BioFire Respiratory Panel 2.1 (RP2.1)

• K Number: DEN200031
• Device Name: BioFire Respiratory Panel 2.1 (RP2.1)
• Manufacturer: Biofire Diagnostics, LLC
• Date Cleared: 2021-03-17 ( 302 days)
• Product Code: QOF
• Regulation Number: 866.3981
• Type: Direct
• Panel: MI
• Reference & Predicate Devices: K170604

Intended Use

The BioFire Respiratory Panel 2.1 (RP2.1) is a PCR-based multiplexed nucleic acid test intended for use with the BioFire FilmArray 2.0 or BioFire FilmArray Torch systems for the simultaneous qualitative detection and identification of multiple respiratory viral and bacterial nucleic acids in nasopharyngeal swabs (NPS) obtained from individuals suspected of respiratory tract infections, including COVID-19.

The following organism types and subtypes are identified using the BioFire RP2.1:

• Adenovirus, ●
• Coronavirus 229E. ●
• Coronavirus HKU1, ●
• Coronavirus NL63, ●
• Coronavirus OC43.
• Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2), ●
• Human Metapneumovirus.
• Human Rhinovirus/Enterovirus,
• Influenza A, including subtypes H1, H1-2009, and H3, ●
• Influenza B,
• Parainfluenza Virus 1,
• Parainfluenza Virus 2,
• Parainfluenza Virus 3, ●
• Parainfluenza Virus 4. ●
• Respiratory Syncytial Virus, ●
• Bordetella parapertussis (IS1001),
• Bordetella pertussis (ptxP), ●
• Chlamydia pneumoniae, and ●
• Mycoplasma pneumoniae ●

Nucleic acids from the respiratory viral and bacterial organisms identified by this test are generally detectable in NPS specimens during the acute phase of infection. The detection and identification of specific viral and bacterial nucleic acids from individuals exhibiting signs and/or symptoms of respiratory infection is indicative of the presence of the identified microorganism and aids in the diagnosis of respiratory infection if used in conjunction with other clinical and epidemiological information. The results of this test should not be used as the sole basis for diagnosis, treatment, or other patient management decisions.

Negative results in the setting of a respiratory illness may be due to infection with pathogens that are not detected by this test, or lower respiratory tract infection that may not be detected by an NPS specimen. Positive results do not rule out coinfection with other organisms. The agent(s) detected by the BioFire RP2.1 may not be the definite cause of disease. Additional laboratory testing (e.g. bacterial and viral culture, immunofluorescence, and radiography) may be necessary when evaluating a patient with possible respiratory tract infection.

Device Description

The BioFire Respiratory Panel 2.1 is designed to simultaneously identify 22 different potential pathogens of the respiratory tract infection, including the novel coronavirus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), from a single NPS specimen in transport medium or saline. BioFire RP2.1 is compatible with BioFire's PCR-based in vitro diagnostic BioFire FilmArray 2.0 and BioFire FilmArray Torch systems for infectious disease testing. A specific software module (i.e., BioFire RP2.1 Pouch Module Software) is used to perform BioFire RP2.1 testing on these systems.

The RP2.1 reagent kit contains all the materials required to complete tests and includes the RP2.1 pouch, hydration solution, sample buffer, and sample handling components such as transfer pipettes. The RP2.1 pouches are used to test patient samples and is a closed-system disposable that stores all the necessary reagents for sample preparation reverse transcription. polymerase chain reaction (PCR), and detection in order to isolate, amplify, and detect nucleic acid from multiple pathogens within a single NPS specimen. The rigid plastic component ("fitment") of the pouch contains reagents in freeze-dried form. The flexible plastic portion of the pouch is divided into discrete segments ("blisters") where the required chemical processes are carried out. After sample collection, the user injections hydration solution and sample combined with BioFire Sample Buffer into the pouch, places the pouch into a FilmArray instrument, and starts the run. All other operations are automated.

