Sulopenem SPM 2 µg

K251879 · Liofilchem · JTN · Aug 12, 2025 · Microbiology

Device Facts

• Record ID: K251879
• Device Name: Sulopenem SPM 2 µg
• Applicant: Liofilchem
• Product Code: JTN · Microbiology
• Decision Date: Aug 12, 2025
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.1620
• Device Class: Class 2
• Attributes: PCCP

Indications for Use

Sulopenem SPM 2 μg is an in vitro semi-quantitative method for antimicrobial susceptibility of clinical isolates tested on agar media using overnight incubation. The Sulopenem SPM 2 μg is intended to determine susceptibility of Enterobacterales to sulopenem, as recognized by the FDA Susceptibility Test Interpretive Criteria (STIC). Sulopenem at concentrations of 2 μg should be interpreted at 16-18 hours of incubation. The Sulopenem SPM 2 μg demonstrated acceptable performance with the following organisms: Enterobacterales (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Citrobacter freundii, Citrobacter koseri, Enterobacter cloacae complex, Klebsiella aerogenes, Klebsiella oxytoca, Proteus vulgaris, Providencia alcalifaciens, and Providencia stuartii).

Device Story

Sulopenem SPM 2 μg is an antimicrobial susceptibility test (AST) disc; used in clinical microbiology laboratories to determine susceptibility of Enterobacterales to sulopenem. Device consists of a disc containing 2 μg of sulopenem; placed on agar media inoculated with clinical isolates. Following 16-18 hours of overnight incubation, zone of inhibition is measured; results interpreted against FDA Susceptibility Test Interpretive Criteria (STIC). Output assists clinicians in selecting appropriate antibiotic therapy for patients with bacterial infections. Device is intended for professional use in clinical laboratory settings.

Clinical Evidence

No clinical data. Performance supported by analytical data from microbiology disk studies evaluated by CDER, including quality control, disk-to-MIC correlation, and reproducibility studies conducted in accordance with CDER guidance for antimicrobial susceptibility testing.

Technological Characteristics

Antimicrobial susceptibility test disc containing 2 μg sulopenem; used for in vitro semi-quantitative testing on agar media; requires 16-18 hour incubation.

Indications for Use

Indicated for in vitro semi-quantitative antimicrobial susceptibility testing of Enterobacterales clinical isolates (including E. coli, K. pneumoniae, P. mirabilis, C. freundii, C. koseri, E. cloacae complex, K. aerogenes, K. oxytoca, P. vulgaris, P. alcalifaciens, and P. stuartii) to sulopenem using agar media with 16-18 hour incubation.

Regulatory Classification

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.

Submission Summary (Full Text)

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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

K251879

B Applicant

Liofilchem

C Proprietary and Established Names

Sulopenem SPM 2 µg

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:

In this Traditional 510(k) submission, Liofilchem seeks the following:

1. Obtain a substantial equivalence determination for sulopenem antimicrobial susceptibility test disk.
2. Establish a Pre-Determined Change Control Plan (PCCP) to address future revisions to device labeling in response to breakpoint changes that are recognized on the FDA STIC webpage.

### B Measurand:

Sulopenem 2 µg

### 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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## III Intended Use/Indications for Use:

### A Intended Use(s):
See Indications for Use below.

### B Indication(s) for Use:
Sulopenem SPM 2 µg is an *in vitro* semi-quantitative method for antimicrobial susceptibility of clinical isolates tested on agar media using overnight incubation.

The Sulopenem SPM 2 µg is intended to determine susceptibility of Enterobacterales to sulopenem, as recognized by the FDA Susceptibility Test Interpretive Criteria (STIC). Sulopenem at concentrations of 2 µg should be interpreted at 16-18 hours of incubation.

The Sulopenem SPM 2 µg demonstrated acceptable performance with the following organisms:
- Enterobacterales (*Escherichia coli*, *Klebsiella pneumoniae*, *Proteus mirabilis*, *Citrobacter freundii*, *Citrobacter koseri*, *Enterobacter cloacae* complex, *Klebsiella aerogenes*, *Klebsiella oxytoca*, *Proteus vulgaris*, *Providencia alcalifaciens*, and *Providencia stuartii*)

### C Special Conditions for Use Statement(s):
Rx - For Prescription Use Only

### D Special Instrument Requirements:
Not applicable.

## IV Device/System Characteristics:

### A Device Description:
Sulopenem at concentrations of 2 µg is a high quality 6 mm diameter white filter paper disk that is impregnated with 2 µg sulopenem. The disks are clearly marked on both sides with SPM2, designating the agent and the drug content. The disks are supplied in plastic cartridges containing 50 disks each. Sulopenem SPM 2 µg is intended to be used for *in vitro* agar diffusion susceptibility testing.

