Sirna against tmprss6 for treating polycythemia vera

Abstract

The present invention relates to the therapeutic inhibition of TMPRSS6 by SLN124 for the prevention, prophylaxis, or treatment of Polycythaemia vera (PV) and in particular to effective doses and dosage regimes for the therapeutic use of the SLN124 double stranded siRNA molecule in the prevention, prophylaxis or treatment of conditions associated with Polycythaemia vera (PV).

Description

[0001] SIRNA AGAINST TMPRSS6 FOR TREATING POLYCYTHEMIA VERA

[0002] Field of the invention

[0003] The present invention relates to the therapeutic inhibition of TMPRSS6 by SLN124 for the prevention, prophylaxis, or treatment of polycythaemia vera (PV) and in particular to effective doses and dosage regimes for the therapeutic use of the SLN124 double stranded siRNA molecule in the prevention, prophylaxis or treatment of conditions associated with Polycythaemia vera (PV).

[0004] Background

[0005] Polycythemia vera (PV) is a rare blood disease where the body makes too many red blood cells (RBC). Other blood cell types, including whole blood cells and platelets, may also be increased. The increase in RBC and other cells cause the blood to thicken, corresponding to a substantial elevation of haematocrit which leads to higher risks related to thrombotic, or blood clotting, events including deep vein thrombosis, pulmonary embolism, and other cardiovascular (CV) outcomes such as heart attack and stroke. PV is associated with a range of burdensome symptoms including fatigue, cognitive disturbance and pruritis and additionally, longer term can transform to myelofibrosis and Acute Myeloid Leukemia. PV impacts around 150 thousand people in the United States and around 3.5 million people worldwide.

[0006] The bone marrow (BM) of subjects with PV contain normal stem cells and abnormal clonal stem cells that suppress normal stem cell growth and maturation. PV is characterized by bone marrow erythroid and megakaryocytic hyperplasia, erythrocytosis, fatigue, aquagenic pruritus, microvascular symptoms, and symptomatic splenomegaly (reviewed by Ginzburg et al., Leukemia. 2018 Oct;32(10) :2105-21 16). The disease is caused by a driver mutation in the haematopoietic stem cells. Most commonly, the gene defect involves Janus kinase 2 (JAK2) involved with intracellular signaling.

[0007] JAK2 is a non-receptor tyrosine kinase that transduces the erythropoietin receptor (EpoR) as well as granulocyte-colony stimulating factor and thrombopoietin receptor signalling. Activation of JAK2 triggers multiple signalling pathways regulating erythroid precursor cell survival, proliferation and differentiation. The most common JAK2 driver mutation is JAK2 V617F, which results in constitutive, erythropoietin independent JAK2 / STAT signalling and upregulation of genes downstream of the JAK2 / STAT pathway (reviewed by Ginzburg et al., Leukemia. 2018 Oct;32(10):2105-2116). The vast majority of PV patients (96%) are JAK2 V617F positive, 2- 3% of them harbour mutations in exon 12 of JAK2 and in some rare occasions, mutations were identified in genes that function as negative regulators of JAK2, indicating the predominant function of JAK2 activation in the aetiology of PV. In addition, the JAK2 V617F mutation is found in ~ 50% of ET and PMF patients. JAK2 V617F positive ET patients generally have higher haemoglobin (HGB) levels and lower platelet counts compared to JAK2 V617F negative ET patients, which points to a prominent role of JAK2 activation in promoting erythropoiesis. As a result of chronic hyperproliferation of erythroid cells and erythrocytosis, patients with PV have elevated haemoglobin (HGB), haematocrit (HCT) and red blood cell mass, which puts them at increased risk for arterial and venous thrombosis. Indeed, thrombosis is the most immediate health threat in PV patients (Spivak JL Blood. 2019 Jul 25;134(4):341 -352).

[0008] The risk of blood clotting and associated conditions in patients with PV are currently treated by making frequent blood withdrawals (phlebotomies), alone or in combination with other therapies e.g., low dose aspirin and cytoreductive agents, such as hydroxyurea or ruxolitinib. The aim of treatment is to maintain haematocrit at less than 45%, a level that is associated with a reduced incidence of thrombosis and CV-associated death. Treatment usually requires routine phlebotomy (venipuncture and blood removal) along with low dose aspirin. Phlebotomy induces iron deficiency, which lowers the haemoglobin and haematocrit levels and reduces the risk of blood clotting. Phlebotomies, however, while helpful, may not maintain patients at safer haematocrit levels consistently, and can contribute to iron deficiency and overall symptom burden. Thus, treatments that could reduce the dependency on this intervention could potentially benefit patients. In PV patients, SLN124 could potentially reduce the requirement of phlebotomy and reduce the daily dosing of cytoreducing therapies to control red blood cells levels. The common adverse events associated with ruxolitinib have not been seen in humans treated with SLN124 to date, thus providing a safe first line and potentially second alternative to this only approved PV treatment.

[0009] SLN124 specifically targets TMPRSS6 mRNA which encodes the transmembrane serine protease matriptase-2 that is expressed predominantly in liver hepatocytes. The GalNAc moiety of SLN124 is designed to optimally bind to the asialoglycoprotein receptor (ASGPR) which is also predominantly expressed on hepatocytes. There is therefore a triple mechanism ensuring the specificity of action of SLN124; the targeting to a hepatocyte specific receptor, the sequence specificity of the siRNA to the TMPRSS6 mRNA and the fact that TMPRSS6 mRNA is predominantly expressed by hepatocytes. The GalNAc moiety of SLN124 binds specifically to the hepatocyte ASGPR and is endocytosed via the clathrin-mediated pathway. In the acidic environment of the endosome, the GalNAc-siRNA is released and escapes from the endosomal compartment into the cytoplasm and the free ASGPR is recycled back to the cell surface. In the cytoplasm the guide (antisense) strand of the SLN124 siRNA duplex enters the RNA-induced silencing complex (RISC) where it specifically induces the cleavage and degradation of its target TMPRSS6 mRNAs thereby specifically inhibiting the production of matriptase-2. Production of the iron regulating hormone hepcidin is largely stimulated by activation of the BMP receptors which require the active coreceptor hemojuvelin (HJV) to fully activate the SMAD signaling pathway. The membrane bound serine protease, matriptase-2 normally cleaves the coreceptor HJV thereby attenuating the BMP / SMAD signaling pathway and reducing the production of hepcidin by the hepatocyte. By silencing the expression of TMPRSS6 mRNA, SLN124 blocks the production of matriptase-2, activating the BMP / SMAD pathway which stimulates hepcidin production. Elevated hepcidin then reduces the efflux of iron from storage cells such as macrophages and iron absorption by the Gl. This is mediated by binding and inhibiting ferroportin, the only cellular iron export protein, which will reduce systemic iron levels, transferrin saturation and iron overloading. It is also expected that elevated hepcidin will benefit the availability of iron to the bone marrow. The reduction of toxic NTBI (labile plasma iron) and the reduction of labile cellular iron will also improve erythropoiesis in iron loading anemias.

[0010] MT2 (Matriptase-2) is the protein product of the TMPRSS6 gene and is a type II transmembrane serine protease that plays a critical role in the regulation of iron homeostasis. MT2 is a negative regulator for synthesis induction of the peptide hormone hepcidin. TMPRSS6 is primarily expressed in the liver, although high levels of TMPRSS6 mRNA are also found in the kidney, with lower levels in the uterus and much lower amounts detected in many other tissues (Ramsay et al., Haematologica (2009), 94(*6), 84-849). Particularly inhibition of MT2 by reducing the expression of the TMPRSS6 gene appears to be a promising approach having advantages compared to other available treatment options, such as phlebotomy. See e.g., WO2022 / 229150 and references cited therein.

[0011] Current treatments of polycythaemia vera all have drawbacks. There is therefore a clear need in the art for new ways of treating such disorders. The present invention addresses this need. The use of SLN124, an MT2 inhibitor comprising a GalNAc-conjugated TMPRSS6 siRNA, presents a promising therapeutic strategy for treating polycythaemia vera.

[0012] SLN124 is a short-interfering RNA (siRNA) to target TMPRSS6 messenger RNA. SLN124 is a 19-mer siRNA covalently linked to a tri-antennary N-acetyl-galactosamine (GalNAc) moiety. The GalNAc conjugate binds to asialoglycoprotein receptors, which are expressed almost exclusively on hepatocytes. This approach results in selective uptake and concentration of SLN124 in hepatocytes enabling the drug to bind and degrade the messenger RNA that encodes for TMPRSS6 protein, described in WO2018 / 185240 and WO2022 / 229150 (each of which is incorporated by reference hereinin its entirety.

