← Product Code [JTN](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JTN) · K193504

# HardyDisk AST Cefiderocol 30ug (FDC30) (K193504)

_Hardy Diagnostics · JTN · Jan 23, 2020 · Microbiology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JTN/K193504

## Device Facts

- **Applicant:** Hardy Diagnostics
- **Product Code:** [JTN](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JTN.md)
- **Decision Date:** Jan 23, 2020
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 866.1620
- **Device Class:** Class 2
- **Review Panel:** Microbiology

## Indications for Use

HardyDisk AST Disks are used for semi-quantitative in vitro susceptibility testing by the agar diffusion test procedure (Kirby-Bauer) of rapidly growing and certain fastidious bacterial pathogens. Standardized methods for agar diffusion testing have been described for Enterobacteriaceae, Staphylococcus spp., Pseudomonas spp., Acinetobacter spp., Listeria monocytogenes, Enterococcus spp., and by modified procedures, Haemophilus spp., Neisseria gonorrhoeae, N. meningitidis and Streptococcus spp., including Streptococcus pneumoniae. Use of HardyDisk AST Cefiderocol 30μg (FDC30) for in vitro agar diffusion susceptibility testing is indicated when there is the need to determine the susceptibility of bacteria to Cefiderocol. HardyDisk AST Cefiderocol at concentration 30μg can be used to determine the zone diameter (mm) of Cefiderocol against the following bacteria for which Cefiderocol has been shown to be active both clinically and in vitro: - Escherichia coli - Enterobacter cloacae complex - Klebsiella pneumoniae - Proteus mirabilis - Pseudomonas aeruginosa

## Device Story

HardyDisk AST Cefiderocol 30μg (FDC30) consists of 6-mm filter paper disks impregnated with 30μg of Cefiderocol. Used in clinical microbiology laboratories by trained personnel to perform Kirby-Bauer disk diffusion susceptibility testing. Disks are placed on inoculated Mueller Hinton agar (or Mueller Hinton with 5% Sheep Blood for Streptococcus spp.). After 16-18 hours of incubation at 35±2°C, the zone of inhibition around the disk is measured in millimeters. Results are compared to established interpretive criteria (S/I/R) to determine bacterial susceptibility to Cefiderocol. This information assists healthcare providers in selecting appropriate antimicrobial therapy for patients with infections caused by susceptible organisms.

## Clinical Evidence

No clinical trials performed. Substantial equivalence supported by disk-to-MIC correlation, stability, and reproducibility data generated in accordance with CDER guidance. Breakpoints and QC ranges established via CDER review and FDA-recognized STIC.

## Technological Characteristics

Antimicrobial susceptibility test disk; paper disk impregnated with 30ug of cefiderocol. Principle of operation: Kirby-Bauer disk diffusion. Standardized for use with non-fastidious Gram-negative organisms. Manual application and measurement of zones of inhibition.

## Regulatory Identification

An antimicrobial susceptibility test disc is a device that consists of antimicrobic-impregnated paper discs used to measure by a disc-agar diffusion technique or a disc-broth elution technique the in vitro susceptibility of most clinically important bacterial pathogens to antimicrobial agents. In the disc-agar diffusion technique, bacterial susceptibility is ascertained by directly measuring the magnitude of a zone of bacterial inhibition around the disc on an agar surface. The disc-broth elution technique is associated with an automated rapid susceptibility test system and employs a fluid medium in which susceptibility is ascertained by photometrically measuring changes in bacterial growth resulting when antimicrobial material is eluted from the disc into the fluid medium. Test results are used to determine the antimicrobial agent of choice in the treatment of bacterial diseases.

## Predicate Devices

- HardyDisk AST Tigecycline 15μg ([K062245](/device/K062245.md))

## Submission Summary (Full Text)

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>
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FDA

U.S. FOOD & DRUG

ADMINISTRATION

# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

ASSAY ONLY

## I Background Information:

A 510(k) Number

K193504

B Applicant

Hardy Diagnostics

C Proprietary and Established Names

HardyDisk AST Cefiderocol 30μg (FDC30)

D Regulatory Information

|  Product Code(s) | Classification | Regulation Section | Panel  |
| --- | --- | --- | --- |
|  JTN | Class II | 21 CFR 866.1620 - Antimicrobial Susceptibility Test Disc | MI - Microbiology  |

## II Submission/Device Overview:

A Purpose for Submission:

To obtain a substantial equivalence determination for Cefiderocol Antimicrobial Susceptibility Test Disk

B Measurand:

Cefiderocol 30μg

C Type of Test:

