AlloMap Heart Molecular Expression Testing is an In Vitro Diagnostic Multivariate Index assay (IVDMIA) test service, performed in a single laboratory, assessing the gene expression profile of RNA isolated from peripheral blood mononuclear cells (PBMC). AlloMap Heart Testing is intended to aid in the identification of heart transplant recipients with stable allograft function who have a low probability of moderate/severe acute cellular rejection (ACR) at the of testing in conjunction with standard clinical assessment.

Indicated for use in heart transplant recipients:

· 15 years of age or older

· At least 2 months (>55 days) post-transplant

Device Description

AlloMap Heart Molecular Expression Testing is an In Vitro Diagnostic Multivariate Index Assay (IVDMIA) test service performed in a single laboratory, assessing the gene expression profile of RNA isolated from peripheral blood mononuclear cells (PBMC). AlloMap Heart Testing is a non-invasive blood test that uses genomic technologies to identify the absence of cardiac rejection. When used in conjunction with standard clinical assessments, AlloMap Heart Testing may help identify patients with stable allograft function who have a low probability of moderate to severe acute cellular rejection (ACR) at the time of Testing.

AlloMap is a panel of 20 gene assays, 11 informative and 9 used for normalization and quality control, which produces gene expression data used to calculate a reported AlloMap test score - an integer ranging from 0 to 40. The Score is an algorithmic composite of the expression of 11 differentially weighted informative genes that have a role in rejection and reflect host immune response, representing multiple diverse molecular pathways. The clinician uses the AlloMap Score and other standard clinical assessments to evaluate the patient's probability of rejection and the need for additional diagnostic evaluations. Compared with patients in the same post-transplant period, the lower the Score, the lower the probability of acute cellular rejection at the time of Testing. AlloMap Heart Testing is only performed at the CLIA-certified and CAP-accredited clinical laboratory at CareDx in Brisbane, California.

AI/ML Overview

The provided text describes the acceptance criteria and the study results for the AlloMap Heart Molecular Expression Testing, specifically focusing on the performance of the Roche LightCycler 480 II (LC480) instrument compared to the predicate ABI 7900HT instrument.

Here's a breakdown of the requested information:

1. A table of acceptance criteria and the reported device performance

Test Category	Acceptance Criteria	Reported Device Performance (LC480 vs ABI 7900HT)
Software V&V	Per Verification Plan against requirement specification. Meet product requirements and user needs/Intended Use.	Modified Software Analyzer v1.2 and its specifications meet product requirements and conform to user needs and Intended Use.
Precision – Between Instrument Variability	Variance ratios of LC480 over 7900HT less than (<) 1 for Low, Medium, and High AlloMap score sample pools.	Variance ratios of LC480 over 7900HT are < 1 for Low (0.459), Medium (0.316), and High (0.132) AlloMap score sample pools. Passed the pre-specified acceptance criteria. Between-instrument variability for LC480 is acceptable and comparable to 7900HT.
Precision – Reproducibility	Total variance ratio (σ_LC480^2 / σ_7900HT^2) less than (<) 1, or not statistically significant.	Total variance ratio is < 1 for Low (0.459, p<0.05), Medium (0.316, p<0.05), and High (0.132, p<0.05) AlloMap score sample pools, with F-test p-value < 0.05. LC480 met acceptance criteria and demonstrated acceptable precision, with total variances smaller than 7900HT.
Linearity	R2 value for linear regression of normalized factors vs. input log10RNA concentration should be acceptable. The variability of raw scores at each RNA input level should meet established acceptance criteria for the predicate device.	R2 value of 0.989 was obtained. LC480 met acceptance criteria and is comparable to the predicate device, 7900HT. Linearity of the AlloMap Heart test across various RNA inputs is maintained, especially around the current RNA input of 300ng.
Method Comparison – Accuracy (Passing-Bablok)	95% CI of the slope includes 1.0 and 95% CI of the intercept includes 0.0.	For both LC480_7296 vs 7900HT and LC480_7371 vs 7900HT: - Intercept: 0 (-0.53, 0.53) and 0 (-0.34, 0.34) respectively (both include 0). - Slope: 1 (0.99, 1.01) and 1 (0.99, 1.01) respectively (both include 1.0). All prespecified passing criteria were met at a two-sided significance level of 0.05.
Method Comparison – Accuracy (ATD Zones)	For each LC480, over 95% of samples across the entire clinical range fall within the ATD zones, with a lower limit of 95% one-sided CI > 90%.	For LC480_7296, 99.4% (lower 95% CI 96.6%) of all samples were within ATD zones. For LC480_7371, 98.2% (lower 95% CI 94.7%) of all samples were within ATD zones. The measurements by LC480 are within the analytical variation of the 7900HT and are considered equivalent.
Method Comparison – Clinical Equivalence (Projected NPV/PPV)	Absolute differences between the two system platforms (LC480 vs 7900HT) within 1% or 95% CI including 0 for NPV, and within 2% or 95% CI including 0 for PPV, for both 2-6 months and >6 months post-transplant periods.	The absolute differences between the two system platforms were within 1% or 95% CI including 0 for NPV, and within 2% or 95% CI including 0 for PPV, for both 2-6 months (55-182 days) and >6 months (>182 days) post-transplant periods.