The FilmArray instruments (FilmArray 2.0 and FilmArray Torch systems) interact with the pouch mechanically, thermally, and optically to drive the multi-step chemical process required for purification and detection of specific nucleic acid targets from the patient sample. FilmArray instruments follow a protocol defined in the BioFire RP2.1 Pouch Module Software that is downloaded from the host computer prior to runtime. The instrument protocol defines the specific sequence of the testing process, including the times and temperatures, as the instrument performs bead-based extraction/isolation/purification of nucleic acids, performs reverse transcription and a 2-stage nested PCR reaction, executes DNA melt and fluorescent signal detection, and monitors system performance in real time, and communicates results and errors to the user via software. The primary difference between the FilmArray 2.0 and FilmArray Torch systems is the external configuration of multiple modules in a system. Up to eight FilmArray 2.0 modules can be connected to one computer and pouch loading station, while up to 12 FilmArray Torch modules can be connected to one system base in a vertical stack to a computer and pouch loading station. In addition, the pouches are front-loaded via an automated mechanism for the Torch system whereas the pouches are manually inserted, removed, and there is pouch and lid sensing in the FilmArray 2.0.

Once a test run is completed, the software automatically interprets the results and displays a test report. The report can be printed and/or saved as a file. The test report is a single page containing three sections: Run Summary, Result Summary, and Run Details. An additional section, Change Summary, is present in specific situations. The overall layout of the report was previously described in the BioFire RP2 510(k) [K170604] and remains unchanged for the BioFire RP2.1.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study proving the BioFire Respiratory Panel 2.1 (RP2.1) meets those criteria, based on the provided text.

Acceptance Criteria and Reported Device Performance

The acceptance criteria are generally implied by the successful performance demonstrated in the various analytical and clinical studies. For qualitative tests like this, the key performance metrics are sensitivity (Positive Percent Agreement - PPA) and specificity (Negative Percent Agreement - NPA). The reproducibility study also defines implicit acceptance for consistent detection.

Table of Acceptance Criteria and Reported Device Performance (Summary for SARS-CoV-2 - a key new analyte)

Performance Metric	Acceptance Criteria (Implicit)	Reported Device Performance (SARS-CoV-2)
Prospective Clinical Study
PPA (Sensitivity)	High agreement (e.g., >95%)	98.4% (61/62) with 95% CI: 91.4-99.7%
NPA (Specificity)	High agreement (e.g., >95%)	98.9% (457/462) with 95% CI: 97.5-99.5%
Retrospective Clinical Study
PPA (Sensitivity)	High agreement (e.g., >95%)	98.0% (48/49) with 95% CI: 89.3-99.6%
NPA (Specificity)	High agreement (e.g., >95%)	100% (49/49) with 95% CI: 92.7-100%
Contrived Clinical Specimen Study
PPA (Sensitivity)	High agreement (e.g., 100%)	100% (50/50) with 95% CI: 92.9-100%
NPA (Specificity)	High agreement (e.g., 100%)	100% (10/10) with 95% CI: 72.2-100%
Analytical LoD (SARS-CoV-2 Inactivated)	≥95% detection at 1x LoD, Positive (if 2 of 3 EUA tests are positive, regardless of the third)

*   `Rule 2`: Neg/Neg/Any -> Negative (if 2 of 3 EUA tests are negative, regardless of the third)
*   `Rule 3`: Pos/Neg/Inv -> Specimen excluded (no clear consensus)
*   `Rule 4`: Inv/Inv/Any -> Specimen excluded (no clear consensus)

• No explicit human expert adjudication method is described. The adjudication relies on the consensus of the comparator FDA EUA tests.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• No MRMC comparative effectiveness study was done or reported.
• This device is an automated in vitro diagnostic (IVD) test, not an AI-assisted diagnostic tool for human readers. Therefore, there's no "human readers improve with AI vs without AI assistance" effect size to report. The comparison studies are on the device's performance against comparator devices or known ground truth.