Antimicrobial Susceptibility Test Disks

Food and Drug Administration

10903 New Hampshire Avenue

Silver Spring, MD 20993-0002

www.fda.gov

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K193504 - Page 2 of 7

# III Intended Use/Indications for Use:

## A Intended Use(s):

HardyDisk AST Disks are used for semi-quantitative *in vitro* susceptibility testing by the agar diffusion test procedure (Kirby-Bauer) of rapidly growing and certain fastidious bacterial pathogens. Standardized methods for agar diffusion testing have been described for *Enterobacteriaceae*, *Staphylococcus* spp., *Pseudomonas* spp., *Acinetobacter* spp., *Listeria monocytogenes*, *Enterococcus* spp., and by modified procedures, *Haemophilus* spp., *Neisseria gonorrhoeae*, *N. meningitidis* and *Streptococcus* spp., including *Streptococcus pneumoniae*.

## B Indication(s) for Use:

HardyDisk AST Disks are used for semi-quantitative *in vitro* susceptibility testing by the agar diffusion test procedure (Kirby-Bauer) of rapidly growing and certain fastidious bacterial pathogens. Standardized methods for agar diffusion testing have been described for *Enterobacteriaceae*, *Staphylococcus* spp., *Pseudomonas* spp., *Acinetobacter* spp., *Listeria monocytogenes*, *Enterococcus* spp., and by modified procedures, *Haemophilus* spp., *Neisseria gonorrhoeae*, *N. meningitidis* and *Streptococcus* spp., including *Streptococcus pneumoniae*.

Use of HardyDisk AST Cefiderocol 30μg (FDC30) for *in vitro* agar diffusion susceptibility testing is indicated when there is the need to determine the susceptibility of bacteria to Cefiderocol.

HardyDisk AST Cefiderocol at concentration 30μg can be used to determine the zone diameter (mm) of Cefiderocol against the following bacteria for which Cefiderocol has been shown to be active both clinically and *in vitro*:

- *Escherichia coli*
- *Enterobacter cloacae complex*
- *Klebsiella pneumoniae*
- *Proteus mirabilis*
- *Pseudomonas aeruginosa*

## C Special Conditions for Use Statement(s):

Rx - For Prescription Use Only

## D Special Instrument Requirements:

None

## IV Device/System Characteristics:

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K193504 - Page 3 of 7

# A Device Description:

HardyDisk AST Disks utilize 6-mm diameter white filter paper disks. The disks are prepared by impregnating absorbent paper with a known concentration of 30μg Cefiderocol. The disks are marked with the code FDC30, on both sides.

HardyDisk AST Disks are supplied in plastic cartridges containing 50 disks each. They are also packaged as one cartridge per vial with desiccant or five cartridges per vial with desiccant.

# B Principle of Operation:

The HardyDisk AST Disk is based on the agar diffusion (Kirby-Bauer) methodology. It utilizes dried filter paper disks impregnated with a known concentration of an antimicrobial agent that are placed onto the test medium surface. Mueller Hinton agar is recommended for agar diffusion testing of non-fastidious organisms and Mueller Hinton with 5% Sheep Blood is recommended for Streptococcus spp. Three to five similar colonies are transferred to 4-5 mL of a suitable broth medium. The broth is incubated at 35°C for 2-6 hours to develop a turbidity that exceeds or is equivalent to a 0.5 McFarland standard. Alternatively, a direct broth or saline suspension of colonies may be prepared from an overnight culture. The final inoculum density should be equivalent to a 0.5 McFarland turbidity standard. The inoculum density may also be standardized photometrically.

Within 15 minutes of inoculum preparation, the Mueller Hinton agar plate is streaked with an inoculated swab to obtain an even inoculation of organism. Disks are aseptically placed onto the agar surface with a disk dispenser and the disks are pressed down with a sterile needle or forceps to make contact with the agar surface. Agar plates are incubated in an ambient air incubator at 35±2°C for 16 - 18 hours. Fastidious organisms are tested using appropriate media incubated in an atmosphere enriched with 5% CO₂, as recommended in the CLSI M02 approved standard document.

After incubation the agar medium is examined for a zone of inhibition around the disks. The zones of inhibition are measured to the nearest millimeter and compared to recognized zone size ranges for the antimicrobial agent being tested.