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

Between Instrument Variability: Not explicitly stated, but implies multiple samples across low, medium, and high score ranges.
Reproducibility:
- Low Sample Pool: 88 samples
- Medium Sample Pool: 90 samples
- High Sample Pool: 90 samples
- Total: 268 samples
Linearity: Six different amounts of the same patient RNA sample.
Method Comparison - Accuracy (Passing-Bablok and ATD Zones): 163 patient RNA samples.
Method Comparison - Clinical Equivalence (Projected NPV/PPV): Based on the "300 samples in the original clinical validation study from the predicate device, K073482." No specific country of origin is mentioned, but the testing was done at CareDx in Brisbane, CA, USA, implying the samples were processed there. The samples were "previously tested heart transplant patient samples with clinical relevance to AlloMap score... after deidentification," suggesting a retrospective origin.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

The document does not describe the use of experts to establish a "ground truth" in the traditional sense of diagnostic interpretation. This is an analytical performance study comparing two instruements, where the ground truth is essentially the quantitative measurement produced by the predicate device (ABI 7900HT) and the clinical relevance (NPV/PPV) established in its original clinical validation. The "ground truth" for the patient samples' AlloMap scores were their scores obtained from the 7900HT.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not applicable. This was an analytical comparison study of test instrumentation, not a diagnostic interpretation study requiring expert adjudication of cases.

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 is not an AI-assisted diagnostic device or a MRMC study. It is an analytical validation of an in vitro diagnostic (IVD) assay instrument change.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Yes, in a sense. The study primarily evaluated the standalone performance of the new instrument (LC480) and its adapted software (SAX v1.2) against the predicate instrument (ABI 7900HT) to ensure equivalent analytical and clinical equivalency of the AlloMap score calculation. The AlloMap test itself is an algorithm-based test ("Multivariate Index Assay") performed in a lab environment. The "standalone" evaluation here refers to the instrument's ability to produce equivalent scores.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)

The primary ground truth for the analytical performance studies was the AlloMap scores generated by the predicate ABI 7900HT instrument. For the clinical equivalence projection (NPV/PPV), it refers back to the clinical outcomes data that supported the original clearance of the predicate device (K073482).

8. The sample size for the training set

The document does not explicitly describe a "training set" for the current submission, as it focuses on the analytical and clinical equivalency verification of an instrument change. The "Software Analyzer, SAX v1.2" was modified to support the LC480, and it applied "two gene-level correction factors" to map LC480 response to 7900HT response. The data used to derive these correction factors (which could be considered analogous to a training step for the software adaptation) is not specified in terms of sample size or methodology. However, the original AlloMap algorithm itself was likely developed and "trained" on a much larger dataset during its initial development and clearance (DEN080007 / K073482), but that information is not part of this specific submission's details.

