Therapeutic apheresis filter system combination of separator filter and l-tryptophan TSO bioreactor and a fractionator

Abstract

The invention relates to an apheresis device and to a filter system for filtering plasma, comprising a separator, a fractionator and a bioreactor which is connected between the separator and the fractionator and which has silica and immobilised tryptophan side chain oxidase (TSO) as an enzyme.

Description

[0001] Ayus Medical Devices AG 1 January 20, 2026

[0002] THERAPEUTIC APHERESIS FILTER SYSTEM COMBINATION OF SEPARATOR FILTER AND L-TRYPTOPHAN TSO BIOREACTOR AND A FRACTIONATOR

[0003] Technical field

[0004] Filter systems for therapeutic apheresis as an adjunct to cancer therapies. The disclosure of German utility model number 202025 100 368.6, whose priority is claimed, is hereby incorporated in its entirety.

[0005] State of the art and shortcomings of current designs

[0006] One of the greatest obstacles in modern cancer therapy is the development of resistance to chemotherapeutic agents and new targeted therapies such as kinase inhibitors and monoclonal antibodies (1, 2). This resistance makes it difficult to sustainably control tumor growth. Furthermore, there is currently no therapeutic approach that is effective for all types of cancer. Existing options are often associated with severe side effects, which significantly impairs patients' quality of life (2). Due to these limitations, there is an urgent need for new therapeutic approaches that are both more effective and better tolerated. In particular, reference is made to the following sources, which are hereby fully incorporated by reference:

[0007] 1. Reichle A, Diddens H, Rastetter J, Berdel WE (1991). Resistance mechanisms of malignant cells to cytostatic drugs. Dtsch Med Wschr 116:186-191.

[0008] 2. Volm M, Mattern J, Samsel B (1991). Häufung von zytostatica-resistenten Lungentumoren bei Rauchern. Dtsch Med Wschr 116:1303 -1306.

[0009] 3. Rosenfeld HJ, Watanabe AK, Roberts J(1977). Mechanism of action of indolyl-3- alkane-cx- hydroxylase. Biol Chem 252:6970-6973.

[0010] 221271PCAyus Medical Devices AG 2 20. Januar 2026

[0011] 4. Roberts J Schmid FA, Rosenfeld HJ (1979). Biologic and antineoplastic effects of enzyme- mediated in vivo depletion of L-glutamine, L-tryptophan and L.-histidine. Cancer Treat Rep

[0012] 63:1045-1054.

[0013] 5. Cook SJ, Pogson Cl, Smith SA (1980). Indoleamine 2,3dioxygenase. Biochem J 189:461- 466,

[0014] 6. Kidd JG (1953). Regression of transplanted lymphoma induced in vive by means of normal

[0015] Guinea pig serum: II. Studies on the nature of the active serum constituent: histological

[0016] mechanism of regression: tests for effects of guinea pig serum on lymphoma cells in vitro:

[0017] Discussion. J Exp Med 98:565.

[0018] 7. Kidd JG (1953). Regression of transplanted lymphoma induced in vivo by means of normal

[0019] Guinea pig serum: II. Studies on the nature of the active serum constituent histological

[0020] mechanism of regression: tests for effects of guinea pig serum on lymphoma cell in vitro:

[0021] Discussion. J Exp Med 98:583.

[0022] 8. Broome JD (1961). Evidence that the L-asparaginase activity in guinea pig serum is responsible for its antilymphoma effects. Nature 191:114.

[0023] 9. Schmer G, Roberts J (1979). Molecular engineering of the L-tryptophan- depleting enzyme

[0024] indolyl-3-alkane-ochydroxylase. Cane Treat Rep 63:1123-1126.

[0025] 10. Schmer G, Roberts J (1979). Induction of hypothermia in mice by semiartificial cell containing indolyl-3-alkane-ochydroxylase. Trans Am Soc Artif Int Org 25:39-43. 11. Dennis MB, Jensen WH, Bauermeister U Vienken J, Schmer G (1988).