[0013] Summary of the invention In a first aspect, the invention provides SLN124 for use in a method of prevention, prophylaxis or treatment of polycythaemia vera (PV), as well as associated diagnostic or therapeutic methods, wherein said SLN124 is administered to a human subject in need thereof at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight. Preferably, an individual dose of SLN124 ranges from 3 mg / kg to 9 mg / kg (i.e., at 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, 8 mg / kg or 9 mg / kg). Assuming that PV patients range in weight from about 50 kilograms (kg) to about 95 kg, this translates to an individual dose of from 50mg to 950mg, and preferably, from 150 mg to 855 mg.

[0014] In a further aspect, the invention provides a method of prevention, prophylaxis or treatment of polycythaemia vera (PV) in a human subject in need thereof, wherein said SLN124 is administered in an individual dose of from 1 mg / kg to 10mg / kg. Also provided is the use of SLN124 in the preparation of a medicament or pharmaceutical composition for the prevention, prophylaxis or treatment of polycythaemia vera (PV), wherein said SLN124 is administered in an individual dose of from 1 mg / kg to 10mg / kg to a human subject. Preferably, an individual dose of SLN124 ranges from 3 mg / kg to 9 mg / kg (i.e., at 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, 8 mg / kg or 9 mg / kg).

[0015] In a further aspect, the invention provides SLN124 for use in maintaining the haematocrit of a polycythaemia vera (PV) subject at or below a haematocrit threshold level, wherein said SLN124 is administered to a human subject in need thereof at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight. In a further aspect, the invention provides a method of maintaining the haematocrit of a PV subject at or below a haematocrit threshold level, the method comprising the step of administering SLN124 at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight to a human subject. Also provided is the use of SLN124 for the preparation of a medicament or pharmaceutical composition for maintaining the haematocrit of a polycythaemia vera (PV) subject at or below a haematocrit threshold level, wherein said SLN124 is administered to a human subject in need thereof at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight. Preferably, an individual dose of SLN124 ranges from 3 mg / kg to 9 mg / kg (i.e., at 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, 8 mg / kg or 9 mg / kg). The haematocrit threshold level may be about 45%.

[0016] In a further aspect, provided is SLN124 for use in reducing the dependency on phlebotomy for a polycythaemia vera (PV) subject, wherein said SLN124 is administered to a human subject in need thereof at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight. The invention also provides a method of reducing the dependency on phlebotomy for a polycythaemia vera (PV) subject, wherein said SLN124 is administered to a human subject in need thereof at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight. A further aspect provides the use of SLN124 for the preparation of a medicament or pharmaceutical composition for reducing the dependency on phlebotomy for a polycythaemia vera (PV) subject, wherein said SLN124 is administered to a human subject in need thereof at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight. Preferably, an individual dose of SLN124 ranges from 3 mg / kg to 9 mg / kg (i.e., at 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, 8 mg / kg or 9 mg / kg). In some embodiments, SLN124 reduces the number of phlebotomies required to maintain the haematocrit of a PV subject at or below a haematocrit threshold level. In further embodiments, the haematocrit threshold level is about 45%.

[0017] In each of the above methods, SLN124 may be administered in an individual dose of from about 1 mg / kg to 10mg / kg, and preferably, from about 3 mg / kg to 9 mg / kg (i.e., at 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, 8 mg / kg or 9 mg / kg) in order to regulate haematocrit.

[0018] A medicament or pharmaceutical composition of the invention may be formulated as a unit or individual dose, or may be formulated for multiple unit doses depending on the specific needs of the health care provider.

[0019] One aspect of the invention is a composition comprising SLN124 as described herein and a solvent, preferably water, and / or a delivery vehicle and / or a physiologically acceptable excipient and / or a carrier and / or a salt, preferably a sodium salt, and / or a diluent and / or a buffer and / or a preservative. In certain embodiments, the SLN124 is formulated for administration as a single unit dosage form. In other embodiments, the SLN124 is formulated for multiple doses. In certain aspects, the SLN124 composition further comprises at least one additional therapeutic agent.

[0020] One aspect relates to the use of SLN124 and / or a composition as disclosed herein in the prevention (decrease of the risk of suffering from), prophylaxis (decrease the severity of) or treatment of polycythaemia vera (PV).

[0021] One aspect relates to a method of prevention, prophylaxis or treatment of polycythaemia vera (PV)), comprising administering a pharmaceutically effective amount of SLN124 and / or a composition as disclosed herein to an individual in need of treatment.

[0022] Thus, in all aspects, an individual dose may provide SLN124 in an amount of, for example: 50-1000 mg, 75-1000 mg, 100-1000 mg, 125-1000 mg, 150-1000 mg, 175-1000 mg, 200-1000 mg, 225-1000 mg, 250-1000 mg, 275-1000 mg, 300-1000 mg, 325-1000 mg, 350-1000 mg, 375-1000 mg, 400-1000 mg, 425-1000 mg, 450-1000 mg, 475-1000 mg, 500-1000 mg, 525- 1000 mg, 550-1000 mg, 575-1000 mg, 600-1000 mg, 625-1000 mg, 650-1000 mg, 675-1000 mg, 700-1000 mg, 725-1000 mg, 750-1000 mg, 775-1000 mg, 800-1000 mg, 825-1000 mg, 850-1000 mg, 875-1000 mg, 900-1000 mg, 925-1000 mg, 950-1000 mg, 975-1000 mg;

[0023] 50-950 mg, 75-950 mg, 100-950 mg, 125-950 mg, 150-950 mg, 175-950 mg, 200-950 mg, 225-950 mg, 250-950 mg, 275-950 mg, 300-950 mg, 325-950 mg, 350-950 mg, 375-950 mg,

[0024] 400-950 mg, 425-950 mg, 450-950 mg, 475-950 mg, 500-950 mg, 525-950 mg, 550-950 mg,

[0025] 575-950 mg, 600-950 mg, 625-950 mg, 650-950 mg, 675-950 mg, 700-950 mg, 725-950 mg,

[0026] 750-950 mg, 775-950 mg, 800-950 mg, 825-950 mg, 850-950 mg, 875-950 mg, 900-950 mg,

[0027] 925-950 mg;

[0028] 50-850 mg, 75-850 mg, 100-850 mg, 125-850 mg, 150-850 mg, 175-850 mg, 200-850 mg, 225-850 mg, 250-850 mg, 275-850 mg, 300-850 mg, 325-850 mg, 350-850 mg, 375-850 mg,

[0029] 400-850 mg, 425-850 mg, 450-850 mg, 475-850 mg, 500-850 mg, 525-850 mg, 550-850 mg,

[0030] 575-850 mg, 600-850 mg, 625-850 mg, 650-850 mg, 675-850 mg, 700-850 mg, 725-850 mg,

[0031] 750-850 mg, 775-850 mg, 800-850 mg, 825-850 mg;

[0032] 50-750 mg, 75-750 mg, 100-750 mg, 125-750 mg, 150-750 mg, 175-750 mg, 200-750 mg, 225-750 mg, 250-750 mg, 275-750 mg, 300-750 mg, 325-750 mg, 350-750 mg, 375-750 mg, 400-750 mg, 425-750 mg, 450-750 mg, 475-750 mg, 500-750 mg, 525-750 mg, 550-750 mg, 575-750 mg, 600-750 mg, 625-750 mg, 650-750 mg, 675-750 mg, 700-750 mg, 725-750 mg;

[0033] 50-650 mg, 75-650 mg, 100-650 mg, 125-650 mg, 150-650 mg, 175-650 mg, 200-650 mg, 225-650 mg, 250-650 mg, 275-650 mg, 300-650 mg, 325-650 mg, 350-650 mg, 375-650 mg, 400-650 mg, 425-650 mg, 450-650 mg, 475-650 mg, 500-650 mg, 525-650 mg, 550-650 mg, 575-650 mg, 600-650 mg, 625-650 mg;

[0034] 50-550 mg, 75-550 mg, 100-550 mg, 125-550 mg, 150-550 mg, 175-550 mg, 200-550 mg, 225-550 mg, 250-550 mg, 275-550 mg, 300-550 mg, 325-550 mg, 350-550 mg, 375-550 mg, 400-550 mg, 425-550 mg, 450-550 mg, 475-550 mg, 500-550 mg, 525-550 mg;

[0035] 50-450 mg, 75-450 mg, 100-450 mg, 125-450 mg, 150-450 mg, 175-450 mg, 200-450 mg, 225-450 mg, 250-450 mg, 275-450 mg, 300-450 mg, 325-450 mg, 350-450 mg, 375-450 mg, 400-450 mg, 425-450 mg;

[0036] 50-350 mg, 75-350 mg, 100-350 mg, 125-350 mg, 150-350 mg, 175-350 mg, 200-350 mg, 225-350 mg, 250-350 mg, 275-350 mg, 300-350 mg, 325-350 mg; 50-250 mg, 75-250 mg, 100-250 mg, 125-250 mg, 150-250 mg, 175-250 mg, 200-250 mg, 225-250 mg;

[0037] 50-200 mg, 75-200 mg, 100-200 mg, 125-200 mg, 150-200 mg, 175-200 mg;

[0038] 50-150 mg, 75-150 mg, 100-150 mg, 125-150 mg;

[0039] 50-100 mg, or 75-100 mg.