9. How the ground truth for the training set was established

As mentioned above, the current submission focuses on instrument equivalency. For the underlying AlloMap algorithm, the ground truth for its initial development would have involved patient outcomes related to acute cellular rejection (ACR), likely correlated with biopsy results (pathology) which is the gold standard for ACR diagnosis, and potentially other clinical assessments in heart transplant recipients. This background is implied by the "Indications for Use" and the nature of the "Cardiac Allograft Gene Expression Profiling Test System." However, the specifics for the original training set's ground truth establishment are not provided in this document.

Summary

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September 13, 2023

CareDx, Inc. Camilla Lu Associate Director, Regulatory Affairs 3260 Bayshore Boulevard Brisbane, CA 94005

Re: K221640

Trade/Device Name: AlloMap Heart Molecular Expression Testing Regulation Number: 21 CFR 862.1163 Regulation Name: Cardiac Allograft Gene Expression Profiling Test System Regulatory Class: Class II Product Code: OJQ Dated: April 7, 2023 Received: April 10, 2023

Dear Camilla Lu:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR

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for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely.

Paula V. Caposino -S

Paula Caposino, Ph.D. Acting Deputy Director Division of Chemistry and Toxicology Devices OHT7: Office of In Vitro Diagnostics Office of Product Evaluation and Quality Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K221640

Device Name

AlloMap Heart Molecular Expression Testing

Indications for Use (Describe)

Indicated for use in heart transplant recipients:

· 15 years of age or older

· At least 2 months (>55 days) post-transplant

Type of Use (Select one or both, as applicable)
X Prescription Use (Part 21 CFR 201 Subpart D) Over-The-Counter Use (21 CFR 201 Subpart C)	X Prescription Use (Part 21 CFR 201 Subpart D)	Over-The-Counter Use (21 CFR 201 Subpart C)
X Prescription Use (Part 21 CFR 201 Subpart D)	Over-The-Counter Use (21 CFR 201 Subpart C)

| > Prescription Use (Part 21 CFR 801 Subpart D)

| | Over-The-Counter Use (21 CFR 801 Subpart C)

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Image /page/3/Picture/0 description: The image is a logo for CareDx. The logo features a stylized red blood drop with white squares inside, followed by the company name "CareDx" in black font. Below the company name is the tagline "Your Partner in Transplant Care".

TRADITIONAL 510(K) SUMMARY

(Complying with 21 CFR 807.92)

I. SUBMITTER

CareDx, Inc. 3260 Bayshore Boulevard Brisbane, CA 94005 USA

Phone : (415) 287-2300 x 5336 FAX : (415) 287 2427

Contact Person:	Camilla Lu, PhD.
Date Prepared:	September 6, 2023

II. DEVICE

Trade Name:	AlloMap Heart Molecular Expression Testing
Common Name:	AlloMap Heart Testing
Classification Name:	Cardiac Allograft Gene Expression Profiling Test System
Regulatory Class:	Class II
Regulation Number:	21 CFR 862.1163
Product Code:	OJQ
510(K) Number:	K221640

III. PREDICATE DEVICE

Trade Name:	AlloMap Molecular Expression Testing
Common Name:	AlloMap Testing
De Novo Number:	DEN080007
510(K) Number:	K073482

IV DEVICE DESCRIPTION

Principle of Operation: AlloMap Heart Molecular Expression Testing is an In Vitro Diagnostic Multivariate Index Assay (IVDMIA) test service performed in a single laboratory, assessing the gene expression profile of RNA isolated from peripheral blood mononuclear cells (PBMC). AlloMap Heart Testing is a non-invasive blood test that uses genomic technologies to identify the absence of cardiac rejection. When used in conjunction with standard clinical assessments, AlloMap Heart Testing may help identify patients with stable allograft function who have a low probability of moderate to severe acute cellular rejection (ACR) at the time of Testing.

