(119 days)
The RNARetain® device is a single-use, prefilled container intended for the collection, storage, and transportation of fresh breast tissue specimens for subsequent RNA isolation and further molecular diagnostic testing. For Professional Use Only.
The RNARetain® device consists of an aqueous, hypertonic tissue preservation solution that is provided in a single-use, non-sterile vial intended to serve as the container for the collection, storage, and transport of breast tissue specimens. The ability of the solution formulation to preserve fresh tissue and nucleic acids within the tissue is due to its rapid permeation of tissue to protect cellular nucleic acids from nucleases that would otherwise rapidly degrade the nucleic acids within the specimen. The demonstrated inhibitory effect of the RNARetain® solution on the growth of bacteria, yeast and mold protects the specimen from inadvertent microbial contamination during storage or usage of the device.
The RNARetain® device is a single-use, prefilled container intended for the collection, storage, and transportation of fresh breast tissue specimens for subsequent RNA isolation and further molecular diagnostic testing. The device's performance was evaluated through several non-clinical analytical studies, including precision/reproducibility, stability of MammaPrint® outcomes, comparison with a predicate device, and internal analytical performance by Asuragen.
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Reproducibility of RNA Isolation & MammaPrint® Index: No statistically significant difference in MammaPrint® risk group assignment or MammaPrint® index between replicate RNA isolations. | Precision/Reproducibility (K070675): Five previously analyzed tumor samples (one borderline, two high risk, two low risk) were isolated in duplicate. No statistically significant difference in MammaPrint® risk group assignment or MammaPrint® index was observed between the two separate RNA isolations. (Table 3) |
| Stability of MammaPrint® outcomes in RNARetain®: MammaPrint® indices from samples stored in RNARetain® should be stable and comparable to immediately snap-frozen samples. | Stability of MammaPrint® outcomes in RNARetain® (K070675): Tumors shipped in RNARetain® showed greater stability in MammaPrint® index (Std dev 0.022) compared to immediately frozen samples (Std dev 0.042). An unpaired T-test showed no significant difference in MammaPrint® indices (p=0.24) between RNARetain® and frozen samples. The difference (Δ 0.027) was within acceptable limits. |
| Equivalence to Flash-Frozen Method for RNA Quality: RNARetain® preserved RNA yield, purity, and integrity should be equivalent to flash-frozen tissue. | Comparison Studies (K070675): A set of 33 breast tumor samples showed a median difference of 0.070 in MammaPrint® Indices between RNARetain®-preserved and snap-frozen samples. Pearson correlation was 0.94 and regression analysis showed R=0.90, indicating high similarity. This was comparable to the variation observed between two snap-frozen samples (median difference 0.105), with no statistically significant difference (t-test, p=0.57) between the two comparison series. |
| RNA Purity (A260/A280): ≥ 1.6 | Analytical Performance Asuragen (Table 4): |
| Subject 1: RNARetain® AVG 1.97, Frozen AVG 1.92 | |
| Subject 2: RNARetain® AVG 2.03, Frozen AVG 2.01 | |
| Subject 3: RNARetain® AVG 1.96, Frozen AVG 1.96 | |
| All values met the criteria. | |
| RNA Integrity (28S:18S): ≥ 1.0 or RIN ≥ 7.0 | Analytical Performance Asuragen (Table 4): |
| Subject 1: RNARetain® AVG 1.5, Frozen AVG 1.6 | |
| Subject 2: RNARetain® AVG 1.6, Frozen AVG 1.5 | |
| Subject 3: RNARetain® AVG 1.5, Frozen AVG 1.5 | |
| All values met the criteria (implied, as 28S:18S ratios are ≥ 1.0). | |
| RNA Yield: Comparable to flash-frozen specimens. | Analytical Performance Asuragen (Table 4): |
| Subject 1: RNARetain® AVG 148, Frozen AVG 131 | |
| Subject 2: RNARetain® AVG 62, Frozen AVG 43 | |
| Subject 3: RNARetain® AVG 101, Frozen AVG 81 | |
| Yields were comparable or higher in RNARetain® samples. | |
| Sample Stability in RNARetain®: Acceptable RNA yield, purity, and integrity over various storage conditions and durations. | Sample Stability (Asuragen): Samples passed acceptance criteria up to 3 days at 35-39 °C, 15 days at 18-25 °C, 60 days at 2-8 °C, and up to 3 years at -15 to -30 °C. |
| RNARetain® Reagent Stability: Reagent stability at room temperature. | RNARetain® Reagent Stability (Asuragen): 8mL vial (6 mL volume) stable up to 20 months at room temperature. 6 mL vial (5 mL volume) and 2 mL vial (1 mL volume) configurations stable up to 36 months. All passed acceptance criteria. |
2. Sample Size Used for the Test Set and the Data Provenance:
- Reproducibility (K070675): 5 tumor samples, each isolated in duplicate (total 10 isolations). Origin: Not explicitly stated, but part of Agendia's MammaPrint® submission. Retrospective.