6. Standalone (Algorithm Only) Performance

• Yes, standalone performance was done. The entire evaluation described in the "Performance Characteristics" section (analytical performance, comparison studies, and clinical studies) represents the standalone performance of the BioFire RP2.1 device, as it is an automated system that provides a qualitative result without human interpretation of raw signals. The software within the FilmArray instruments interprets the melt curve data and applies interpretation rules to determine the final test results.

7. Type of Ground Truth Used

• For Clinical Studies (SARS-CoV-2):
  • Prospective Clinical Study: Comparator Gold Standard (composite of three U.S. FDA EUA tests).
  • Retrospective Clinical Study: Comparator Gold Standard (previous EUA assay results at collection sites).
  • Contrived Clinical Specimen Study: Known Sample Composition / Definitive Ground Truth (spiked inactivated virus at known concentrations, or known negative specimens).
• For Analytical Studies (e.g., LoD, Reactivity, Specificity): Known Sample Composition / Definitive Ground Truth (contrived samples with specific isolates/strains at known concentrations).

8. Sample Size for the Training Set

• The document does not explicitly state the sample size for the training set.
• As an in vitro diagnostic (IVD) device, the development process typically involves internal analytical characterization and optimization (which can be considered analogous to "training" for a traditional assay, albeit not a machine learning model in the modern sense), followed by formal verification and validation studies. The analytical performance data (LoD, reactivity, specificity, etc.) are gathered on well-characterized samples to confirm the assay's performance.

9. How the Ground Truth for the Training Set Was Established

• The concept of a "training set" with ground truth in the context of this traditional IVD device (not an AI/ML model) refers to the development and optimization of the assays themselves.
• The ground truth for these developmental/training phases would be established through a combination of:
  • Defined concentrations of specific viral/bacterial isolates or nucleic acids: This is seen in the LoD and analytical reactivity studies where concentrations are precisely measured (e.g., copies/mL, TCID50/mL, CFU/mL) using established quantification methods (e.g., ddPCR, qPCR, plate counting).
  • Known sample compositions: Creating samples with specific organisms present or absent at controlled levels.
  • Previous BioFire RP2 data: The document notes that the RP2.1 builds upon the previous RP2 panel, meaning much of the "training" (i.e., assay design, optimization of reaction conditions, primer selection for common pathogens) for the shared analytes was likely carried over and validated.
  • In silico analysis: Used for SARS-CoV-2 primer design and reactivity prediction against sequence databases (NCBI, GISAID) as a form of "training" or initial validation for robustness against known variants. This informs assay design.

Regulation Number and Section

§ 866.3981 Device to detect and identify nucleic acid targets in respiratory specimens from microbial agents that cause the SARS-CoV-2 respiratory infection and other microbial agents when in a multi-target test.

