Becton, Dickinson and Company · Class II · Cleared May 19, 2025
| K-number | K250447 |
| Device name | BD Phoenix Automated Microbiology System - GN Imipenem-relebactam (0.0625/4 - 16/4 µg/mL) |
| Applicant | Becton, Dickinson and Company |
| Product code | LON |
| Device class | Class II |
| Decision date | May 19, 2025 |
| Decision | Substantially Equivalent |
| Regulation | 866.1645 |
The BD Phoenix Automated Microbiology System with Imipenem-relebactam is an automated antimicrobial susceptibility testing device that quantitatively determines the minimal inhibitory concentration (MIC) of the antibiotic combination imipenem-relebactam against Gram-negative bacteria (Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter calcoaceticus-baumannii complex). Results are reported as MIC values and categorical interpretations (susceptible, intermediate, or resistant) within 16 hours.
The device uses a broth-based microdilution method with a redox indicator (colorimetric oxidation-reduction detection) in a sealed, self-inoculating polystyrene panel containing 136 micro-wells with dried reagents. Key difference from the predicate: the reporting range is 0.0625/4–16/4 µg/mL (vs. predicate's 0.0625–32 µg/mL), and the breakpoints are organism-specific and based on the imipenem-relebactam combination ratio rather than imipenem alone.
CLSI Performance Standards for Antimicrobial Susceptibility Testing (33rd ed., M100, 2023) and CLSI Methods for Dilution Antimicrobial Susceptibility Tests (11th ed., M07, 2018). FDA Susceptibility Test Interpretive Criteria (STIC) website and FDA Class II Special Controls Guidance Document for AST Systems (August 28, 2009).
The device is substantially equivalent because it uses the identical BD Phoenix platform, methodology, and automated read system as the predicate (K123404), differing only in the specific antimicrobial agent tested (imipenem-relebactam vs. imipenem). Clinical and challenge testing demonstrated >93% Essential Agreement and >96.6% Category Agreement with CLSI reference methods across all tested organisms, with zero major or very major errors in the primary manual inoculation method. Both inoculation methods (manual PhoenixSpec and Phoenix AP) met acceptance criteria of ≥90%, and quality control testing showed >95% acceptable results, establishing that the system performs reliably for this new drug combination without requiring changes to the fundamental device design or operational principles.
View the full FDA submission: accessdata.fda.gov