### B Principle of Operation:
The disks are applied to the surface of a culture medium inoculated with a pure colony suspension of the microorganisms under examination. The simultaneous growth of the bacteria and diffusion of the antimicrobials compounds forms a zone of inhibition of growth. After incubation, the plates are examined, the zone diameter around each disk are examined and compared with the standard inhibition zone diameter. The microorganisms are defined as being susceptible, intermediate or resistant to the tested antimicrobial agents.

### V Substantial Equivalence Information:

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A Predicate Device Name(s):

BD BBL Sensi-Disc Cefiderocol 30ug (FDC-30)

B Predicate 510(k) Number(s):

K221826

C Comparison with Predicate(s):

| Device & Predicate Device(s): | Device K251879 | Predicate K221826 |
| --- | --- | --- |
| Device Trade Name | Sulopenem SPM 2 μg | BD BBL Sensi-Disc Cefiderocol 30μg (FDC-30) |
| General Device Characteristic Similarities | | |
| Intended Use | Semi-quantitative susceptibility to antimicrobial agents against specified gram-negative organisms. | Semi-quantitative agar diffusion test method for in vitro susceptibility testing. |
| Test Method | Antimicrobial susceptibility testing using paper disks impregnated with an antimicrobial agent. | 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 | Same |

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| Device & Predicate Device(s): | Device K251879 | Predicate K221826 |
| --- | --- | --- |
| | agent to the surface of the plate. The temperature, atmospheric conditions and duration of incubation is dependent on the organism tested. | |
| Reading Method | The user will interpret the zone diameters according to the established interpretive criteria for the drug. | Same |
| General Device Characteristic Differences | | |
| Antimicrobial Agent | Sulopenem | Cefiderocol |
| Concentration | 2 μg | 30 μg |

VI Standards/Guidance Documents Referenced:

- CLSI M02-14th ed. Performance Standards for Antimicrobial Disk Susceptibility Tests (March 2024).
- CLSI M100-35th ed. Performance Standards for Antimicrobial Susceptibility Testing (January 2025).

VII Performance Characteristics (if/when applicable):

The premarket submission for Sulopenem SPM 2 μg included a letter dated June 24, 2025, indicating the right of reference to NDA 213972. Descriptive characteristics were sufficient for the Sulopenem SPM 2 μg based on data from microbiology disk studies evaluated by CDER which were used to generate the breakpoints identified by FDA on the susceptibility test interpretive criteria (STIC) 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 with STIC-recognized breakpoints.

Data obtained from quality control, disk to MIC correlation, and 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 interpretive criteria are applied to Enterobacterales according to the FDA STIC website. As required under 511A(2)(2)(B) of the Federal Food, Drug and Cosmetic Act, the following statement is included in the Precautions section of the Sulopenem SPM 2 μg package insert:

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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.

## A Analytical Performance:

1. Precision/Reproducibility:
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:
Not applicable.

2. Matrix Comparison:
Not applicable.

## C Clinical Studies:

1. Clinical Sensitivity:
Not applicable.

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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-identified susceptibility interpretive criteria for sulopenem are listed below in Table 1.

Table 1. FDA-Identified Disk Diffusion Interpretive Criteria (zone diameter in mm) for Sulopenem

| Organisms | Interpretive Criteria (mm)a | | |
| --- | --- | --- | --- |
| | Susceptible (S) | Intermediate (I) | Resistant (R) |
| Enterobacterales | ≥ 19 | 16 – 18 | ≤ 15 |

a FDA STIC Webpage

# 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.

To support the implementation of changes to FDA-recognized susceptibility test interpretive criteria (i.e., breakpoints), this submission included a predetermined change control plan (PCCP) that was reviewed and accepted by FDA. This PCCP 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 PCCP outlined the specific procedures and acceptance criteria that Liofilchem intends to use to evaluate the Sulopenem SPM $2\mu \mathrm{g}$ when revised breakpoints for sulopenem are published on the FDA STIC webpage. The PCCP included with the submission indicated that if specific criteria are met, Liofilchem will update the Sulopenem SPM $2\mu \mathrm{g}$ disk device label to include the new breakpoints.

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