The multiFlux 130 and 160 filters are intended for single use only for extracorporeal blood purification during continuous veno-venous hemofiltration (CVVH), continuous veno-venous hemodialysis (CVVHD), and continuous veno-venous hemodiafiltration (CVVHDF) using pre-, post- or mixed-dilution modes for patients suffering from acute kidney injury.

Device Description

The multiFlux 130 and 160 hemofilters are high-flux, single-use, steam-sterilized filters. The hemofilters are provided blood pathway sterile and non-pyrogenic. The hemofilters allow for the transfer of water and solutes between blood and dialysate using semipermeable, hollow fiber membranes.

The multiFlux 130 and 160 hemofilters are high-flux, sterile devices designed for single-use acute hemodialysis. The hemofilters are configured to connect to a bloodline set which connects to a patient's vascular access system when used with a hemodialysis machine equipped with ultrafiltration control. During hemodialysis, blood is pumped from the patient's body through an extracorporeal circuit, one component of which is the hemofilters. The hemofilters contain semi-permeable membranes that allow for diffusion and/or ultrafiltration to transport toxins and excess fluid from the blood compartment (fiber lumen) to the dialysate compartment. Hemofilters utilize a counter-current flow in which dialysate and blood flow in opposite directions in the hemofilter. The counter-current flow maintains the concentration gradient across the membrane for waste and fluid removal.

The multiFlux 130 and 160 hemofilters' components are composed of the following materials:
Housing: Polypropylene
Potting Resin: Polyurethane
Fiber Bundle: Polysulfone-polyvinylpyrrolidone blend, alpha-tocopherol (vitamin E)
Sealing Ring: Silicone
Flange: Polypropylene
Blood Port Cap(s): Polypropylene
Dialysate Port Cap(s): Styrol-Ethylen-Butylen-Styrol, Polypropylene

AI/ML Overview

N/A

Summary

FDA 510(k) Clearance Letter - multiFlux 130 and 160 Hemofilters

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U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov

Doc ID # 04017.08.03

February 10, 2026

Fresenius Medical Care Renal Therapies Group, LLC
Timothy Groves
Regulatory Affairs - Senior Lead
920 Winter Street
Waltham, Massachusetts 02451

Re: K252459
Trade/Device Name: multiFlux 130 (F00013123); multiFlux 160 (F00013124)
Regulation Number: 21 CFR 876.5860
Regulation Name: High Permeability Hemodialysis System
Regulatory Class: Class II
Product Code: KDI
Dated: January 12, 2026
Received: January 12, 2026

Dear Timothy Groves:

We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device"

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(https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality Management System Regulation (QMSR) (21 CFR Part 820), which includes, but is not limited to, ISO 13485 clause 7.3 (Design controls), ISO 13484 clause 8.3 (Nonconforming product), and ISO 13485 clause 8.5 (Corrective and preventative action). Please note that regardless of whether a change requires premarket review, the QMSR requires device manufacturers to review and approve changes to device design and production (ISO 13485 clause 7.3 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the Quality Management System Regulation (QMSR) (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

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Sincerely,

MAURA ROONEY -S

Maura Rooney
Assistant Director
DHT3A: Division of Renal, Gastrointestinal,
Obesity, and Transplant Devices
OHT3: Office of Gastrorenal, ObGyn,
General Hospital, and Urology Devices
Office of Product Evaluation and Quality
Center for Devices and Radiological Health

Enclosure

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Indications for Use

Please type in the marketing application/submission number, if it is known. This textbox will be left blank for original applications/submissions. K252459

Please provide the device trade name(s).

multiFlux 130
multiFlux 160

Please provide your Indications for Use below.

Please select the types of uses (select one or both, as applicable).
☑ Prescription Use (Part 21 CFR 801 Subpart D)
☐ Over-The-Counter Use (21 CFR 801 Subpart C)

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510(k) Summary

multiFlux 130 and 160 Hemofilters Traditional 510(k)

K252459
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1. 510(K) SUMMARY

This 510(k) Summary is in accordance with the requirements of the Safe Medical Device Act (SMDA) of 1990. The content of this 510(k) summary is provided in conformance with 21 CFR § 807.92.