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differentially weighted informative genes that have a role in rejection and reflect host immune response, representing multiple diverse molecular pathways. The clinician uses the AlloMap Score and other standard clinical assessments to evaluate the patient's probability of rejection and the need for additional diagnostic evaluations. Compared with patients in the same post-transplant period, the lower the Score, the lower the probability of acute cellular rejection at the time of Testing. AlloMap Heart Testing is only performed at the CLIA-certified and CAP-accredited clinical laboratory at CareDx in Brisbane, California.

AlloMap Heart Test Process: A whole blood sample is collected at the patient site in a BD Vacutainer® CPT™ Cell Preparation tube with sodium citrate anticoagulant. Peripheral blood mononuclear cells (PBMC) are isolated and lysed, and frozen PBMC lysate is shipped using kits provided by CareDx to the CareDx laboratory in Brisbane, CA. RNA is purified from the PBMC lysate and converted to cDNA using commercial reagents on a thermal cycler following a standard reverse transcriptase protocol. Using liquid handling instruments, the cDNA is diluted and dispensed into a 384-well AlloMap HTx assay plate. The AlloMap plate comprises pre-aliquoted qRT-PCR reagents created by CareDx Manufacturing, containing sequence-specific primers, probes, and Universal Master Mix to measure each of the 20 genes in triplicate. Gene expression levels are determined via the qRT-PCR instrument for each of the eleven (11) informative and nine (9) control genes. The Analyzer Software, SAX, converts sample data generated from the qRT-PCR plate to an AlloMap Test Score. Multiple automated QC checks are performed on every sample. AlloMap scores are calculated for all samples that pass QC. The AlloMap Test Score is then reported to the physician.

AlloMap Heart Test System: The test system consists of assay reagents, instruments, and system software. The test components have not changed from the predicate device K073482, including sample processing, reagents, formulations, and assay plates containing qRT-PCR reagents created by CareDx Manufacturing to measure each of the 20 genes. The difference between the subject device, the AlloMap Heart Testing, and the predicate device is the replacement of the current eight ABI 7900HT thermal cyclers in the CareDx laboratory with eight Roche LightCycler 480 II (LC480) thermal cyclers. Consequently, the Software Analyzer has been modified to support the LC480 Instrument and achieve AlloMap Heart test equivalency with the current ABI 7900HT instrument.

V. INTENDED USE

1. Intended Use (s):

The Intended Use of the subject device is the same as the predicate device, K073482. See Indications for Use below.

2. Indications (s) for Use:

AlloMap Heart Molecular Expression Testing is an In Vitro Diagnostic Multivariate Index assay (IVDMIA) test service, performed in a single laboratory, assessing the gene expression profile of RNA isolated from peripheral blood mononuclear cells (PBMC). AlloMap Heart Testing is intended to aid in the identification of heart transplant recipients with stable allograft function who have a low probability of moderate/severe acute cellular rejection (ACR) at the time of testing in conjunction with standard clinical assessment.

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Indicated for use in heart transplant recipients:

15 years of age or older ●
At least 2 months (≥55 days) post-transplant ●

VI. COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE

Similarities

First, the subject device has the same Intended Use as the predicate device. Second, the subject device has the same technological characteristics as the predicate device. At a high level, the subject and predicate devices are based on the following same technological elements:

