For In Vitro Diagnostic Use. The Prostate-63 Cancer Diagnostic Test features a mouse monoclonal antibody, clone 4A4, that recognizes the human p63 protein in the nucleus of prostatic basal cells and urothelial tissues. This test is intended for laboratory use to qualitatively identify by immunohistochemistry the p63 antigen in histological sections from formalin-fixed paraffin-embedded tissue of normal and/or pathological prostate tissue obtained by needle biopsy or surgical procedures. The presence or absence of p63 staining aids the pathologist in the differential diagnosis of prostate cancer in conjunction with morphological findings seen with hematoxylin and eosin staining complemented by proper controls. The clinical interpretation of any staining or its absence should be evaluated within the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.
Device Story
Prostate-63 Cancer Diagnostic Test uses mouse monoclonal antibody (clone 4A4) to detect p63 protein in prostatic basal cell nuclei. Reagent applied to formalin-fixed paraffin-embedded tissue sections; antibody binding visualized via anti-mouse IgG secondary antibody conjugated to horseradish peroxidase (HRP) and chromogenic substrate. Pathologist evaluates staining patterns using light microscopy. Basal cells, which express p63, are typically absent in invasive prostate carcinoma. Absence of p63 staining in glandular structures assists pathologist in identifying potential malignancy. Used in clinical pathology laboratories; results interpreted alongside morphological findings (H&E staining) and clinical history to support prostate cancer diagnosis.
Clinical Evidence
No clinical trials performed by the applicant. Evidence relies on published scientific literature. Studies (e.g., Signoretti et al. 2000, Shah et al. 2002) demonstrate p63 sensitivity for basal cells in normal glands approaching 100% and high specificity for the absence of basal cells in invasive prostate carcinoma (97-100% of cases).
Technological Characteristics
Mouse monoclonal antibody (clone 4A4) against human p63 protein; provided in buffer (50 mM Tris-HCl, pH 7.2, 15 mM sodium azide). Immunogen: recombinant protein (amino acids 1-205 of N-terminal human ΔNp63). Principle: immunohistochemical staining of nuclear p63 antigen. Form factor: liquid reagent for laboratory use.
Indications for Use
Indicated for laboratory use to qualitatively identify p63 antigen via immunohistochemistry in formalin-fixed paraffin-embedded prostate tissue (needle biopsy or surgical) to aid pathologists in the differential diagnosis of prostate cancer.
Regulatory Classification
Identification
Immunohistochemistry test systems (IHC's) are in vitro diagnostic devices consisting of polyclonal or monoclonal antibodies labeled with directions for use and performance claims, which may be packaged with ancillary reagents in kits. Their intended use is to identify, by immunological techniques, antigens in tissues or cytologic specimens. Similar devices intended for use with flow cytometry devices are not considered IHC's.
Special Controls
(2) Class II (special control, guidance document: “FDA Guidance for Submission of Immunohistochemistry Applications to the FDA,” Center for Devices and Radiologic Health, 1998). These IHC's are intended for the detection and/or measurement of certain target analytes in order to provide prognostic or predictive data that are not directly confirmed by routine histopathologic internal and external control specimens. These IHC's provide the pathologist with information that is ordinarily reported as independent diagnostic information to the ordering clinician, and the claims associated with these data are widely accepted and supported by valid scientific evidence. Examples of class II IHC's are those intended for semiquantitative measurement of an analyte, such as hormone receptors in breast cancer.
Reference Devices
34betaE12 (cited in literature)
Basal cell cocktail (34betaE12 + p63) (cited in literature)
Submission Summary (Full Text)
{0}
1
# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY
A. 510(k) Number:
K050063
B. Purpose for Submission:
New submission
C. Measurand:
P63 protein
D. Type of Test:
Immunohistochemistry reagent
E. Applicant:
Asymmetrx Inc.
F. Proprietary and Established Names:
Trade/Proprietary Name: Prostate-63 Cancer Diagnostic Test
Common Name: Anti-p63 Prostatic basal cell antibody
G. Regulatory Information:
1. Regulation section:
21 CFR 864.1860, Immunohistochemistry reagents and kits
2. Classification:
Class I. Device exceeded the limitations to 21 CFR 864.9 (limitations to exemption from premarket notification) since a new indication for use that differed from other reagents or kits of this generic type (such as immunohistochemical anti-cytokeratin antibodies) was utilized.
