Medical use of functionalized polymer

Abstract

The present disclosure relates to a functionalized polymer for use in a hemodialysis treatment for the extraction of at least one metal cation, the metal being iron, in a subject in need thereof, wherein said functionalized polymer has a weight average molecular mass between 100 kDa and 1000 kDa, and wherein a part of the monomeric units are functionalized with a chelating moiety, and is present in the dialysate of the hemodialysis treatment, the concentration of said chelating moiety in the dialysate being less than 0.35 mM, preferably between 0.0035 mM and 0.315 mM.

Description

[0001] MEDICAL USE OF FUNCTIONALIZED POLYMER

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to medical use of functionalized polymer. In particular, the disclosure relates to a functionalized polymer with statistic macromolecular structure for use in a hemodialysis treatment for the extraction of at least one metal cation, the metal being iron, in a subject in need thereof.

[0004] BACKGROUND

[0005] Iron plays a crucial role in numerous vital biological processes, such as oxygen transport, DNA synthesis, and ATP production (Galaris D, et al. BBA Mol Cell Res. 2019; 1866: 118535). The metabolism of iron is precisely regulated by several proteins that ensure its absorption, circulation, storage, and recycling. When iron homeostasis is disrupted, various pathologies can arise, including anemia due to iron deficiency and hemochromatosis resulting from iron overload (Anderson GJ, McLaren GD. Iron physiology and pathophysiology in humans. Berlin: Springer; 2012.). While hemochromatosis is a well- known chronic condition characterized by excessive iron levels, acute dysregulation of iron homeostasis has also been linked to several pathologies, including sepsis (Liu Q, et al. Free Radic Biol Med. 2021 ;165:1-13), stroke (Selim MH, Ratan RR. Ageing Res Rev. 2004;3:345-53.), acute kidney injury (AKI) (Leaf DE, et al. J Am Soc Nephrol. 2019;30:493- 504. ; Leaf DE, et al. Kidney Int. 2015;87:1046-54. ; Leaf DE, et al. CJASN. 2014;9:1849- 56.), and critical illness (Tacke F, et al. Crit Care Med. 2016; 44:1049-58.).

[0006] These trace amounts of iron constitute a small percentage of the serum iron, yet they are heavily implicated in the exacerbation of diseases, primarily by catalyzing the formation of reactive oxygen species, which promote oxidative stress. Additionally, catalytic iron activates macrophages and facilitates the growth of pathogens.

[0007] The overload of non-transferrin bound iron (NTBI) has emerged as a crucial therapeutic target to enhance clinical outcomes in critically ill patients, particularly in cases of Acute Kidney Injury (AKI). Considering the diverse sources of iron release, several strategies have been investigated to counteract this pool of NTBI.

[0008] The two main strategies proposed are : (i) targeting iron metabolism proteins or (ii) iron chelation therapy. For the first therapeutic method, different biomolecules have been tested preclinically or in clinical trials. Zarjou et al. (Zarjou A, et al. J Clin Investig. 2013;123:4423- 34) have demonstrated the protective role of ferritin in murine models of AKI. Administration of hepcidin has also been investigated for its interest in the prevention and treatment of AKI (Chawla LS, et al. Crit Care Clin. 2019;35:357-74). Using haptoglobin has also been considered for the scavenging of free hemoglobin whose degradation can lead to very detrimental effects (Van Avondt K, et al., Nat Rev Nephrol. 2019;15:671-92). In animal models, hemopexin has been proposed to scavenge free hemes with controversial results. Iron chelation therapy has been developed for the treatment of secondary hemochromatosis. More recently, use of clinically approved iron chelate has been proposed for the treatment of AKI. The ongoing clinical trial (DEFEAT-AKI, clinicaltrials.gov NCT04633889) is based on the intravenous administration of deferoxamine (DFO) to prevent AKI after cardiac surgery. Three iron chelators are currently approved by FDA, each presenting its own limitations for the treatment of NTBI in Intensive Care Unit (ICU) patients. Deferasirox is contraindicated for patients with chronic kidney disease. Deferiprone is limited by its oral administration for patients in ICU and by its short half-life requiring multiple administrations per day. DFO is a natural siderophore and so it can increase the risk of infections by certain pathogens.

[0009] In conclusion, despite the proven therapeutic effects of common iron-chelating agents in iron overload diseases, these agents may not be well suited for the burst liberation of iron observed in the intensive care unit for example, primarily due to their side effects. However, new iron-chelating agents, including chelating polymers, offer a promising alternative.

[0010] WO2021 / 224569 discloses medical devices for extracting circulating molecules from the blood of a mammal, in particular for the treatment of sepsis.

[0011] WO2022 / 023677 describes a statistical polysaccharide with a weight-average molecular weight of between 100 kDa and 1000 kDa and its use in a dialysis process in order to capture at least one metal, in an MRI imaging process, in a brachytherapy process or in a process for marking foodstuffs to prevent forgeries.

[0012] W02023 / 007096 discloses a method for treating dialysis water and fluids, in particular for capturing certain toxic metals such as lead, aluminium, chromium, nickel or cadmium, and preventing their passage into the blood of a patient during dialysis, i.e. hemodialysis, hemofiltration or hemodiafiltration.

[0013] It remains therefore a challenge to design a safe and efficient hemodialysis treatment which meets this clinical need of mitigating the detrimental effect of blood iron overload in a subject in need thereof. The present disclosure solves this problem by providing the combination of hemodialysis treatment with the use of a functionalized polymer in the dialysate.

[0014] SUMMARY

[0015] A first aspect of the disclosure relates to a functionalized polymer for use in a hemodialysis treatment for the extraction of at least one metal cation, the metal being iron, in a subject in need thereof, wherein said functionalized polymer has a weight average molecular mass between 100 kDa and 1000 kDa, and wherein a part of the monomeric units are functionalized with a chelating moiety, and is present in the dialysate of the hemodialysis treatment, the concentration of said chelating moiety in the dialysate being less than 0.35 mM, preferably between 0.0035 mM and 0.315 mM.

[0016] In specific embodiments, the hemodialysis treatment in combination with the functionalized polymer as disclosed herein are provided for intensive care subjects at risk of sepsis or septic shock, or present a sepsis or a septic shock.

[0017] In an embodiment, the hemodialysis treatment in combination with the functionalized polymer as disclosed herein are provided for intensive care subjects with myelodysplasia or myelodysplastic syndromes or myelofibrosis.

[0018] In another embodiment, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subjects presenting Acute-on-Chronic Liver Failure.

[0019] DETAILED DESCRIPTION

[0020] DEFINITIONS

[0021] In the following, terms as used herein are defined in their meaning.

[0022] The term “about” or “ca.” has herein the meaning that the following value may vary for ± 20%, preferably ± 10%, more preferably ± 5%, even more preferably ± 2%, even more preferably ± 1 %.

[0023] Unless otherwise defined, “%” has herein the meaning of weight percent (wt%), also referred to as weight by weight percent (w / w%).

[0024] The chelating agent in the context of the present disclosure may be DOTA: 1 ,4,7,10-tetraazacyclododecane-N,N',N",N"'-teracetic acid;

[0025] NOTA: 1 ,4,7-triazacyclononane-1 ,4, 7-triacetic acid;

[0026] NODAGA: 1 ,4,7-triazacyclononane-1-glutaric-4,7-diacetic acid;

[0027] DOTAGA:2-(4,7,10-tris(carboxymethyl)-1,4,7, 10-tetraazacyclododecan-1- yl)pentanedioicacid;

[0028] DOTAM : 1 ,4,7, 10-tetrakis(carbamoylmethyl)-1 ,4,7, 10-tetraazacyclodecane;

[0029] NOTAM: 1 ,4,7-tetrakis(carbamoylmethyl)-1, 4,7-triazacyclononane;

[0030] DOTP: 1 ,4,7,10-tetraazacyclododecane 1 ,4,7,10-tetrakis(methylene phosphonate;

[0031] NOTP: 1 ,4,7-tetrakis(methylene phosphonate)-1, 4,7-triazacyclononane;

[0032] TETA: 1 ,4,8,11-tetraazacyclotetradecane-N,N',N",N"'-teracetic acid;

[0033] TETAM : 1 ,4,8, 11-tetraazacyclotetradecane-N,N',N",N"'-tetrakis(carbamoyl methyl);

[0034] DTPA: diethylene triaminopentaacetic acid;

[0035] Bz-DFO: benzyl deferoxamine;

[0036] DFO: deferoxamine.

[0037] As used herein, the terms “effective amount” or “therapeutically efficient amount” of a compound refer to an amount of the compound that will induce the biological or medical response of a subject, for example, ameliorate the symptoms, alleviate conditions, slow or delay disease progression, or prevent a disease.

[0038] As used herein, the term “independently” for the Rc moiety i.e. the chelating agent, means that each Rc of the functionalized statistic chitosan of formula (I) is a chelating agent that may be different from one to another, or may be identical. For example, each Rc is identical i.e., there is one type of Rc throughout the functionalized statistic chitosan, or there may be more than one type of Rc throughout the functionalized statistic chitosan i.e. two, three, four, five or even n different Rc, n being an integer.

[0039] As used herein “combination” refers to either a fixed combination in one dosage unit form, or a combined administration where a compound of the present disclosure; for example a functionalized polymer in the dialysate, and a combination partner (e.g. another drug as explained below, also referred to as “therapeutic agent” or “co-agent”) may be administered to the subject, or added in the dialysate, independently, at the same time or separately within time intervals, especially where these time intervals allow that the combination partners show a cooperative, e.g. synergistic effect. The single components may be packaged in a kit or separately. One or both of the components (e.g., powders or liquids) may be reconstituted or diluted to a desired dose prior to administration. The terms “coadministration” or “combined administration” or the like as utilized herein are meant to encompass administration of the selected combination partner to a single subject in need thereof (e.g. a patient), and are intended to include treatment regimens in which the agents can be added in the dialysate to provide a synergistic effect with the functionalized polymer.

[0040] The terms “patient”, “subject”, “individual”, and the like, are used interchangeably herein, and refer to a mammal, preferably a human. In some embodiments, the patient, subject or individual in need of treatment includes those who already have the disease, condition, or disorder, i.e. disease correlated with heavy metal-induced toxicity or heavy metal-induced carcinogenicity.

[0041] The terms “prevention” and / or “treatment” are understood to mean a method aiming to reduce, block advancement of, hinder or eliminate one or more symptoms in an individual suffering from a pathology or disease causing this or these symptom(s) or capable of causing them. For example, in the case of sepsis or septic shock, the treatment can consist in reducing, decreasing, blocking progression or hindering blood iron overload. For example, in the case of myelodysplasia or myelodysplastic syndromes or myelofibrosis, the treatment can consist in reducing, decreasing, blocking progression or hindering the blood iron overload. For example, in the case of Acute-on-Chronic Liver Failure, the treatment can consist in reducing, decreasing, blocking progression or hindering the blood iron overload.