(a)
Identification. A device to detect and identify nucleic acid targets in respiratory specimens from microbial agents that cause the SARS-CoV-2 respiratory infection and other microbial agents when in a multi-target test is an in vitro diagnostic device intended for the detection and identification of SARS-CoV-2 and other microbial agents when in a multi-target test in human clinical respiratory specimens from patients suspected of respiratory infection who are at risk for exposure or who may have been exposed to these agents. The device is intended to aid in the diagnosis of respiratory infection in conjunction with other clinical, epidemiologic, and laboratory data or other risk factors.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The intended use in the labeling required under § 809.10 of this chapter must include a description of the following: Analytes and targets the device detects and identifies, the specimen types tested, the results provided to the user, the clinical indications for which the test is to be used, the specific intended population(s), the intended use locations including testing location(s) where the device is to be used (if applicable), and other conditions of use as appropriate.
(2) Any sample collection device used must be FDA-cleared, -approved, or -classified as 510(k) exempt (standalone or as part of a test system) for the collection of specimen types claimed by this device; alternatively, the sample collection device must be cleared in a premarket submission as a part of this device.
(3) The labeling required under § 809.10(b) of this chapter must include:
(i) A detailed device description, including reagents, instruments, ancillary materials, all control elements, and a detailed explanation of the methodology, including all pre-analytical methods for processing of specimens;
(ii) Detailed descriptions of the performance characteristics of the device for each specimen type claimed in the intended use based on analytical studies including the following, as applicable: Limit of Detection, inclusivity, cross-reactivity, interfering substances, competitive inhibition, carryover/cross contamination, specimen stability, precision, reproducibility, and clinical studies;
(iii) Detailed descriptions of the test procedure(s), the interpretation of test results for clinical specimens, and acceptance criteria for any quality control testing;
(iv) A warning statement that viral culture should not be attempted in cases of positive results for SARS-CoV-2 and/or any similar microbial agents unless a facility with an appropriate level of laboratory biosafety (
e.g., BSL 3 and BSL 3+, etc.) is available to receive and culture specimens; and(v) A prominent statement that device performance has not been established for specimens collected from individuals not identified in the intended use population (
e.g., when applicable, that device performance has not been established in individuals without signs or symptoms of respiratory infection).(vi) Limiting statements that indicate that:
(A) A negative test result does not preclude the possibility of infection;
(B) The test results should be interpreted in conjunction with other clinical and laboratory data available to the clinician;
(C) There is a risk of incorrect results due to the presence of nucleic acid sequence variants in the targeted pathogens;
(D) That positive and negative predictive values are highly dependent on prevalence;
(E) Accurate results are dependent on adequate specimen collection, transport, storage, and processing. Failure to observe proper procedures in any one of these steps can lead to incorrect results; and
(F) When applicable (
e.g., recommended by the Centers for Disease Control and Prevention, by current well-accepted clinical guidelines, or by published peer-reviewed literature), that the clinical performance may be affected by testing a specific clinical subpopulation or for a specific claimed specimen type.(4) Design verification and validation must include:
(i) Detailed documentation, including performance results, from a clinical study that includes prospective (sequential) samples for each claimed specimen type and, as appropriate, additional characterized clinical samples. The clinical study must be performed on a study population consistent with the intended use population and compare the device performance to results obtained using a comparator that FDA has determined is appropriate. Detailed documentation must include the clinical study protocol (including a predefined statistical analysis plan), study report, testing results, and results of all statistical analyses.
(ii) Risk analysis and documentation demonstrating how risk control measures are implemented to address device system hazards, such as Failure Modes Effects Analysis and/or Hazard Analysis. This documentation must include a detailed description of a protocol (including all procedures and methods) for the continuous monitoring, identification, and handling of genetic mutations and/or novel respiratory pathogen isolates or strains (
e.g., regular review of published literature and periodic in silico analysis of target sequences to detect possible mismatches). All results of this protocol, including any findings, must be documented and must include any additional data analysis that is requested by FDA in response to any performance concerns identified under this section or identified by FDA during routine evaluation. Additionally, if requested by FDA, these evaluations must be submitted to FDA for FDA review within 48 hours of the request. Results that are reasonably interpreted to support the conclusion that novel respiratory pathogen strains or isolates impact the stated expected performance of the device must be sent to FDA immediately.(iii) A detailed description of the identity, phylogenetic relationship, and other recognized characterization of the respiratory pathogen(s) that the device is designed to detect. In addition, detailed documentation describing how to interpret the device results and other measures that might be needed for a laboratory diagnosis of respiratory infection.
(iv) A detailed device description, including device components, ancillary reagents required but not provided, and a detailed explanation of the methodology, including molecular target(s) for each analyte, design of target detection reagents, rationale for target selection, limiting factors of the device (
