VITEK 2 AST-Gram Negative Ciprofloxacin (?0.06 - ?4 µg/mL)

{0} FDA U.S. FOOD & DRUG ADMINISTRATION # 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY ## I Background Information: A 510(k) Number K214023 B Applicant bioMérieux, Inc C Proprietary and Established Names VITEK 2 AST-Gram Negative Ciprofloxacin (≤0.06 - ≥4 μg/mL) D Regulatory Information | Product Code(s) | Classification | Regulation Section | Panel | | --- | --- | --- | --- | | LON | Class II | 21 CFR 866.1645 - Fully Automated Short-Term Incubation Cycle Antimicrobial Susceptibility System | MI - Microbiology | | LTT | Class II | 21 CFR 866.1640 - Antimicrobial susceptibility test powder | MI - Microbiology | | LTW | Class II | 21 CFR 866.1640 - Antimicrobial susceptibility test powder | MI - Microbiology | ## II Submission/Device Overview: ### A Purpose for Submission: To update the VITEK 2 AST Gram Negative Ciprofloxacin device labeling to include updated FDA-recognized breakpoints for Enterobacterales and Pseudomonas aeruginosa, as published in the FDA STIC website. Breakpoints for Salmonella spp. (also indicated for use with this device) remain unchanged. Previously obtained QC and reproducibility data is applicable to this reevaluation. Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993-0002 www.fda.gov {1} B Measurand: Ciprofloxacin (≤0.06 – ≥4 μg/ml) C Type of Test: Automated quantitative or qualitative antimicrobial susceptibility test III Intended Use/Indications for Use: A Intended Use(s): The VITEK 2 Gram-Negative Susceptibility Card is intended for use with the VITEK 2 Systems in clinical laboratories as an in vitro test to determine the susceptibility of clinically significant aerobic Gram-negative bacilli to antimicrobial agents when used as instructed. B Indication(s) for Use: VITEK 2 AST-Gram Negative Ciprofloxacin is designed for antimicrobial susceptibility testing of Gram negative bacilli and is intended for use with the VITEK 2 and VITEK 2 Compact Systems as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents. VITEK 2 AST-Gram Negative Ciprofloxacin is a quantitative test. Ciprofloxacin has been shown to be active against most strains of the microorganisms listed below, according to the FDA label for this antimicrobial. Active both in vitro and in clinical infections: - Citrobacter koseri - Citrobacter freundii - Enterobacter cloacae - Escherichia coli - Klebsiella pneumoniae - Morganella morganii - Proteus mirabilis - Proteus vulgaris - Providencia rettgeri - Providencia stuartii - Pseudomonas aeruginosa - Salmonella typhi - Serratia marcescens - Shigella sonnei In vitro data available but clinical significance is unknown: - Klebsiella aerogenes - Klebsiella oxytoca - Salmonella enteritidis The VITEK 2 Gram-Negative Susceptibility Card is intended for use with the VITEK 2 Systems in clinical laboratories as an in vitro test to determine the susceptibility of clinically significant aerobic Gram-negative bacilli to antimicrobial agents when used as instructed. K214023 - Page 2 of 14 {2} C Special Conditions for Use Statement(s): Rx - For Prescription Use Only Due to the occurrence of minor errors (resulting in a category agreement below 90% for the following species), perform an alternative method of testing prior to reporting of results for the following antibiotic/organism combination: Ciprofloxacin (cip02): MICs of 0.25μg/mL or 0.5 μg/mL for P. rettgeri Due to the occurrence of minor errors (resulting in a categorical agreement below 90% for the manual dilution option), perform an alternative method of testing prior to reporting of results generated with the manual dilution option for the following antibiotic/organism combinations: Ciprofloxacin (cip02): MIC of 0.5 μg/mL for S. marcescens, K. pneumoniae The ability of the AST card to detect resistance with the following combination(s) is unknown because resistant strains were not available at the time of comparative testing: Ciprofloxacin: Salmonella enteridis, Salmonella typhi and Shigella sonnei D Special Instrument Requirements: VITEK 2 and VITEK 2 Compact Systems using VITEK 2 Systems 8.01 software (or later) IV Device/System Characteristics: A Device Description: The VITEK 2 AST card is a miniaturized, abbreviated and automated version of the doubling dilution technique for determining the minimum