300 nM BCE 1000 nM BCE 3000 nM BCE Antibody Conjugate Concentrate Antibody Conjugate Diluent Level I and Level II Urine Controls 30X Wash Concentrate Buffered Substrate Chromogen Reagent Stopping Reagent
The solid phase utilizes microwells onto which NTx has been adsorbed. NTx in the specimen or Calibrator competes with the solid phase NTx for antibody binding sites. The resulting amount of Antibody Conjugate bound to the solid phase is indirectly proportional to the amount of NTx in the specimen or Calibrator. The quantity of NTx in the specimen is determined from a standard calibration curve using reagents supplied in the kit. Assay values are standardized to an equivalent amount of bone collagen, and are expressed in nanomole bone collagen equivalents per liter (nM BCE). BCE reflects the amount of immunoreactive NTx, as measured by Osteomark, liberated from human bone collagen following digestion with bacterial collagenase, as measured by hydroxyproline by high performance liquid chromatography (HPLC).
Here's an analysis of the provided text, outlining the acceptance criteria and the studies performed for the Osteomark® device:
Acceptance Criteria and Device Performance Study for Osteomark®
The Osteomark® device is a urinary assay designed to quantitatively measure N-telopeptides of type I collagen (NTx) as an indicator of human bone resorption. The provided documentation details several performance characteristics and studies that likely served as the basis for acceptance criteria.
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state acceptance criteria with defined pass/fail thresholds for a regulatory submission. Instead, it presents performance characteristics and reference ranges derived from studies. Based on the "Performance Characteristics" section, we can infer the following:
| Acceptance Criteria (Inferred) | Reported Device Performance |
|---|---|
| Expected Values: | |
| Premenopausal Women (mean age 36) | Mean: 35 nM BCE/mmol creatinine, Std Dev: 15, Range: 9-84 |
| Postmenopausal Women ( |
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(80 days)
OSTEX INTL., INC.
Osteomark® is a urinary assay that provides a quantitative measure of the excretion of crosslinked N-telopeptides of type I collagen (NTx) as an indicator of human bone resorption. Elevated levels of urinary NTx indicate elevated human bone resorption. Measurement of NTx is intended for use in:
A. Predicting skeletal response (bone mineral density) to hormonal antiresorptive therapy in postmenopausal women
B. Therapeutic monitoring of:
-
- anti-resorptive therapies in postmenopausal women
-
- anti-resorptive therapies in individuals diagnosed with osteoporosis
-
- anti-resorptive therapies in individuals diagnosed with Paget's disease of bone
-
- estrogen-suppressing therapies
The measurement range of Osteomark is 20 to 3000 nM Bone Collagen Equivalents (BCE) of NTx.
Osteomark is a competitive enzyme-linked immunosorbent assay (ELISA) which utilizes a horseradish peroxidase labeled monoclonal antibody directed against the cross-linked Ntelopeptides (NTx) present in urine specimens. An Osteomark® kit is comprised of the following reagents:
Antigen Coated 96-Well Plate Calibrators: 1 nM BCE 30 nM BCE 100 nM BCE 300 nM BCE 1000 nM BCE 3000 nM BCE Antibody Conjugate Concentrate Antibody Conjugate Diluent Level I and Level II Urine Controls 30X Wash Concentrate Buffered Substrate Chromogen Reagent Stopping Reagent
The solid phase utilizes microwells onto which NTx has been adsorbed. NTx in the specimen or Calibrator competes with the solid phase NTx for antibody binding sites. The resulting amount of Antibody Conjugate bound to the solid phase is indirectly proportional to the amount of NTx in the specimen or Calibrator. The quantity of NTx in the specimen is determined from a standard calibration curve using reagents supplied in the kit. Assay values are standardized to an equivalent amount of bone collagen, and are expressed in nanomole bone collagen equivalents per liter (nM BCE). BCE reflects the amount of immunoreactive NTx, as measured by Ostcomark, liberated from human bone collagen following digestion with bacterial collagenase, as measured by hydroxyproline by high performance liquid chromatography (HPLC).
Acceptance Criteria and Device Performance for Osteomark®
This response synthesizes information from the provided text to describe the acceptance criteria and the studies that prove the Osteomark® device meets these criteria.