[0040] In some embodiments, an individual dose may provide SLN124 in an amount of, for example: 100-1000 mg, 125-1000 mg, 150-1000 mg, 175-1000 mg, 200-1000 mg, 225-1000 mg, 250- 1000 mg, 275-1000 mg, 300-1000 mg, 325-1000 mg, 350-1000 mg, 375-1000 mg, 400-1000 mg, 425-1000 mg, 450-1000 mg, 475-1000 mg, 500-1000 mg, 525-1000 mg, 550-1000 mg or 575-1000 mg, 600-1000 mg, 625-1000 mg, 650-1000 mg, 675-1000 mg, 700-1000 mg, 725- 1000 mg, 750-1000 mg, 775-1000 mg, 800-1000 mg, 825-1000 mg, 850-1000 mg, 875-1000 mg, 900-1000 mg, 925-1000 mg, 950-1 OOOmg or 975-1000 mg;

[0041] 100-975 mg, 125-975 mg, 150-975 mg, 175-975 mg, 200-975 mg, 225-975 mg, 250-975 mg,

[0042] 275-975 mg, 300-975 mg, 325-975 mg, 350-975 mg, 375-975 mg, 400-975 mg, 425-975 mg,

[0043] 450-975 mg, 475-975 mg, 500-975 mg, 525-975 mg, 550-975 mg, 575-975 mg, 600-975 mg,

[0044] 625-975 mg, 650-975 mg, 675-975 mg, 700-975 mg, 725-975 mg, 750-975 mg, 775-975 mg,

[0045] 800-975 mg, 825-975 mg, 850-975 mg, 875-975 mg, 900-975mg, 925-975 mg or 950-975 mg;

[0046] 100-950 mg, 125-950 mg, 150-950 mg, 175-950 mg, 200-950 mg, 225-950 mg, 250-950 mg,

[0047] 275-950 mg, 300-950 mg, 325-950 mg, 350-950 mg, 375-950 mg, 400-950 mg, 425-950 mg,

[0048] 450-950 mg, 475-950 mg, 500-950 mg, 525-950 mg, 550-950 mg, 575-950 mg, 600-950 mg,

[0049] 625-950 mg, 650-950 mg, 675-950 mg, 700-950 mg, 725-950 mg, 750-950 mg, 775-950 mg,

[0050] 800-950 mg, 825-950 mg, 850-950 mg, 875-950 mg, 900-950mg or 925-950 mg;

[0051] 100-925 mg, 125-925 mg, 150-925 mg, 175-925 mg, 200-925 mg, 225-925 mg, 250-925 mg,

[0052] 275-925 mg, 300-925 mg, 325-925 mg, 350-925 mg, 375-925 mg, 400-925 mg, 425-925 mg,

[0053] 450-925 mg, 475-925 mg, 500-925 mg, 525-925 mg, 550-925 mg, 575-925 mg, 600-925 mg,

[0054] 625-925 mg, 650-925 mg, 675-925 mg, 700-925 mg, 725-925 mg, 750-925 mg, 775-925 mg,

[0055] 800-925 mg, 825-925 mg, 850-925 mg, 875-925 mg or 900-925 mg;

[0056] 100-900 mg, 125-900 mg, 150-900 mg, 175-900 mg, 200-900 mg, 225-900 mg, 250-900 mg,

[0057] 275-900 mg, 300-900 mg, 325-900 mg, 350-900 mg, 375-900 mg, 400-900 mg, 425-900 mg,

[0058] 450-900 mg, 475-900 mg, 500-900 mg, 525-900 mg, 550-900 mg, 575-900 mg, 600-900 mg,

[0059] 625-900 mg, 650-900 mg, 675-900 mg, 700-900 mg, 725-900 mg, 750-900 mg, 775-900 mg,

[0060] 800-900 mg, 825-900 mg, 850-900 mg or 875-900 mg; 100-875 mg, 125-875 mg, 150-875 mg, 175-875 mg, 200-875 mg, 225-875 mg, 250-875 mg,

[0061] 275-875 mg, 300-875 mg, 325-875 mg, 350-875 mg, 375-875 mg, 400-875 mg, 425-875 mg,

[0062] 450-875 mg, 475-875 mg, 500-875 mg, 525-875 mg, 550-875 mg, 575-875 mg, 600-875 mg,

[0063] 625-875 mg, 650-875 mg, 675-875 mg, 700-875 mg, 725-875 mg, 750-875 mg, 775-875 mg,

[0064] 800-875 mg, 825-875 mg or 850-875 mg;

[0065] 100-850 mg, 125-850 mg, 150-850 mg, 175-850 mg, 200-850 mg, 225-850 mg, 250-850 mg,

[0066] 275-850 mg, 300-850 mg, 325-850 mg, 350-850 mg, 375-850 mg, 400-850 mg, 425-850 mg,

[0067] 450-850 mg, 475-850 mg, 500-850 mg, 525-850 mg, 550-850 mg, 575-850 mg, 600-850 mg,

[0068] 625-850 mg, 650-850 mg, 675-850 mg, 700-850 mg, 725-850 mg, 750-850 mg, 775-850 mg,

[0069] 800-850 mg or 825-850 mg;

[0070] 100-825 mg, 125-825 mg, 150-825 mg, 175-825 mg, 200-825 mg, 225-825 mg, 250-825 mg,

[0071] 275-825 mg, 300-825 mg, 325-825 mg, 350-825 mg, 375-825 mg, 400-825 mg, 425-825 mg,

[0072] 450-825 mg, 475-825 mg, 500-825 mg, 525-825 mg, 550-825 mg, 575-825 mg, 600-825 mg,

[0073] 625-825 mg, 650-825 mg, 675-825 mg, 700-825 mg, 725-825 mg, 750-825 mg, 775-825 mg or 800-825 mg;

[0074] 100-800 mg, 125-800 mg, 150-800 mg, 175-800 mg, 200-800 mg, 225-800 mg, 250-800 mg,

[0075] 275-800 mg, 300-800 mg, 325-800 mg, 350-800 mg, 375-800 mg, 400-800 mg, 425-800 mg,

[0076] 450-800 mg, 475-800 mg, 500-800 mg, 525-800 mg, 550-800 mg, 575-800 mg, 600-800 mg,

[0077] 625-800 mg, 650-800 mg, 675-800 mg, 700-800 mg, 725-800 mg, 750-800 mg or 775-800 mg;

[0078] 100-775 mg, 125-775 mg, 150-775 mg, 175-775 mg, 200-775 mg, 225-775 mg, 250-775 mg,

[0079] 275-775 mg, 300-775 mg, 325-775 mg, 350-775 mg, 375-775 mg, 400-775 mg, 425-775 mg,

[0080] 450-775 mg, 475-775 mg, 500-775 mg, 525-775 mg, 550-775 mg, 575-775 mg, 600-775 mg,

[0081] 625-775 mg, 650-775 mg, 675-775 mg, 700-775 mg, 725-775 mg or 750-775 mg;

[0082] 100-750 mg, 125-750 mg, 150-750 mg, 175-750 mg, 200-750 mg, 225-750 mg, 250-750 mg,

[0083] 275-750 mg, 300-750 mg, 325-750 mg, 350-750 mg, 375-750 mg, 400-750 mg, 425-750 mg,

[0084] 450-750 mg, 475-750 mg, 500-750 mg, 525-750 mg, 550-750 mg, 575-750 mg, 600-750 mg,

[0085] 625-750 mg, 650-750 mg, 675-750 mg, 700-750 mg or 725-750 mg;

[0086] 100-725 mg, 125-725 mg, 150-725 mg, 175-725 mg, 200-725 mg, 225-725 mg, 250-725 mg,

[0087] 275-725 mg, 300-725 mg, 325-725 mg, 350-725 mg, 375-725 mg, 400-725 mg, 425-725 mg,

[0088] 450-725 mg, 475-725 mg, 500-725 mg, 525-725 mg, 550-725 mg, 575-725 mg, 600-725 mg,

