(170 days)
The Banyan BTI is an in vitro diagnostic chemiluminescent enzyme-linked immunosorbent assay (ELISA). The assay provides a semi-quantitative measurement of the concentrations of ubiquitin C-terminal hydrolase-L1 (UCH-L1) and glial fibrillary acidic protein (GFAP) in human serum, and is used with the Synergy 2 Multi-mode Reader.
The assay results obtained from serum collected within 12 hours of suspected head injury are used, along with other available clinical information, to aid in the evaluation of patients 18 years of age and older with suspected traumatic brain injury (Glasgow Coma Scale score 13-15). A negative assay result is associated with the absence of acute intracranial lesions visualized on a head CT (computed tomography) scan.
The Banyan BTI is for prescription use only.
The Banyan BTI consists of two kits, one for the UCH-L1 assay components and one for GFAP assay components. Each kit is packaged individually in a box and consists of the following: 96-well microtiter strip plate, each well coated with mouse monoclonal UCH-L1 antibody or mouse monoclonal GFAP capture antibody (1 plate); UCH-L1 or GFAP calibrators (1 vial); UCH-L1 or GFAP calibrator diluent (1 vial, 4 mL); UCH-L1 or GFAP control 1 (1 vial); UCH-L1 or GFAP control 2 (1 vial); mouse monoclonal UCH-L1 or mouse monoclonal GFAP detection antibody (1 vial, 0.23 mL); UCH-L1 or GFAP detection antibody diluent (2 vials, 6.5 mL per vial for UCH-L1 or 1 vial, 14 mL for GFAP); ready-to-use assay diluent (2 vials, 5 mL per vial for UCH-L1 or 1 vial, 10 mL for GFAP), chemiluminescent substrate solution A (2 vials, 4.5 mL per vial) and solution B (2 vials, 4.5 mL per vial); a wash tablet and four adhesive plate seals. Components within the same kit are intended to be used together. In each kit, sufficient quantities of each component are provided to test samples from up to 30 patients. Each kit is stored at 2°C to 8°C until ready for use.
Here's an analysis of the Banyan Brain Trauma Indicator (BTI) based on the provided document, addressing each of your points:
1. A table of acceptance criteria and the reported device performance
The document doesn't explicitly state "acceptance criteria" in a single table with performance targets. Instead, it describes various performance evaluations and their results, implying that the observed performance met the manufacturer's pre-determined acceptance criteria (as stated under "Analytical performance: All results met the manufacturer's pre-determined acceptance criteria.").
However, we can infer some key acceptance criteria for clinical performance based on the discussion of clinical validity and Special Controls. The FDA's classification specifies that the device must demonstrate clinical sensitivity and specificity, and positive and negative predictive value.
Here's a table summarizing the clinical performance and related analytical performance highlights:
| Acceptance Criterion (Inferred from regulatory requirements and study design) | Reported Device Performance (Banyan BTI) |
|---|---|
| Clinical Performance | |
| Pivotal Clinical Trial (ALERT-TBI) | |
| Clinical Sensitivity (ability to correctly identify CT-positive cases) | 97.5% (117/120) (95% CI: 92.9-99.5) |
| Clinical Specificity (ability to correctly identify CT-negative cases) | 36.5% (666/1827) (95% CI: 34.2-38.7) |
| Negative Predictive Value (NPV) (probability that a negative result is truly negative) | 99.6% (666/669) (95% CI: 98.7-99.9) |
| Positive Predictive Value (PPV) (probability that a positive result is truly positive) | 9.2% (117/1278) (95% CI: 7.6-10.9) |
| Analytical Performance (Key Highlights) | |
| Precision/Reproducibility | |
| Within-laboratory precision (UCH-L1) | %CV generally between 2-5% across range |
| Within-laboratory precision (GFAP) | %CV generally between 3-10% across range |
| Qualitative precision (% Correct Call) (UCH-L1) | 100% (except 95% at one panel member due to proximity to cutoff) |
| Qualitative precision (% Correct Call) (GFAP) | 100% (except 65% at one panel member due to proximity to cutoff) |
| Semi-quantitative internal reproducibility (e.g., between-operator/lot) | %CV generally between 4-16% (UCH-L1) and 4-10% (GFAP) |
| Qualitative internal reproducibility (% Correct Call) | 95-100% (GFAP Panel 2: 96%) |
| Semi-quantitative external reproducibility (site-to-site) | %CV generally between 3-7% (UCH-L1) and 3-10% (GFAP) |
| Qualitative external reproducibility (% Correct Call) | 92-100% (UCH-L1 Panel 2: 92%) |
| Linearity/Assay Reportable Range | |
| UCH-L1 Linear Range | 80 pg/mL - 2560 pg/mL (y=0.97x-4.7, R=0.99) |
| GFAP Linear Range | 10 pg/mL - 320 pg/mL (y=0.92x+0.14, R=0.99) |
| Hook Effect | No false negatives observed (run aborts interpreted as 'Above' cutoff) |
| Detection Limit | |
| UCH-L1 LLoQ/ULoQ (%CV |
§ 866.5830 Brain trauma assessment test.
