ATELLICA IM CA 19-9 (CA19-9)

Description of Event or Problem

THE CUSTOMER REPORTED AN OBSERVATION OF DISCORDANCE BETWEEN THE UNDILUTED AND DILUTED RESULTS OF A PATIENT SERUM SAMPLE TESTED WITH ATELLICA IM CA 19-9 LOT 539. THE INITIAL UNDILUTED RESULT WAS LOWER THAN EXPECTED BASED ON THE CLINICAL HISTORY OF THE PATIENT. THE RESULT WAS NOT REPORTED AND WAS RETESTED BY DILUTION (ON-BOARD AND MANUAL) ON A DIFFERENT ATELLICA IM ANALYZER. THE RESULTS WERE HIGHER AS EXPECTED AND CONSIDERED CORRECT. THERE ARE NO REPORTS OF ALTERED TREATMENT OR ADVERSE HEALTH CONSEQUENCES DUE TO THE DISCORDANT LOW CA 19-9 RESULT.

Additional Manufacturer Narrative

THIS INCIDENT OCCURRED OUTSIDE THE UNITED STATES (OUS). THE OUS CUSTOMER REPORTED AN OBSERVATION OF DISCORDANCE BETWEEN THE UNDILUTED AND DILUTED RESULTS OF A PATIENT SERUM SAMPLE TESTED WITH ATELLICA IM CA 19-9 LOT 539. THE INITIAL UNDILUTED RESULT WAS LOWER THAN EXPECTED BASED ON THE CLINICAL HISTORY OF THE PATIENT. THE RESULT WAS NOT REPORTED AND WAS RETESTED BY DILUTION (ON-BOARD AND MANUAL) ON A DIFFERENT ATELLICA IM ANALYZER. THE RESULTS WERE HIGHER AS EXPECTED AND CONSIDERED CORRECT. THERE ARE NO REPORTS OF ALTERED TREATMENT OR ADVERSE HEALTH CONSEQUENCES DUE TO THE DISCORDANT LOW CA 19-9 RESULT. THE INITIAL SAMPLE WAS ALSO TESTED WITH ALTERNATE METHODS (SIEMENS AND NON -SIEMENS) BY THE CUSTOMER. ACTUAL RESULTS HAVE NOT BEEN PROVIDED, BUT IT WAS NOTED THAT THE RESULTS WERE HIGHER THAN ATELLICA IM. THE ASSAY'S INSTRUCTIONS FOR USE (IFU) STATES THE FOLLOWING, UNDER INTERPRETATION OF RESULTS: "RESULTS OF THIS ASSAY SHOULD ALWAYS BE INTERPRETED IN CONJUNCTION WITH THE PATIENT'S MEDICAL HISTORY, CLINICAL PRESENTATION, AND OTHER FINDINGS." SIEMENS IS INVESTIGATING.

Additional Manufacturer Narrative

SIEMENS CONCLUDED INVESTIGATION FOR AN OUTSIDE OF THE US CUSTOMER COMPLAINT OF DISCORDANCE BETWEEN THE UNDILUTED AND DILUTED RESULTS OF A PATIENT SAMPLE TESTED WITH THE ATELLICA IM CA 19-9 ASSAY, LOT 539. SIEMENS INVESTIGATED CA 19-9 DILUTION-RECOVERY PERFORMANCE ACROSS MULTIPLE REAGENT LOTS, WHICH INCLUDED BOTH MANUAL AND AUTO 1:10 DILUTIONS WITH MEDICAL DECISION POOL (MDP) LEVEL 5, WHICH IS COMMUTABLE TO PATIENT SAMPLES, HIGH CALIBRATOR LOTS C941H, C943H AND C945H AND HIGH DOSE PATIENT SAMPLES. THE OBSERVED PERFORMANCE MET THE ATELLICA IM DESIGN VERIFICATION REQUIREMENTS, WHICH ALLOW A +/- 30% TOLERANCE FOR AUTO-DILUTION RECOVERY. FURTHER INVESTIGATION DEMONSTRATED THAT THE CA 19-9 ASSAY HAS MET ACCURACY SPECIFICATIONS FOR ALL INTERNAL CONTROL MATERIALS TESTED DURING LOT-QUALIFICATION TESTING OF LOTS RELEASED WITHIN THE PAST TWO YEARS. IT IS NOTED THAT DILUTION-RECOVERY PERFORMANCE IS NOT CONSISTENT ACROSS ALL SAMPLES, AND IT IS POSSIBLE THAT SOME PATIENT SAMPLES MAY EXHIBIT DILUTION OVER-RECOVERY WITH MUCIN/MUCIN-LIKE ASSAYS SUCH AS CA 19-9. THE PRODUCT¿S INSTRUCTIONS FOR USE (IFU) STATES ¿SAMPLE-DEPENDENT NONLINEAR DILUTIONS CAN BE OBSERVED.¿ [REFERENCE: WILD D, ED. THE IMMUNOASSAY HANDBOOK. 4TH ED. OXFORD, UK: ELSEVIER SCIENCE; 2013:842] ADDITIONALLY, IT IS IMPORTANT TO NOTE THAT THE ATELLICA IM CA19-9 IFU STATES THAT THE ASSAY IS USEFUL AS AN AID IN MONITORING THE STATUS OF PATIENTS HAVING CONFIRMED PANCREATIC CANCER WHO HAVE LEVELS OF SERUM AT SOME POINT EXCEEDING THE MEDIAN CONCENTRATION. THE ASSAY IS NOT INTENDED FOR SCREENING PURPOSES AND SHOULD ALWAYS BE USED IN CONJUNCTION WITH ALL OTHER CLINICAL AND LABORATORY DATA. THE ASSAY PROVIDES RESULTS FROM 1.20 ¿ 700 U/ML. ONLY SAMPLES WITH LEVELS >700 U/ML SHOULD BE DILUTED BEFORE RE-TESTING. BASED ON THE AVAILABLE INFORMATION, NO PRODUCT PROBLEM WAS IDENTIFIED, AND NO FURTHER INVESTIGATION IS REQUIRED. SIEMENS FILED MDR 1219913-2024-00444 WITH THE FDA ON 23-OCT-2024. IN SECTION H6 OF THIS REPORT, THE TYPE OF INVESTIGATION, INVESTIGATION FINDING, AND CONCLUSION CODES WERE UPDATED BASED ON THE INVESTIGATION RESULTS.