[0042] The functionalized polymer for use according to the present disclosure

[0043] A functionalized polymer for use in a hemodialysis treatment for the extraction of at least one metal cation, the metal being iron, in a subject in need thereof, wherein said functionalized polymer has a weight average molecular mass between 100 kDa and 1000 kDa, and wherein a part of the monomeric units are functionalized with a chelating moiety, and is present in the dialysate of the hemodialysis treatment, the concentration of said chelating moiety in the dialysate being less than 0.35 mM, preferably between 0.0035 mM and 0.315 mM.

[0044] In certain embodiment, the functionalized polymer has a weight average molecular mass between 150 kDa and 750 kDa, more preferably between 200 kDa and 600 kDa, even more preferably between 250 kDa and 400 kDa, and even more preferably about 300 kDa.

[0045] In an embodiment, the cut-off threshold of the dialysis membrane is equal or below the weight average molecular mass of said functionalized polymer, for example 100 kDa, and said functionalized polymer having a weight average molecular mass between 100 kDa and 1000 kDa. In an embodiment, said functionalized polymer comprises at least 1wt% of chelating moiety based on the total weight of the functionalized polymer, for example between 1wt% and 40wt%, preferably between 5wt% and 30wt%, more preferably between 10wt% and 25wt%, even more preferably about 10wt% or 15wt% or 15.5 wt% or 17wt% or 22wt%.

[0046] Said chelating moiety enables chelation of at least one metal cation, the metal cation being iron.

[0047] Each of the chelating moiety may comprise two or more coordination sites. Preferably, the coordination site is a nitrogen or oxygen atom. Advantageously, each of the chelating moiety comprises between 4 and 8 coordination sites, more preferably between 6 and 8 coordination sites.

[0048] As used herein, the term “coordination site” refers to a single function capable of complexing a metal. For example, an amine function represents a coordination site by the formation of a dative bond between the nitrogen atom and the metal, and a hydroxamic acid function also represents a coordination site by the formation of a dative bond between the oxygen of the carbonyl unit and by a covalent bond with the oxygen of the N-oxide unit the coordination site thus forming a five-membered ring.

[0049] In an embodiment, each chelating moiety is obtained by grafting to the polymer the following chelating agent selected from the group consisting of DOTA (1 ,4,7,10-tetraazacyclododecane- N,N',N",N"'-teracetic acid), NOTA (1 ,4,7-triazacyclononane-1 ,4, 7-triacetic acid), NODAGA (1 ,4,7-triazacyclononane-1-glutaric-4,7-diacetic acid), DOTAGA (2-(4,7,10- tris(carboxymethyl)-1 ,4,7, 10-tetraazacyclododecan-1-yl)pentanedioic acid), DOTAM (1 ,4,7, 10-tetrakis(carbamoylmethyl)-1 ,4,7, 10-tetraazacyclodecane), NOTAM (1 ,4,7- tetrakis(carbamoylmethyl)-1 , 4,7-triazacyclononane), DOTP (1 ,4,7,10-tetraazacyclododecane 1 ,4,7,10-tetrakis(methylene phosphonate), NOTP (1 ,4,7-tetrakis(methylene phosphonate)-1 , 4,7-triazacyclononane), TETA (1 ,4,8,11-tetraazacyclotetradecane-N,N',N",N"'-teracetic acid), TETAM (1 ,4,8, 11-tetraazacyclotetradecane-N,N',N",N"'-tetrakis(carbamoyl methyl), DTPA (diethylene triaminopentaacetic acid) Bz-DFO (benzyl deferoxamine), DFO (deferoxamine), and mixtures thereof, preferably from the group consisting of DOTAGA, Bz- DFO, DFO, DOTAM and DTPA, and more preferably the chelating moiety is DOTAGA, or DOTAM, or DTPA, or a mixture of DOTAGA and Bz-DFO, or a mixture of DOTAGA and NODAGA, or a mixture of DOTAGA and DTPA, or a mixture of DOTAGA and DOTAM. In an embodiment, the chelating moiety is selected from the group consisting of:

[0050] DFO

[0051] nw*

[0052] The functionalized polymer may be selected from the group consisting of polysaccharides, polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyacrylic acid (PAA), poly allylamine (PAH), wherein a part of the monomeric units is functionalized with a chelating moiety. In specific embodiment, polysaccharides may be chosen among digestible polysaccharides such as starch, or non-digestible polysaccharides such as chitosan, cellulose, chitin, - glucan, xylan, pectin, mucilage, gums, lignin, galactan, agar, fructan, fucoidans galactoglucans, sulfated polysaccharides, hyaluronic acid or mixtures thereof, preferably among chitosan. In preferred embodiment, polysaccharides are chosen among non-digestible polysaccharides. Indeed, non-digestible polysaccharides possess beta glycosidic bonds which will be less easily digested compared to digestible polysaccharides which possess alpha glycosidic bonds that are digested more quickly via the alpha amylases present in the digestive tract. In specific embodiments, the functionalized polymer of the present disclosure is selected among polymers which have a size greater than the cutoff threshold of the porous dialysis membrane used in hemodialysis treatment so that such polymers do not reach the bloodstream of the subject in need thereof. Indeed, without wishing to be bound by any theory, the inventors believe that by remaining in the dialysis fluid, the polymer advantageously acts locally by chelating a portion of the heavy metals present in the blood of the subject in need thereof and avoids the common adverse effects of the presence of a chelating moiety in the systemic compartment as observed in prior art treatments.

[0053] Preferred embodiments of the polymer: The functionalized statistic chitosan

[0054] In a specific embodiment, the functionalized polymer is a functionalized statistic chitosan of formula (I): wherein each Rc is the chelating moiety, each Z is independently a linker which is a single bond or a hydrocarbon chain containing between 1 and 12 carbon atoms, said hydrocarbon chain is linear or branched and optionally contains one or more unsaturations and being able to contain one or more heteroatoms, preferably chosen from nitrogen, oxygen, sulfur and halogens, x is between 0.005 and 0.7, preferably between 0.05 and 0.7, y is between 0.01 and 0.7, preferably between 0.05 and 0.2, the ratio y / x being greater than or equal to 0.05, preferably greater than or equal to 0.15, and the sum x + y being greater than or equal to 0.15, preferably greater than or equal to 0.30, more preferably greater than or equal to 0.35.

[0055] It is understood that, in the above formula I, more than one Rc group may be present in the functionalized statistic chitosan. These Rc groups may be the same or different from each other. They are all independently selected from the groups carrying a chelating moiety. The same applies to the Z-linkers, several Z-linkers may be present, and they may be identical or different from each other.

[0056] In an embodiment, in formula I, x is between 0.005 and 0.7; y is between 0.01 and 0.7; the ratio y / x being greater than 0.05 ; and the sum x + y being greater than 0. 15. In an embodiment, in formula I, x is between 0.05 and 0.7; y is between 0.05 and 0.2; the ratio y / x being greater than 0.15 ; and the sum x + y being greater than 0.30.

[0057] In an embodiment, in formula I, x is about 0.3; y is about 0.07.

[0058] In a specific embodiment, the functionalized statistic chitosan of the present disclosure has a complexation constant, in particular with iron, of at least 1015for a d or f transition element.

[0059] In an embodiment, the functionalized statistic chitosan of formula I is a functionalized statistic chitosan of formula (II): wherein

[0060] Rci and RC2 are different chelating moieties,

[0061] Zi and Z2, identical or different, are linkers which are a single bond or a hydrocarbon chain containing between 1 and 12 carbon atoms, said hydrocarbon chain is linear or branched and optionally contains one or more unsaturations and one or more heteroatoms, preferably chosen from nitrogen, oxygen, sulfur and halogens, x is between 0.005 and 0.7, preferably between 0.05 and 0.7, and more preferably between 0.2 and 0.6, y=z+w is between 0.01 and 0.7, preferably between 0.05 and 0.2, the ratio y / x being greater than or equal to 0.05, preferably greater than or equal to 0.15, the sum x + y being greater than or equal to 0.15, preferably greater than or equal 0.30, more preferably greater than or equal to 0.35, and z / y is between 0.5 and 1.

[0062] In this embodiment, the functionalized statistic chitosan of formula (II) may comprise either a single type of moiety comprising a chelating moiety, Rc1 , when z is equal to 1 , or 2 types of moieties comprising a chelating moiety, Rc1 and Rc2, when 0.5 < z < 1.

[0063] In an embodiment, z / y is between 0.8 and 0.99, Rci moiety is thus in the majority. In another embodiment, in formula II, x is between 0.005 and 0.6; y is between 0.1 and 0.9; the ratio y / x being greater than 0.3; and z is between 0.5 and 1.

[0064] Rc moiety (Rc, Rc1 and Rc2)

[0065] As used herein, the term “Rc moiety” refers to Rc moiety of formula I, and the terms “Rc1 and Rc2 moiety” refer to Rci and RC2 of formula II, when RC2 is present. According to the present disclosure, Rci and RC2 groups are chelating moieties. In other words, the Rc, Rci and RC2 moieties enable chelation of one or more metals by forming a complex.

[0066] Each of the Rc, Rci and RC2 moiety may comprise two or more coordination sites. Preferably, the coordination site is a nitrogen or oxygen atom. Advantageously, each of the Rc, Rci and RC2moiety comprises between 4 and 8 coordination sites, more preferably between 6 and 8 coordination sites.

[0067] In an embodiment, for the functionalized statistic chitosan of formula I, each Rc moiety is independently selected from the group consisting of DOTA (1 ,4,7,10-tetraazacyclododecane- N,N',N",N"'-teracetic acid), NOTA (1 ,4,7-triazacyclononane-1 ,4, 7-triacetic acid), NODAGA (1 ,4,7-triazacyclononane-1-glutaric-4,7-diacetic acid), DOTAGA (2-(4,7,10- tris(carboxymethyl)-1 ,4,7, 10-tetraazacyclododecan-1-yl)pentanedioic acid), DOTAM (1 ,4,7, 10-tetrakis(carbamoylmethyl)-1 ,4,7, 10-tetraazacyclodecane), NOTAM (1 ,4,7- tetrakis(carbamoylmethyl)-1 , 4,7-triazacyclononane), DOTP (1 ,4,7,10-tetraazacyclododecane 1 ,4,7,10-tetrakis(methylene phosphonate), NOTP (1 ,4,7-tetrakis(methylene phosphonate)-1 , 4,7-triazacyclononane), TETA (1 ,4,8,11-tetraazacyclotetradecane-N,N',N",N"'-teracetic acid), TETAM (1 ,4,8, 11-tetraazacyclotetradecane-N,N',N",N"'-tetrakis(carbamoyl methyl), DTPA (diethylene triaminopentaacetic acid) Bz-DFO (benzyl deferoxamine), and DFO (deferoxamine), preferably from the group consisting of DOTAGA, Bz- DFO, DFO, DOTAM and DTPA, and more preferably the Rc group is DOTAGA.

[0068] In another embodiment, for the functionalized statistic chitosan of formula II, Rc1 and Rc2 are independently selected from the group consisting of DOTA, NOTA, NODAGA, DOTAGA, DOTAM, NOTAM, DOTP, NOTP, TETA, TETAM, DTPA, Bz-DFO and DFO, preferably from the group consisting of DOTAGA, Bz-DFO, DFO, DOTAM and DTPA.