1. Table of Acceptance Criteria and Reported Device Performance
Given that Osteomark is a diagnostic assay, acceptance criteria typically revolve around its analytical and clinical performance in fulfilling its intended use. Here's a table based on the provided data:
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Analytical Performance | |
| Lower Limit of Detection (LLOD) | 20 nM BCE |
| Intra-assay Variability | Average 8% CV (range 5-19% CV) |
| Inter-assay Variability | Average 4% CV (range 3-5% CV) |
| Antigen Recovery | Average 105% (over 200-2500 nM BCE range) |
| Dilutional Linearity | Correlation coefficients of r=0.999 to 1.000 (over 44-2940 nM BCE range) |
| Clinical Performance (Predicting Skeletal Response to HRT) | |
| Sensitivity for >30% decrease in Osteomark predicting positive BMD response | 80% (95% C.I. 70%, 88%) |
| Specificity for >30% decrease in Osteomark predicting positive BMD response | 59% (95% C.I. 36%, 79%) |
| Predictive Value Positive (PVP) for 30% change (at 80% prevalence) | 88.6% |
| Predictive Value Negative (PVN) for 30% change (at 80% prevalence) | 42.4% |
| Association between baseline Osteomark and risk of BMD loss without HRT | High baseline Osteomark (≥67 nM BCE/mM creatinine) indicated 17.3 times higher risk of spine BMD loss without HRT. |
| Clinical Performance (Monitoring Estrogen Suppressing Therapy) | |
| Mean increase in Osteomark during estrogen suppression | 68% increase from baseline (correlated with -3.7% decrease in lumbar spine BMD) |
| Percentage of subjects with ≥30% increase in Osteomark during estrogen suppression | 63% (55/88) |
| Clinical Performance (Monitoring Anti-Resorptive Therapy in Paget's Disease) | |
| Clinically significant change (≥30%) in Osteomark achieved (all therapies) | Yes, at each timepoint (Month 1, 3, 6) |
| Correlation with total alkaline phosphatase | High positive correlation at baseline and 6 months (r=0.72-0.88, p=0.0001-0.0003) |
| Earlier assessment of therapeutic response compared to total alkaline phosphatase | Osteomark showed 19% responders at Month 1 vs. 2% for total alkaline phosphatase |
| Clinical Performance (Monitoring Anti-Resorptive Therapy in Osteoporosis) | |
| Percentage of alendronate group with Osteomark 40% decrease at 3 months | 87% (76/87) |
2. Sample Sizes and Data Provenance
The document provides details for several studies:
- Reference Range Determination (Premenopausal Women):
- Sample Size: 258 women
- Data Provenance: Multi-center, cross-sectional study; likely prospective for urine collection after study definition.
- Reference Range Determination (Men):
- Sample Size: 81 men
- Data Provenance: Study conducted at a large reference laboratory. Implied prospective since it's for reference range establishment.
- Within-Subject Variability:
- Sample Size: 8 healthy subjects
- Data Provenance: Urine specimens collected every 2-3 days over 2 months. Prospective.
- Intra-assay Variability:
- Sample Size: 8 urine specimens, each tested in replicates of 10.
- Data Provenance: Not specified, likely internal lab testing.
- Inter-assay Variability:
- Sample Size: 3 urine specimens, each tested in duplicate over 20 separate assay runs.
- Data Provenance: Not specified, likely internal lab testing.
- Antigen Recovery:
- Sample Size: 3 normal urine specimens.
- Data Provenance: Not specified, likely internal lab testing.
- Dilutional Linearity:
- Sample Size: 4 urine specimens.
- Data Provenance: Not specified, likely internal lab testing.
- Clinical Study: Predicting Skeletal Response & Monitoring HRT in Postmenopausal Women:
- Sample Size (completed study): 227 women (109 HRT group, 118 calcium group)
- Data Provenance: Multi-center, randomized, prospective clinical trial. (Campodarve et. al., 1995)
- Clinical Study: Monitoring Estrogen Suppressing Therapy:
- Sample Size: Not explicitly stated for all analyses, but for percent change analysis: 88 subjects (55/88 had ≥30% change, 33/88 had
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