inhibitory concentration (MIC). Each VITEK 2 AST card contains 64 wells. A control well(s) which contain only nutrient medium is resident on all cards. The remaining wells contain premeasured portions of antimicrobials combined with the nutrient media. The isolate to be tested is diluted to a standardized concentration with 0.45% to 0.50% saline before being used to rehydrate the antimicrobial medium within the card. The VITEK 2 System will automatically (or allow operator to manually) dilute the bacterial suspension to prepare an inoculum for susceptibility cards. Then, the VITEK 2 will fill, seal and place the card into the incubator/reader. The VITEK 2 Compact has a manual filling, sealing, and loading operation. The VITEK 2 Systems monitor the growth of each well in the card over a defined period of time. The analysis program determines when a well demonstrates growth based on attenuation of light measured by an optical scanner. This data is used to determine the minimum inhibitory concentration or "MIC" values for the antimicrobial agent. At the completion of the incubation cycle, a report is generated that contains the MIC value along with the interpretive category result for each antimicrobial contained on the card. VITEK 2 AST-Gram Negative Ciprofloxacin has the following concentrations in the card: 0.06, 0.12, 0.5 and 1 μg/mL (equivalent standard method concentration by efficacy in μg/mL). The ciprofloxacin MIC result range for the VITEK 2 is ≤0.06 to ≥4 μg/mL. For all species, the VITEK 2 system is capable of reporting the following MIC results: ≤0.06, 0.12, 0.25, 0.5, 1, 2, and ≥4 μg/mL for the AST-Gram Negative Ciprofloxacin test. K214023 - Page 3 of 14 {3} K214023 - Page 4 of 14 B Principle of Operation: The VITEK 2 and VITEK 2 Compact Systems utilize automated growth-based detection using attenuation of light measured by an optical scanner. The optics in the systems use visible light to directly measure organism growth within each of the 64 micro-wells. Transmittance optics is based on an initial light reading of a well before significant growth has begun. Every 15 minutes throughout the incubation cycle (defined period of time based on the VITEK 2 card), light transmittance readings of each well determine organism growth by the amount of light that is prevented from passing through the well. At the completion of the incubation period, the MIC values and their associated interpretive category results for each antimicrobial on the test card are displayed in an automatically generated report. V Substantial Equivalence Information: A Predicate Device Name(s): VITEK 2 AST-Gram Negative Eravacycline (≤0.12 - ≥4μg/mL) B Predicate 510(k) Number(s): K191766 C Comparison with Predicate(s): | | Device: K214023 | Predicate: K191766 | | --- | --- | --- | | Device Trade Name | VITEK 2 AST-Gram Negative Ciprofloxacin (≤0.06 - ≥4 μg/mL) | VITEK 2 AST-Gram Negative Eravacycline (≤0.12 - ≥4μg/mL) | | General Device Characteristic Similarities | | | | Intended Use | The VITEK 2 Gram-Negative Susceptibility Card is intended for use with the VITEK 2 Systems in clinical laboratories as an in vitro test to determine the susceptibility of clinically significant aerobic Gram-negative bacilli to antimicrobial agents when used as instructed. | Same | | Test Method | Automated quantitative antimicrobial susceptibility test for use with the VITEK 2 and VITEK 2 Compact Systems to determine the in vitro susceptibility of Gram-negative bacilli | Same | | Inoculum | Standardized saline suspension of test organism | Same | | Test Card | VITEK 2 Gram Negative Susceptibility Test Card | Same | | Instrument | VITEK 2 and VITEK 2 Compact Systems | Same | {4} | | Device: K214023 | Predicate: K191766 | | --- | --- | --- | | Analysis Algorithm | Growth pattern analysis | Same | | General Device Characteristic Differences | | | | Antimicrobial Agent | Ciprofloxacin | Eravacycline | | Antimicrobial Concentrations | 0.06, 0.12, 0.5 and 1 μg/mL | 0.25, 1, 2 and 4 μg/mL | | Reporting Range | ≤0.06 to ≥4 μg/mL | ≤0.12 to ≥4 μg/mL | | Indicated Organisms | Active in vitro and in clinical infections: Citrobacter koseri, Citrobacter freundii, Enterobacter cloacae Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Proteus mirabilis Proteus vulgaris, Providencia rettgeri, Providencia