(39 days)
The Prodesse® ProFAST + Assay is a multiplex Real Time RT-PCR in vitro diagnostic test for the qualitative detection and discrimination of seasonal Influenza A/H1, seasonal Influenza A/H3 and 2009 H1N1 Influenza viral nucleic acids isolated and purified from nasopharyngeal (NP) swab specimens from human patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors. This Assay targets conserved regions of the Hemagglutinin (HA) gene for seasonal Influenza A/H1, seasonal Influenza A/H3 and 2009 H1N1 Influenza Virus, respectively. This Assay is not intended to detect Influenza B or Influenza C Viruses.
A negative ProFAST+ Assay result is a presumptive negative result for Influenza A. These results should be confirmed by an FDA cleared nucleic acid-based test (NAT) detecting Influenza A.
Negative results do not preclude Influenza virus infection and should not be used as the sole basis for treatment or other patient management decisions.
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 department for testing. Viral culture should not be attempted in these cases unless a BSL 3+ facility is available to receive and culture specimens.
The Prodesse® ProFAST + Assay is a multiplex Real Time RT-PCR in vitro diagnostic test for the qualitative detection and discrimination of seasonal Influenza A/H1, seasonal Influenza A/H3 and 2009 H1N1 Influenza viral nucleic acids isolated and purified from nasopharyngeal (NP) swab specimens from human patients with signs and symptoms of respiratory infection in conjunction with clinical and epidemiological risk factors. This Assay targets conserved regions of the Hemagglutinin (HA) gene for seasonal Influenza A/H1, seasonal Influenza A/H3 and 2009 H1N1 Influenza Virus, respectively. This Assay is not intended to detect Influenza B or Influenza C Viruses.
The ProFAST+ Assay enables detection and discrimination of Influenza A Virus subtypes: seasonal A/H1, seasonal A/H3, and 2009 H1N1 and internal control nucleic acid. Nasopharyngeal swab specimens are collected from patients with signs and symptoms of a respiratory infection using a polyester, rayon or nylon tipped swab and placed into viral transport medium.
A Universal Internal Control (UIC) is added to each sample prior to nucleic acid isolation to monitor for inhibitors present in the specimens. The isolation and purification of the nucleic acids is performed using either a MagNA Pure LC Instrument (Roche) and the MagNA Pure Total Nucleic Acid Isolation Kit (Roche) or a NucliSENS® easyMAG™ System (bioMérieux) and the Automated Magnetic Extraction Reagents (bioMérieux).
The purified nucleic acids are added to ProFAST+ Supermix along with enzymes included in the ProFAST+ Assay Kit. The ProFAST+ Supermix contains oligonucleotide primers and targetspecific oligonucleotide probes. The primers are complementary to highly conserved regions of the Hemagglutinin (HA) gene for seasonal influenza A/H1, seasonal influenza A/H3 and 2009 H1N1 Influenza Virus. The probes are dual-labeled with a reporter dye attached to the 5'-end and a quencher dye attached to the 3'-end.
Reverse transcription of the RNA in the sample into complementary DNA (cDNA) and subsequent amplification of DNA is performed in a Cepheid SmartCycler® II instrument. In this process, the probe anneals specifically to the template followed by primer extension and amplification. The ProFAST+ Assay is based on Tagman chemistry, which utilizes the 5' - 3' exonuclease activity of the Taq polymerase to cleave the probe thus separating the reporter dye from the quencher. This generates an increase in fluorescent signal upon excitation from a light source. With each cycle, additional reporter dye molecules are cleaved from their respective probes, further increasing fluorescent signal. The amount of fluorescence at any given cycle is dependent on the amount of amplification products present at that time. Fluorescent intensity is monitored during each PCR cycle by the SmartCycler II instrument.
The provided text describes a special 510(k) submission for the Prodesse® ProFAST®+ Assay, primarily focusing on modifications to the internal control and positive control, and an additional reactivity claim for H3N2v. The submission argues for substantial equivalence to a predicate device (K101855, ProFAST 101+ Assay).
Crucially, the document does not present acceptance criteria or detailed results from a study that "proves the device meets the acceptance criteria" in the format of a typical clinical validation study. Instead, it focuses on demonstrating that modifications did not negatively impact performance compared to the previously cleared predicate device.
Here's an attempt to extract the requested information, noting where details are missing based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state quantitative acceptance criteria (e.g., minimum sensitivity, specificity, or agreement percentages) for a clinical performance study of the modified device. Instead, it refers to the previous performance claims of the ProFAST+ Assay (the predicate device for the modifications) and states that the modified assay "continues to meet the performance claims."