- Stability of MammaPrint® outcomes in RNARetain® (K070675): One tumor, with sections preserved in RNARetain® and immediately snap-frozen. Both sections were labeled 5 times. Origin: Not explicitly stated, but part of Agendia's MammaPrint® submission. Retrospective.
- Comparison Studies (K070675):
- RNARetain® vs. snap-frozen: 33 breast tumor samples. One part of each sample stored in RNARetain®, another part snap-frozen. Origin: Collected in 2003 as a pilot study for the Dutch Raster clinical trial. Retrospective.
- Frozen vs. frozen: 18 tumors, with two parts of each immediately snap-frozen. Origin: Collected in the same time period as the 33 breast tumor samples. Retrospective.
- Repeatability and Reproducibility (Asuragen): 10 adjacent pairs of breast tissue from 3 subjects (total 30 tissue samples). Origin: Asuragen, within the US. Prospective (implied, as it was specifically collected for this study).
- Sample Stability (Asuragen for storage conditions): Human breast cancer cell line MCF-7. Quantitative sample size for each condition not explicitly stated (e.g., how many replicates per condition), but various time points and temperatures were tested. Origin: Asuragen labs.
- RNARetain® Reagent Stability: 3 lots of the 8mL vial (6 mL volume); unspecified number of lots for 6 mL vial (5 mL volume) and 2 mL vial (1 mL volume). Origin: Asuragen.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts:
- Comparison Studies (K070675): "HE stained sections were re-examined by a pathologist to confirm invasive ductal carcinoma and sufficient tumor cell content." Specific number and qualifications of pathologists are not given beyond "a pathologist".
4. Adjudication Method for the Test Set:
- Not applicable as the reported studies primarily involve analytical performance metrics (RNA purity, integrity, yield, MammaPrint® index correlation) rather than subjective assessments by multiple readers.
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:
- No MRMC comparative effectiveness study was done. This device is a pre-analytical system for tissue preservation, not an AI diagnostic tool that assists human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, the performance studies described are essentially standalone analytical performance evaluations of the RNARetain® device's ability to preserve RNA, mimicking the "algorithm only" concept in the context of a pre-analytical device. The device's performance is measured directly through RNA metrics and comparison to a gold standard (flash-frozen tissue) or established assay (MammaPrint®).
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.):
- MammaPrint® Index: The MammaPrint® assay itself serves as a reference, with the "original index" used for reproducibility studies (Table 3), implying an established ground truth for those samples.
- Pathology: For tissue samples in the comparison studies, "HE stained sections were re-examined by a pathologist to confirm invasive ductal carcinoma and sufficient tumor cell content." This indicates pathology review was used to establish the suitability of the tissue samples.
- Reference Methods: The "gold standard" for tissue preservation (flash-frozen tissue) was used as a comparator/ground truth for RNA yield, purity, and integrity measurements. Fresh Frozen cells were used as a comparator for sample stability studies.
8. The Sample Size for the Training Set:
- Information on a separate "training set" for the RNARetain® device, in the context of an algorithm or learnable system, is not applicable. RNARetain® is a chemical preservation solution and does not involve AI or machine learning that would require a distinct training set. The studies described are validation studies of its chemical and physical performance.
9. How the Ground Truth for the Training Set Was Established:
- Not applicable, as there is no training set in the context of an AI/ML algorithm for this device.
§ 866.4070 RNA Preanalytical Systems.
(a)
Identification. RNA Preanalytical Systems are devices intended to collect, store, and transport patient specimens, and stabilize intracellular RNA from the specimens, for subsequent isolation and purification of the intracellular RNA for RT-PCR used in in vitro molecular diagnostic testing.(b)
Classification. Class II (special controls). The special control is FDA's guidance document entitled “Class II Special Controls Guidance Document: RNA Preanalytical Systems (RNA Collection, Stabilization and Purification System for RT-PCR Used in Molecular Diagnostic Testing).” See § 866.1(e) for the availability of this guidance document.