[0089] 625-725 mg, 650-725 mg, 675-725 mg or 700-725 mg;

[0090] 100-700 mg, 125-700 mg, 150-700 mg, 175-700 mg, 200-700 mg, 225-700 mg, 250-700 mg,

[0091] 275-700 mg, 300-700 mg, 325-700 mg, 350-700 mg, 375-700 mg, 400-700 mg, 425-700 mg, 450-700 mg, 475-700 mg, 500-700 mg, 525-700 mg, 550-700 mg, 575-700 mg, 600-700 mg, 625-700 mg, 650-700 mg or 675-700 mg;

[0092] 100-675 mg, 125-675 mg, 150-675 mg, 175-675 mg, 200-675 mg, 225-675 mg, 250-675 mg,

[0093] 275-675 mg, 300-675 mg, 325-675 mg, 350-675 mg, 375-675 mg, 400-675 mg, 425-675 mg,

[0094] 450-675 mg, 475-675 mg, 500-675 mg, 525-675 mg, 550-675 mg, 575-675 mg, 600-675 mg,

[0095] 625-675 mg or 650-675 mg;

[0096] 100-650 mg, 125-650 mg, 150-650 mg, 175-650 mg, 200-650 mg, 225-650 mg, 250-650 mg,

[0097] 275-650 mg, 300-650 mg, 325-650 mg, 350-650 mg, 375-650 mg, 400-650 mg, 425-650 mg,

[0098] 450-650 mg, 475-650 mg, 500-650 mg, 525-650 mg, 550-650 mg, 575-650 mg, 600-650 mg or 625-650 mg;

[0099] 100-625 mg, 125-625 mg, 150-625 mg, 175-625 mg, 200-625 mg, 225-625 mg, 250-625 mg,

[0100] 275-625 mg, 300-625 mg, 325-625 mg, 350-625 mg, 375-625 mg, 400-625 mg, 425-625 mg,

[0101] 450-625 mg, 475-625 mg, 500-625 mg, 525-625 mg, 550-625 mg, 575-625 mg or 600-625 mg;

[0102] 100-600 mg, 125-600 mg, 150-600 mg, 175-600 mg, 200-600 mg, 225-600 mg, 250-600 mg,

[0103] 275-600 mg, 300-600 mg, 325-600 mg, 350-600 mg, 375-600 mg, 400-600 mg, 425-600 mg,

[0104] 450-600 mg, 475-600 mg, 500-600 mg, 525-600 mg, 550-600 mg or 575-600 mg;

[0105] 100-575 mg, 125-575 mg, 150-575 mg, 175-575 mg, 200-575 mg, 225-575 mg, 250-575 mg,

[0106] 275-575 mg, 300-575 mg, 325-575 mg, 350-575 mg, 375-575 mg, 400-575 mg, 425-575 mg,

[0107] 450-575 mg, 475-575 mg, 500-575 mg, 525-575 mg or 550-575 mg;

[0108] 100-550 mg, 125-550 mg, 150-550 mg, 175-550 mg, 200-550 mg, 225-550 mg, 250-550 mg,

[0109] 275-550 mg, 300-550 mg, 325-550 mg, 350-550 mg, 375-550 mg, 400-550 mg, 425-550 mg,

[0110] 450-550 mg, 475-550 mg, 500-550 mg or 525-550 mg;

[0111] 100-525 mg, 125-525 mg, 150-525 mg, 175-525 mg, 200-525 mg, 225-525 mg, 250-525 mg,

[0112] 275-525 mg, 300-525 mg, 325-525 mg, 350-525 mg, 375-525 mg, 400-525 mg, 425-525 mg,

[0113] 450-525 mg, 475-525 mg or 500-525 mg;

[0114] 100-500 mg, 125-500 mg, 150-500 mg, 175-500 mg, 200-500 mg, 225-500 mg, 250-500 mg,

[0115] 275-500 mg, 300-500 mg, 325-500 mg, 350-500 mg, 375-500 mg, 400-500 mg, 425-500 mg,

[0116] 450-500 mg or 475-500 mg;

[0117] 100-475 mg, 125-475 mg, 150-475 mg, 175-475 mg, 200-475 mg, 225-475 mg, 250-475 mg,

[0118] 275-475 mg, 300-475 mg, 325-475 mg, 350-475 mg, 375-475 mg, 400-475 mg, 425-475 mg or 450-475 mg;

[0119] 100-450 mg, 125-450 mg, 150-450 mg, 175-450 mg, 200-450 mg, 225-450 mg, 250-450 mg, 275-450 mg, 300-450 mg, 325-450 mg, 350-450 mg, 375-450 mg, 400-450 mg or 425-450 mg; 100-425 mg, 125-425 mg, 150-425 mg, 175-425 mg, 200-425 mg, 225-425 mg, 250-425 mg, 275-425 mg, 300-425 mg, 325-425 mg, 350-425 mg, 375-425 mg or 400-425 mg;

[0120] 100-400 mg, 125-400 mg, 150-400 mg, 175-400 mg, 200-400 mg, 225-400 mg, 250-400 mg, 275-400 mg, 300-400 mg, 325-400 mg, 350-400 mg or 375-400 mg;

[0121] 100-375 mg, 125-375 mg, 150-375 mg, 175-375 mg, 200-375 mg, 225-375 mg, 250-375 mg, 275-375 mg, 300-375 mg, 325-375 mg or 350-375 mg;

[0122] 100-350 mg, 125-350 mg, 150-350 mg, 175-350 mg, 200-350 mg, 225-350 mg, 250-350 mg, 275-350 mg, 300-350 mg or 325-350 mg;

[0123] 100-325 mg, 125-325 mg, 150-325 mg, 175-325 mg, 200-325 mg, 225-325 mg, 250-325 mg, 275-325 mg or 300-325 mg;

[0124] 100-300 mg, 125-300 mg, 150-300 mg, 175-300 mg, 200-300 mg, 225-300 mg, 250-300 mg or 275-300 mg;

[0125] 100-275 mg, 125-275 mg, 150-275 mg, 175-275 mg, 200-275 mg, 225-275 mg or 250-275 mg;

[0126] 100-250 mg, 125-250 mg, 150-250 mg, 175-250 mg, 200-250 mg or 225-250 mg;

[0127] 100-225 mg, 125-225 mg, 150-225 mg, 175-225 mg or 200-225 mg;

[0128] 100-200 mg, 125-200 mg, 150-200 mg or 175-200 mg;

[0129] 100-175 mg, 125-175 mg or 150-175 mg;

[0130] 100-150 mg or 125-150 mg; or 100-125 mg.

[0131] It may be desirable for an individual dose to provide SLN124 in an amount of 150 to 300 mg, for example: 150-300 mg, 160-300 mg, 170-300 mg, 175-300 mg, 200-300 mg, 225-300 mg, 250-300 mg or 275-300 mg; 150-275 mg, 160-275 mg, 170-275 mg, 175-275 mg, 200-275 mg, 225-275 mg or 250-275 mg.

[0132] It may be desirable for an individual dose to provide SLN124 in an amount of 300 to 550 mg, for example: 300-550 mg, 350-550 mg, 375-550 mg, 400-550 mg, 425-550 mg, 450-550 mg, 475-550, 500-550 or 525-550; 300-525mg, 300-500 mg, 300-475 mg, 300-450 mg, 300-425 mg, 300-400 mg, 300-375 mg, 300-350 mg, or 300-325 mg.

[0133] It may be desirable for an individual dose to provide SLN124 in an amount of 450 to 950 mg, for example: 450-950 mg, 475-950 mg, 500-950 mg, 525-950 mg, 550-950 mg, 575-950 mg, 600-950 mg, 625-950 mg, 650-950 mg, 675 - 950 mg, 700-950 mg, 725-950 mg, 750-950 mg, 775-950 mg, 800-950 mg, 825-950 mg; 450-475 mg, 450-500 mg, 450-525 mg, 450-575 mg, 450-600 mg, 450-625 mg, 450-650 mg, 450-675 mg, 450-700 mg, 450-725 mg, 450-750 mg, 450-775 mg, 450-800 mg, 450-825 mg, 450-850 mg, 450-900 mg, or 450-950 mg.

[0134] For example, an individual dose may provide SLN124 in an amount of about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, about 500 mg, about 525 mg, about 550 mg, about 575 mg, about 600 mg, about 625 mg, about 650 mg, about 675 mg, about 700 mg, about 725 mg, ab about 750 g, about 775 mg, about 800 mg, about 825 mg, about 850 mg, about 875 mg, about 900 mg, about 925 mg, about 950 mg, about 975 mg, or about 1 gm.