Sample processing
. Reagents used for RNA purification and cDNA synthesis
The panel of 20 genes (11 informative and 9 control genes)
. AlloMap HTx assay plates containing qRT-PCR reagents created by CareDx Manufacturing measure the expression of each of the 20 genes
. Instruments used for RNA Quantification, cDNA Synthesis Pipetting, and cDNA Synthesis Reaction
. The Assay Quality Control rules and criteria for the AlloMap Heart test: rules of Data quality, PCR success, Genomic DNA contamination, Sample quality & quantity, Efficiency, Assay Ranges, Normalization genes, and Process control expected values
. The LIS software used to manage the workflow for the processing, reporting AlloMap Heart tests, and the AlloMap Score has not changed
. AlloMap Heart Report software has not changed
Analyzer Software, SAX, which converts sample data to an AlloMap score, has not . changed its primary functions, and the four modules, including the Algorithm to calculate the AlloMap Score, remain unchanged

Differences

The following assay component differences exist between the subject and predicate devices:

The predicate device uses eight ABI 7900 HT thermal cyclers, which are replaced with eight Roche LightCycler 480 II (LC480) for the subject device in the CareDx laboratory.
. The Software Analyzer, SAX, has been modified in the subject device to support the LC480 Instrument and achieve AlloMap test equivalency with the current ABI 7900HT instrument. SAX changed its version from SAX v1.0 (for predicate device) to v1.2 (for subject device) to update existing modules:
- SAX v1.2 extracts the raw fluorescence data generated by the LC480 from the resulting o XML Summary output files
- O SAX v1.2 applies two gene-level correction factors additive correction coefficient (oga) and multiplicative correction coefficient (Sgb) - to map the LC480 response to the ABI 7900 HT response.

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PERFORMANCE DATA VII.

The following performance data were provided in support of the substantial equivalence determination.

Software Verification and Validation Testing

Verification of the Software Analyzer, SAX v1.2, was conducted per Verification Plan against its requirement specification, followed by a software validation test at CareDx in Brisbane, CA, including Analyzer QC Criteria, Analyzer Algorithm Score, and Integration with LIMS. As demonstrated by the V&V reports in this submission, the modified Software Analyzer v1.2 and its specifications (design outputs) meet the product requirements (design inputs) and conform to the user's needs and Intended Use.

Analytical Performance Validation Testing

Four analytical validation studies were performed to evaluate the performance characteristics of the Roche LC480 Instrument (subject device) compared to the current AB17900HT Instrument (predicate device). Previously tested heart transplant patient samples with clinical relevance to AlloMap score were used after deidentification in the studies. The modified Analyzer Software SAX v1.2 was used for the LC480 workflow during the validation, and SAX v1.0 was used for the data analysis of 7900HT.

1. Precision - Between Instrument Variability

Variance component analysis was performed to estimate the between-instrument variability for the AlloMap scores. This study demonstrated the between-instrument variability for LC480 to be comparable to that of the predicate device, the 7900HT instrument. The variance ratios of LC480 over 7900HT are less than (<) 1 for the Low, Medium, and High AlloMap score sample pools, respectively, and passed the pre-specified acceptance criteria. Hence, between-instrument variability for LC480 is acceptable.

2. Precision – Reproducibility

The study evaluated the within-lab precision of the LC480 versus the 7900HT using variance component analysis. The reproducibility for the AlloMap Heart test process was established for the following individual variance components: day-to-day, operator, instrument-toinstrument, plate lot-to-lot, plate-to-plate nested within plate lot, and plate section-to-section nested within the instrument. The variability of AlloMap scores was analyzed separately in three sample pools representing low, medium, and high AlloMap scores. The within-lab precision of LC480 is summarized in Table 2-1, Overall Statistics of LC480 Data for the 3 sample pools.

Table 2-1: Overall Statistics of LC480 Within-Lab Precision for the 3 Samples Pools, Representing Low, Medium, and High AlloMap Scores, tested using 2 Operators, 3 Instruments, and 3 Plate lots over 5 Non-Consecutive Days.