3. Product code:
NTR, Immunohistochemical reagent, antibody (monoclonal or polyclonal) to p63 protein in nucleus of prostatic basal cells
4. Panel:
Pathology (88)
H. Intended Use:
1. Intended use(s):
For In Vitro Diagnostic Use. The Prostate-63 Cancer Diagnostic Test features a mouse monoclonal antibody, clone 4A4, that recognizes the human p63 protein in the nucleus of prostatic basal cells and urothelial tissues. This test is intended for laboratory use to qualitatively identify by immunohistochemistry the p63 antigen in histological sections from formalin-fixed paraffin-embedded tissue of normal and/or pathological prostate tissue obtained by needle biopsy or surgical procedures. The presence or absence of p63 staining aids the pathologist in the differential diagnosis of prostate cancer in conjunction with morphological findings seen with hematoxylin and eosin staining complemented by proper
{1}
controls. The clinical interpretation of any staining or its absence should be evaluated within the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.
2. Indication(s) for use:
This test is intended for laboratory use to qualitatively identify by immunohistochemistry the p63 antigen in histological sections from formalin-fixed paraffin-embedded tissue of normal and/or pathological prostate tissue obtained by needle biopsy or surgical procedures. The presence or absence of p63 staining aids the pathologist in the differential diagnosis of prostate cancer in conjunction with morphological findings seen with hematoxylin and eosin staining complemented by proper controls. The clinical interpretation of any staining or its absence should be evaluated within the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.
3. Special conditions for use statement(s):
In Vitro diagnostic Use
4. Special instrument requirements:
None
I. Device Description:
The reagent is described in 2 configurations: reagent only or reagent with a buffer for antigen retrieval methods. The antibody is provided in concentrated form within an appropriate buffer. Other general reagents and equipment commonly used in immunohistochemical staining methods are required but not supplied with the antibody reagent.
J. Substantial Equivalence Information:
1. Predicate device name(s):
There currently is no similar device currently cleared by premarket notification, therefore there is no legally marketed predicate device.
2. Predicate 510(k) number(s):
None
3. Comparison with predicate:
The device is similar to the general analytical methods of other immunohistochemical reagents but is used to assist the pathologist in the diagnosis of prostate cancer rather than aiding the determination of tissue type of cancerous or normal cells.
| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| | | |
| Differences | | |
| --- | --- | --- |
| Item | Device | Predicate |
| | | |
K. Standard/Guidance Document Referenced (if applicable):
None referenced.
{2}
L. Test Principle:
The anti-p63 monoclonal antibody (clone 4A4) detects p63 protein by Immunohistochemical staining of formalin-fixed paraffin-embedded tissue obtained by needle biopsy or surgical procedures by standard immunocytochemical procedures. Antibody binding to portions of a tissue section is detected by using an anti-mouse IgG secondary antibody conjugated to horseradish peroxidase (HRP), which in turn enzymatically converts a chromogenic substrate to a visible reaction product to reveal prostatic basal cells. The specimen may then be counterstained and coverslipped. Results are analyzed by a qualified pathologist using light microscopy. The p63 protein is highly expressed in prostatic basal cells. These cells are typically absent in prostate carcinoma. The pattern of staining, or its absence, in appropriate cell structures and locations in a histological section assists in the diagnosis of prostate cancer.
M. Performance Characteristics (if/when applicable):
1. Analytical performance:
a. Precision/Reproducibility:
No specific precision data was provided since no common set of reagents is included in the device and laboratory use will employ other reagents, equipment, and biological stains common to many clinical histology laboratories. Use characteristics and performance will vary according to the conditions used in a particular laboratory.
b. Linearity/assay reportable range:
Not applicable
c. Traceability, Stability, Expected values (controls, calibrators, or methods):
Not applicable
d. Detection limit:
Not applicable
e. Analytical specificity:
A typical staining pattern in both normal and prostate cancer tissue, sectioned and stained with the antibody reagent, is shown in the following figure.