stuartii, Pseudomonas aeruginosa, Salmonella typhi, Serratia marcescens, Shigella sonnei In vitro data available but clinical significance is unknown: Klebsiella aerogenes, Klebsiella oxytoca, Salmonella enteritidis | Active in vitro and in clinical infections: Citrobacter freundii, Enterobacter cloacae, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae In vitro data available but clinical significance is unknown: Citrobacter koseri, Klebsiella (Enterobacter) aerogenes | VI Standards/Guidance Documents Referenced: Data that was reanalyzed to support this submission was obtained from a previously completed clinical study. The clinical study was reviewed and cleared in K162737. The CLSI Standards and FDA guidance document listed below were effective during the original clearance: - CLSI M100-S24: Performance Standards for Antimicrobial Susceptibility Testing; Twenty-fourth Informational Supplement, Vol. 34 No. 1 (January 2014) - CLSI M07-A9: Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standard-Ninth Edition” Vol. 32 No, 2 (January 2012) - Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA (Issued August 28, 2009) Additional testing (described below) was performed and included in support of this submission. The CLSI Standards and FDA guidance document listed below were effective during the additional testing: - CLSI M100-S29: Performance Standards for Antimicrobial Susceptibility Testing; Twenty-ninth Informational Supplement, Vol. 39 No. 1 (January 2019) K214023 - Page 5 of 14 {5} - CLSI M07-A10: Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standard-Tenth Edition” Vol. 35 No, 2 (January 2015) - Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA (Issued August 28, 2009) A revised edition of the CLSI M100 document became available after receipt of this submission by FDA. As noted below, the revised version updated the recommended quality control reporting range for *P. aeruginosa* ATCC 27853. The CLSI Standard listed below was effective during the clearance of this submission: - CLSI M100-S31: Performance Standards for Antimicrobial Susceptibility Testing; Thirty-first Informational Supplement, Vol. 41 No. 3 (March 2021) ## VII Performance Characteristics (if/when applicable): ### A Analytical Performance: 1. **Precision/Reproducibility:** Reproducibility of the VITEK 2 AST-GN Ciprofloxacin was previously evaluated during review of K162737 and was determined to be acceptable. In summary, a 10-isolate panel composed of species consistent with the intended use were tested at three sites using both inoculation methods (manual and automatic) for testing with the VITEK 2 and the manual inoculation method for testing with the VITEK 2 Compact. 2. **Linearity:** Not applicable 3. **Analytical Specificity/Interference:** Not applicable 4. **Assay Reportable Range:** Not applicable 5. **Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):** Quality Control (QC) testing, Inoculum and Growth failure for the VITEK 2 GN-AST Ciprofloxacin were previously evaluated during review of K162737 and were determined to be acceptable. QC specific to the change in breakpoints was not performed since the QC ranges used in K162737 were either unchanged (*E. coli* ATCC 25922) or expanded (*P. aeruginosa* ATCC 27853; range expanded from 0.25 – 1 µg/mL to 0.12 – 1 µg/mL) and therefore would not negatively impact QC performance. QC results with unchanged and expanded QC ranges are shown in Table 1. In summary, QC organisms recommended by both the FDA and CLSI, namely *E. coli* ATCC 25922 and *P. aeruginosa* ATCC 27853, were tested using the reference broth microdilution (BMD) method and the VITEK 2 GN-AST Ciprofloxacin during the clinical study. The overall QC results for both the reference and VITEK 2 were acceptable. Both the BMD dilution range (≤0.008 – ≥8 µg/mL) and the VITEK 2 Ciprofloxacin card (≤0.06 – ≥4 µg/mL) covered the full expected result range of *P. aeruginosa* ATCC 27853 (expected range of K214023 - Page 6 of 14 {6} 0.12-1 μg/mL); however, resulted in off-scale MIC values for E. coli ATCC 25922 (expected range of 0.004-0.016 μg/mL). An E. coli ATCC 25922 MIC value of ≤0.008 μg/mL (with BMD) and ≤0.06 μg/mL (with VITEK 2) indicated that the quality control test results were acceptable. To address the expected off-scale QC results when testing E. coli ATCC 