[0135] The term “about” in relation to a numerical value should be taken to mean + / - 10%, e.g., + / - 5%.

[0136] In some embodiments, SLN124 is formulated for administration in an individual dose of 3mg / kg, 6mg / kg or 9mg / kg, where mg / kg defines the dose in milligrams per kilogram of a subject’s weight. For example, 3 mg / kg for a subject 50-95 kg in weight equals 150mg to 285 mg dose per subject, 6 mg / kg for people 50-95 kg in weight equals 300mg to 570 mg dose per subject, or 9 mg / kg for people 50-95 kg in weight equals 450mg to 855 mg dose per subject.

[0137] In certain embodiments, an individual dose preferably provides SLN124 in an amount of 150 mg, 200 mg, 250 mg, 300 mg, 350 mg, 400 mg, 450 mg, 500 mg, 550 mg, 600 mg, 650 mg, 700 mg, 750 mg, 800 mg, 850 mg, 900 mg, 950 mg or 1000 mg, preferably, in an amount of 350 mg, 400 mg, 450 mg, 500 mg, 550 mg, or 600 mg.

[0138] It will be understood that the amount of SLN124 to be administered in an individual dosage is typically independent of the body weight of the recipient subject. As disclosed herein, however, the dosages administered to PV patients (i.e., 3 mg / kg, 6 mg / kg or 9 mg / kg) were based on body weight of the recipient subject. Accordingly, flat dosing or weight-based dosing may alternatively be used according to the present invention, as selected by the skilled practitioner.

[0139] It may be desirable that SLN124 is administered to a subject via a dosing regime comprising a plurality or course of doses.

[0140] Typically, administration under the dosing regime will be once every 2 weeks, once every three weeks, once every 4 weeks, once every 5 weeks, once every 6 weeks, once every 7 or 8 weeks or once every 9 or 10 weeks; or once monthly, or less frequent, e.g., 2-monthly (once every 2 months), 3-monthly (once every 3 months), 4-monthly (once every 4 months), 5- monthly (once every 5 months), 6-monthly (once every 6 months), 7-monthly (once every 7 months), 8-monthly (once every 8 months), 9-monthly (once every 9 months), 10-monthly (once every 10 months), 11 -monthly (once every 11 months) or 12-monthly (once every 12 months) administration, optionally where SLN124 is administered in an amount of 150 mg, 200 mg, 250 mg, 300 mg, 350 mg, 400 mg, 450 mg, 500 mg, 550 mg, 600 mg, 650 mg, 700 mg, 750 mg, 800 mg, 850 mg, 900 mg, 950 mg or 1000 mg, preferably where SLN124 is administered in an amount of 350 mg, 400 mg, 450 mg, 500 mg, 550 mg, or 600 mg.

[0141] In certain embodiments, administration under the dosing regime is preferably every 4-weeks or every 6-weeks.

[0142] In certain embodiments, an individual dose preferably provides SLN124 in an amount of 3 mg / kg of recipient body weight, and administration under the dosing regime is once every 4 weeks.

[0143] In certain embodiments, an individual dose preferably provides SLN124 in an amount of 3mg / kg of recipient body weight, and administration under the dosing regime is once every 6 weeks.

[0144] In certain embodiments, an individual dose preferably provides SLN124 in an amount of 6 mg / kg of recipient body weight, and administration under the dosing regime is once every 4 weeks.

[0145] In certain embodiments, an individual dose preferably provides SLN124 in an amount of 6 mg / kg of recipient body weight, and administration under the dosing regime is once every 6 weeks.

[0146] In certain embodiments, an individual dose preferably provides SLN124 in an amount of 9 mg / kg of recipient body weight, and administration under the dosing regime is once every 4 weeks.

[0147] In certain embodiments, an individual dose preferably provides SLN124 in an amount of 9 mg / kg of recipient body weight, and administration under the dosing regime is once every 6 weeks.

[0148] Detailed Description of the Invention

[0149] SLN124

[0150] SLN124 is a double stranded RNA (dsRNA) or siRNA capable of inhibiting expression of the human TMPRSS6 gene. Without wishing to be bound by theory, inhibition is believed to occur by RNA interference. See, e.g., WO2018 / 185240, incorporated by reference herein in its entirety. The inventors have found that treatment of PV subjects with a TMPRSS6 siRNA, SLN124, is beneficial for alleviating some of the burdensome symptoms of PV, which is associated with an increase in erythrocytosis, or red blood cell (RBC) production and potentially other blood cell types, which his associated with higher haematocrit levels, a higher incidence of thrombotic, or clotting, events and an increase in adverse CV outcomes. See, e.g., WO2022 / 229150. SLN124 has now been taken into human clinical trial studies in human subjects having PV and the present invention relates to SLN124 dosing regimens in subjects in need thereof, e.g., for use in the prevention, prophylaxis, decrease of the risk of suffering from or treatment of PV, as well as associated diagnostic or therapeutic methods.

[0151] SLN124 is a double stranded nucleic acid which consists of:

[0152] (i) a first (antisense) strand having the sequence:

[0153] 5'mA (ps) fA (ps) mC fC mA fG mA fA mG fA mA fG mC fA mG fG mil (ps) fG (ps) mA 3'

[0154] (SEQ ID NO: 1 ) and

[0155] (ii) a second (sense) strand having the sequence:

[0156] 5'[M]-fU mC fA mC fC mU fG mC fU mU fC mU fU mC fU mG fG (ps) mU (ps) fU 3'

[0157] (SEQ ID NO: 2)

[0158] In the context of the above formula, the following abbreviations are used: where [M] is a triantennary ligand moiety linked to the 5’ end of the second strand and having the structure: where Z denotes the siRNA.

[0159] Thus, the terminal phosphorothioate group of the ligand moiety [M] is bonded directly to the 5’ position of the 5’ terminal nucleotide of the second strand (i.e., to the 5’-carbon of the 2’-F ribose moiety of the fll residue at the 5’ end of the second strand).

[0160] Where no group is specifically indicated between adjacent nucleotides, they are linked by a conventional phosphodiester linkage. Thus, the first strand contains phosphorothioate linkages between each of the three terminal nucleotides at the 5’ end and each of the three terminal nucleotides at the 3’ end (i.e., 2 phosphorothioate linkages at each end of the strand). The other nucleotides of the first strand are linked by phosphodiester linkages. The second strand contains phosphorothioate linkages between each of the three terminal nucleotides at the 3’ end (i.e., 2 phosphorothioate linkages at the 3’ end of the strand only). The other nucleotides of the first strand are linked by phosphodiester linkages.

[0161] Sequences are shown in the conventional 5’ to 3’ direction.

[0162] The first and second strands (without the ligand moiety [M]) are referred to in WO2018 / 185240 as SEQ ID NOs: 17 and 18, respectively. WO2018 / 185240 also describes SLN124 as “Duplex ID: GN3-TMPRSS6-hcm9”. The ligand moiety [M], (including its phosphorothioate link to the second strand) is designated in that document as “[ST23(ps)]3 C4XTL (ps)”.

[0163] The SLN124 nucleic acids or compositions of the present invention can be produced using routine methods in the art including chemical synthesis, such as solid phase chemical synthesis. See e.g. WO 2018 / 185240 A1 . In one embodiment, SLN124 reduces the expression of TMPRSS6 mRNA by 10%, 20%, 30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100%. These reduced expression levels may be measured in a cell or a hepatocyte or the liver of a subject treated with the inhibitor. The reduced expression levels of Matriptase-2 may result in increased hepcidin levels which may be measured in serum or plasma.

[0164] The inhibition activity of the nucleic acids according to the present invention relies on the formation of a duplex region between all or a portion of a strand of the nucleic acid and a portion of a target nucleic acid. The portion of the target nucleic acid that forms a duplex region with the strand of the nucleic acid, defined as beginning with the first base pair formed between the first strand and the target sequence and ending with the last base pair formed between the first strand and the target sequence, inclusive, is the target nucleic acid sequence or simply, target sequence. In the case of double-stranded nucleic acids, the duplex region formed between the first strand and the second strand need not be the same as the duplex region formed between the first strand and the target sequence. That is, the second strand may have a sequence different from the target sequence; however, the first strand must be able to form a duplex structure with both the second strand and the target sequence, at least under physiological conditions.

[0165] The complementarity between the first strand and the target sequence may be perfect (i.e., 100% identity with no nucleotide mismatches or insertions or deletions in the first strand as compared to the target sequence). The complementarity between the first strand and the target sequence may not be perfect. The complementarity may be from about 70% to about 100%. More specifically, the complementarity may be at least 70%, 80%, 85%, 90% or 95% and intermediate values.