3
{3}
f. Assay cut-off: Not applicable
2. Comparison studies:
a. Method comparison with predicate device: Not performed
b. Matrix comparison: Not Applicable
3. Clinical studies:
The labeling notes the following information and scientific literature : The 4A4 anti-p63 monoclonal antibody recognizes all forms of p63 protein on western blots, and shows strong nuclear staining of baby hamster kidney (BHK) cells expressing p63 cDNAs but not BHK cells expressing control vectors (Yang et al., 1998). By immunohistochemistry in mouse tissues, the 4A4 anti-p63 monoclonal antibody recognizes basal cells of skin, breast, prostate, urothelia, among other tissues, but does not show significant staining in corresponding tissues of embryos lacking the p63 gene (Yang et al., 1999)
p63 stains prostatic basal cells of normal glands in needle biopsies with a sensitivity approaching 100% (Wu et al., 2004). Benign glands were also positive in 11 of 12 (95%) sections derived from transurethral resection of the prostate (TURP; Shah et al., 2002). p63 does not stain neuroendocrine or luminal, secretory cells of the prostate (Signoretti et al., 2000). As basal cells are absent from invasive prostate carcinoma (Hedrick and Epstein, 1989), p63 staining aids in the diagnosis of prostate carcinoma in biopsy sections. In one
{4}
study, p63-positive cells were absent in 126 of 130 (97%) needle biopsy specimens of invasive prostate cancers (Signoretti et al., 2000). In the remaining four cases, p63-positive signal was detected but in less than 1% of cells. In a similar study of needle biopsies, p63 staining was absent in 67 of 67 (100%) cases of prostate cancer (Shah et al., 2002). Despite the high sensitivity and specificity of the 4A4 anti-p63 antibody, not all glands stain uniformly with basal cell markers and some conditions that mimic prostate carcinoma display reduced or absent basal cell markers (Epstein, 2004). Therefore, failure to demonstrate p63-positive basal cells in any particular prostatic gland or group of glands may not be conclusive for malignant infiltration. Pathologists should interpret basal cell absence in the context of all histologic and cytologic features. When doubt remains, recutting the tissue block for deeper tissue levels is recommended. Literature cited:
1. Epstein JI. Diagnosis and reporting of limited adenocarcinoma of the prostate on needle biopsy. Mod Pathol. 2004 Mar; 17(3):307-15.
2. Hedrick L, Epstein JI. Use of keratin 903 as an adjunct in the diagnosis of prostate carcinoma. Am J Surg Pathol. 1989 May; 13(5):389-96.
3. Shah RB, Zhou M, LeBlanc M, Snyder M, Rubin MA. Comparison of the basal cell-specific markers, 34betaE12 and p63, in the diagnosis of prostate cancer. Am J Surg Pathol. 2002 Sep;26(9):1161-8.
4. Signoretti S, Waltregny D, Dilks J, Isaac B, Lin D, Garraway L, Yang A, Montironi R, McKeon F, Loda M. p63 is a prostate basal cell marker and is required for prostate development. Am J Pathol. 2000 Dec;157(6):1769-75.
5. Yang A, Kaghad M, Wang Y, Gillett E, Fleming MD, Dotsch V, Andrews NC, Caput D, McKeon F. p63, a p53 homolog at 3q27-29, encodes multiple products with transactivating, death-inducing, and dominant-negative activities. Mol Cell. 1998 Sep;2(3):305-16.
6. Yang A, Schweitzer R, Sun D, Kaghad M, Walker N, Bronson RT, Tabin C, Sharpe A, Caput D, Crum C, McKeon F. p63 is essential for regenerative proliferation in limb, craniofacial and epithelial development. Nature. 1999 Apr 22;398(6729):714-8.
a. Clinical Sensitivity: Not applicable
b. Clinical specificity: Not applicable
c. Other clinical supportive data (when a. and b. are not applicable): Not applicable
4. Clinical cut-off: Not applicable
5. Expected values/Reference range: See Figure above.
{5}
N. Proposed Labeling:
The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.
O. Conclusion:
The submitted information in this premarket notification is complete and supports a substantial equivalence decision.
6
Predicate graph will load when search results are available.
Embedding visualization will load when search results are available.
PDF viewer will load when search results are available.
Loading panels...
Select an item from Submissions
Click any panel, subpart, regulation, product code, or device to see details here.
Section Matches
Results will appear here.
Product Code Matches
Results will appear here.
Special Control Matches
Results will appear here.
Loading collections...
Loading
My Alerts
You will receive email notifications based on the filters and frequency you set for each alert.
Sort by:
Create Alert
Search Filters
Agent Token
Create a read-only bearer token for Claude, ChatGPT, or other agents that can call HTTP APIs.
Copy this now. It will not be shown again.
Connected apps
Apps you authorized through browser sign-in. Disconnecting revokes their access immediately.
Learn the FDA Browser
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.