[0026] Successful use of a

[0027] 221271PCAyus Medical Devices AG 3 20. Januar 2026

[0028] miniturized plasmapheresis circuit for long-term use in rabbits. Trans Am Soc Artif I nt Org. 34:651-654.

[0029] 12. Bambauer R, Yefu W. (2023). L-Tryptophan Depletion Using a New Bioreactor: A Possible New Cancer Therapy. Br J Healthc Med Res. 10(l):120-130.

[0030] Doi:10.14738 / jbe mi.101.13737.

[0031] 13. Schmer G, Kruegger M, Cole JJ (1977). Gel-bound resealed red cell membranes: A new

[0032] type of semiartificial organs. J Biol Chem 252:2640-2647.

[0033] 14. Straube R, Müller G, Voit-Bak K, et al. (2019). Metabolic and nonmetabolic peripheral

[0034] neuropathy: Is there a place for therapeutic apheresis? Hormones Metab Res.

[0035] 51(12):779-784.

[0036] 15. Bornstein SR, Voit-Bak K, Rosenthal P, et al. (2020). Extracorporeal apheresis therapy for

[0037] Alzheimer's disease-targeting lipids, stress, and inflammation. Molec Psych.

[0038] 25:275-282.

[0039] Technical problem and its solution

[0040] Recent studies have shown that extracorporeal systems with so-called anti-tumor enzymes, known as bioreactors, offer a promising approach to tumor treatment (3-5). One such approach focuses on the depletion of essential amino acids, particularly L-tryptophan, which tumor cells use for protein synthesis and survival (6-8). By removing L-tryptophan, tumor growth can be significantly reduced and even stopped (9). A crucial advantage of this strategy is that L-tryptophan is an essential amino acid that the tumor cannot synthesize itself, unlike other amino acids such as L-asparagine, which the tumor can obtain through other means.

[0041] 221271PCAyus Medical Devices AG 4 January 20, 2026

[0042] novo synthesis can be replaced (9). This prevents the development of resistance to treatment and makes L-tryptophan an ideal target for extracorporeal depletion.

[0043] For this purpose, the enzyme tryptophan side chain oxidase (TSO) is used, which can degrade L-tryptophan in blood plasma. There are three isoenzymes, TSO I, II, and III, with TSO III exhibiting the highest efficiency in the degradation of L-tryptophan (10). However, a key problem is that these enzymes, when derived from bacterial sources, can be contaminated with high levels of endotoxins, which have toxic effects on the human body (11). To circumvent this, this invention utilizes endotoxin-free TSO enzymes from fungal sources (11, 12).

[0044] To solve these problems, the features of independent claims are proposed. Advantageous further developments are found in dependent claims.

[0045] A plasma filtration system can comprise a separator (primary filter) and a fractionator (secondary filter), with a bioreactor positioned between the separator and the fractionator. The bioreactor can contain silica and immobilized tryptophan side-chain oxidase (TSO) as the enzyme.

[0046] The TSO can advantageously be an isoenzyme TSO I, preferably an isoenzyme TSO II, and most preferably an isoenzyme TSO III. The TSO can preferably be an endotoxin-free TSO from fungal sources.

[0047] The fractionator can be a highly selective filter system made of biocompatible hollow fiber membranes that removes specific molecules from the plasma, particularly those with a molecular size greater than 1 µm. The bioreactor can include silica spheres coupled to the TSO enzymes. The TSO enzymes can be coupled to Zetaffinity microcolumns. The Zetaffinity microcolumns can be made of polyacrylic cellulose copolymer.

[0048] 221271PCAyus Medical Devices AG 5 January 20, 2026

[0049] A first pump can be installed upstream of the bioreactor and / or a second pump can be installed downstream of the bioreactor. A first expansion chamber can be installed upstream of the first pump and / or a second expansion chamber can be installed downstream of the second pump.