[0166] Nucleic acids that are capable of hybridising under physiological conditions are nucleic acids that are capable of forming base pairs, preferably Watson-Crick or wobble base-pairs, between at least a portion of the opposed nucleotides in the strands so as to form at least a duplex region. Such a double-stranded nucleic acid is preferably a stable double-stranded nucleic acid under physiological conditions (for example in PBS at 37°C at a concentration of 1 pM of each strand), meaning that under such conditions, the two strands stay hybridised to each other. The Tm of the double-stranded nucleotide is preferably 45°C or more, preferably 50°C or more.

[0167] Compositions, uses and methods

[0168] The present invention also provides SLN124 compositions of the invention which may be used as medicaments or as diagnostic agents, alone or in combination with other agents, for polycythaemia vera. Compositions disclosed herein are preferably pharmaceutical compositions. Such compositions are suitable for administration to a subject.

[0169] In one aspect, the composition comprises SLN124 or a pharmaceutically acceptable salt or solvate thereof (preferably as the sodium salt form), and a solvent (preferably water) and / or a delivery vehicle and / or a physiologically acceptable excipient and / or a carrier and / or a salt and / or a diluent and / or a buffer and / or a preservative. In particular embodiments, the SLN124 drug product will be provided as a solution for injection for subcutaneous use in glass vials. The SLN124 drug product contains the excipients sodium chloride (NaCI) for osmolality adjustment and NaOH / HCI as required for pH adjustment.

[0170] Pharmaceutically acceptable carriers or diluents include those used in formulations suitable for oral, rectal, nasal or parenteral (including subcutaneous, intramuscular, intravenous, intradermal, and transdermal) administration. The formulations may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy. Subcutaneous or transdermal modes of administration may be particularly suitable for the compounds described herein.

[0171] The therapeutically effective amount of SLN124 will depend on the route of administration, the type of mammal being treated, and the physical characteristics of the specific mammal under consideration. These factors and their relationship to determining this amount are well known to skilled practitioners in the medical arts. This amount and the method of administration can be tailored to achieve optimal efficacy, and may depend on such factors as weight, diet, concurrent medication and other factors, well known to those skilled in the medical arts. The dosage sizes and dosing regimen most appropriate for human use may be guided by the results obtained by the present invention, and may be confirmed in properly designed clinical trials.

[0172] An effective dosage and treatment protocol may be determined by conventional means, starting with a low dose in laboratory animals and then increasing the dosage while monitoring the effects, and systematically varying the dosage regimen as well. Numerous factors may be taken into consideration by a clinician when determining an optimal dosage for a given subject. Such considerations are known to the skilled person.

[0173] Pharmaceutical compositions are typically sterile and stable under the conditions of manufacture and storage. The pharmaceutical composition may be a sterile injectable aqueous suspension or solution, or in a lyophilised form. The composition may be formulated as a solution, microemulsion, liposome, or other ordered structure suitable to high drug concentration. The carrier may be a solvent or dispersion medium containing, for example, water, alcohol such as ethanol, polyol (e.g., glycerol, propylene glycol, and liquid polyethylene glycol), or any suitable mixtures. The proper fluidity may be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by use of surfactants according to formulation chemistry well known in the art. In certain embodiments, isotonic agents, e.g., sugars, polyalcohols such as mannitol, sorbitol, or sodium chloride may be desirable in the composition. Prolonged absorption of injectable compositions may be brought about by including in the composition an agent that delays absorption for example, monostearate salts and gelatine.

[0174] The pharmaceutical compositions of the invention can be in unit dosage form. In such form, the composition is divided into unit doses containing appropriate quantities of the active component. The unit dosage form can be a packaged preparation, the package containing discrete quantities of the preparations, for example, packeted tablets, capsules, and powders in vials or ampoules. The unit dosage form can also be a capsule, cachet, or tablet itself, or it can be the appropriate number of any of these packaged forms. It may be provided in single dose injectable form, for example in the form of a pen. Compositions may be formulated for any suitable route and means of administration.

[0175] Pharmaceutical compositions of the invention may be administered alone or in combination with one or more other therapeutic or diagnostic agents. A combination therapy may include an inhibitor or nucleic acid of the present invention combined with at least one other therapeutic agent selected based on the particular patient or conditions to be treated. Examples of other such agents include, inter alia, a therapeutically active small molecule or polypeptide, a single chain antibody, a classical antibody or fragment thereof, or a nucleic acid molecule which modulates gene expression of one or more additional genes, and similar modulating therapeutics which may complement or otherwise be beneficial in a therapeutic or prophylactic treatment regimen.

[0176] One aspect of the invention is a SLN124 nucleic acid or a composition thereof as disclosed herein for use as a medicament. The nucleic acid or composition is preferably for use in the prevention, prophylaxis, decrease of the risk of suffering from, or treatment of PV.

[0177] One aspect is the use of a SLN124 nucleic acid or a composition thereof as disclosed herein in the manufacture of a medicament for treating PV. A medicament is a pharmaceutical composition.

[0178] The invention further provides methods of treatment, prophylaxis or prevention of PV, the method comprising the step of administering to a subject in need thereof (e.g., a patient) a therapeutically effective amount of a SLN124 nucleic acid or pharmaceutical composition of the invention. The most desirable therapeutically effective amount is an amount that will produce a desired efficacy of a particular treatment selected by one of skill in the art for a given subject in need thereof. This amount will vary depending upon a variety of factors understood by the skilled worker, including but not limited to the characteristics of the therapeutic compound (including activity, pharmacokinetics, pharmacodynamics, and bioavailability), the physiological condition of the subject (including age, sex, disease type and stage, general physical condition, responsiveness to a given dosage, and type of medication), the nature of the pharmaceutically acceptable carrier or carriers in the formulation, and the route of administration. One skilled in the clinical and pharmacological arts will be able to determine a therapeutically effective amount through experimentation, namely by monitoring a subject's response to administration of a compound and adjusting the dosage accordingly. See, e.g., Remington: The Science and Practice of Pharmacy 21 st Ed., Univ, of Sciences in Philadelphia (USIP), Lippincott Williams & Wilkins, Philadelphia, PA, 2005.

[0179] Administration of a "therapeutically effective dosage" of an inhibitor or nucleic acid or composition of the invention may result in a decrease in severity of disease symptoms, an increase in frequency and duration of disease symptom-free periods, or a prevention of impairment or disability due to the disease affliction.

[0180] An exemplary treatment regime, no matter what the dosage in mg / kg, is administration of SLN124 or compositions thereof once every 2 weeks, every 3 weeks, every 4 weeks, every 5 weeks, every 6 weeks, every 7 weeks, every 8 weeks, every 9 weeks, every 10 weeks, every 11 weeks or every 12 week, or more. In certain embodiments, no matter what the SLN124 dosage in mg / kg, the interval may preferably be every 1 month, every 2 months, every 3 months or every 4 months - or in regimens with varying dosing frequency such as combinations of the before-mentioned intervals.

[0181] Dosages may be selected and readjusted by the skilled health care professional as required to maximize therapeutic benefit for a particular subject, e.g., patient. The inhibitors or nucleic acids will typically be administered on multiple occasions. Intervals between administrations can also be irregular, based on nucleic acid target gene product levels for example in the blood or liver of the subject or patient.

[0182] In the context of the present disclosure, a month may be a calendar month, or a period of 28 to 31 days, e.g., a period of 30 days. However, it will be understood that precise monthly dosing may not be practical for any individual subject. Thus, consecutive doses may be separated by the relevant number of months, plus or minus 7 days, e.g., plus or minus 5 days, e.g., plus or minus 3 days, e.g., plus or minus 2 days, e.g., plus or minus 1 day. Thus, where monthly dosing is indicated, consecutive doses may be separated by 1 calendar month or 30 days, plus or minus 7 days, e.g., plus or minus 5 days, e.g., plus or minus 3 days, e.g., plus or minus 2 days, e.g., plus or minus 1 day; where 2-monthly dosing is indicated, consecutive doses may be separated by 2 calendar months or 60 days, plus or minus 7 days, e.g., plus or minus 5 days, e.g., plus or minus 3 days, e.g., plus or minus 2 days, e.g., plus or minus 1 day; where 3-monthly dosing is indicated, consecutive doses may be separated by 3 calendar months or 90 days, plus or minus 7 days, e.g., plus or minus 5 days, e.g., plus or minus 3 days, e.g., plus or minus 2 days, e.g., plus or minus 1 day; where 4-monthly dosing is indicated, consecutive doses may be separated by 4 calendar months or 120 days, plus or minus 7 days, e.g., plus or minus 5 days, e.g., plus or minus 3 days, e.g., plus or minus 2 days, e.g., plus or minus 1 day;

[0183] In certain embodiments, SLN124 is administered to a subject via a dosing regime comprising for example a first dose, a second dose, a third dose, and optionally one or more subsequent doses. In the data reported herein, SLN124 was administered to each PV subject in four doses. It is envisioned, however, that other dosage regimens may be more beneficial depending on the subject and the severity of the subject’s conditions.