[0069] In an embodiment, the chelating moiety is selected from the group consisting of: nw*

[0070] In an embodiment, for the functionalized statistic chitosan of formula I, the group Rc is DOTAGA, and preferably, z / y=1.

[0071] In another embodiment, for the functionalized statistic chitosan of formula II, the group Rc1 is DOTAGA and the group Rc2 is Bz-DFO.

[0072] Z linkers (Z, Z1 andZ2)

[0073] As used herein, the term “Z linkers” refers to Z linker of formula I, and the terms “Zi and Z2 linkers” refer to Z1 and Z2 linkers of formula II, when the Z2 binder is present.

[0074] The choice of the Z, Z1 and Z2 linkers in formula I and II depends essentially on the Rc, Rci and RC2moieties and the metal to be chelated. Indeed, for stearic reasons in particular, the Rc, Rci and RC2 moieties may be more or less close to the 6-membered ring of the nitrogen of the glucosamine unit.

[0075] In formula I, each Z is independently a linker which is a single bond or a hydrocarbon chain containing between 1 and 12 carbon atoms, said hydrocarbon chain is linear or branched and optionally contains one or more unsaturation and one or more heteroatoms, preferably chosen from nitrogen, oxygen, sulfur and halogens.

[0076] In an embodiment, in formula I, each Z is independently selected from the group consisting of: a bond, a linear or branched alkyl chain having between 1 and 12 carbon atoms, and a linear or branched alkenyl chain having between 2 and 12 carbon atoms, said alkyl and alkenyl chains may be interrupted by one or more C6-C10 aryl groups, and / or by one or more heteroatoms or groups selected from the group consisting of -O-, -S-, -C(O)-, -NR'-, - C(O)NR'-, -NR'-C(O)-, -NR'-C(O)-NR'-, -NR'-C(O)-O-, -O-C(O)NR', -C(S)NR'-, -NR'-C(S)-, - NR'-C(S)-NR’, said alkyl and alkenyl chains may be substituted with one or more groups selected from the group consisting of halogen, -OR', -COOR', -SR', -NR'2, each R' being independently H or C1-C6 alkyl.

[0077] Advantageously, in Formula I, each Z is independently selected from the group consisting of: a bond and a linear or branched alkyl chain having between 1 and 12 carbon atoms, said alkyl chain may be interrupted by one or more C6-C10 aryl groups, and / or by one or more heteroatoms or groups selected from the group consisting of -O-, -S-, -C(O)-, -NR'-, - C(O)NR'-, -NR'-C(O)-, -C(S)NR'-, -NR'-C(S)-NR', each R' being independently H or C1 -C6 alkyl.

[0078] In an embodiment each Z is an alkyl chain having between 1 and 12 carbon atoms.

[0079] In another embodiment, each Z is a polyethylene glycol (PEG).

[0080] Advantageously, in Formula II, Zi and Z2 are independently a single bond or a hydrocarbon chain having between 1 and 12 carbon atoms, wherein said chain may be linear or branched and may have one or more unsaturations and may have one or more heteroatoms, preferably selected from nitrogen, oxygen, sulfur, and halogens.

[0081] In an embodiment, in formula II, Z1 and Z2 are independently selected from the group consisting of: a bond, a linear or branched alkyl chain having between 1 and 12 carbon atoms, and a linear or branched alkenyl chain having between 2 and 12 carbon atoms, said alkyl and alkenyl chains may be interrupted by one or more C6-C10 aryl groups, and / or by one or more heteroatoms or groups selected from the group consisting of -O-, -S-, -C(O)-, -NR'-, -C(O)NR'-, -NR'-C(O)-, -NR'-C(O)-NR'-, -NR'-C(O)-O-, -O-C(O)NR', -C(S)NR'-, -NR'- C(S)-, -NR'-C(S)-NR’, said alkyl and alkenyl chains may be substituted with one or more groups selected from the group consisting of halogen, -OR', -COOR', -SR', -NR'2, each R' being independently H or C1-C6 alkyl.

[0082] In an embodiment, in Formula II, Zi and Z2 are independently selected from the group consisting of: a bond and a straight or branched alkyl chain having between 1 and 12 carbon atoms, wherein said alkyl chain may be interrupted by one or more C6-C10 aryl groups, and / or by one or more heteroatoms or groups selected from the group consisting of -O-, - S-, -C(O)-, -NR'-, -C(O)NR'-, -NR'-C(O)-, -C(S)NR'-, -NR'-C(S)-NR', each R' being independently H or C1-C6 alkyl.

[0083] In a specific embodiment Z1 and / or Z2 is an alkyl chain having between 1 and 12 carbon atoms.

[0084] In another specific embodiment, Z1 and / or Z2 is a polyethylene glycol (PEG).

[0085] Monomeric units of the functionalized statistic chitosan

[0086] The functionalized statistic chitosan in formula I of the present disclosure is composed of 3 different monomeric units, namely an N-acetyl glucosamine type A unit, a glucosamine type B unit and a glucosamine type C unit functionalized by a chelating moiety (of the Rc type) linked by a linker (of the Z type) to the nitrogen of the glucosamine.

[0087] The functionalized statistic chitosan is statistic polymer. In other words, the sequence of the individual monomer units A, B and type C is random.

[0088] The functionalized statistic chitosan in formulae II of the present disclosure is composed of 4 different monomeric units, namely an N-acetyl glucosamine type A unit, a glucosamine type B unit and two glucosamine type C unit, namely C1 and 02, functionalized by a chelating moiety (of the Rc1 type or Rc2 type) linked by a linker (of the Z1 type or Z2 type) to the nitrogen of the glucosamine.

[0089] The functionalized statistic chitosan in formulae II is statistic polymer. In other words, the sequence of the individual monomer units A, B, 01 and 02 is random.

[0090] In formulae I and II, x represents the proportion of A units and x is between 0.005 and 0.7, preferably between 0.05 and 0.7, more preferably between 0.2 and 0.6, even more preferably x is between 0.25 and 0.4, typically about 0.3. In another embodiment, x is between 0.025 and 0.075, for example between 0.04 and 0.06, typically about 0.05.

[0091] In formulae I and II, y represents the proportion of C-type units and y is between 0.01 and 0.7, preferably between 0.05 and 0.2. In an embodiment, y is between 0.03 and 0.2, preferably between 0.05 and 0.1 , even more preferably between 0.07 and 0.08, typically about 0.072. In another embodiment, y is between 0.05 and 0.3, more preferably between 0.1 and 0.2, typically about 0.15 or 0.12.

[0092] In another embodiment, when the Rc1 and Rc2 of formula II are independently selected from the group consisting of:

[0093] DFO

[0094] 01 PA preferably from the group consisting of DOTAGA, Bz-DFO, DFO, DOTAM and DTPA, and y is between 0.05 and 0.3, more preferably between 0.1 and 0.2, typically about 0.12, Rc1 is between 0.06 and 0.08, typically about 0.07 and Rc2 is between 0.04 and 0.06, typically about 0.05.

[0095] The rest of the monomer units in formulae I and II are B units. Thus, in formulae I and II, the proportion of B units is equal to 1-x-y.

[0096] According to the disclosure, in formulae I and II, the ratio y / x is greater than or equal to 0.05, preferably greater than or equal to 0.15. Indeed, effectiveness of the functionalized statistic chitosan is determined by the number of chelation sites, which is directly related to the number of metals required, for example, for extracting of at least one metal cation, the metal being iron, during the hemodialysis treatment of a subject in need thereof.

[0097] In accordance with the disclosure, z / y is between 0.5 and 1 . In other words, the C-type units may be exclusively units having Z1 as a linker and Rc1 as a chelating moiety-bearing group. The functionalized statistic chitosan has a weight average molecular mass between 100 kDa and 1000 kDa, preferably between 150 kDa and 750 kDa, more preferably between 200 kDa and 600 kDa, even more preferably between 250 kDa and 400 kDa, and even more preferably about 300 kDa.

[0098] In an embodiment, the functionalized statistic chitosan is selected from the following functionalized statistic chitosan:

[0099] - a functionalized statistic chitosan of formula II where z / y = 1 , Rc1 is DOTAGA and Z1 is a bond;

[0100] - a functionalized statistic chitosan of formula II where z / y = 1 , Rc1 is DTPA and Z1 is a bond; and

[0101] - a functionalized statistic chitosan of formula II where 0.5 < z / y < 1 , Rd is DOTAGA and Z1 is a bond, and Rc2 is Bz-DFO and Z2 is selected from the group consisting of: a bond and a straight or branched alkyl chain having between 1 and 12 carbon atoms, wherein said alkyl chain may be interrupted by one or more C6-C10 aryl groups, and / or by one or more heteroatoms or groups selected from the group consisting of -O-, -S-, -C(O)-, -NR'-, - C(O)NR'-, -NR'-C(O)-, -C(S)NR'-, -NR'-C(S)-NR', each R' being independently H or C1 -C6 alkyl.

[0102] In an embodiment, the functionalized statistic chitosan has the following formula (III): wherein x is between 0.25 and 0.4, typically about 0.3, and y is between 0.05 and 0.2, typically about 0.07.

[0103] In a more preferred embodiment, the functionalized statistic chitosan is MexCDI polymer of the following formula (III): wherein x is about 0.3, and y is about 0.07.

[0104] In an embodiment, the functionalized statistic chitosan is soluble in aqueous solution at physiological pH i.e. pH of between 4.8 and 8 and responds the following : (DS DOTAGA(%)+3.5)*(DA(%)+8) > 150 wherein DS is the degree of substitution of the DOTAGA and DA is the degree of acetylation of the functionalized statistic chitosan.

[0105] In another embodiment, the functionalized statistic chitosan has the formula (III), wherein x is between 0.025 and 0.075, more preferably between 0.04 and 0.06, typically about 0.05, and y is between 0.05 and 0.3, more preferably between 0.1 and 0.2, typically about 0.15. In another embodiment, the functionalized statistic chitosan has the following formula (IV): wherein x is between 0.2 and 0.6, more preferably x is between 0.25 and 0.4, typically about 0.3, and y=z+w is between 0.05 and 0.3, more preferably between 0.1 and 0.2, typically about 0.12. Synthesis of the functionalized polymers of formula I and II

[0106] The compounds of formulae I and II can be synthesized using the methods disclosed in WO 2022 / 023677 and in the reference Natuzzi, M., Grange, C., Grea, T. et al. Feasibility study and direct extraction of endogenous free metallic cations combining hemodialysis and chelating polymer. Sci Rep 11, 19948 (2021).

[0107] Methods of treatment using said functionalized polymer

[0108] The present disclosure relates to methods of extracting at least one metal cation, the metal being iron, by hemodialysis treatment in a subject in thereof, said method comprising adding an efficient amount of a functionalized polymer in the dialysate during the hemodialysis treatment of said subject, wherein said functionalized polymer has a weight average molecular mass between 100 kDa and 1000 kDa and wherein a part of the monomeric units are functionalized with a chelating moiety, and is present in the dialysate of the hemodialysis treatment, the concentration of said chelating moiety in the dialysate being less than 0.35 mM, preferably between 0.0035 mM and 0.315 mM.