1.1. Submitter's Information

Name: Fresenius Medical Care Renal Therapies Group, LLC
Address: 920 Winter Street
Waltham, MA 02451-1457
Phone: (781) 460-1087
Fax: (781) 699-9635
Contact Person: Timothy Groves, Senior Lead
Preparation Date: 5 August 2025

1.2. Device Name

Trade Name: multiFlux 130 and 160
Common Name: Dialyzer/Hemofilter
Regulation Name: High Permeability hemodialysis system
Regulatory Class: Class II per 21 CFR § 876.5860
Product Code: KDI
Product Code Name: Dialyzer, High Permeability With or Without Sealed Dialysate System
FDA Review Panel: Gastroenterology/Urology

1.3. Legally Marketed Predicate Device

The legally marketed primary predicate device for the proposed multiFlux 130 and 160 hemofilters is the multiFlux 1000 hemofilter cleared under K240394. The FX CorAL dialyzers cleared under K243784 are being used as a secondary predicate to support the labeling modifications.

The FX CorAL 50 dialyzer (K242053) and Prismaflex ST Sets (K212216) are being used as reference devices. The predicate, secondary predicate, and reference devices have not been subject to a design-related recall.

1.4. Device Description

1.4.1. Device Identification

The multiFlux hemofilters are the subject of this 510(k) and are available in two (2) configurations as shown in Table 1.

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Table 1: multiFlux Hemofilters

Trade Name	Product Number	Surface Area (m²)
multiFlux 130	F00013123	1.3
multiFlux 160	F00013124	1.6

1.4.2. Device Characteristics

1.4.3. Environment of Use

The multiFlux 130 and 160 hemofilters are used in environments where acute hemodialysis is performed.

1.4.4. Brief Written Description of the Device

1.4.5. Materials of Use

The multiFlux 130 and 160 hemofilters are classified as externally communicating devices having direct contact via circulating blood and prolonged contact (>24 hours to 30 days) duration, Class II in accordance with FDA guidance Use of International Standard ISO 10993-1, Biological evaluation of medical devices – Part 1: Evaluation and testing within a risk management process (08 September 2023).

The multiFlux 130 and 160 hemofilters' components are composed of the following materials:

Component	Material
Housing	Polypropylene
Potting Resin	Polyurethane
Fiber Bundle	Polysulfone-polyvinylpyrrolidone blend, α-tocopherol (vitamin E)
Sealing Ring	Silicone
Flange	Polypropylene

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Component	Material
Blood Port Cap(s)	Polypropylene
Dialysate Port Cap(s)	Styrol-Ethylen-Butylen-Styrol, Polypropylene

1.4.6. Key Performance Specifications/Characteristics

Urea clearance is a key performance specification of the multiFlux 130 and 160 hemofilters. FMCRTG uses sodium clearance as a marker for urea clearance because sodium and urea exhibit similar movement across the membrane. Urea clearance data from the Instructions for Use (IFU) is provided in Table 2, where Qb = blood flow rate, Qd = dialysate flow rate, and Qf = filtration flow rate. The Qf is equal to the ultrafiltration rate (Quf) plus the substitution flow rate (Qs), where Qs = 0 in hemodialysis.

Table 2: In vitro Urea Clearance for the multiFlux 130 and 160 hemofilters

Trade Name	Flow Rate Conditions (mL/min)	Typical Urea Clearance (mL/min)
	Qb	Qd
multiFlux 130	100	33
multiFlux 160	200	67

1.5. Intended Use

Removal of uremic toxins including excess water and correction of blood electrolytes and acid-base balance in an extracorporeal treatment.

1.6. Indications for Use

1.7. Comparison of Technological Characteristics with the Predicate Device

The following technological characteristics of the proposed multiFlux 130 and 160 hemofilters are equivalent to the predicate multiFlux 1000 (K240394) and secondary predicate FX CorAL dialyzers (K243784):

Intended Use and Indications for Use
Principle of Operation
Design and Configuration
Technological Characteristics
Materials
Performance Requirements

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1.8. Performance Data

Performance testing was conducted in accordance with ISO 8637 First Edition 2017-11 and Guidance for the Content of Premarket Notifications for Conventional and High Permeability Hemodialyzers, August 1998. Testing conducted to support the determination of substantial equivalence is summarized in Table 3.