[0050] An apheresis device may include a filter system, particularly for extracorporeal plasmapheresis. The filter system may comprise at least one separator and one fractionator, wherein the fractionator may be a highly selective filter system that removes specific molecules from the plasma, particularly those with a molecular size greater than 1 µm. Furthermore, at least one tryptophan side-chain oxidase (TSO) bioreactor may be provided, wherein the TSO bioreactor may be based on activated silica, preferably silica spheres, coupled with immobilized tryptophan side-chain oxidase enzymes.

[0051] Methods for performing apheresis, in particular extracorporeal plasmapheresis with double-membrane filtration, can be proposed, wherein drawn whole blood is passed through a filter system. The filter system can comprise a separator and a fractionator, the separator separating plasma from solid blood components of the whole blood. The fractionator can be a highly selective filter system that removes specific molecules from the plasma, particularly those with a molecular size greater than 1 µm. At least one tryptophan side-chain oxidase (TSO) bioreactor can be provided, and the TSO bioreactor can be based on activated silica, preferably silica spheres, coupled with immobilized tryptophan side-chain oxidase enzymes. The plasma of the drawn whole blood can be purified by passing through the filter system, which can then be recombined to produce whole blood.

[0052] Advantageous embodiments and further details of the present invention are described below with reference to various exemplary embodiments and schematic figures. The connection is explained in more detail in the schematic drawings.

[0053] 221271PCAyus Medical Devices AG 6 January 20, 2026

[0054] Brief description of the character

[0055] Figure 1: Figure 1 shows a therapeutic apheresis filter system combination, with a fractionator (TKM-58) filter and an L-tryptophan TSO bioreactor.

[0056] Explanation of the invention with application example

[0057] The invention describes an innovative therapeutic apheresis filter system combination comprising a fractionator (TKM-58) filter and an L-tryptophan TSO bioreactor. The bioreactor is based on activated silica spheres coupled with TSO enzymes, which in turn are rigidly coupled to Zetaffinity microcolumns made of polyacrylic cellulose copolymer. The TSO bioreactor is integrated into the plasmapheresis system downstream of the membrane that separates the blood into blood cells and plasma. The plasma is passed through the bioreactor, where the L-tryptophan is broken down into metabolites by enzymatic reactions. The filtered plasma is then recombined with the blood cells and returned to the patient, where the metabolites are excreted by the human kidneys (13).

[0058] Zetaffinity microcolumns are specialized chromatographic columns used in protein analysis, biomolecule separation, and affinity chromatography. The name combines the terms "zeta" (often referring to charge effects) and "affinity" (i.e., specific interactions). They can be used for the separation and purification of proteins, peptides, and other biomolecules.

[0059] The treatment cycle, consisting of 15-20 sessions (5 times / week for 4-5 hours) and repeatable every 2-3 months, keeps the patient's blood L-tryptophan level consistently low, forcing the tumor to release its intracellular L-tryptophan (13). This effectively suppresses tumor growth without the serious side effects that can occur with longer treatments. Plasma filtration itself is highly efficient, and potential side effects, such as immunological reactions, are minimal.

[0060] 221271PCAyus Medical Devices AG 7 January 20, 2026

[0061] Reactions can be controlled by regular plasmapheresis (14, 15).

[0062] Furthermore, the disclosure in the “American Journal of Biomedical Science & Research” entitled “A New Bioreactor For L-Tryptophan Depletion as A New Cancer Therapy”, ISSN: 2642-1747 on pages 148-154 (12 / 2024) is fully incorporated into the present application by reference.

[0063] The features, components, and specific details provided can be exchanged and / or combined to create further embodiments, depending on the required purpose. Any modifications that are within the knowledge of a person skilled in the art are implicitly disclosed in this description.

