CEO SUMMARY: In May, the FDA announced clearance for Leica Biosystems to market its Aperio AT2 DX System for clinical diagnosis in the United States. The Aperio AT2 DX System is intended for in vitro diagnostic use as an aid to pathologists reviewing and interpreting digital images of surgical pathology slides prepared from formalin-fixed paraffin embedded (FFPE) tissue. U.S. pathologists now can choose between two FDA-cleared systems for digital pathology and whole-slide imaging.
PATHOLOGISTS INTERESTED IN USING DIGITAL PATHOLOGY AND WHOLE SLIDE IMAGING (WSI) for clinical diagnosis now have two systems to choose from after the Food and Drug Administration (FDA) cleared the Leica Biosystems Aperio AT2 DX System for clinical diagnosis in this country.
The agency’s action ended Philips’ two-year monopoly on the market for digital pathology and whole-slide imaging systems. In April 2017, the FDA authorized the marketing of the Philips IntelliSite Pathology Solutions (PIPS) whole-slide imaging system for the review and interpretation of digital surgical pathology slides prepared from biopsied tissue.
In May, Leica Biosystems of Vista, Calif., announced the FDA’s clearance to market of the Aperio AT2 DX System.
The AT2 DX is a scanning and viewing platform that will be launched commercially with clinical image management software, Leica said.
This second FDA clearance may accelerate the pathology profession’s transition to digital images as the standard of care in anatomic pathology.
In February, Leica submitted a 510(K) premarket submission to the FDA. For such an application, Leica needed to show that the device—or system in this case—is at least as safe and effective as another legally-marketed device, meaning the previously-cleared whole-slide imaging system from Philips.
In its application, Leica compared the AT2 DX to what the FDA calls a predicate device, the Philips IntelliSite Pathology Solution (PIPS). In 2017, the FDA cleared the PIPS for marketing in the United States. (See, “FDA Clears Digital Pathology for Primary Diagnosis,” TDR, April 24, 2017.)
In a two-page letter to Leica Biosystems Imaging on May 20, Yun-Fu Hu, PhD, Deputy Director of the FDA’s Division of Molecular Genetics and Pathology, explained that after the FDA reviewed Aperio’s application to market the device (the aforementioned Section 510(k) pre-market notification of intent to market), it determined that the AT2 DX system is substantially equivalent to the PIPS.
The AT2 DX system can create digital slides and allow pathologists to view those slides, the FDA said. “The system capabilities include digitizing microscope slides at diagnostic resolution, retrieving and displaying digital slides, including support for remote intranet access over computer networks, providing tools for annotating digital slides, entering data associated with digital slides, and displaying the scanned slide images for primary diagnoses by pathologists,” Aperio said.
To support the application, Leica conducted a study with pathologists at the University of California Davis, Pacific Rim Pathology, Dignity Health, TriCore Reference Laboratories, and Intermountain Healthcare.
16,000 Slides in the Study
The study was, “One of the largest clinical concordance studies ever completed on digital whole slide images,” Leica said in a news release. In the study, pathologists read approximately 16,000 cases and compared their reads of pathology slides under a microscope with on-screen digital reads, Leica added.
In reviewing Aperio’s application, the FDA said, “The precision of the device was based on five reading pathologists’ assessments and identification of specific histopathologic ‘features’ that are observed in FFPE hematoxylin and eosin (H&E) stained slides. Twenty-three (23) primary features were selected for the analytical studies. The selected primary features were evaluated at their relevant magnifications with twelve (12) primary features evaluated at 20x magnification level and eleven (11) primary features evaluated at 40x magnification level.”
The application also compared the predicate device with what the FDA called the “candidate device,” which was the Aperio AT2 DX system. The specimen types were the same for both: surgical pathology slides prepared from FFPE tissue.
The principles of operation also were the same: “During review, the pathologist opens WSI images acquired with the WSI scanner from the image storage, performs further QC, and reads WSI images of the slides to make a diagnosis.”
Intended Use of DP System
The intended use and indications for use were similar as well. In its application, Aperio described the intended use of the AT2 DX system and PIPS saying, both were “intended for in vitro diagnostic use as an aid to the pathologist to review and interpret digital images of surgical pathology slides prepared from formalin-fixed paraffin embedded (FFPE) tissue.”
Aperio also said neither the AT2 DX system nor the PIPS is intended for use “with frozen section, cytology, or non-FFPE hematopathology specimens.”
One significant difference was the Aperio AT2 DX scanner has a loading capacity of 400 slides, while the PIPS has a loading capacity of 300 slides. Aperio summarized the conclusions from the study, saying, “The clinical study results demonstrate that the AT2 DX system is substantially equivalent to the predicate device.”
For this article, Leica said it was not prepared “to communicate further” given The Dark Report’s deadline. Sources say that Leica may be developing a new strategy for how it will position the Aperio digital pathology system.