Toxogen is an in vitro diagnostic, rapid latex particle agglutination test for the qualitative and semiquantitative determination of total anti-toxoplasma antibodies in human serum. The test may be used with a single specimen to estimate the immunologic response of the individual or with paired acute and convalescent sera as an aid in the diagnosis of primary, acute or reactivated toxoplasmosis. This assay is not FDA cleared for use in blood or plasma donor screening.

Device Description

Toxogen is an in vitro diagnostic, rapid latex particle agglutination test for the qualitative and semiquantitative determination of total anti-toxoplasma antibodies in human serum. The new Toxogen is a modified version of the predicate Toxogen with a larger latex particle size to increase sensitivity from 10 IU/mL to 5 IU/mL.

AI/ML Overview

The provided text describes the Toxogen device, an in vitro diagnostic test for Toxoplasma gondii antibodies. Here's a breakdown of the acceptance criteria and study details:

1. Acceptance Criteria and Reported Device Performance

The acceptance criteria are implied by the comparison to a predicate device, focusing on maintaining or improving sensitivity and overall agreement.

Acceptance Criteria Category	Specific Metric	Reported Device Performance
Sensitivity	Improve or maintain sensitivity compared to predicate (target: 10 IU/mL to 5 IU/mL)	Relative sensitivity of 100% (compared to predicate Toxogen for qualitative method)
Specificity	Maintain specificity compared to predicate	Relative specificity of 91% (compared to predicate Toxogen for qualitative method)
Reproducibility	100% agreement within one 2-fold dilution for semiquantitative results	100% reproducibility (for semi-quantitative procedure)
Substantial Equivalence	Performance, intended use, safety, and effectiveness	Found substantially equivalent to predicate device

2. Sample Size and Data Provenance

Test Set Sample Size: 100 serum samples were used for the method comparison study (qualitative method). 9 serum samples (3 negative, 3 weak positive, 3 high positive) were used for the reproducibility study.
Data Provenance: Not explicitly stated (e.g., country of origin, retrospective/prospective).

3. Number of Experts and Qualifications for Ground Truth

Experts for Ground Truth: Not applicable or not specified. Ground truth appears to be based on comparison to a predicate device's results.
Qualifications of Experts: Not applicable, as expert involvement in establishing a gold standard is not mentioned.

4. Adjudication Method

Adjudication method: Not applicable. The study compares the new device's results directly against the predicate device's results, not an independent expert adjudication process.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

MRMC Study: No, there is no mention of a Multi-Reader Multi-Case (MRMC) comparative effectiveness study, nor any evaluation of human readers with or without AI assistance. This device is an in-vitro diagnostic test kit, not an AI or imaging device that would typically involve human reader studies.

6. Standalone Performance Study

Standalone Performance: Yes, the device's performance was evaluated in terms of its qualitative sensitivity and specificity against a predicate device, and its reproducibility. This is an evaluation of the algorithm/device's standalone performance.

7. Type of Ground Truth Used

Ground Truth Type: For the qualitative method comparison, the "ground truth" was established by the predicate Toxogen device's results. For the reproducibility study, the results were compared to each other across different operators and days to assess consistency.

8. Sample Size for the Training Set

Training Set Sample Size: Not applicable. The document describes a performance study for a diagnostic test kit, not a machine learning model, so there is no concept of a "training set" in this context.

9. How Ground Truth for the Training Set was Established

Ground Truth for Training Set: Not applicable, as there is no training set for this type of device.

Summary

{0}------------------------------------------------

SECTION 3 Toxogen - 510(k) SUMMARY (Summary of Safety and Effectiveness)

Submitted by:

Carol Marble Senior Regulatory Affairs Specialist Instrumentation Laboratory Company 113 Hartwell Avenue Lexington, MA 02173 Phone: (781) 861-4467 (781) 861-4464 Fax:

Contact Person:

Carol Marble Phone: (781) 861-4467

Summary Prepared:

April 6, 1997

Name of the device:

Toxogen

Classification name(s):

866.3780 Toxoplasma gondii serological reagents Class II

Identification of predicate device(s):

K913467/D Toxogen

Description of the device/intended use(s):

Statement of how the Technological Characteristics of the Device compare to the Predicate device:

The new Toxogen is a modified version of the predicate Toxogen with a larger latex particle size to increase sensitivity from 10 IU/mL to 5 IU/mL. It is substantially equivalent in performance, intended use, safety and effectiveness to the predicate device as supported by the performance data and labeling.

Summary of Performance Data:

In a method comparison study evaluating 100 serum samples using the qualitative method, the relative sensitivity of the modified Toxogen as compared to the predicate Toxogen was 100% and the relative specificity was 91%.

In a reproducibility study, a panel of 9 serum samples (3 negative, 3 weak positive and 3 high positive) was tested by three different operators on 3 consecutive days following the semiquantitative procedure for Toxogen. The results, as defined by the ability to give agreement to within one 2-fold dilution on the replicates indicated 100% reproducibility.

{1}------------------------------------------------

Image /page/1/Picture/1 description: The image is a black and white logo for the U.S. Department of Health & Human Services. The logo features a stylized image of an eagle with three lines forming its body and head. The words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" are arranged in a circular pattern around the eagle.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

AUG 6 1998

Carol Marble Senior Regulatory Affairs Specialist Instrument Laboratory 101 Hartwell Avenue Lexington, MA 02173-3190

K981263 Re: Trade Name: Toxogen Regulatory Class: II Product Code: GMM Dated: June 10, 1998 Received: June 11, 1998

Dear Ms. Marble:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we 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). You may, therefore, market the device, subject to the general controls provisions of the Act. 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.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic OS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

{2}------------------------------------------------

Page 2

Under the Clinical Laboratory Improvement Amendments of 1988 (CLIA-88), this device may require a CLIA complexity categorization. To determine if it does, you should contact the Centers for Disease Control and Prevention (CDC) at (770)488-7655.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll free number (800) 638-2041 or at (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html"

Sincerely vours.

Steven Butman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

{3}------------------------------------------------

Indications for Use Statement

510(k) Number (if known): ____________________________________________________________________________________________________________________________________________________

Device Name: Toxogen

Indications for Use:

This assay is not FDA cleared for use in blood or plasma donor screening.

(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Woody Dubois

510(k) Number

Prescription Use
(Per 21 CFR 801.019)

Over-The-Counter Use

Toxogen 510(k)

Regulation Number and Section

§ 866.3780

Toxoplasma gondii serological reagents.(a)
Identification. Toxoplasma gondii serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies toToxoplasma gondii in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye (immunofluorescent reagents) used to identifyToxoplasma gondii from clinical specimens. The identification aids in the diagnosis of toxoplasmosis caused by the parasitic protozoanToxoplasma gondii and provides epidemiological information on this disease. Congenital toxoplasmosis is characterized by lesions of the central nervous system, which if undetected and untreated may lead to brain defects, blindness, and death of an unborn fetus. The disease is characterized in children by inflammation of the brain and spinal cord.(b)
Classification. Class II (performance standards).