25922, the device labeling reviewed in the current submission includes the following footnote under the Quality Control Table: “Does not include the full CLSI/FDA recommended dilution range for QC testing with this organism”. Table 1. Quality Control Result Frequencies for VITEK 2 (Auto-Dilution and Manual Dilution Methods) and VITEK 2 Compact (Manual Dilution Method) | Organism | VITEK 2 Result Range^{1} (μg/mL) | BMD^{2} Result Range (μg/mL) | VITEK 2 Auto-Dilution | BMD | VITEK 2 Manual Dilution | BMD | VITEK 2 Compact Manual Dilution | BMD | | --- | --- | --- | --- | --- | --- | --- | --- | --- | | E. coli (ATCC 25922) Expected Range: 0.004-0.016 μg/mL | | ≤0.008 | | 200 | | 102 | | 102 | | | 0.016 | | 21 | | 7 | | 7 | | | 0.03 | | | | | | | | ≤0.06 | 0.06 | 222 | | 109 | | 109 | | | 0.125 | 0.12 | | | | | | | | 0.25 | 0.25 | | | | | | | | 0.5 | 0.5 | | | | | | | | 1 | 1 | | | | | | | | 2 | 2 | | | | | | | | ≥4 | 4 | | | | | | | | | ≥8 | | | | | | | | P. aeruginosa (ATCC 27853) Expected Range: 0.12-1 μg/mL | | ≤0.008 | | | | | | | | | 0.016 | | | | | | | | | 0.03 | | | | | | | | ≤0.06 | 0.06 | 1 | | | | | | | 0.12 | 0.12 | 1 | 1 | | 1 | | 1 | | 0.25 | 0.25 | 18 | 98 | 9 | 52 | 13 | 52 | | 0.5 | 0.5 | 200 | 119 | 98 | 52 | 93 | 52 | | 1 | 1 | | 2 | | 2 | 1 | 2 | | 2 | 2 | | | | | | | | ≥4 | 4 | | | | | | | | | ≥8 | | | | | | | 1 VITEK 2 Card range for Ciprofloxacin is ≤0.06 - ≥4 μg/mL and does not include the full CLSI/FDA-recommended dilution range for QC testing of E. coli ATCC 25922. The lowest concentration of the VITEK 2 Ciprofloxacin MIC range is 0.06 μg/mL. Obtaining a value of ≤0.06 μg/mL was considered an indication that the quality control test results were acceptable. Similarly, the lowest concentration of the BMD Ciprofloxacin MIC range is 0.008 μg/mL. Obtaining a value of ≤0.008 μg/mL was considered an indication that the quality control test results were acceptable. 2 BMD: CLSI reference broth microdilution. Since the full QC range was covered for P. aeruginosa ATCC 27853, the QC performance data is acceptable for the purpose of re-evaluating Enterobacteriales and P. aeruginosa performance when the updated breakpoints are applied. K214023 - Page 7 of 14 {7} 6. Detection Limit: Not applicable 7. Assay Cut-Off: Not applicable ## B Comparison Studies: ### 1. Method Comparison with Reference Method: #### Performance after reanalysis and additional testing The VITEK 2 AST-GN Ciprofloxacin ($\leq 0.06 - \geq 4\ \mu\mathrm{g/mL}$) was originally cleared in premarket submission K162737. Since there were no changes to the design or dilution range of the VITEK 2 AST card, performance evaluation was achieved via reanalysis of the MIC data provided in the original 510(k) submission (K162737) using revised interpretive criteria currently recognized by FDA for ciprofloxacin against Enterobacterales and *P. aeruginosa*. An additional 88 isolates were added to the original 890 Enterobacteriaceae (Enterobacterales) data set for evaluation of the VITEK 2/automatic dilution method to address a lack of resistant isolates and potential categorical errors as a consequence of the revised interpretive criteria (43 Serratia marcescens, 6 Enterobacter cloacae, 2 Enterobacter cloacae cloacae, 22 Enterobacter cloacae complex, and 15 Providencia rettgeri isolates). In addition, one Klebsiella pneumonia pneumoniae isolate was removed from the reanalysis due to a prior misidentification; this isolate has now been identified as Acinetobacter baumannii complex, a species for which FDA does not have recognized breakpoints, resulting in a total of 977 (908 clinical and 69 challenge) Enterobacterales isolates for analysis using revised interpretive criteria for Enterobacterales. No additional testing was performed for *P. aeruginosa* and the original 236 (146 clinical and 90 challenge) isolate data set was reanalyzed using the revised interpretive criteria for *P. aeruginosa*. The VITEK 2 with automatic dilution method results are shown in Table 2 for the reanalysis of data based on the updated interpretive criteria for Enterobacterales and *P. aeruginosa*. For Enterobacterales, this included the original clinical and challenge data combined with the data after additional testing. For *P. aeruginosa*, this was based only on the original clinical and challenge data combined