[0109] The present disclosure also relates to a functionalized polymer for use in a hemodialysis treatment for the extraction of at least one metal cation, the metal being iron, in a subject in need thereof, wherein said functionalized polymer has a weight average molecular mass between 100 kDa and 1000 kDa, and wherein a part of the monomeric units are functionalized with a chelating moiety, and is present in the dialysate of the hemodialysis treatment, the concentration of said chelating moiety in the dialysate being less than 0.35 mM, preferably between 0.0035 mM and 0.315 mM.

[0110] The present disclosure also relates to the use of a functionalized polymer in a hemodialysis treatment wherein said functionalized polymer has a weight average molecular mass between 100 kDa and 1000 kDa, and wherein a part of the monomeric units are functionalized with a chelating moiety , and is present in the dialysate of the hemodialysis treatment, the concentration of said chelating moiety in the dialysate being less than 0.35 mM, preferably between 0.0035 mM and 0.315 mM for the manufacture of a medicament or medical device for the extraction by hemodialysis of at least one metal cation, the metal being iron, in a subject in need thereof. In an embodiment, the cut-off threshold of the dialysis membrane is equal or below the weight average molecular mass of said functionalized polymer, for example 100 kDa, and said functionalized polymer having a weight average molecular mass between 100 kDa and 1000 kDa.

[0111] After introduction of the functionalized polymer, e.g. MexCDI , into the dialysate of the hemodialysis treatment the polymer is solubilized or creates a colloidal suspension which, when used, for example in combination with continuous venovenous haemodialysis (CVVHD), enables the indirect extraction of free iron from the blood of a subject in need thereof. Accordingly, the method advantageously extracts free iron.

[0112] Indeed, the use of the functionalized polymer, e.g. MexCDI , into the dialysate of the hemodialysis treatment in a subject in need thereof has at least the following two advantages:

[0113] - The first is that this strategy increases both the iron extraction capacity of standard dialysis (which is very limited due to the low level of free iron, around 1 % of total iron) and the chelation capacity of the functionalized polymer, e.g. MexCDI , (because the countercurrent circulation of blood and dialysate increases the free iron gradient between the blood and dialysate compartments).

[0114] - The second advantage is that, due to their molecular mass between 100 kDa and 1000 kDa, the functionalized polymer, e.g. MexCDI , cannot cross the dialysis membrane and therefore do not enter the systemic circulation, thereby avoiding the adverse effects caused by currently approved intravenous iron chelators.

[0115] Hemodialysis treatment

[0116] For the purposes of the disclosure, the term “dialysis” encompasses processes for purifying blood in patients who require it, for example patients suffering from acute or chronic renal failure, notably terminal chronic renal failure, and comprising the use of a dialyzer.

[0117] The dialyzer comprises a porous or semi-permeable membrane (hereafter referred as a dialysis membrane), allowing the passage of small molecules by diffusion or convection, while at the same time blocking the passage of larger molecules, for example proteins.

[0118] The membrane thus has a “cut-off” threshold, i.e. the molecular mass above which the membrane is considered strictly impermeable, i.e. capable of blocking 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, or even up to at least 99.9% of molecules with a molecular mass greater than the cut-off threshold. The term “dialysis” or “extra-renal purification” in particular covers hemodialysis, hemofiltration and hemodiafiltration. Dialysis denotes all the extrarenal purification methods allowing uremic toxins to be purified and the hydroelectrolytic disorders resulting from renal dysfunction (potassium, calcium, phosphorus, acid, base) to be corrected. In practice, the cut-off point of a semi-permeable membrane for hemodialysis is less than 20 to 50 kDa for high-permeability membranes. In the hemodialysis context, exchanges across the porous or semi-permeable membrane take place mainly via a concentration gradient on either side of the membrane, the mechanism known as diffusion. In the context of hemofiltration, exchanges take place via a pressure gradient, from the dialyzate to the blood, known as convection. Hemodiafiltration is the most commonly prescribed technique, combining diffusion and convection (B. Canaud, Principes et modalites d'application de I'hemodialyse au traitement de I'insuffisance renale chronique. Nephrology and Therapeutics 2009).

[0119] The extrarenal purification devices used with the present disclosure thus allow exchanges between dialysate and blood through a semi-permeable membrane, and comprise (1) a tank containing ultra-pure water, (2) a generator which ensures extracorporeal blood circulation, the circulation of the dialysate and generates the dialysate, (3) a semi- permeable membrane, also referred as dialysis membrane, (4) an extracorporeal blood circulation device and (5) a vascular access.

[0120] The term “extracorporeal blood circulation device” typically means a device that allows venous blood flow to be diverted into a circuit outside the body, with a circulation flow rate of 300 to 400 ml / min in adults (variable in children, in neonatology >10 ml / min). By way of example, suitable device are for example a dialyzer or a blood oxygenation circuit made up of a vessel and an oxygenator. Said Extracorporeal blood circulation device is understood to mean a device enabling diversion of the venous blood flow into a circuit situated outside the body with a circulation flow rate of at least 10 ml / min. For example, the conventional hemodialysis systems or blood oxygenation devices such as the one described in the publication: Extrarenal purification in intensive care (Didier Journois, Frederuqe Schorgen, 2003, Masson) or for example developed or marketed by the companies Baxter, Fresenius, Dialife, Asahi Kasei, Debiotech, Medtronic, Nipro, Torray and Braun

[0121] The term “dialysate” refers to the fluid prepared by the generator, and used during the dialysis session.

[0122] The dialysate may be a bath mixture of acid (acetic acid, citric acid or hydrochloric acid), ions (potassium, sodium, chlorine, calcium, magnesium), glucose, sterile ultrapure water and a bicarbonate buffer. When using an ultrafiltration purification device (e.g. DIASAFE(R) Plus or DIACLEAR(R) Ultrafiltrate), the dialysate composition may be measured upstream or downstream of an ultrapurification filter. It is preferentially intended to be measured upstream of these filters, at the inlet connection. Since the dialyzate flow rate is generally 500 to 700 ml / min, and dialysis sessions last 4 hours, a dialyzate generator produces continuously and extemporaneously 120 to 170 liters of dialyzate per session. Certain short hemodialysis protocols (2 hours per session, and 6 sessions per week), known as daily hemodialysis, use generators (NxStage, Physidia S3) that require dialyzate in 5-liter sterile bags, of the same composition as described previously.

[0123] The term “dialysis composition” thus refers to any composition that is suitable for use in the preparation of a dialysate. Thus, for the purposes of the present disclosure, the term “dialysis composition” encompasses the dialysate, or a concentrated solution (additive) allowing the preparation of the dialysate after dilution in sterile water, and, where appropriate with other additives.

[0124] Typically, in one embodiment, the dialysis composition for use according to the disclosure is a concentrated dialysis solution or a concentrated-solution additive comprising the functionalized polymer as used herein. Said concentrated solutions notably comprise acidic concentrated solutions, comprising at least a sufficient amount of acid, for example chosen from acetic acid, hydrochloric acid or citric acid, combined with a mixture of ions, such as potassium, sodium, chlorine, calcium or magnesium, with glucose, to which solution is added bicarbonate buffer and sterile ultrapure water.

[0125] In another embodiment, the dialysis composition according to the disclosure is a concentrated solution also comprising one or more electrolytes, in particular chosen from sodium, potassium, chlorine, magnesium or calcium, and bicarbonates.

[0126] In one particular embodiment, the dialysis composition is a concentrated solution comprising, in addition to said polymer, an acid and several electrolytes, in particular chosen from sodium, potassium, chlorine, magnesium and calcium, and bicarbonates.

[0127] In another particular embodiment, the dialysis composition according to the disclosure is a concentrated solution packaged in a bag suitable for a dialysis device, preferably a bag containing a solution volume of between 500 and 5000 mL and an amount of said polymer of between 5 and 5000 mg and preferably between 10 and 100 mg.

[0128] In specific embodiments, the cut-off threshold of the dialysis membrane is 20 kDa or less, 30 kDa or less, or 40 kDa or less, preferably 30 kDa or less, or 40 kDa or less. Therefore, in specific embodiments, the systems of dialysis for use according to the present disclosure enables the extraction of circulating molecules in the blood of the subject in need thereof, the size whereof is less than the cutoff threshold of the dialysis membrane, and in particular circulating molecules the size whereof is less than 40 kDa, or even less than 30 kDa. In particular, the threshold will be determined so that the principal protein of human blood plasma, albumin (65 kDa), does not cross the dialysis membrane. The order of 20 to 30 kDa is the threshold currently used for hemo(dia)filtration treatments in renal replacement therapy (RRT).

[0129] In a specific embodiment, the hemodialysis treatment comprises continuous veno-venous hemodialysis.

[0130] In another specific embodiment, the hemodialysis treatment is a slow low-volume continuous veno-venous hemodialysis. In specific embodiment, the dialysis dose of the slow low-volume continuous veno-venous hemodialysis is from 10 mL / kg-1 / h-1to 5.5 ml / kg-1 / h-1.

[0131] In an embodiment, the hemodialysis treatment is conducted for at least 3 hours, or at least 4 hours, or at least 6 hours, or at least 12 hours, or at least 18 hours, or at least 24 hours, preferably for at least 3 hours, or at least 4 hours, or at least 24 hours.

[0132] Methods of use

[0133] The functionalized polymer, e.g. MexCDI , of the present disclosure is for use in a dialysate of a hemodialysis treatment for the extraction of at least one metal cation, the metal being iron, in a subject in need thereof.

[0134] Hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein may be used for patients with acute kidney injury. Its purpose is to support renal function by maintaining fluid and electrolyte balance and eliminating toxins through a dialysis membrane, thereby preventing complications associated with acute kidney injury, such as volume overload and electrolyte and acid-base imbalances.

[0135] Without to be bound by any theory, the inventors proposes potential solution for iron extraction in patients requiring hemodialysis treatment involving the use of a functionalized polymer, e.g. MexCDI , in combination with hemodialysis, such functionalized polymer having a weight average molecular mass between 100 kDa and 1000 kDa, and wherein a part of the monomeric units of said polymer are functionalized with a chelating moiety, the concentration of said chelating moiety in the dialysate is less than 0.35 mM, preferably between 0.0035 mM and 0.315 mM. In pathological conditions associated with heavy iron overload, NTBI can be in the range of 1- 10 pM which corresponds to a quantity of 5-50 pmol of iron considering 5 L of blood for a patient. Using a dialysis bag of 5 L, even for high iron overload, concentration of polymer under 0.35 mM are sufficient to have chelates in strong excess in comparison with iron. Moreover, about 20% of the polymer are adsorbed on the membrane assuring that polymer will be present during the whole dialysis and in excess in comparison with NTBI.

[0136] In another aspect, the concentration of said functionalized polymer, for example a polymer of formula I, II or III, preferably MexCDI , in the dialysate is less than 1 g / L, preferably between 0.01 g / L and 0.9g / L. Even at low concentration in the dialysate, it has been observed that the adsorption of the polymer on the membrane ensured that polymer is present in sufficient amount to chelate iron during the whole process. In a specific embodiment, the concentration of said functionalized polymer, e.g. MexCDI , in the dialysate is such that 20- 80% of said functionalized polymer, e.g. MexCDI , is adsorbed onto the dialysis membrane, as determined by two methods: ICP-MS after labelling of DOTAGA by Gd3+and by standard addition method on DOTAGA after degradation of the polymer.