[0184] The first dose provides SLN124 in an amount of 50 mg - 1000 mg and the second, the third and any subsequent dose provides SLN124 in the same or a different amount.

[0185] In certain embodiments the interval between the first two doses is 2 weeks, 3 weeks, 4 weeks, 5 weeks or 6 weeks, while the interval between the second and third doses, and between any subsequent doses may be different. In certain embodiments, the interval between the first two doses is 4 weeks, while the interval between the second and third doses, and between any subsequent doses is 6 weeks. In certain embodiments, the interval between the first two doses is 6 weeks, as is the interval between the second and third doses, and between any subsequent doses.

[0186] However, it will be understood that precise weekly dosing may not be practical for any individual subject. Thus, consecutive doses may be separated by the relevant number of weeks, plus or minus 7 days, e.g., plus or minus 5 days, e.g., plus or minus 3 days, e.g., plus or minus 2 days, e.g., plus or minus 1 day.

[0187] In one preferred embodiment, SLN124 is administered to a PV subject in need thereof at 3 mg / kg body weight about every six weeks. In certain embodiments, SLN124 is administered to a PV subject in need thereof at 3 mg / kg body weight on day 1 , day 43, day 85, day 127 and so on, for a duration to be determined by the health care professional. In another preferred embodiment, SLN124 is administered to a PV subject in need thereof at

[0188] 4 mg / kg body weight about every six weeks. In certain embodiments, SLN124 is administered to a PV subject in need thereof at 4 mg / kg body weight on day 1 , day 43, day 85, day 127 and so on, for a duration to be determined by the health care professional.

[0189] In another preferred embodiment, SLN124 is administered to a PV subject in need thereof at

[0190] 5 mg / kg body weight about every six weeks. In certain embodiments, SLN124 is administered to a PV subject in need thereof at 5 mg / kg body weight on day 1 , day 43, day 85, day 127 and so on, for a duration to be determined by the health care professional.

[0191] In another preferred embodiment, SLN124 is administered to a PV subject in need thereof at

[0192] 6 mg / kg body weight about every six weeks. In certain embodiments, SLN124 is administered to a PV subject in need thereof at 6 mg / kg body weight on day 1 , day 43, day 85, day 127 and so on, for a duration to be determined by the health care professional.

[0193] In another preferred embodiment, SLN124 is administered to a PV subject in need thereof at

[0194] 7 mg / kg body weight about every six weeks. In certain embodiments, SLN124 is administered to a PV subject in need thereof at 7 mg / kg body weight on day 1 , day 43, day 85, day 127 and so on, for a duration to be determined by the health care professional.

[0195] In another preferred embodiment, SLN124 is administered to a PV subject in need thereof at

[0196] 8 mg / kg body weight about every six weeks. In certain embodiments, SLN124 is administered to a PV subject in need thereof at 8 mg / kg body weight on day 1 , day 43, day 85, day 127 and so on, for a duration to be determined by the health care professional.

[0197] In another preferred embodiment, SLN124 is administered to a PV subject in need thereof at

[0198] 9 mg / kg body weight about every six weeks. In certain embodiments, SLN124 is administered to a PV subject in need thereof at 9 mg / kg body weight on day 1 , day 43, day 85, day 127 and so on, for a duration to be determined by the health care professional.

[0199] In another preferred embodiment, SLN124 is administered to a PV subject in need thereof at

[0200] 10 mg / kg body weight about every six weeks. In certain embodiments, SLN124 is administered to a PV subject in need thereof at 10 mg / kg body weight on day 1 , day 43, day 85, day 127 and so on, for a duration to be determined by the health care professional.

[0201] However, it will be understood that precise daily dosing may not be practical for any individual subject. Thus, consecutive doses may be separated by the relevant number of days, plus or minus 7 days, e.g., plus or minus 5 days, e.g., plus or minus 3 days, e.g., plus or minus 2 days, e.g., plus or minus 1 day.

[0202] In cells and / or subjects treated with or receiving a SLN124 nucleic acid or composition as disclosed herein, Matriptase-2 (MT2) protein and / or TMPRSS6 mRNA expression may be inhibited compared to untreated cells and / or subjects by a range from 15% up to 100% but at least about 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, or 100% or intermediate values. Preferably, inhibition is at least about 45%. The level of inhibition may allow treatment of PV or may serve to further investigate the functions and physiological roles of the TMPRSS6 gene products in PV and associated conditions. The level of inhibition is preferably measured in the liver or in the blood or in the kidneys, preferably in the liver, of the subject treated with the inhibitor or nucleic acid or composition.

[0203] Each of the uses of SLN124 nucleic acids or compositions e.g., pharmaceutically acceptable salts and solvates thereof, constitutes an individual embodiment of the invention for use in any one of the methods disclosed herein.

[0204] Solutions or suspensions used for intradermal or subcutaneous application typically include one or more of: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates; and / or tonicity adjusting agents such as, e.g., sodium chloride or dextrose. The pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide, or buffers with citrate, phosphate, acetate and the like. Such preparations may be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic.

[0205] Sterile injectable solutions may be prepared by incorporating an inhibitor or a nucleic acid in the required amount in an appropriate solvent with one or a combination of ingredients described above, as required, followed by sterilization microfiltration. Dispersions may be prepared by incorporating the active compound into a sterile vehicle that contains a dispersion medium and optionally other ingredients, such as those described above. In the case of sterile powders for the preparation of sterile injectable solutions, the methods of preparation are vacuum drying and freeze-drying (lyophilization) that yield a powder of the active ingredient in addition to any additional desired ingredient from a sterile-f iltered solution thereof.

[0206] SLN124 or a composition thereof may be for use subcutaneously, intravenously or using any other application routes such as oral, rectal, pulmonary, intramuscular or intraperitoneal. Preferably, it is for use subcutaneously.

[0207] Dosage regimens may be adjusted to provide the optimum desired response (e.g., a therapeutic response). For example, a dose may be administered, several divided doses may be administered over time, or the dose may be proportionally reduced or increased as indicated by the particular circumstances of the therapeutic situation, on a case-by-case basis. It is especially advantageous to formulate parenteral compositions in dosage unit forms for ease of administration and uniformity of dosage when administered to the subject or patient. As used herein, a dosage unit form refers to physically discrete units suitable as unitary dosages for the subjects to be treated; each unit containing a predetermined quantity of active compound calculated to produce a desired therapeutic effect. The specification for the dosage unit forms of the invention depend on the specific characteristics of the active compound and the particular therapeutic effect(s) to be achieved and the treatment and sensitivity of any individual patient.

[0208] When a therapeutically effective amount of SLN124 or composition of the invention is administered by, e.g., intravenous, cutaneous or subcutaneous injection, SLN124 will be in the form of a pyrogen-free, parenterally acceptable aqueous solution. Methods for preparing parenterally acceptable solutions, taking into consideration appropriate pH, isotonicity, stability, and the like, are within the skill in the art. A preferred pharmaceutical composition for intravenous, cutaneous, or subcutaneous injection will contain, in addition to an inhibitor or nucleic acid, an isotonic vehicle such as sodium chloride injection, Ringer's injection, dextrose injection, dextrose and sodium chloride injection, lactated Ringer's injection, or other vehicle as known in the art. A pharmaceutical composition of the present invention may also contain stabilizers, preservatives, buffers, antioxidants, or other additives well known to those of skill in the art.

[0209] The amount of SLN124 which can be combined with a carrier material to produce a single dosage form will vary depending on a variety of factors, including the subject being treated, and the particular mode of administration. In general, it will be an amount of the composition that produces an appropriate therapeutic effect under the particular circumstances. Generally, out of one hundred percent, this amount will range from about 0.01 % to about 99% of inhibitor or nucleic acid, from about 0.1% to about 70%, or from about 1% to about 30% of inhibitor or nucleic acid in combination with a pharmaceutically acceptable carrier.