e.g., saturation level of hybridization and maximum amplification and detection cycle number, etc.), internal and external controls, and computational path from collected raw data to reported result (e.g., how collected raw signals are converted into a reported signal and result), as applicable.(v) A detailed description of device software, including software applications and hardware-based devices that incorporate software. The detailed description must include documentation of verification, validation, and hazard analysis and risk assessment activities, including an assessment of the impact of threats and vulnerabilities on device functionality and end users/patients as part of cybersecurity review.
(vi) For devices intended for the detection and identification of microbial agents for which an FDA recommended reference panel is available, design verification and validation must include the performance results of an analytical study testing the FDA recommended reference panel of characterized samples. Detailed documentation must be kept of that study and its results, including the study protocol, study report for the proposed intended use, testing results, and results of all statistical analyses.
(vii) For devices with an intended use that includes detection of Influenza A and Influenza B viruses and/or detection and differentiation between the Influenza A virus subtypes in human clinical specimens, the design verification and validation must include a detailed description of the identity, phylogenetic relationship, or other recognized characterization of the Influenza A and B viruses that the device is designed to detect, a description of how the device results might be used in a diagnostic algorithm and other measures that might be needed for a laboratory identification of Influenza A or B virus and of specific Influenza A virus subtypes, and a description of the clinical and epidemiological parameters that are relevant to a patient case diagnosis of Influenza A or B and of specific Influenza A virus subtypes. An evaluation of the device compared to a currently appropriate and FDA accepted comparator method. Detailed documentation must be kept of that study and its results, including the study protocol, study report for the proposed intended use, testing results, and results of all statistical analyses.
(5) When applicable, performance results of the analytical study testing the FDA recommended reference panel described in paragraph (b)(4)(vi) of this section must be included in the device's labeling under § 809.10(b) of this chapter.
(6) For devices with an intended use that includes detection of Influenza A and Influenza B viruses and/or detection and differentiation between the Influenza A virus subtypes in human clinical specimens in addition to detection of SARS-CoV-2 and similar microbial agents, the required labeling under § 809.10(b) of this chapter must include the following:
(i) Where applicable, a limiting statement that performance characteristics for Influenza A were established when Influenza A/H3 and A/H1-2009 (or other pertinent Influenza A subtypes) were the predominant Influenza A viruses in circulation.
(ii) Where applicable, a warning statement that reads if infection with a novel Influenza A virus is suspected based on current clinical and epidemiological screening criteria recommended by public health authorities, specimens should be collected with appropriate infection control precautions for novel virulent influenza viruses and sent to State or local health departments for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
(iii) Where the device results interpretation involves combining the outputs of several targets to get the final results, such as a device that both detects Influenza A and differentiates all known Influenza A subtypes that are currently circulating, the device's labeling must include a clear interpretation instruction for all valid and invalid output combinations, and recommendations for any required followup actions or retesting in the case of an unusual or unexpected device result.
(iv) A limiting statement that if a specimen yields a positive result for Influenza A, but produces negative test results for all specific influenza A subtypes intended to be differentiated (
i.e., H1-2009 and H3), this result requires notification of appropriate local, State, or Federal public health authorities to determine necessary measures for verification and to further determine whether the specimen represents a novel strain of Influenza A.(7) If one of the actions listed at section 564(b)(1)(A) through (D) of the Federal Food, Drug, and Cosmetic Act occurs with respect to an influenza viral strain, or if the Secretary of Health and Human Services determines, under section 319(a) of the Public Health Service Act, that a disease or disorder presents a public health emergency, or that a public health emergency otherwise exists, with respect to an influenza viral strain:
(i) Within 30 days from the date that FDA notifies manufacturers that characterized viral samples are available for test evaluation, the manufacturer must have testing performed on the device with those influenza viral samples in accordance with a standardized protocol considered and determined by FDA to be acceptable and appropriate.
(ii) Within 60 days from the date that FDA notifies manufacturers that characterized influenza viral samples are available for test evaluation and continuing until 3 years from that date, the results of the influenza emergency analytical reactivity testing, including the detailed information for the virus tested as described in the certificate of authentication, must be included as part of the device's labeling in a tabular format, either by:
(A) Placing the results directly in the device's labeling required under § 809.10(b) of this chapter that accompanies the device in a separate section of the labeling where analytical reactivity testing data can be found, but separate from the annual analytical reactivity testing results; or
(B) In a section of the device's label or in other labeling that accompanies the device, prominently providing a hyperlink to the manufacturer's public website where the analytical reactivity testing data can be found. The manufacturer's website, as well as the primary part of the manufacturer's website that discusses the device, must provide a prominently placed hyperlink to the website containing this information and must allow unrestricted viewing access.