[0137] By adding the functionalized polymer, e.g. MexCDI , to the dialysate, the diffusion equilibrium for iron is altered through metal complexation and the Fick diffusion law. This leads to enhanced extraction of metals while preventing their return to circulation, as the size of the functionalized polymer, e.g. MexCDI , and the cutoff of the pores of the dialysis membrane hinder their passage.

[0138] Therefore, this approach offers a noninvasive therapeutic option for iron extraction without requiring additional treatment or significant modification of the current standard of care.

[0139] Accordingly, in an embodiment, the functionalized polymer, e.g. MexCDI , is for use in the prevention and / or treatment of blood iron overload present in subject in need thereof.

[0140] In an embodiment, the functionalized polymer, e.g. MexCDI , allows to extract iron at least 5 pg / h, preferably at least 10 μg / h, more preferably at least 15 μg / h and even more preferably at least 20μg / h , or between 5μg / h to 300 μg / h, preferably between 15μg / h and 250 μg / h , more preferably of about 20 μg / h or of about 125 μg / h , or of about 250pg / h. The extraction of iron is measured using the dialysate by ICP-MS.

[0141] The sudden and substantial release of iron, often triggered by specific events that are associated with a significant amount of cell deaths may occur in hepatic diseases, after cardiac surgery, in cancer diseases notably because of treatments or radio-chimiotherapy, in neurological diseases such as intracranial hemorrhage and stroke, or even in patients subjected to rhabdomyolysis.

[0142] Intensive care

[0143] Dysregulation of iron homeostasis has been observed in various pathologies commonly encountered in the intensive care unit. Thus, according to an aspect, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subject in need thereof.

[0144] Acute renal failure

[0145] The kidneys are often affected by catalytic iron-binding proteins released during acute crises, such as hemoglobin and myoglobin, as well as by excessive non-transferrin bound iron, which can induce oxidative stress and inflammation. Elevated iron parameters, particularly transferrin saturation and non-transferrin bound iron, are correlated with unfavorable clinical outcomes in the intensive care unit.

[0146] In another embodiment, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subjects at risk of acute renal failure or present acute renal failure.

[0147] Hepatic diseases - Acute-on-Chronic Liver Failure

[0148] Such hepatic diseases may be Acute-on-Chronic Liver Failure (ACLF) or Acute Liver Failure (ALF). Indeed, the liver plays a crucial role in maintaining iron homeostasis by synthesizing most of the proteins involved in iron metabolism, such as hepcidin and transferrin, and serving as the primary storage site for iron. Iron accumulation has been observed in the livers of patients with hemochromatosis and chronic liver disease. Again, the buildup of iron in the liver triggers the production of ROS, necrosis and apoptosis of hepatocytes, and inflammation. Thus, according to an embodiment, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subjects presenting Acute-on-Chronic Liver Failure.

[0149] ACLF is a severe condition characterized by acute deterioration of liver function in patients with pre-existing chronic liver disease. It represents an acute exacerbation of chronic liver disease, leading to organ failure and high short-term mortality rates. ACLF is typically classified into different grades based on the severity of liver dysfunction and associated organ failures. The grading systems may vary, but a commonly used classification is the European Association for the Study of the Liver (EASL) and the Chronic Liver Failure Consortium (CLIF- C) ACLF score.

[0150] This classification system categorizes ACLF into three grades. Grade 1 ACLF is diagnosed with one of the following: Single kidney failure or ; Single liver, coagulation, circulatory or lung failure that is associated with a serum creatinine level of 1.5-1.9 mg per dl and / or hepatic encephalopathy grade 1 or grade 2, or ; Single brain failure with a serum creatinine level of 1.5-1.9 mg per dl. Grade 2 ACLF is diagnosed when there are two organ failures of any combination. Patients with Grade 2 ACLF have a higher short-term mortality risk compared to Grade 1. ACLF grade 3 is diagnosed when there are three (3a) or more (3b) organ failures of any combination. Grade 3 ACLF is associated with the highest short-term mortality risk among the three grades. By 28 days, the mortality rate of ACLF Grade 1 , ACLF Grade 2, and ACLF Grade 3 is 20%, 30%, and 80%, respectively (Arroyo et al., 2016; Journal of Hepatology, August 2023.vol.79; 461-491).

[0151] In an embodiment of the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein, subjects are grade 1 ACLF or grade 2 ACLF. The administration of the functionalized polymer, e.g. MexCDI , thus allows to promote improvement of ACLF grade at previous grade or to no ACLF.

[0152] In another embodiment, subjects are grade 3a ACLF or 3b ACLF, in particular subjects are grade 3a ACLF or 3b ACLF ineligible for liver transplantation. The administration of the functionalized polymer, e.g. MexCDI , thus allows to stop the progression of ACLF and restore the eligibility to liver transplantation.

[0153] In other aspects, patients present decompensated cirrhosis. Decompensated cirrhosis is characterized by an impairment in the function of the liver and extrahepatic organs and systems. Importantly, organ failure (by contrast with organ dysfunction) is the feature that differentiates ACLF from decompensated cirrhosis without ACLF. ACLF is thus characterized by an intense systemic inflammation. The administration of the functionalized polymer, e.g. MexCDI , thus allows to prevent clinical deterioration into ACLF.

[0154] Without to be bound to any theory, the extraction of free iron with the use of the functionalized polymer, e.g. MexCDI , could restore the eligibility of ACLF subjects to liver transplantation, and, with or without liver transplantation, allow an earlier discharge from intensive care and prolong survival. Thereby, the extraction of free iron with the use of the functionalized polymer, e.g. MexCDI , is considered as a bridge to transplant for subject in need thereof or is for use in restoring eligibility of subject in need thereof to liver transplantation. The slow low-volume CVVHD treatment aims to extract efficiently free iron which is accessible via the blood circulation while limiting whole blood epuration (dialysis dose from 10 mL.kg'1.h'1to 5.5 mL.kg'1.h'1). Indeed, blood epuration strategies are numerous to date with a large choice of membrane surfaces, fiber compositions, pore size cut-offs but also dialyzer configurations with the very efficient continuous veno-venous hemodiafiltration (CVVHDF) which includes a convective force on top of the diffusion force used in the CVVHD method. In ACLF patients which require the use of blood epuration techniques, varied protocol such as MARS (Molecular Absorbent Recirculation System) and / or albumin-CVVHD or plasmapheresis and / or intermittent or continuous HDF are reported. Thus, blood epuration per se must be carefully chosen according to the individual patient’s needs, age and weight and cannot be replaced by the MEXCD1 slow low-volume CVVHD treatment which is dedicated to the extraction of free iron overload only.

[0155] Cancer - myelodysplasia or myelofibrosis

[0156] Post-transfusion iron overload is a major complication of repeated transfusions in hematological diseases such as myelodysplasia and myelofibrosis. As iron stores increase, plasma transferrin rapidly becomes saturated, resulting in free iron in the circulation, which can cross the cell membrane in certain organs and act as a catalyst to form reactive oxygen species and cause cell damage. Patients with myelodysplastic syndromes frequently present with anaemia, requiring regular transfusions. Patients with transfusion-dependent MDS also have inefficient erythropoiesis, which can disturb iron balance and lead to iron overload. Tissue iron overload is detectable in the months following the start of transfusions, and is responsible for a marked increase in mortality linked to organ damage, particularly in the heart and liver. The marrow is also affected, and iron overload worsens dysmelopoiesis and the risk of myelodysplasia transformation and influences the prognosis of stem cell transplants. Furthermore, hematopoietic stem cell transplantation is also a situation with a high risk of iron overload, which is extremely rapid due to the blocking of erythropoiesis by conditioning. Iron overload therefore has a major impact on the morbidity and management of polytransfused patients, despite the advent of chelation therapy which is why it is important to find other ways of reducing iron overload.

[0157] Thus, according to an embodiment, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subjects which are polytransfused. Without to be bound to any theory, the use of the functionalized polymer, e.g. MexCDI , allows to improve the prognosis of polytransfused subject in need thereof. In an embodiment, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subjects with myelodysplasia or myelodysplastic syndromes or myelofibrosis.

[0158] In certain aspects, the patients with myelodysplasia or myelodysplastic syndromes or myelofibrosis have post-transfusion iron overload and are intolerant or refractory to conventional chelation therapy.

[0159] Without to be bound to any theory, the use of the functionalized polymer, e.g. MexCDI , allows to improve the prognosis of stem cell transplants and then improve the hematopoietic stem cell engraftment in subjects with myelodysplasia or myelodysplastic syndromes or myelofibrosis.

[0160] Surgical procedures - cardiac surgery

[0161] During surgical procedures, such as cardiac surgery, where extracorporeally circulated blood is exposed to nonphysiological surfaces and shear forces that may harm red blood cells, hemolysis could happen, and excess release of iron could occur. Indeed, ischemia / reperfusion injury may also result in an increase in iron blood level. This release of iron can induce oxidative stress and cellular damage in the kidneys, which can be aggravated during the reperfusion phase as the released iron is carried to the kidneys, introducing additional iron. Thus, according to an embodiment, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subjects having undergone a cardiac surgery.

[0162] Without to be bound to any theory, the use of the functionalized polymer, e.g. MexCDI , allows to improve the prognosis of subjects having undergone a cardiac surgery.

[0163] Seps / s

[0164] In the context of sepsis, the scenario is less distinct. During sepsis, iron is released through hemolysis, macrophage degranulation and hepatic cytolysis. Sepsis and septic shock are the leading causes of acute renal failure in critical care patients and are associated with very high mortality. Furthermore, iron is an essential nutrient for almost all microorganisms, Grampositive such as Staphylococcus spp. and Gram-negative such as Escherichia coli and Pseudomonas aeruginosa, and its presence in the blood promotes bacterial growth and exacerbates sepsis.

[0165] Although there is a hypothesis that non-transferrin bound iron is released with the occurrence of cell death, the intricate interplay between highly active microbes and macrophages further complicates the picture, as they avidly consume the liberated iron. Excess free iron is thus associated with a poor prognosis.

[0166] In an embodiment, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subjects at risk of sepsis or septic shock, or present a sepsis or a septic shock.

[0167] Neurological diseases - ICH and stroke

[0168] Intracranial hemorrhage (ICH) refers to bleeding within the skull, which can occur spontaneously or due to trauma. It is a critical medical condition associated with high morbidity and mortality rates. Stroke is a leading cause of disability and mortality worldwide, refers to the sudden interruption of blood flow to the brain, resulting in neurological deficits. In some cases of ischemic stroke, particularly those associated with large vessel occlusion or reperfusion injury following thrombolytic therapy, hemorrhagic transformation can occur. Therefore, Intracranial hemorrhage (ICH) and stroke are both serious medical conditions involving bleeding within the brain, and thus blood cell lysis which may also result in an increase in iron blood level.

[0169] In an embodiment, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subjects at risk of intracranial hemorrhage, or presenting intracranial hemorrhage or a stroke.