since no additional testing was performed. The VITEK 2 and VITEK 2 Compact systems with manual dilution method results of the reanalyzed challenge data with updated Enterobacterales and *P. aeruginosa* interpretive criteria are summarized in Table 3. Original data obtained with Salmonella spp. was not reanalyzed since the interpretive criteria remain unchanged since the original submission. Table 2. Reanalysis of Performance with the Original and Expanded Enterobacterales Isolates and Original *P. aeruginosa* Isolates with the VITEK 2 (Auto Dilution)ᵃ | | Tot | No.EA | EA % | Eval EA Tot | No. Eval EA | Eval EA % | No. CA | CA % | No. R | No. S | min | maj | vmj | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Enterobacteralesᵇ, ≤0.25 (S), 0.5 (I), ≥1 (R) | | | | | | | | | | | | | | | Clinical | 908 | 888 | 97.8 | 110 | 90 | 81.8 | 874 | 96.3 | 216 | 681 | 32 | 1 | 1 | | Challenge | 69 | 69 | 100 | 37 | 37 | 100 | 56 | 81.2 | 25 | 33 | 13 | 0 | 0 | | Combined | 977 | 957 | 97.9 | 147 | 127 | 86.4 | 930 | 95.2 | 241 | 714 | 45 | 1 | 1 | ᵃ: 510 (K162737) = 510 (K162737) ᵇ: 236 (K162737) = 236 (K162737) ᶜ: 908 (K162737) = 908 (K162737) ᵈ: 236 (K162737) = 236 (K162737) K214023 - Page 8 of 14 {8} | | Tot | No.EA | EA % | Eval EA Tot | No. Eval EA | Eval EA % | No. CA | CA % | No. R | No. S | min | maj | vmj | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Pseudomonas aeruginosa, ≤0.5 (S), 1 (I), ≥2 (R) | | | | | | | | | | | | | | | Clinical | 146 | 132 | 90.4 | 95 | 81 | 85.3 | 140 | 95.9 | 32 | 107 | 6 | 0 | 0 | | Challenge | 90 | 89 | 98.9 | 24 | 23 | 95.8 | 88 | 97.8 | 67 | 22 | 2 | 0 | 0 | | Combined | 236 | 221 | 93.6 | 119 | 104 | 87.4 | 228 | 96.6 | 99 | 129 | 8 | 0 | 0 | | Organism Group: Salmonellaa, ≤0.0625 (S), 0.12-0.5 (I), ≥1 (R) | | | | | | | | | | | | | | | Clinical | 11 | 11 | 100 | 4 | 4 | 100 | 11 | 100 | 3 | 6 | 0 | 0 | 0 | | Challenge | 10 | 10 | 100 | 2 | 2 | 100 | 10 | 100 | 0 | 8 | 0 | 0 | 0 | | Combined | 21 | 21 | 100 | 6 | 6 | 100 | 21 | 100 | 3 | 14 | 0 | 0 | 0 | aPerformance with Salmonella spp. was not reanalyzed since breakpoints remain unchanged. $^b$ Enterobacterales isolates evaluated include: 54 C. freundii, 45 C. koseri, 47 E. aerogenes, 38 E. cloacae, 43 E. cloacae complex, 26 E. cloacae ssp. cloacae, 152 E. coli, 51 K. oxytoca, 53 K. pneumoniae, 112 K. pneumoniae ssp. pneumoniae, 12 M. morganii, 18 M. morganii ssp. morganii, 59 P. mirabilis, 29 P. vulgaris, 57 P. rettgeri, 26 P. stuartii, 134 S. marcescens, 21 Shigella ssp. EA - Essential Agreement min - minor errors CA - Category Agreement maj - major errors EVAL - Evaluable isolates vmj - very major errors R - Resistant isolates Essential Agreement (EA) occurs when there is agreement between the MIC result of the reference method and that of the VITEK 2 test card within plus or minus one serial two-fold dilution of the antibiotic. Evaluable results are those that are on scale for both the VITEK 2 test card and the reference method or those in which an off scale result is at least two doubling dilutions from the on scale result. Category Agreement (CA) occurs when the interpretation of the result of the reference method agrees exactly with the interpretation of the VITEK 2 test card. The combined Essential Agreement (EA) for Enterobacterales is $>90\%$ which is acceptable, as described in the "Class II Special Control Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA, August 2009" (AST guidance). The updated breakpoints for Enterobacterales lowered the susceptible, intermediate and resistant breakpoints by two two-fold dilutions. Applying the updated breakpoints for Enterobacterales reduced the combined Category Agreement (CA) from $97.8\%$ in K162737 to $95.2\%$ in the current submission, due to an increase in minor errors from 18 $(2.0\%)$ to 45 $(4.6\%)$ and very major errors from 0 $(0\%)$ to 1 $(0.4\%)$ . These results are acceptable. The combined EA for $P$ aeruginosa is $>90\%$ which is acceptable, as described in the AST guidance. The updated breakpoints for $P$ aeruginosa lowered the susceptible, intermediate and resistant breakpoints by one two-fold dilution. Applying the updated breakpoints for $P$ aeruginosa increased the combined CA from $94.1\%$ in K162737 to $96.6\%$ in the current submission, due to a decrease in minor errors from 12 (5.1%) to 