The closest to "reported device performance" are the results of the verification/validation studies for the modifications:
| Modification | Verification/Validation Result (Performance) |
|---|---|
| Outsourcing of internal control leading to minor changes in sequence. Incorporation of a Universal Internal Control (UIC), containing both RNA and DNA internal control sequences. | The UIC did not affect the ability of the ProFAST+ Assay to detect target organisms at the limit of detection as evinced by the results of Analytical Sensitivity, IC Interference, Extractor Equivalency, and Sample Stability studies. Additionally, the results of a retrospective clinical comparison study demonstrated the modified ProFAST+ Assay with UIC continues to meet the performance claims for the current ProFAST+ Assay. |
| Positive control provided "at use" concentration, no dilution is necessary. | A Positive Control Effectiveness Study demonstrated the positive control's continued ability to monitor for global assay failures at the increased testing concentration. |
| H3N2v Reactivity Claims | Results of the Reactivity Study demonstrated the ability of the ProFAST+ Assay to detect A/Indiana/10/2011 (H3N2v) nucleic acids at concentrations near the limit of detection of the assay. |
Note: The document explicitly states that "the performance characteristics of this device with clinical specimens that are positive for H3N2v influenza virus have not been established." This means for H3N2v, only analytical reactivity was shown, not clinical performance.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: The document mentions a "retrospective clinical comparison study" for the UIC modification but does not provide the sample size used in this study.
- Data Provenance: The document states "clinical comparison study," implying human patient samples were used. The term "retrospective" indicates that these samples were collected in the past. The country of origin is not specified but is implicitly the US given the FDA submission.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not provided. The nature of the ground truth (e.g., a reference method like viral culture or another FDA-cleared NAT) is not detailed, nor is the number or qualifications of experts, if any, involved in establishing it. It's likely the "ground truth" for the clinical comparison study would have been established by the reference method against which the predicate device's original performance claims were made.
4. Adjudication Method for the Test Set
Not provided. Given that this appears to be a comparison study against a historical reference or predicate, an adjudication method might not have been
explicitly described in this type of submission.
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
Not applicable. This device is an in vitro diagnostic (IVD) RT-PCR assay for detecting viral nucleic acids, not an AI-assisted diagnostic tool that would be used by "human readers" in the sense of image interpretation. Therefore, an MRMC study with human readers and AI assistance is not relevant to this device. The "reader" here is the instrument interpreting PCR amplification curves.
6. If a Standalone (i.e. algorithm only without human-in-the loop performance) was done
Yes, the device is inherently a standalone algorithm/assay without human-in-the-loop performance influencing its primary result. It provides a qualitative (positive/negative) detection and discrimination of influenza A subtypes. The "retrospective clinical comparison study" would represent the standalone performance of the modified assay.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)
Not explicitly stated in the provided text. For RT-PCR assays, the ground truth for clinical studies is typically established by:
- A "gold standard" laboratory method (e.g., viral culture if available and sensitive enough, or a highly sensitive and specific FDA-cleared reference molecular test).
- A composite reference method combining multiple tests or clinical findings.
Given it's a "clinical comparison study," it implies comparison to established clinical diagnoses or reference lab results, but the specifics are absent.
8. The Sample Size for the Training Set
Not applicable/Not provided. This is an RT-PCR assay, not a machine learning or AI algorithm that requires a "training set" in the conventional sense. The "training" for such a device involves assay optimization and analytical validation using characterized samples (e.g., contrived samples with known viral concentrations, characterized clinical samples) to establish parameters like limit of detection, linearity, and specificity. The document refers to "Analytical Sensitivity, IC Interference, Extractor Equivalency, and Sample Stability studies," which utilize such characterized samples, but a specific "training set sample size" as per AI/ML terminology is not relevant here.
9. How the Ground Truth for the Training Set Was Established
Not applicable/Not provided in the AI/ML context. For analytical studies, the "ground truth" (e.g., viral presence and concentration) is established by using characterized stocks, reference materials, or quantified clinical samples whose status is independently verified (e.g., by culture, sequencing, or quantitative PCR methods).
§ 866.3332 Reagents for detection of specific novel influenza A viruses.
(a)
Identification. Reagents for detection of specific novel influenza A viruses are devices that are intended for use in a nucleic acid amplification test to directly detect specific virus RNA in human respiratory specimens or viral cultures. Detection of specific virus RNA aids in the diagnosis of influenza caused by specific novel influenza A viruses in patients with clinical risk of infection with these viruses, and also aids in the presumptive laboratory identification of specific novel influenza A viruses to provide epidemiological information on influenza. These reagents include primers, probes, and specific influenza A virus controls.(b)
Classification. Class II (special controls). The special controls are:(1) FDA's guidance document entitled “Class II Special Controls Guidance Document: Reagents for Detection of Specific Novel Influenza A Viruses.” See § 866.1(e) for information on obtaining this document.
(2) The distribution of these devices is limited to laboratories with experienced personnel who have training in standardized molecular testing procedures and expertise in viral diagnosis, and appropriate biosafety equipment and containment.