[0170] Rhabdomyolysis

[0171] Rhabdomyolysis is a serious medical condition characterized by the rapid breakdown of skeletal muscle tissue, leading to the release of intracellular contents into the bloodstream. This can result in various systemic complications, including kidney injury, electrolyte imbalances, and potentially life-threatening complications such as acute kidney injury and compartment syndrome.

[0172] In an embodiment, the hemodialysis treatment in combination with the functionalized polymer, e.g. MexCDI , as disclosed herein are provided for intensive care subjects at risk of rhabdomyolysis, or presenting a rhabdomyolysis.

[0173] SPECIFIC EMBODIMENTS

[0174] 1. A method of extracting at least one metal cation, the metal being iron, by hemodialysis treatment in a subject in thereof, said method comprising adding an efficient amount of a functionalized polymer during the hemodialysis treatment of said subject, and said functionalized polymer having a weight average molecular mass between 100 kDa and 1000 kDa, and wherein a part of the monomeric units are functionalized with a chelating moiety, and is present in the dialysate of the hemodialysis treatment, and the concentration of said chelating moiety in the dialysate being less than 0.35 mM, preferably between 0.0035 mM and 0.315 mM. The method of embodiment 1 , wherein the cut-off threshold of the dialysis membrane is equal or below the weight average molecular mass of said functionalized polymer, for example 100 kDa, and said functionalized polymer having a weight average molecular mass between 100 kDa and 1000 kDa. The method of embodiment 1 , wherein said functionalized polymer comprises at least 1 wt% of chelating moiety, for example between 1wt% and 40w%. The method of embodiment 1 , wherein said chelating moiety is selected from the group consisting of :

[0175]

[0176]

[0177] DFO and mixtures thereof, preferably from the group consisting of DOTAGA, Bz-DFO, DFO, DOTAM, DTPA and mixtures thereof. The method of embodiment 1 , wherein the functionalized polymer is selected from the group consisting of polysaccharides, such as chitosan, polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyacrylic acid (PAA), poly allylamine (PAH), wherein a part of the monomeric units is functionalized with a chelating moiety. The method of embodiment 1 , wherein the functionalized polymer is a functionalized statistic chitosan of formula (I): wherein each Rc is independently the chelating moiety, each Z is independently a linker which is a single bond or a hydrocarbon chain containing between 1 and 12 carbon atoms, said hydrocarbon chain is linear or branched and optionally contains one or more unsaturations and one or more heteroatoms, preferably chosen from nitrogen, oxygen, sulfur and halogens, x is between 0.005 and 0.7, preferably between 0.05 and 0.7, y is between 0.01 and 0.7, preferably between 0.05 and 0.2, the ratio y / x being greater than or equal to 0.05, preferably greater than or equal to 0.15, and the sum x + y being greater than or equal to 0.15, preferably greater than or equal to 0.30, more preferably greater than or equal to 0.35. The method of embodiment 1 , wherein the concentration of said functionalized polymer in the dialysate is less than 1 g / L, preferably between 0.01 g / L and 0.9g / L. The method of embodiment 1 , wherein the hemodialysis treatment comprises continuous veno-venous hemodialysis. The method of embodiment 1 , wherein the functionalized polymer is of formula (II): wherein

[0178] Rci and RC2 are different, and are chelating moieties, Zi and Z2, identical or different, are linkers which are a single bond or a hydrocarbon chain containing between 1 and 12 carbon atoms, said hydrocarbon is linear or branched and optionally contains one or more unsaturations and one or more heteroatoms, preferably chosen from nitrogen, oxygen, sulfur and halogens, x is between 0.005 and 0.7, preferably between 0.05 and 0.7, and more preferably between 0.2 and 0.6, y=z+w is between 0.01 and 0.7, preferably between 0.05 and 0.2, the ratio y / x being greater than or equal to 0.05, preferably greater than or equal to 0.15, the sum x + y being greater than or equal to 0.15, preferably greater than or equal to

[0179] 0.30, more preferably greater than or equal to 0.35, and z / y is between 0.5 and 1. The method of embodiment 8, wherein Rci and RC2 are independently selected from the group consisting of :

[0180] DFO preferably from the group consisting of DOTAGA, Bz-DFO, DFO, DOTAM and DTPA. he method of embodiment 1 , having the following formula (III):

[0181] wherein x is between 0.25 and 0.4, typically about 0.3, and y is between 0.05 and 0.2, typically about 0.07.

[0182] 12. The method of embodiment 1 , wherein the functionalized polymer for use according to claims 10, wherein x is about 0.3 and y is about 0.07.

[0183] 13. The method of embodiment 1 or 8, wherein said functionalized polymer is for use in the prevention and / or treatment of blood iron overload present in subject in need thereof.

[0184] 14. The method of embodiment 1 or 8, wherein the subject is intensive care patient.

[0185] 15. The method of embodiment 1 or 8, wherein the subject is at risk of sepsis or septic shock, or present a sepsis or a septic shock.

[0186] 16. The method of embodiment 1 or 8, wherein the subject is at risk of acute renal failure or present acute renal failure.

[0187] 17. The method of embodiment 1 or 8, wherein the subject has myelodysplasia or myelodysplastic syndromes or myelofibrosis.

[0188] 18. The method of embodiment 1 or 8, wherein the subject has myelodysplasia or myelodysplastic syndromes or myelofibrosis, post-transfusion iron overload and is intolerant or refractory to chelation therapy. 19. The method of embodiment 1 or 8, wherein said functionalized polymer improves the hematopoietic stem cell engraftment in subject having myelodysplasia or myelodysplastic syndromes or myelofibrosis.

[0189] 20. The method of embodiment 1 or 8, wherein the subject presents Acute-on-Chronic Liver Failure.

[0190] 21. The method of embodiment 1 or 8, wherein the subject presents Acute-on-Chronic Liver Failure grade 3a or 3b ineligible for liver transplantation.

[0191] 22. The method of embodiment 1 or 8, wherein the subject presents Acute-on-Chronic Liver Failure grade 1 or grade 2.

[0192] 23. The method of embodiment 1 or 8, wherein the subject presents decompensated cirrhosis.

[0193] 24. The method of embodiment 1 or 8, wherein said functionalized polymer is a bridge to transplant for subject in need thereof or is for use in restoring eligibility of subject in need thereof to liver transplantation.

[0194] 25. The method of embodiments 1 to 24, wherein said method of extracting is a method for extracting free iron.

[0195] FIGURES

[0196] Figure 1 : Treatment scheme of the example 2 study.

[0197] Figure 2: Treatment scheme of the example 3 study (ARF: acute renal failure; ERT: extra- renal purification).

[0198] Figure 3: Results of Example 1. A. Ferritin follow up in patient 1 and patient 3 from D1 to D7 after the day of dialysis (Sc). B. C-reactive protein (CRP) follow up in patient 1 and patient 3 from D1 to D7 after the day of dialysis (Sc). C. Transferrin saturation rate (TSAT) follow up in patient 1 and patient 3 from D1 to D7 after the day of dialysis (Sc). D. ACLF grade evolution for patient 1 and patient 3 from the day of the dialysis (Sc) to D7 after the dialysis. Figure 4: Results on metal extraction - Comparison of iron, zinc and manganese extraction during the dialysis. A. Kinetic of metal extraction over 300 min of dialysis. B. Total of metal extracted (pg) of iron, zinc and manganese.

[0199] EXAMPLES

[0200] Hereinafter, the present disclosure is described in more details and specifically with reference to the examples, which however are not intended to limit the present disclosure.

[0201] Example 1 : Feasibility pilot study to evaluate the Safety and Performance of the MEXCD1 medical device in Acute-on-Chronic Liver Failure (ACLF)

[0202] 10 patients under Continuous Renal Replacement Therapy (CRRT) or extracorporeal artificial liver device will receive the MEXCD1 slow low-volume CVVHD treatment dedicated to non-transferrin bound iron extraction in an early feasibility monocentric, single arm open label, pilot study to evaluate the safety and performance of the MEXCD1 medical device for iron extraction.

[0203] Product

[0204] The MEXCD1 solution is contained in a vial of 50 mL. MEXCD1 is formulated at a concentration of 10 g / L in a slightly hypotonic solution (NaCI 7 g / L).

[0205] Population of patients

[0206] In this clinical investigation, the use of the MEXCD1 medical device will focus on patients with ACLF grade 2, 3a and 3b for whom CRRT is required.

[0207] This choice was driven by three arguments:

[0208] • ACLF patients are in life threatening situation. The choice of initiating extracorporeal therapy is often double-edged as it may improve renal (CRRT) or hepatic (extracorporeal artificial liver device) conditions, but, in the case of ACLF patients where coagulation and / or circulation failure, as well as bacterial infection are often reported, the implementation of such technique must be carefully balanced. The choice of initiating the MEXCD1 slow low-volume treatment in patients that requires extracorporeal therapy is based on patients’ safety.

[0209] • ACLF patients with multiple organ failures are in the most beneficial window for the use of the MEXCD1 slow low-volume CVVHD treatment as their survival often only relies on supportive care due to non-eligibility for liver transplantation. ACLF patients with multiple organ failures display higher level of free iron overload. The assessment of free iron extraction by way of the MEXCD1 slow low-volume CVVHD treatment will be clearer by having a larger amount of free iron to extract.

[0210] Primary Objective

[0211] To evaluate the safety of the MEXCD1 slow low-volume CVVHD treatment in ACLF patients under continuous renal replacement therapy or extracorporeal artificial liver device.

[0212] Secondary objectives

[0213] • To assess the performance of the MEXCD1 slow low-volume CVVHD treatment in terms of iron extraction in dialysate bags.

[0214] • To assess the performance of the MEXCD1 slow low-volume CVVHD treatment in terms of clinical benefice in the frame of ACLF.

[0215] Outcomes

[0216] The performance of the MEXCD1 slow low-volume CVVHD treatment in terms of iron extraction will be measured by the amount of iron extracted in the dialysate bags per treatment.

[0217] The performance of the MEXCD1 slow low-volume CVVHD treatment in terms of clinical benefice in the frame of ACLF will be measured by:

[0218] • Change in ACLF Grade

[0219] • Change in CLIF-C ACLF score (with CLIF-sequential organ failure score)

[0220] • Improvement in individual organ function: liver, kidneys, brain, coagulation, circulation, and respiration using the CLIF sequential OF score (individuals and total)

[0221] • Development of secondary infection

[0222] • Status of ICU and hospital discharge (including discharge to a hospice for palliative care)

[0223] • Length of stay in ICU and hospital

[0224] • Mortality

[0225] Inclusion criteria

[0226] • Male or female subjects >18 years and <80 years • Subject is able to provide informed consent to participate in the study, otherwise written consent must be obtained on behalf of the subject by a next of kin or legal representative in accordance with local ethical and legal requirements

[0227] • History of an acute decompensation event (including but not limited to ascites, gastrointestinal bleeding, hepatic encephalopathy and / or acute bacterial infections), occurring within <6 weeks of screening

[0228] • Cirrhosis (diagnosed based on clinical, biological, morphological parameters or liver biopsy)

[0229] • Subject with: o ACLF Grade 2, 3a or 3b based on the CLIF-C OF score o Under continuous renal replacement therapy (CRRT) or any organ support device that requires catheter placement

[0230] Exclusion criteria

[0231] • Subjects with acute or sub-acute liver failure without an underlying cirrhosis

[0232] • Subjects not considered appropriate for full active treatment including organ support or those with a Do Not Attempt Cardio-Pulmonary Resuscitation order (DNACPR)

[0233] • Subjects who have received any investigational drug or device within 30 days of dosing or who are scheduled to receive another investigational drug or device in the course of the study; concomitant observational studies are allowed

[0234] • Evidence of uncontrolled seizures

[0235] • In females: known pregnancy or lactating

[0236] • Patients with a known allergy to shellfish

[0237] • Patients for who, in the opinion of the investigator, it would be unsafe to be considered for the study

[0238] • Vulnerable population according to Articles 64 to 68 of the Regulations (EU) 2017 / 745 on Medical Devices

[0239] • Patient with weight < 30 kg

[0240] Procedures

[0241] Treatment will be undertaken in an intensive care unit (ICU).