8 (3.4%), major errors from 1 (0.7%) to 0 (0%), and very major errors from 1 (1.1%) to 0 (0%). K214023 - Page 9 of 14 {9} Table 3. Reanalysis of Performance with the Original Enterobacterales and P. aeruginosa Challenge Isolates with the VITEK 2 and VITEK 2 Compact Systems (Manual Dilution)ᵃ | | Tot | No.EA | EA % | Eval EA Tot | No. Eval EA | Eval EA % | No. CA | CA % | No. R | No. S | min | maj | vmj | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Enterobacterales, ≤0.25 (S), 0.5 (I), ≥1 (R) | | | | | | | | | | | | | | | VITEK 2 | 69 | 69 | 100 | 38 | 38 | 100 | 57 | 82.61 | 25 | 33 | 12 | 0 | 0 | | VITEK 2 Compact | 69 | 67 | 97.1 | 37 | 35 | 94.59 | 54 | 78.26 | 25 | 33 | 15 | 0 | 0 | | Pseudomonas aeruginosa, ≤0.5 (S), 1 (I), ≥2 (R) | | | | | | | | | | | | | | | VITEK 2 | 90 | 90 | 100 | 23 | 23 | 100 | 87 | 96.67 | 67 | 22 | 3 | 0 | 0 | | VITEK 2 Compact | 90 | 89 | 98.89 | 24 | 23 | 95.83 | 87 | 96.67 | 67 | 22 | 3 | 0 | 0 | | Salmonellaᵃ, ≤0.0625 (S), 0.12-0.5 (I), ≥1 (R) | | | | | | | | | | | | | | | VITEK 2 | 10 | 10 | 100 | 2 | 2 | 100 | 10 | 100 | 0 | 8 | 0 | 0 | 0 | | VITEK 2 Compact | 10 | 10 | 100 | 2 | 2 | 100 | 10 | 100 | 0 | 8 | 0 | 0 | 0 | ᵃPerformance with Salmonella spp. was not reanalyzed since breakpoints remain unchanged. EA – Essential Agreement min – minor errors CA – Category Agreement maj – major errors EVAL – Evaluable isolates vmj – very major errors R – Resistant isolates Essential Agreement (EA) occurs when there is agreement between the MIC result of the reference method and that of the VITEK 2 test card within plus or minus one serial two-fold dilution of the antibiotic. Evaluable results are those that are on scale for both the VITEK 2 test card and the reference method or those in which an off scale result is at least two doubling dilutions from the on scale result. Category Agreement (CA) occurs when the interpretation of the result of the reference method agrees exactly with the interpretation of the VITEK 2 test card. The EA of Enterobacterales challenge isolates is >90% with the manual dilution option of the VITEK 2 and VITEK 2 Compact instruments, which is acceptable. However, applying the updated breakpoints for Enterobacterales resulted in low CA for both VITEK 2 and VITEK 2 Compact, which was caused by the large number of minor errors. Since the EA of evaluable results is >90% and the majority of the categorical errors were minor errors, the following limitations are added to the package insert to address the low CA with the manual dilution option and the number of minor errors generated with the automatic and manual dilution options: Due to the occurrence of minor errors (resulting in a category agreement below 90% for the following species), perform an alternative method of testing prior to reporting of results for the following antibiotic/organism combination: Ciprofloxacin (cip02): MICs of 0.25μg/mL or 0.5 μg/mL for P. rettgeri Due to the occurrence of minor errors (resulting in a categorical agreement below 90% for the manual dilution option), perform an alternative method of testing prior to reporting of results generated with the manual dilution option for the following antibiotic/organism combinations: Ciprofloxacin (cip02): MIC of 0.5 μg/mL for S. marcescens, K. pneumoniae K214023 - Page 10 of 14 {10} The EA of *P. aeruginosa* challenge isolates is >90% with the manual dilution option of the VITEK 2 and VITEK 2 Compact instruments, which is acceptable. Applying the updated breakpoints for *P. aeruginosa* resulted in >90% CA, three minor errors (3.3%), and zero major or very major errors, which is acceptable. As required under 511A(b)(2)(C)(ii)(I) of the Federal Food, Drug and Cosmetic Act, the following statement is included in the device labeling to address testing of non-indicated species: Per the FDA-Recognized Susceptibility Test Interpretive Criteria website, the safety and efficacy of antimicrobial drugs, for which antimicrobial susceptibility is tested by this AST device, may or may not have been established in adequate and well-controlled clinical trials for treating clinical infections due to microorganisms outside of those found in the indications and usage in the drug label. The clinical significance of susceptibility information in those instances is unknown. The approved labeling for