(a)
Identification. A brain trauma assessment test is a device that consists of reagents used to detect and measure brain injury biomarkers in human specimens. The measurements aid in the evaluation of patients with suspected mild traumatic brain injury in conjunction with other clinical information to assist in determining the need for head imaging per current standard of care.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The 21 CFR 809.10(b) compliant labeling must include detailed descriptions of and results from performance testing conducted to evaluate precision, accuracy, linearity, analytical sensitivity, interference, and cross-reactivity. This information must include the following:
(i) Performance testing of device precision must, at minimum, use one unmodified clinical specimen from the intended use population with concentration of the brain injury biomarker(s) near the medical decision point. Contrived specimens that have been generated from pooling of multiple samples or spiking of purified analyte to cover the measuring range may be used, but the contrived samples must be prepared to mimic clinical specimens as closely as possible. This testing must evaluate repeatability and reproducibility using a protocol from an FDA-recognized standard.
(ii) Device performance data must be demonstrated through a clinical study and must include the following:
(A) Data demonstrating clinical validity including the clinical sensitivity and specificity, and positive and negative predictive value of the test in the intended use population of patients with suspected mild traumatic brain injury (
i.e., Glasgow Coma Score (GCS) of 13-15), or equivalent standard of care for determination of severity of traumatic brain injury (TBI).(B) Study must be performed using the operators and in settings that are representative of the types of operators and settings for which the device is intended to be used.
(C) All eligible subjects must meet the well-defined study inclusion and exclusion criteria that define the intended use population. The prevalence of diseased or injured subjects in the study population must reflect the prevalence of the device's intended use population, or alternatively, statistical measures must be used to account for any bias due to enrichment of subpopulations of the intended use population.
(D) All eligible subjects must have undergone a head computerized tomography (CT) scan or other appropriate clinical diagnostic standard used to determine the presence of an intracranial lesion as part of standard of care and must also be evaluated by the subject device. All clinical diagnostic standards used in the clinical study must follow standard clinical practice in the United States.
(E) Relevant demographic variables and baseline characteristics including medical history and neurological history. In addition, head injury characteristics, neurological assessments, and physical evidence of trauma must be provided for each subject. This information includes but is not limited to the following: Time since head injury, time from head injury to CT scan, time from head injury to blood draw, GCS score or equivalent, experience of loss of consciousness, presence of confusion, episodes of vomiting, post-traumatic amnesia characteristics, presence of post-traumatic seizures, drug or alcohol intoxication, mechanism of injury, acute intracranial lesion type, neurosurgical lesion, and cranial fracture.
(F) Each CT scan or other imaging result must be independently evaluated in a blinded manner by at least two board-certified radiologists to determine whether it is positive or negative as defined by the presence or absence of acute intracranial lesions. This independent review must be conducted without access to test results of the device. Prior to conducting the review, the criteria and procedures to be followed for scoring the images must be established, including the mechanism for determining consensus.
(G) All the clinical samples must be tested with the subject device blinded to the TBI status and the neurological-lesion-status of the subject.
(H) Details on how missing values in data are handled must be provided.
(I) For banked clinical samples, details on storage conditions and storage period must be provided. In addition, a specimen stability study must be conducted for the duration of storage to demonstrate integrity of archived clinical samples. The samples evaluated in the assay test development must not be used to establish the clinical validity of the assays.
(iii) Performance testing of device analytical specificity must include the most commonly reported concomitant medications present in specimens from the intended use population. Additionally, potential cross-reacting endogenous analytes must be evaluated at the highest concentration reported in specimens from the intended use population.
(iv) Expected/reference values generated by testing a statistically appropriate number of samples from apparently healthy normal individuals.
(2) The 21 CFR 809.10(a) and (b) compliant labeling must include the following limitations:
(i) A limiting statement that this device is not intended to be used a stand-alone device but as an adjunct to other clinical information to aid in the evaluation of patients who are being considered for standard of care neuroimaging.
(ii) A limiting statement that reads “A negative result is generally associated with the absence of acute intracranial lesions. An appropriate neuroimaging method is required for diagnosis of acute intracranial lesions.”
(iii) As applicable, a limiting statement that reads “This device is for use by laboratory professionals in a clinical laboratory setting.”