[0242] Patients will undergo the following:

[0243] • Screening assessment (up to 72 hours) • Day 0 - MEXCD1 slow low-volume CVVHD treatment may start on this day if all day 1 requirements have been met

[0244] • Day 1 , day 3 & day 5 treatment phase (MEXCD1 slow low-volume CVVHD treatment)

[0245] • Day 1 assessments

[0246] • Day 3 assessments

[0247] • Day 5 assessments

[0248] • Day 7 assessments

[0249] • Day 28 assessments

[0250] 10 patients under CRRT or any organ support device that requires catheter placement will be enrolled for 3 MEXCD1 slow low-volume CVVHD treatment performed within 5 days and then followed until day 28.

[0251] Administration of the MEXCD1

[0252] Patients will receive 3 MEXCD1 slow low-volume CVVHD treatments at D1 , D3 and D5.

[0253] Each treatment will be set up with four doses of MEXCD1 diluted in a 2 L of dialysate (MEXCD1 final concentration 0.9 g / L). The MEXCD1 slow low-volume CVVHD treatment will be conducted for 3 hours and 20 minutes (3h20) with a EMIC2 membrane one day apart from each other and should be implemented alternating with the standard of care (CRRT or extracorporeal artificial liver device).

[0254] The patient’s connection will be performed using a medical disposable blood catheter with the size adapted to the patient’s weight. The dialysis flow rate (QD) will be set at 0.6 L / h and the blood flow rate (QB) will be defined by the practician according to the patient’s weight within the framework 100 to 350 mL / min (<200 mL / min is recommended).

[0255] Results

[0256] Two ACLF patients (P1 and P3) have been treated with MEXCD1 medical device at day 0 (Sc). The concentration of ferritin, the concentration in CRP and the TSAT have been followed up during the 7 days following the treatment. A significant effect is observed for these three parameters (Figure 3 A-B-C). A significant improvement in the patient's overall clinical situation was also observed, since both patients who were classified as ACLF grade 3a before treatment, became classified as ACLF grade 2, 7 days after the treatment per dialysis (Figure 3 D.) Example 2: Feasibility, safety and efficacy of extracorporeal iron purification in patients treated for myelodysplastic syndrome or myelofibrosis with intolerance or contraindication to oral or subcutaneous chelation therapy.

[0257] The MEXIRON study is a category 2 clinical investigation (Cl), meeting the definition of Article 62.1 of Ell Regulation 2017 / 745 of Cis conducted to establish DM compliance. It is a prospective, single-centre, multisite HCL study aimed at demonstrating proof of concept for the use of the MEXCD1 extracorporeal purification device in patients with myelodysplasias or myelofribrosis who have post-transfusion iron overload and are intolerant or refractory to chelation therapies.

[0258] The MEXIRON Cl is a non-comparative, open-label pilot study involving a cohort of 10 sequentially treated patients.

[0259] Product

[0260] The MEXCD1 solution is contained in a vial of 50 mL. MEXCD1 is formulated at a concentration of 10 g / L in a slightly hypotonic solution (NaCI 7 g / L).

[0261] Population of patients

[0262] Patients with myelodysplasia or myelofibrosis who have post-transfusion iron overload and are intolerant or refractory to chelation therapy.

[0263] Primary Objective

[0264] Describe the tolerability of Extracorporeal Purification sessions with MEXCD1.

[0265] Secondary objectives

[0266] • Describe the free iron chelation kinetics of MEXCD1 during each of the three sessions of an Extracorporeal Cleansing cycle.

[0267] • Describe the free iron chelation capacity of MEXCD1 at the end of each of the three sessions of an Extracorporeal Purification cycle.

[0268] • Assess the effect of MEXCD1 Extracorporeal Depuration on short-term iron balance parameters.

[0269] • To assess the effect of MEXCD1 on transfusion requirements.

[0270] • To describe the feasibility of the experimental treatment

[0271] • To describe the patient's overall tolerance of the session. Describe the changes in the patient's quality of life after the cycle of Extracorporeal Purification sessions.

[0272] Inclusion criteria

[0273] - Patients aged 18 years and over.

[0274] - Patients being monitored for myelodysplastic syndrome or myelofibrosis.

[0275] - Patients with a platelet count >50 giga / L.

[0276] - Patients with intolerance or contraindication to oral or subcutaneous chelation therapy.

[0277] - Ferritinaemia >1000 pg / L OR hepatic iron concentration >7 mg / g OR cardiac T2* <20 ms.

[0278] - Patient able to understand (French-speaking) and comply with the protocol, having signed informed consent.

[0279] - Patient affiliated to a social security scheme or beneficiary of a similar scheme.

[0280] Non-inclusion criteria

[0281] - Patients with primary haemochromatosis (transferrin saturation coefficient CS-Tf >45%).

[0282] - Patients with a contraindication to the use of MEXCD1 : weight <50 kg, iron deficiency.

[0283] - Patients with a known allergy or contraindication to heparin or citrate.

[0284] - Patients for whom allogeneic bone marrow transplantation is indicated.

[0285] - Patients with a known allergy to shellfish (MEXCD1 contains chitosan of animal origin) or to one of the other components of MEXCD1 .

[0286] - Patients with a peripheral vascular access that is difficult to access or that needs to be preserved (particularly if dialysis is planned).

[0287] - Patients treated with azacitidine or any other chemotherapy (or considered as such) for myelodysplastic syndrome or myelofibrosis.

[0288] - Patients taking part in other interventional research that could interfere with the results of the study.

[0289] - Patients of full age under legal protection (guardianship, curatorship) or unable to express their consent.

[0290] - Patients under psychiatric care.

[0291] - Patients deprived of their liberty by judicial or administrative decision.

[0292] - Pregnant or breast-feeding women. Procedures

[0293] Extracorporeal Purification sessions are planned as a single cycle of 3 successive sessions spread over a single calendar week (Figure 1).

[0294] The 3 Extracorporeal Purification sessions follow an identical sequence, as follows: a) Clinical examination by the principal investigator or a co-investigator. b) Collection of a 4 mL EDTA tube for the "pre-session" biological work-up (S1 H0, S2H0, S3H0) [± 10 min. from the start of the session]: free iron, CST, ferritin, CRP, blood ionogram (sodium, potassium, calcium, magnesium) and CBC. c) Connection of the purification device with double puncture of the humeral vein via a peripheral catheter on each arm and taking of vital constants (blood pressure, heart rate, oxygen saturation, temperature). d) Extracorporeal purification sessions (S1 , S2 and S3) carried out on a hemodialysis machine (PRISMAFLEX®, Baxter, USA) dedicated exclusively and set up specifically for the study:

[0295] • Blood flow rate 70 mL / min, MEXCD1 dialysate flow rate (1 g / L) 500 mL / h.

[0296] • Maximum session duration set at 4 hours on haemodialysis monitor, Evodial 1 .0 paediatric dialyser (Gambro Industries) 0.2 m2, 30 kDa.

[0297] • Close monitoring of vital parameters (blood pressure, heart rate, temperature) throughout the Extracorporeal Purification session: H0+2min, H0+3min, H0+120min, H0+180min and before disconnection.

[0298] • Disconnection of the purification device.

[0299] • VAS (Visual Analogue Scale) score on the tolerance of the session [10: normal 0: very tired or intense discomfort],

[0300] • During each session, samples (sterile 15 ml centrifuge tube free of heavy metals - LABCON / DUTSCHER Reference 949892) are taken from the dialysate bag (50 ml at HO and H4), and from the effluent line (10 mL at H1 , H2, H3) and the effluent bag (H4) to measure:

[0301] - the amount of iron chelated by the MEXCD1 solution. Samples are stored at -20°C before being sent to MexBrain for centralised analysis.

[0302] - the quantity of other metals chelated by the MEX-CDI solution. The samples are sent to the Toxic Traces and Metals Analysis Laboratory (Dr Frangois Parant) at Lyon Sud Hospital.

[0303] A sampling procedure and sample management circuits are presented in appendices 3a and 3b. e) Collection of a 4 mL EDTA tube for the "post-session" biological check-up (S1 H4+30min, S2H4+30min, S3H4+30min) [up to 10 min. after the end of the session]: free iron, CST, ferritin, CRP, blood ionogram (sodium, potassium, calcium, magnesium) and CBC.

[0304] Administration of the MEXCD1

[0305] Patients will receive MEXCD1 at D1 , D3 and D5. Each treatment will be set up with two doses of MEXCD1 diluted in a 2 L of dialysate (MEXCD1 final concentration 1 g / L). The MEXCD1 treatment will be conducted for 4 hours with Evodial 1.0 pediatric dialyzer (Gambro Industries), 0,2 m2, 30 kDa membrane.

[0306] The patient’s connection will be performed using a medical disposable blood catheter with the size adapted to the patient’s weight. The dialysis flow rate (QD) will be set at 0.5 L / h and the blood flow rate (QB) will be defined by the practician according to the patient’s weight within the framework 40 to 70 mL / min.

[0307] Example 3: Evaluation of the performance and safety of the new iron chelator for dialysate MEXCD1 in the elimination of excess free catalytic iron in intensive care patients with sepsis-related acute renal failure requiring dialysis - Phase l-ll randomised cross-over pilot study.

[0308] Phase l-ll monocentric randomised cross-over pilot study comparing two treatments: extrarenal renal replacement therapy (ERT) with iron chelator added to the dialysate (experimental "MEXCD1" group) versus standard ERT without chelator added to the dialysate (control "Standard" group).

[0309] The patient circuit corresponds to that of usual care. The only addition made for the purposes of the study was the addition of the chelator MEXCD1 to the dialysate during the EER session in the experimental phase.

[0310] Product

[0311] The MEXCD1 solution is contained in a vial of 50 mL. MEXCD1 is formulated at a concentration of 10 g / L in a slightly hypotonic solution (NaCI 7 g / L).

[0312] Population of patients

[0313] The study population consisted of adult patients hospitalised in intensive care with sepsis or septic shock and acute renal failure requiring extra-renal purification. Primary Objective

[0314] To compare the performance on iron clearance of chelation by adding MEXCD1 to the dialysate versus standard dialysis in intensive care patients with sepsis and acute renal failure requiring dialysis.