specific antimicrobial drugs provides the uses for which the antimicrobial drug is approved. ## Resistant Organisms A total of 129 (14.5%) *Enterobacteriaceae*, 3 (14.2%) *Salmonella* spp., and 90 (38.1%) *P. aeruginosa* isolates) were originally found to be resistant to ciprofloxacin by the reference method (K162737). After applying the updated breakpoints for *Enterobacterales* and *P. aeruginosa* and including data from the additional testing with *Enterobacterales*, a total of 241 (24.7%) *Enterobacterales* isolates and 99 (41.9%) of *P. aeruginosa* isolates were determined to be resistant to ciprofloxacin by the reference method. As an impact from the change in breakpoints and the testing of additional challenge *Enterobacterales* isolates the resistance rates have slightly increased compared to the original clearance providing more datapoints for assessing CA and error rates. Based on the time of initial testing, the resistant strains evaluated in the original study likely represent the current resistance population. Additional testing with 28 *Enterobacter cloacae* spp. and 20 *Providencia rettgeri* resistant isolates resulted in the removal of these species from the original limitation statement regarding a lack of testing with resistant organisms. As such, the limitation statement has been updated as follows: The ability of the AST card to detect resistance with the following combination(s) is unknown because resistant strains were not available at the time of comparative testing: *Ciprofloxacin*: *Salmonella enteritidis*, *Salmonella typhi* and *Shigella sonnei* ## MIC Trending Analysis A trending reanalysis was performed using the combined (clinical and challenge) *Enterobacterales* and *P. aeruginosa* data obtained in K162737 to align with current trending analysis methods utilized and to also assess the data from additional testing with *Enterobacterales* isolates with the VITEK 2 auto-dilution method. This trending calculation takes into account MIC values that are determined to be one or more doubling dilutions lower or higher than the reference method irrespective of whether the device MIC values are on-scale or not. Results that are not clearly at least one dilution K214023 - Page 11 of 14 {11} lower, at least one dilution higher or in exact agreement with the CLSI reference method are not considered in the trending analysis. Organisms in which the difference between the percentage of isolates with higher vs. lower MIC values was $\geq 30\%$ and for which the confidence interval was determined to be statistically significant were considered to show evidence of trending. Trending that showed higher or lower MIC values compared to the reference is addressed in the labeling. Table 4. Trending analysis of the VITEK 2 Gram Negative Ciprofloxacin | Organism Group | Total Evaluable for Trending | >= 1 Dilution Lower No. (%) | Exact No. (%) | >= 1 Dilution Higher No. (%) | Percent Difference (95% CI) | Trending Noted | | --- | --- | --- | --- | --- | --- | --- | | Enterobacterales | 198 | 52 (26.26) | 55 (27.78) | 91 (45.96) | 19.7% (10.26 to 28.65) | No | | Citrobacter freundii | 16 | 3 (18.75) | 8 (50.00) | 5 (31.25) | 12.5% (-17.17 to 39.71) | No | | Citrobacter koseri | 0 | 0 | 0 | 00 | 0 | NA | | Enterobacter aerogenes | 3 | 1 (33.33) | 0 | 2 (66.67) | 33.33% (-31.58 to 71.78) | Yes* | | Enterobacter cloacae^{1} | 18 | 2 (11.11) | 5 (27.78) | 11 (61.11) | 50% (18.75 to 70.24%) | Yes | | Escherichia coli | 17 | 0 | 1 (5.88) | 16 (94.12) | 94.12% (66.10 to 98.95) | Yes | | Klebsiella oxytoca | 9 | 1 (11.11) | 4 (44.44) | 4 (44.44) | 33.33% (-7.93 to 63.63) | Yes* | | Klebsiella pneumoniae^{2} | 22 | 2 (9.09) | 11 (50.00) | 9 (40.91) | 31.82% (6.08 to 53.21) | Yes | | Morganella morganii^{3} | 4 | 0 | 2 (50.00) | 2 (50.00) | 50.00% (-10.21 to 85.00) | Yes* | | Proteus mirabilis | 6 | 1 (16.67) | 1 (16.67) | 4 (66.67) | 50% (-4.04 to 77.32) | Yes* | | Proteus vulgaris | 5 | 0 | 0 | 5 (100) | 100% (38.55 to 100) | Yes | | Providencia rettgeri | 28 | 9 (32.14) | 7 (25.00) | 12 (42.86) | 10.71% (-13.99 to 33.70) | No | | Providencia stuartii | 4 | 0 | 0 | 4 (100) | 100% (30.72 to 100) | Yes | | Serratia marcescens | 64 | 33 (51.56) | 15 (23.44) | 16 (25.00) | -26.56% (-41.40 to -9.73) | No | | Shigella sonnei | 2 | 0 | 1 (50.00) | 1 (50.00) | 50.00% (-27.26 to 90.55) | Yes* | | Shigella spp | 0 | 0 | 0 | 0 | 0 | NA | | Pseudomonas aeruginosa | 134 | 19 (14.18) | 41 (30.60) | 74 (55.22) | 41.04% (30.13 to 50.57) | Yes | | Salmonella spp. | 6 | 0 | 2 (33.33) | 4 (66.67) | 66.67% (13.11 to 90.32) | Yes | | Salmonella ser. Enteritidis | 2 | 0 | 1 (50.00) | 1 (50.00) | 50.00% (-27.26 to 90.55) | Yes* | | Salmonella ser. Typhi | 4 | 0 | 1 (25.00) | 3 (75.00) | 75.00% (8.52 to 95.44) | Yes | *95% Confidence interval not statistically significant. 