Table 3: Performance Testing Summary

Test Conducted	Test Method Description
Blood Compartment Volume	Calculated using the fiber volume and CAD software modeling for the flange volume. Results were compared with the acceptance criteria.
Clearance – Sodium (marker for urea), Creatinine, Phosphate, Vitamin B12, β2-Microglobulin	Calculated by analyzing test samples over the specified range of blood, dialysate, and filtration flow rates.
Protein Sieving Coefficient	The test circuit was stabilized for blood and filtrate flows. All air was removed from the dialyzer. Paired samples for blood and filtrate flows were collected after recirculating for 30 min. The sieving coefficient was calculated in accordance with ISO 8637-1 First Edition 2017-11.
Ultrafiltration (Blood Kuf)	Calculated as the slope from a plot of the measured ultrafiltration rate (UFR) over the applied transmembrane pressure (TMP) range
Pressure Drop	Blood compartment: The blood compartment was perfused with human blood while the dialysate compartment was filled with NaCl solution. Dialysate side: Both compartments were filled with dialysis fluid. Inlet and outlet pressures of the blood and dialysate compartments were measured across the range of flow rates with the dialyzers in a horizontal position.

1.8.1. Biocompatibility Testing

The proposed multiFlux 130 and 160 hemofilters are identical to the predicate multiFlux 1000 hemofilter and secondary predicate FX CorAL dialyzers with respect to materials and sterilization method. The proposed labeling and sieving coefficient changes do not impact the biological safety of the proposed hemofilters.

1.8.2. Human Factors Validation Testing

The multiFlux 130 and 160 hemofilters were validated for safe and effective use in accordance with FDA guidance Applying Human Factors and Usability Engineering to Medical Devices (03 February 2016).

1.8.3. Electrical Safety and Electromagnetic Compatibility (EMC)

Not applicable. The multiFlux 130 and 160 hemofilters are not electrical mechanical devices.

1.8.4. Software Verification and Validation Testing

Not applicable. The multiFlux 130 and 160 hemofilters do not contain software.

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1.8.5. Animal Studies

No animal studies were performed.

1.8.6. Clinical Studies

No clinical studies were performed.

1.9. Conclusion

The intended use, indications for use, principle of operation, technological characteristics, design, materials, and performance requirements are substantially equivalent to those of the predicate and secondary predicate devices. FMCRTG concludes that within the meaning of the Medical Device Amendments Act of 1976, the multiFlux 130 and 160 hemofilters are safe and effective for their intended use.

Regulation Number and Section

§ 876.5860 High permeability hemodialysis system.

(a)
Identification. A high permeability hemodialysis system is a device intended for use as an artificial kidney system for the treatment of patients with renal failure, fluid overload, or toxemic conditions by performing such therapies as hemodialysis, hemofiltration, hemoconcentration, and hemodiafiltration. Using a hemodialyzer with a semipermeable membrane that is more permeable to water than the semipermeable membrane of the conventional hemodialysis system (§ 876.5820), the high permeability hemodialysis system removes toxins or excess fluid from the patient's blood using the principles of convection (via a high ultrafiltration rate) and/or diffusion (via a concentration gradient in dialysate). During treatment, blood is circulated from the patient through the hemodialyzer's blood compartment, while the dialysate solution flows countercurrent through the dialysate compartment. In this process, toxins and/or fluid are transferred across the membrane from the blood to the dialysate compartment. The hemodialysis delivery machine controls and monitors the parameters related to this processing, including the rate at which blood and dialysate are pumped through the system, and the rate at which fluid is removed from the patient. The high permeability hemodialysis system consists of the following devices:(1) The hemodialyzer consists of a semipermeable membrane with an in vitro ultrafiltration coefficient (K
uf ) greater than 8 milliliters per hour per conventional millimeter of mercury, as measured with bovine or expired human blood, and is used with either an automated ultrafiltration controller or anther method of ultrafiltration control to prevent fluid imbalance.(2) The hemodialysis delivery machine is similar to the extracorporeal blood system and dialysate delivery system of the hemodialysis system and accessories (§ 876.5820), with the addition of an ultrafiltration controller and mechanisms that monitor and/or control such parameters as fluid balance, dialysate composition, and patient treatment parameters (e.g., blood pressure, hematocrit, urea, etc.).
(3) The high permeability hemodialysis system accessories include, but are not limited to, tubing lines and various treatment related monitors (e.g., dialysate pH, blood pressure, hematocrit, and blood recirculation monitors).
(b)
Classification. Class II. The special controls for this device are FDA's:(1) “Use of International Standard ISO 10993 ‘Biological Evaluation of Medical Device—Part I: Evaluation and Testing,’ ”
(2) “Guidance for the Content of 510(k)s for Conventional and High Permeability Hemodialyzers,”
(3) “Guidance for Industry and CDRH Reviewers on the Content of Premarket Notifications for Hemodialysis Delivery Systems,”
(4) “Guidance for the Content of Premarket Notifications for Water Purification Components and Systems for Hemodialysis,” and
(5) “Guidance for Hemodialyzer Reuse Labeling.”