[0315] Secondary objectives

[0316] • To assess the safety of iron chelation by adding MEXCD1 to the dialysate of patients with sepsis and acute renal failure requiring dialysis, hospitalised in intensive care.

[0317] • To assess the long-term safety (28-day follow-up) of iron chelation by adding MEXCD1 to the dialysate of patients with sepsis and acute renal failure requiring dialysis, hospitalised in intensive care.

[0318] • To compare the impact on distant iron metabolism (up to 28 days) of chelation by adding MEXCD1 to the dialysate versus standard dialysis in these patients.

[0319] • To assess the impact on copper, zinc and selenium clearance of chelation by addition of MEXCD1 to the dialysate in these patients.

[0320] • To assess the impact of iron chelation by addition of MEXCD1 to the dialysate on oxidative stress.

[0321] • To assess the impact of iron chelation by addition of MEXCD1 to the dialysate on inflammation.

[0322] Inclusion criteria

[0323] - Patient admitted to intensive care with documented or suspected sepsis or septic shock.

[0324] - Presence of sepsis-related acute renal failure requiring extra-renal replacement therapy (ERT) according to one of the following criteria.

[0325] - Hyperkalaemia > 6 mmol / L refractory to medical treatment;

[0326] - Metabolic acidosis with pH < 7.20 refractory to medical treatment;

[0327] - Acute pulmonary oedema with anuria refractory to medical treatment.

[0328] - Patient or his / her trusted person / legal representative / family member having given free and informed consent and having signed the consent form or patient included in an emergency situation.

[0329] - Patient affiliated to or benefiting from a health insurance scheme.

[0330] - Adult patient (>18 years). Exclusion criteria

[0331] - Patient moribund, with a life expectancy too low to benefit from treatment or with a decision to stop treatment.

[0332] - Patient with a known allergy to shellfish

[0333] - Patient participating in another interventional study.

[0334] - Patient in a period of exclusion determined by another study.

[0335] - Patient under court protection, guardianship or curatorship.

[0336] - Patient / trusted person / legal representative / family member for whom it is impossible to give informed information.

[0337] - Pregnant, parturient or breast-feeding patients.

[0338] Procedures

[0339] The duration of the experimental procedure is 24 hours. Depending on the crossover randomisation arm, the experimental procedure may be carried out in the first 24 hours or in the following 24 hours (crossover) after changing the dialysis circuit and membrane. Each EER session lasts 24 hours. The MEXCD1 chelator will be used at a concentration of 50 mg / L (Natuzzi et al. 2021).

[0340] At the end of the first 24-hour session, after changing the dialysis circuit and filter, patients who had initially received dialysis with conventional dialysate will receive dialysis with MEXCD1 and conversely the other patients will receive dialysis with standard dialysate. Each patient will therefore have his or her own control.

[0341] Dialysis will be in continuous venovenous haemodialysis (CVVHD) modality, with the Multifiltrate™ dialyser (Fresenius) and with regional citrate anticoagulation. The dialysis dose will be between 20 and 25 ml / Kg / h, as recommended by learned societies (KDIGO AKI Guideline, Kidney Int 2012), which corresponds for a standard weight patient of 70 Kg to a dialysate flow rate of 1600ml / h and a blood flow rate of 80 ml / min in order to optimise anticoagulation stability. The dialysate will be CiCa™ (Fresenius), to which the metal chelating product MexCDI will be added.

[0342] All settings will remain identical in the 2 arms except for the dialysate with or without MEXCD1 added.

[0343] After this 48-hour experimental phase, a return to normal will take place with a new change of circuit and filter and with the resumption of standard dialysate until weaning from dialysis or the end of the stay in intensive care, with adjustments at the clinician's discretion. During the first 48 hours of dialysis, simultaneous samples of plasma and dialysis effluent will be taken every 8 hours in order to assess iron clearance. This frequency of sampling corresponds to the usual standards for monitoring CVVHD in intensive care.

[0344] No dose escalation is planned for this product in the dialysate, and the product will remain outside the patient's circulatory system throughout the experimental phase, with indirect contact via the semi-permeable membrane of the dialysis filter. All management of the patient apart from experimental iron chelation will be standard management of the intensive care patient in accordance with the recommendations of learned societies. From the 48th hour onwards, the remainder of the dialysis time required to manage the patient will be carried out using standard dialysate.

[0345] A complete martial assessment including sideremia, transferrinemia, transferrin saturation coefficient, soluble transferrin receptor, ferritinemia and hepcidin was carried out on DO, D1 , D2, D7 and D28.

[0346] The patient's participation in the study ended at the end of the 28-day visit.

[0347] Administration of the MEXCD1

[0348] The chelator MEXCD1 will be used at a concentration of 50 mg / L. A dose of 250 mg will therefore be injected into each 5-litre bag of dialysate by the nurse caring for the patient, just before connection to the dialyser.

[0349] Example 4: Feasibility pilot study to evaluate the Safety and Performance of the MEXCD1 medical device in the elimination of free iron in a patient suffering from Wilson’s disease.

[0350] A patient suffering from Wilson’s disease has been dialyzed during 4h with a dialysis system wherein the dialysate comprised MEXCD1 at a concentration of 0,9 g / L and a dialysate fow rate of 500 ml / h.

[0351] Results are presented at Figure 4 which clearly demonstrated the efficacy of MEXCD1 for free iron extraction. One dialysis allows the extraction of more than 1000 pg of free iron. It should also be noted that, interestingly, the extraction of manganese is prevented and the extraction of zinc is limited.

Claims

Claims1. A functionalized polymer for use in a hemodialysis treatment for the extraction of at least one metal cation, the metal being iron, in a subject in need thereof, wherein said functionalized polymer has a weight average molecular mass between 100 kDa and 1000 kDa, and wherein a part of the monomeric units are functionalized with a chelating moiety, and is present in the dialysate of the hemodialysis treatment, the concentration of said chelating moiety in the dialysate being less than 0.35 mM, preferably between 0.0035 mM and 0.315 mM.

2. The functionalized polymer for use according to claim 1 , wherein the cut-off threshold of the dialysis membrane is equal or below the weight average molecular mass of said functionalized polymer, for example 100 kDa, and said functionalized polymer having a weight average molecular mass between 100 kDa and 1000 kDa.

3. The functionalized polymer for use according to claim 1 , wherein said functionalized polymer comprises at least 1 wt% of chelating moiety, for example between 1wt% and 40w%.

4. The functionalized polymer for use according to claim 1 or 2, wherein said chelating moiety is selected from the group consisting of:DFO and mixtures thereof, preferably from the group consisting of DOTAGA, Bz-DFO, DFO, DOTAM, DTPA and mixtures thereof.

5. The functionalized polymer for use according to any one of claims 1 to 3, wherein the functionalized polymer is selected from the group consisting of polysaccharides, such as chitosan, polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyacrylic acid (PAA), poly allylamine (PAH), wherein a part of the monomeric units is functionalized with a chelating moiety.

6. The functionalized polymer for use according to any one of claims 1 to 4, which is a functionalized statistic chitosan of formula (I):wherein each Rc is independently the chelating moiety, each Z is independently a linker which is a single bond or a hydrocarbon chain containing between 1 and 12 carbon atoms, said hydrocarbon chain is linear or branched and optionally contains one or more unsaturations and one or more heteroatoms, preferably chosen from nitrogen, oxygen, sulfur and halogens, x is between 0.005 and 0.7, preferably between 0.05 and 0.7, y is between 0.01 and 0.7, preferably between 0.05 and 0.2, the ratio y / x being greater than or equal to 0.05, preferably greater than or equal to 0.15, and the sum x + y being greater than or equal to 0.15, preferably greater than or equal to 0.30, more preferably greater than or equal to 0.35.

7. The functionalized polymer for use according to any one of claims 1 to 5, wherein the concentration of said functionalized polymer in the dialysate is less than 1 g / L, preferably between 0.01 g / L and 0.9g / L.

8. The functionalized polymer for use according to any one of claims 1 to 6, wherein the hemodialysis treatment comprises continuous veno-venous hemodialysis.The functionalized polymer for use according to claims 1 to 7, wherein the functionalized polymer is of formula (II):whereinRci and RC2 are different, and are chelating moieties,Zi and Z2, identical or different, are linkers which are a single bond or a hydrocarbon chain containing between 1 and 12 carbon atoms, said hydrocarbon is linear or branched and optionally contains one or more unsaturations and one or more heteroatoms, preferably chosen from nitrogen, oxygen, sulfur and halogens, x is between 0.005 and 0.7, preferably between 0.05 and 0.7, and more preferably between 0.2 and 0.6, y=z+w is between 0.01 and 0.7, preferably between 0.05 and 0.2, the ratio y / x being greater than or equal to 0.05, preferably greater than or equal to 0.15, the sum x + y being greater than or equal to 0.15, preferably greater than or equal to 0.30, more preferably greater than or equal to 0.35, and z / y is between 0.5 and 1.

10. The functionalized polymer for use according to claims 1 to 8, wherein Rci and RC2 are independently selected from the group consisting of:DFO, preferably from the group consisting of DOTAGA, Bz-DFO, DFO, DOTAM and DTPA.

11. The functionalized polymer for use according to claims 1 to 9, having the following formula (III):wherein x is between 0.25 and 0.4, typically about 0.3, and y is between 0.05 and 0.2, typically about 0.07.

12. The functionalized polymer for use according to claims 10, wherein x is about 0.3 and y is about 0.07.

13. The functionalized polymer for use according to any one of claims 1 to 11 , wherein said functionalized polymer is for use in the prevention and / or treatment of blood iron overload present in said subject in need thereof.

14. The functionalized polymer for use according to claim 12, wherein the subject is intensive care patient.

15. The functionalized polymer for use according to claim 13, wherein said subject is at risk of sepsis or septic shock, or present a sepsis or a septic shock.

16. The functionalized polymer for use according to claim 13, wherein the subject is at risk of acute renal failure or present acute renal failure.

17. The functionalized polymer for use according to claim 12, wherein the subject has with myelodysplasia or myelodysplastic syndromes or myelofibrosis.

18. The functionalized polymer for use according to claim 16, wherein the subject has myelodysplasia or myelodysplastic syndromes or myelofibrosis, post-transfusion iron overload and is intolerant or refractory to chelation therapy.

19. The functionalized polymer for use according to claim 16 or 17, wherein said functionalized chitosan is for use in improving the hematopoietic stem cell engraftment in subject having myelodysplasia or myelodysplastic syndromes or myelofibrosis.

20. The functionalized polymer for use according to claim 13, wherein the subject presents Acute-on-Chronic Liver Failure.

21. The functionalized polymer for use according to claim 19, wherein the subject presents Acute-on-Chronic Liver Failure grade 3a or 3b ineligible for liver transplantation.

22. The functionalized polymer for use according to claim 19, wherein the subject presents Acute-on-Chronic Liver Failure grade 1 or grade 2.

23. The functionalized polymer for use according to claim 19, wherein the subject presents decompensated cirrhosis.

24. The functionalized polymer for use according to claims 18 to 23, wherein said functionalized chitosan is a bridge to transplant for subject in need thereof or is for use in restoring eligibility of subject in need thereof to liver transplantation.

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