Sample Pool	Number ofSamples	Mean AlloMapScore	SD	CV (%)
Low	88	16.2	2.210	13.613
Medium	90	28.5	1.110	3.887
High	90	37.5	0.353	0.941

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When comparing the precision between the LC480, and the 7900HT, the total variance ratio is less than (<) 1, i.e., the total variances were smaller for the LC480 in each of the AlloMap score sample pools, and the F-test p-value is less than 0.05. Thus, LC480 met the acceptance criteria and demonstrated acceptable precision. See Table 2-2, F-Test Results for the Total Variance Ratio between LC480 and ABI 7900HT.

SamplePool	Variance Ratio1( $σ^LC4802/σ^7900HT2$ )	F Value2	P Value	Acceptance CriteriaVariance Ratio ( $σ^LC4802/σ^7900HT2$ ) is less than (<) 1 ornot statistically significant
Low	0.459	0.446	<0.05	PASS3
Medium	0.316	0.326	<0.05	PASS3
High	0.132	0.154	<0.05	PASS3
1 The ratio of the total variance is generated from the Variance Component Analysis using the Restricted Maximum Likelihood

	Table 2-2. F-Test Results for the Total Variance Ratio between LC480 and ABI 7900HT
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(REML) method.

2 The F value is calculated as the ratio of the total variances as the mean squared of the error.

3 მ². 480 is significantly smaller than მ-200677. Hence, the variance ratio less than (<1) with significant p value.

3. Linearity

Six different amounts of the same patient RNA sample, representing a high AlloMap score (> 34), were used as input into the cDNA synthesis ranging from 150 to 500 ng (regular 300 ng). The linear regression method was used to analyze the mean of the normalized factors vs. the input log10RNA concentration. The result obtained an R2 value of 0.989. The variability of the raw scores at each RNA input level was examined using the acceptance criteria established for the predicate device. The result showed that the LC480 met the acceptance criteria and is comparable to the predicate device, 7900HT. The study demonstrated that linearity of the AlloMap Heart test across various RNA inputs is maintained using the Roche LC480 qRT-PCR instruments especially around the current RNA input of 300ng per patient sample.

4. Method Comparison - Accuracy

The study validated that AlloMap results measured by the Roche LC480 are equivalent across the reportable range to the results measured by the ABI 7900HT in the CareDx Laboratory. The analysis included a total of 163 patient RNA samples processed by 2 LC480 instruments and a single 7900HT. The paired scores were analyzed using Passing-Bablok regression models. All prespecified passing criteria were met at a two-sided significance level of 0.05 for the paired score differences and the regression parameters, i.e., intercept and slope. See Table 4-1.

	Estimate and 95% CI		Acceptance Criteria
Parameters	LC480_7296 vs 7900HT	LC480_7371 vs 7900HT	95% CI of the slope includes 1.0 and95% CI of the intercept includes 0.0
Intercept	0 (-0.53, 0.53)	0 (-0.34, 0.34)	PASS
Slope	1 (0.99, 1.01)	1 (0.99, 1.01)	PASS

		Table 4-1: Passing-Bablok Regression Results
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CAREDX INC.	ALLOMAP HEART MOLECULAR EXPRESSION TESTING
September 2023	TRADITIONAL 510(K) SUBMISSION

Following FDA Guidance for Assay Migration Studies, allowable total difference (ATD) zone were constructed separately for low, medium and high score ranges using reproducibility results for the 7900HT to define the limits for 95% of the differences between repeated measures by the 7900HT. For each LC480, over 95% of the samples across the entire clinical range fell within the ATD zones with a lower limit of 95% one-sided CI > 90%. Thus, the measurements by LC480 are within the analytical variation of the 7900HT and can be considered equivalent to the predicate. (see Table 4-2).