# V Substantial Equivalence Information:

# A Predicate Device Name(s):

HardyDisk AST Tigecycline 15μg

# B Predicate 510(k) Number(s):

K062245

# C Comparison with Predicate(s):

|  Device & Predicate Device(s): | Device K193504 | Predicate K062245  |
| --- | --- | --- |
|  Device Trade Name | HardyDisk AST Cefiderocol | HardyDisk AST Tigecycline  |

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|   | 30μg (FDC30) | 15μg  |
| --- | --- | --- |
|  General Device Characteristic Similarities  |   |   |
|  Intended Use | Semi-quantitative in vitro susceptibility testing by the agar diffusion test procedure (Kirby-Bauer) of rapidly growing and certain fastidious bacterial pathogens. | Same  |
|  Methodology | Kirby-Bauer Disk Diffusion Susceptibility Test Protocol requires the user to determine categorical interpretations (S/I/R) using the measured zone diameters. | Same  |
|  Inoculum | Prepared from pure isolated colonies to match the turbidity equivalent of a 0.5 McFarland in Tryptic Soy Broth. | Same  |
|  Inoculum Method | Dip a sterile swab into the prepared inoculum and streak an appropriate agar plate’s surface three times. Add the disks impregnated with the antimicrobial agent to the surface of the plate. Incubate the agar plate agar side up in a 35 ± 2°C incubator for 16-18 hours. | Same  |
|  Reading Method | The user will interpret the zone diameters according established interpretive criteria for the drug. | Same  |
|  General Device Characteristic Differences  |   |   |
|  Antimicrobial Agent | Cefiderocol | Tigecycline  |
|  Concentration | 30μg | 15μg  |

VI Standards/Guidance Documents Referenced:

CLSI M100, 29th ed., "Performance Standards for Antimicrobial Susceptibility Testing; Twenty-Ninth Informational Supplement, January 2019".

VII Performance Characteristics (if/when applicable):

A Analytical Performance:

1. Precision/Reproducibility:

K193504 - Page 4 of 7

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Not applicable

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):
Not applicable

6. Detection Limit:
Not applicable

7. Assay Cut-Off:
Not applicable

## B Comparison Studies:

1. Method Comparison with Predicate Device:

The premarket submission for HardyDisk Cefiderocol included a letter dated March 27, 2019 indicating the right of reference to NDA 209445. Descriptive characteristics were sufficient for the HardyDisk Cefiderocol 30μg (FDC30) disk based on extensive data from several microbiology disk studies evaluated by CDER which were used to generate the breakpoints, identified by FDA on the susceptibility test interpretive criteria webpage. In addition, CDER concurred with the disk QC ranges that were established by CLSI. The disk data used to support this submission included data from testing organisms for which cefiderocol has been shown to be active both in vitro and in clinical infections within the spectrum of activity of cefiderocol and as noted in the device's intended use.

Data obtained from stability, quality control, disk to MIC correlation, reproducibility (from disk content optimization studies) were generated in accordance with the CDER Clinical/Antimicrobial guidance, Microbiology Data for Systemic Antibacterial Drugs-Development, Analysis, and Presentation to ensure precise, accurate and reproducible results.

For this review, the interpretative criteria are applied to Enterobacteriaceae and Pseudomonas aeruginosa according to the FDA STIC website. As required under 511A(2)(2)(B) of the Federal Food, Drug and Cosmetic Act, the following statements are

K193504 - Page 5 of 7

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added as footnotes to the Cefiderocol 30μg interpretative criteria table in the HardyDisk AST package insert:

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.

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 cefiderocol interpretive criteria for disk diffusion are shown in the table below.

FDA-Identified Disk Diffusion Interpretive Criteria
(Zone diameter in mm for Cefiderocol 30μg)

|  Indications for Use Organism(s) | Interpretive Criteria  |   |   |
| --- | --- | --- | --- |
|   |  S | I | R  |
|  Enterobacteriaceaea | ≥18 | 14 – 17 | ≤13  |
|  Pseudomonas aeruginosa | ≥25 | 19-24 | ≤18  |

aIncludes E. coli, K. pneumoniae, P. mirabilis and E. cloacae complex.

K193504 - Page 6 of 7

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VIII Proposed Labeling:

The labeling supports the finding of substantial equivalence for this device.

IX Conclusion:

The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

K193504 - Page 7 of 7

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**Source:** [https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JTN/K193504](https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JTN/K193504)

**Published by [Innolitics](https://innolitics.com)** — a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices. If you're preparing [a 510(k)](https://innolitics.com/services/510ks/), [a De Novo](https://innolitics.com/services/regulatory/), [a SaMD](https://innolitics.com/services/end-to-end-samd/), [an AI/ML medical device](https://innolitics.com/services/medical-imaging-ai-development/), or [an FDA regulatory strategy](https://innolitics.com/services/regulatory/), [get in touch](https://innolitics.com/contact).

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