1Includes Enterobacter cloacae (5), Enterobacter cloacae complex (8), and Enterobacter cloacae ssp. cloacae (5) isolates. 2Includes Klebsiella pneumoniae (4) and Klebsiella pneumoniae ssp. pneumoniae (18) isolates. 3Includes Morganella morganii (1) and Morganella morganii ssp. morganii (3) isolates. A statistically significant trend toward higher MIC values was observed Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Providencia stuartii, Pseudomonas aeruginosa and Salmonella species. The following footnote to the performance table is included in the package insert to address the trending observed for VITEK 2 AST-GN Ciprofloxacin: Ciprofloxacin MIC values for Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Providencia stuartii, Pseudomonas aeruginosa and Salmonella species tended to be in exact agreement or at least one doubling dilution higher than the reference method. K214023 - Page 12 of 14 {12} 2. Matrix Comparison: Not applicable # C Clinical Studies: 1. Clinical Sensitivity: Not applicable 2. Clinical Specificity: Not applicable 3. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable): Not applicable # D Clinical Cut-Off: Not applicable # E Expected Values/Reference Range: The FDA and CLSI susceptibility interpretive criteria for Ciprofloxacin are as listed in Table 5. Table 5. FDA Recognized Interpretive Criteria for Ciprofloxacin | | Minimum Inhibitory Concentrations (μg/mL)a | | | | --- | --- | --- | --- | | Organisms | S | I | R | | Enterobacteriaceae | ≤0.25 | 0.5 | ≥1 | | Salmonella spp. | ≤0.06 | 0.12 - 0.5 | ≥1 | | Pseudomonas aeruginosa | ≤0.5 | 1 | ≥2 | S = Susceptible; I = Intermediate; R = Resistant aAccording to CLSI M100-Ed31 and FDA STIC Website https://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResour ces/ucm410971.htm # VIII Proposed Labeling: The labeling was updated as follows: - Inclusion of a statement to address testing of non-indicated species, as required by the $21^{\text{st}}$ Century Cures Act legislation - Updated breakpoints for Enterobacterales and Pseudomonas aeruginosa with Ciprofloxacin - Updated performance data using the currently recognized breakpoints, along with limitation statements to reflect results obtained from this evaluation - Inclusion of a footnote to the performance table to reflect results obtained from a trending analysis - Update of the previous limitation statement regarding lack of testing with resistant organisms to only include Salmonella enteritidis, Salmonella typhi and Shigella sonnei The labeling supports the finding of substantial equivalence for this device. K214023 - Page 13 of 14 {13} IX Conclusion: The submitted information in this premarket notification is complete and supports a substantial equivalence decision. To support the implementation of changes to FDA-recognized susceptibility test interpretive criteria (i.e., breakpoints), this submission included a breakpoint change protocol that was reviewed and accepted by FDA. This protocol addresses future revisions to device labeling in response to breakpoint changes that are recognized on the FDA STIC webpage (https://www.fda.gov/Drugs/DevelopmentApprovalProcess/DevelopmentResources/ucm410971.htm). The protocol outlined the specific procedures and acceptance criteria that bioMérieux intends to use to evaluate the VITEK 2 System with Ciprofloxacin when revised breakpoints for Ciprofloxacin are published on the FDA STIC webpage. The breakpoint change protocol included with the submission indicated that if specific criteria are met, BioMérieux will update the Ciprofloxacin device label to include (1) the new breakpoints, (2) an updated performance section after re-evaluation of data in this premarket notification with the new breakpoints, and (3) any new limitations as determined by their evaluation. K214023 - Page 14 of 14