TISSUE OF ORIGIN TEST KIT FFPE

K120489

PATHWORK DIAGNOSTICS, INC. · cleared 2012-05-17 · product code OIW · Clinical Toxcicology

Premarket evidence — what FDA accepted

Device typehardware with ml
source quote (p.2)
“The Pathwork® Tissue of Origin Test Kit-FFPE is a test kit consisting of the Pathchip microarray, reagents, software, and labeling. Product Code: OIW, Software, similarity score algorithm, tissue of origin for malignant tumor types”
AlgorithmThe algorithm uses a machine learning approach based on marker selection to build a predictive model. This model consists of a list of markers, reference (support) samples, and coefficients, which are combined to produce 15 Similarity Scores based on microarray standardized expression (SE) values of selected biomarkers.
source quote (p.2)
“The algorithm of the Pathwork® Tissue of Origin Test was developed using a database of 2196 specimens, divided into independent training and test datasets. The test development used a machine learning approach based on marker selection to build a predictive model. The model consists of a list of markers, a set of reference (support) samples and a set of coefficients. These components are combined to produce 15 Similarity Scores, one for each of the possible tissues on the test panel. Each similarity score ranges from 0 to 100, with a higher score being associated with a higher likelihood that the input specimen has a molecular signature of the corresponding tissue of origin. The 15 similarity scores are scaled to sum up to 100. Each is based on the microarray standardized expression (SE) values of selected biomarkers.”
Adaptive (vs locked)FDA source did not state this
PCCPFDA source did not state this
Cybersecurity addressedYes
source quote (p.3)
“The test report is accessible for clinical interpretation via a secure password protected website.”

Validation studies (1)

Bench

n=43 cases

endpoints: Concordance; Discordance

Reported performance (0 observations)

FDA source did not state a quantitative performance metric — non-reporting is itself the signal.

Each value carries its own analysis unit and task — never compare or pool across devices. Source: 510(k) summary PDF.

Predicate network

Postmarket — what happened after clearance

0
recalls in product code, 24mo
0
MAUDE reports in code, 12mo
—
vs code's own 3-yr baseline
0
drift signals on this device

Recall and MAUDE counts are product-code-level (reports aren't reliably attributable to one device); a recall is shown as device-attributed only when the recall record itself lists this clearance number. Signals are descriptive observables with sources — never a judgment that the device is unsafe or drifting. Snapshot 2026-07-08.

Reimbursement — how devices like this got paid

Not yet tracked — no payment pathway indexed for this clearance (the reimbursement corpus is a growing seed set).

Applicable FDA guidance — what the submission is measured against

FDA guidance documents and guiding principles applicable to 510(k) AI/ML devices in the Clinical Toxcicology panel. A curated reference index, not legal or regulatory advice — each item states its own status, and a draft is never binding.

Applicability is derived from the device's FDA advisory panel and pathway — cross-cutting guidances apply to every AI/ML device; panel-specific ones are flagged. Titles, dates, and links verified against fda.gov as of July 2026.

Constat Precedent · public FDA/CMS data · descriptive decision-support, not regulatory or reimbursement advice. Share this page: constat.dev/precedent/device/K120489