[0064] New advantages through invention

[0065] This novel filter system combination offers several significant advantages. First, the integration of the TSO bioreactor with the fractionator (specifically the TKM-58) filter enables the simultaneous reduction of L-tryptophan and the removal of cellular debris and toxins, thereby increasing treatment efficacy and minimizing side effects. Second, the risk of toxic effects from endotoxins is avoided by using TSO enzymes from fungal sources, which are endotoxin-free (8). Third, the integration of a pump upstream or downstream of the bioreactor, as well as expansion chambers upstream of the plasma pump and upstream of the confluence of the return blood, minimizes the risk of air bubble formation in the tubing system, thus increasing therapy safety.

[0066] Overall, this invention offers a promising new method for treating cancer, based on the targeted depletion of an essential amino acid, while simultaneously ensuring high efficiency and safety through its combination of bioreactor and filter system.

[0067] 221271PC

Claims

Ayus Medical Devices AG 8 January 20, 2026 Claims 1. Filter system for filtering plasma with a separator and a fractionator and a bioreactor connected between the separator and the fractionator, which contains silica and immobilized tryptophan side chain oxidase (TSO) as the enzyme.

2. Filter system according to claim 1, wherein the TSO is an isoenzyme TSO I, preferably an isoenzyme TSO II and particularly preferably an isoenzyme TSO III.

3. Filter system according to claim 1 or 2, wherein the TSO is endotoxin-free TSO from fungal sources.

4. Filter system according to one of the preceding claims, wherein the fractionator is a highly selective filter system that removes specific molecules from the plasma, in particular those with a molecular size of more than 1 µm.

5. Filter system according to one of the preceding claims, wherein the bioreactor comprises silica spheres coupled to the TSO enzymes.

6. Filter system according to claim 5, wherein the TSO enzymes are coupled to Zetaffinity microcolumns.

7. Filter system according to claim 6, wherein the Zetaffinity microcolumns consist of polyacrylic cellulose copolymer.

8. Filter system according to one of the preceding claims, wherein a first pump is provided upstream of the bioreactor and / or a second pump is provided downstream of the bioreactor. 221271PCAyus Medical Devices AG 9 January 20, 2026 9. Filter system according to one of the preceding claims, wherein a first expansion chamber is provided upstream of the first pump and / or a second expansion chamber is provided downstream of the second pump.

10. Device for cancer therapy comprising a plasmapheresis system for separating blood into blood cells and plasma and introducing them into separate channels and a filter system according to one of the preceding claims, and with a supply line for blood from a collection site on the patient to the plasmapheresis system, wherein the filter system is arranged downstream of the plasmapheresis system and is connected to the channel containing the plasma, and with a merging of the plasma from the filter system and the separated blood cells, which leads into a channel that transports blood for introduction into the patient's blood system.

11. Apheresis device with a filter system, in particular for extracorporeal plasmapheresis, the filter system comprising: a separator and a fractionator, wherein the fractionator is a highly selective filter system that removes specific molecules from the plasma, in particular those with a molecular size greater than 1 µm; and at least one tryptophan side chain oxidase (TSO) bioreactor; wherein the TSO bioreactor is based on activated silica, preferably silica spheres, coupled with immobilized tryptophan side chain oxidase enzymes.

12. The device according to claim 11, wherein the bioreactor is arranged between the separator and the fractionator with a pump.

13. The device according to claim 11 or 12, wherein the TSO bioreactor is based on activated silica spheres coupled to TSO enzymes which are rigidly coupled to Zetaffinity microcolumns, and which 221271PCAyus Medical Devices AG 10 January 20, 2026 consist at least partially, preferably completely, of polyacrylic cellulose copolymer.

14. The device according to at least one of the preceding claims, wherein at least one pump is arranged before or after the bioreactor and wherein the pump is in particular a plasma pump.

15. The device according to at least one of the preceding claims, wherein a first expansion chamber is provided, which is preferably arranged upstream of the pump to avoid air in the tubing system of the apheresis device and / or wherein a second expansion chamber is provided, which is arranged upstream of a confluence of the returning blood and the filtered plasma.

16. The device according to at least one of the preceding claims, wherein the separator is a plasma filter and the fractionator is a differential filter for filtering out eluate from the plasma. 221271PC

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