	AlloMap Score Ranges(7900HT)	Low<=20(N=25, 15.3%)	Medium21-33(N=86, 52.8%)	High34-40(N=52, 31.9%)	All Samples(n=163)	Acceptance Criteria95% All Samples within ATD zonesANDLower 95% CI for All Samples 90%
LC480_7296	n (%)	25 (100%)	85 (98.8%)	51 (100%)	162 (99.4%)	PASS
	Lower 95% Cl	-	-	-	96.6%
LC480_7371	n (%)	25 (100%)	83 (96.5%)	52 (100%)	160 (98.2%)	PASS
	Lower 95% CI	-	-	-	94.7%

Table 4-2: Percentages of the Samples within ATD Zones

Using the 300 samples in the original clinical validation study from the predicate device, K073482, we calculated projected NPV and PPV for each Roche LC480 as the mean of the 500 simulated NPV and PPV from the simulated AlloMap scores for the LC480 by adding random errors (estimated from Accuracy study or Reproducibility study) to the 7900HT scores. The projected NPV and PPV for the Roche LC480 were then compared with the NPV and PPV for the 7900HT. The absolute differences between the two system platforms were within 1% or 95% CI including 0 for NPV, and within 2% or 95% CI including 0 for PPV, for both 2-6 months (55-182 days) and >6 months (>182 days) post-transplant periods. These results demonstrated that the Roche LC480 produces AlloMap results that are statistically and clinically equivalent across the whole clinical range to those produced by the ABI 7900HT qRT-PCR thermal cycler in the CareDx Laboratory.

Compliance with FDA Recognized Standards and Guidelines

. CLSI EP09-A3 Measurement Procedure Comparison and Bias Estimation Using Patient Samples; Approved Guideline – Third Edition. Section 6 Measurement Procedure Comparison Studies; Section 7, Considerations for Clinical Laboratories; Section 10.2, Other Comparisons. Clinical and Laboratory Standards Institute; 2013
. CLSI EP31-A-IR Verification of Comparability of Patient Results Within One Health Care System; Approved Guideline (Interim Revision). Section 6.1, Commutability; Section 7.1, Evaluation of Comparability Based on Clinical Outcomes; Section 8.2, Statistical Analysis of Comparability Data. Clinical and Laboratory Standards Institute; 2012
CLSI-EP06-A, Evaluation of the Linearity of Quantitative Measurement Procedures: A ● Statistical Approach; Approved Guideline. Sections 5.3, Determination of the Linear Range and 5.3.1, Summary of Methods - The Polynomial Evaluation of Linearity Wayne, PA: Clinical and Laboratory Standards Institute; 2003.
CLSI EP05-A3, Evaluation of Precision Performance of Quantitative Measurement . Procedures: Approved Guideline Chapter 3, Single-Site Precision Evaluation Study, Wayne, PA: Clinical and Laboratory Standards Institute, 2014.

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. FDA Guidance: Assay Migration Studies for In Vitro Diagnostic Devices. Document issued on April 25, 2013
. FDA Guidance: Cardiac Allograft Gene Expression Profiling Test Systems – Class II Special Controls Guidance for Industry and FDA Staff. Document issued on October 21, 2009

CONCLUSIONS VIII.

CareDx has demonstrated through its evaluation and performance testing that the AlloMap Heart Testing using the Roche LC480 instruments is substantially equivalent to the legally marketed AlloMap Testing using the ABI 7900HT. Same as the predicate device, AlloMap Heart Testing is safe and effective for its intended Use.

Regulation Number and Section

§ 862.1163 Cardiac allograft gene expression profiling test system.

(a)
Identification. A cardiac allograft gene expression profiling test system is a device that measures the ribonucleic acid (RNA) expression level of multiple genes and combines this information to yield a signature (pattern, classifier, index, score) to aid in the identification of a low probability of acute cellular rejection (ACR) in heart transplant recipients with stable allograft function.(b)
Classification. Class II (special controls). The special control is FDA's guidance document entitled “Class II Special Controls Guidance Document: Cardiac Allograft Gene Expression Profiling Test Systems.” See § 862.1(d) for the availability of this guidance document.