[0210] Indications

[0211] In certain embodiments, the SLN124 nucleic acid or composition described herein is for use or is used in a method of prevention, prophylaxis, decreasing the risk of suffering from or treating polycythaemia vera (PV) and one or more various associated symptoms or conditions which may be related thereto, e.g., elevated risk of thrombosis; elevated haematocrit level in the blood; elevated haemoglobin level in the blood; elevated red blood cell mass in the blood; elevated erythropoiesis; elevated level of mature red cell population in the bone marrow; reduced level of progenitor red blood cells in the bone marrow; and bone marrow erythroid and / or megakaryocytic hyperplasia. Each such disease, condition, disorder or symptom is envisioned to be a separate embodiment with respect to uses of a SLN124 nucleic acid or composition according to the invention.

[0212] In certain embodiments, the subject exhibiting symptoms of polycythaemia vera (PV) is characterised by having one or several of the following: a) an elevated risk of thrombosis; b) polycythaemia vera (PV) symptoms; c) a J AK2 mutation; d) the JAK2 mutation V617F; e) a mutation in JAK2 exon 12; f) a mutation in a negative regulator of JAK2; g) constitutive, erythropoietin independent JAK2 / STAT signalling; h) is an acquired disorder; i) is an inherited disorder; j) elevated haematocrit level in the blood; k) elevated haemoglobin level in the blood; l) elevated red blood cell mass; m) elevated erythropoiesis; n) an elevated level of mature red cell population in the bone marrow; o) a reduced level of progenitor red blood cells in the bone marrow; and p) bone marrow erythroid and / or megakaryocytic hyperplasia.

[0213] In one embodiment, the JAK2 mutation is present in haematopoietic stem cells.

[0214] In one embodiment, JAK2 positive polycythaemia vera (JAK2+ PV). JAK2 positive polycythaemia vera (PV) is characterised by one or more activating mutation(s) in the JAK2 (Janus kinase 2) gene / protein. One example of such an activating mutation is the V617F mutation. The JAK2 (V617F) (exon 14) mutation is found in 95% of PV cases. About 5% of the PV patients exhibit a mutation in exon 12 (McMullin MF, Wilkins BS, Harrison CN. Management of polycythaemia vera: a critical review of current data. Br J Haematol. 2016;172(3):337-349; McMullin MF, Harrison CN, Ali S, et al., A guideline for the diagnosis and management of polycythaemia vera. A British Society for Haematology Guideline. Br J Haematol. 2019;184(2):176-191 ).

[0215] In one embodiment, the disorder is JAK2 positive polycythaemia vera (PV) characterised by a V617F mutation of JAK2.

[0216] In one embodiment, the disorder is JAK2 positive polycythaemia vera (PV) characterised by one or more mutation(s) in exon 12 of JAK2 gene. Examples of mutation(s) in exon 12 of JAK2 gene are described for example in Li et al. (Blood 2008;1 11 (7): 3863-3866) and in Kondo et al. (Leukemia & Lymphoma 2008; 49(9): 1784-1791 ).

[0217] Other examples of mutation(s) in exon 12 of JAK2 gene are F537-K539delinsL, H538QK539L, K539L, N542-E543del, which are further described in Scott et al., New England Journal of Medicine 2008; 356(5): 459-468. Further mutations in exon 12 of JAK2 gene are described in Scott, American Journal of Hematology 201 1 ; 86: 668-676: F533IK539L,

[0218] F537IK539L,H538QK539L,H538DK539LI504S, K539L, K539LL545V, I540T, D544G, L545S, F547L,F547V, F537-K539delinsK, F537-K539del, F537-K539delinsL, H538del, H538- K539del,H538-K539delinsF, H538-K539delinsl, H538-K539delinsL, l540-N542delinsS,l540- N542delinsK, l540-N543delinsKK, l540-N543delinsMK, l540-D544delinsMK, I540S, R541 - E543delinsK, R541 -E543delinsK, R541 -D544del, N542-D544delinsN, E543-D544del, D544- L545del, V536-I546dup1 1 , V536-F547dup12, [V536, F37-l546dup10],[F537-l546dup10, F547L], [F547L, l540-F547dup8].

[0219] Testing for JAK2 V617F in peripheral blood is sensitive (Takahashi et al., Blood 2013; 122:3784-3786). Assays which can be used for detection of JAK2 mutations are described, for example, in Bench et al. (British Journal of Haematology 2013; 160: 25-34).

[0220] In one embodiment, the disorder is HFE positive polycythaemia vera (PV). HFE positive polycythaemia vera (PV) is characterised by one or more mutation(s) in the HFE (homeostatic iron regulator) gene / protein resulting in a loss of HFE function. The most common HFE mutations are C282Y, H63D and S65C.

[0221] In one embodiment, the disorder is HFE positive polycythaemia vera (PV) characterised by a homozygous C282Y mutation. In one embodiment, the disorder is HFE positive polycythaemia vera (PV) characterised by a heterozygous C282Y mutation.

[0222] In one embodiment, the disorder is HFE positive polycythaemia vera (PV) characterised by a homozygous H63D mutation. In one embodiment, the disorder is HFE positive polycythaemia vera (PV) characterised by a heterozygous H63D mutation.

[0223] In one embodiment, the disorder is HFE positive polycythaemia vera (PV) characterised by a homozygous S65C mutation. In one embodiment, the disorder is HFE positive polycythaemia vera (PV) characterised by a heterozygous S65C mutation.

[0224] In one embodiment, the disorder is JAK2 positive and HFE positive polycythaemia vera (PV). In one embodiment, the disorder is JAK2 positive and HFE positive PV characterised by a V617F mutation of JAK2 and by a homozygous C282Y mutation of HFE. In one embodiment, the disorder is JAK2 positive and HFE positive PV characterised by a V617F mutation of JAK2 and by a heterozygous C282Y mutation of HFE. In one embodiment, the disorder is JAK2 positive and HFE positive PV characterised by a V617F mutation of JAK2 and by a heterozygous H63D mutation of HFE.

[0225] In one embodiment, the disorder is JAK2 positive and HFE positive PV characterised by a V617F mutation of JAK2 and by a homozygous H63D mutation of HFE. In one embodiment, the disorder is JAK2 positive and HFE positive PV characterised by a V617F mutation of JAK2 and by a heterozygous S65C mutation of HFE. In one embodiment, the disorder is JAK2 positive and HFE positive PV characterised by a V617F mutation of JAK2 and by a homozygous S65C mutation of HFE.

[0226] In one embodiment, the disorder is LNK positive PV.LNK (Lymphocyte Adaptor Protein, also known as SH2B3 adaptor protein) positive polycythaemia vera (PV) which is characterised by one or more mutation(s) in the SH2B3 gene resulting in a loss of LNK function. LNK (SH2B3) belongs to a family of adaptor proteins that contain a proline-rich N-terminal dimerization domain, a pleckstrin homology domain (PH), an Src homology-2 domain (SH2), and a conserved C-terminal tyrosine residue. By binding to cytokine receptors and JAK2 through the SH2 domain, LNK inhibits downstream signaling pathways. LNK mutations are found mainly in exon 2 that, together with exons 3 and 4, encodes the PH domain. Mutations in exon 7 encoding the SH2 domain, and in exon 8 encoding the C-terminal portion, have recently been reported in a few cases, also in association with JAK2V617F mutation (Ha et al., Am J HematoL 201 1 ; 86(10): 866-868). Examples of LNK (SH2B3) mutations are: E208Q, P155L, S213R, T274A (Spolverini et al., Haematologica 2013; 98(9): e101 -e102).

[0227] In one embodiment, the disorder is LNK positive PV characterised by a E208Q mutation of LNK.

[0228] In one embodiment, the disorder is LNK positive PV characterised by a P155L mutation of LNK.

[0229] In one embodiment, the disorder is LNK positive PV characterised by a S213R mutation of LNK. In one embodiment, the disorder is LNK positive PV characterised by a T274A mutation of LNK.

[0230] An elevated haematocrit or haemoglobin level is a level that lies above the level expected in a healthy subject, such as a level that is elevated by 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more, or 40% or more as compared to the level expected in a corresponding healthy subject. The expected level of haematocrit or haemoglobin in a healthy subject can vary depending on age, sex and other factors such as pregnancy, altitude and more. The person skilled in the art will be able to determine for a given subject whether their haemoglobin and haematocrit levels are elevated relative to the level expected in a corresponding healthy subject. For haematocrits, the level expected in a healthy subject is generally about 45% or less for male subjects and about 42% or less for female subjects (the percentage is the number of millilitres of red blood cells per 100 millilitres of blood). A haematocrit of about 40% to about 50%, e.g. about 42% to about 47%, e.g. about 45% may be designated as a universal “threshold” level. Alternatively, and more precisely, a “threshold” haematocrit level may be considered to be about 45% for male subjects and about 42% for female subjects. It will typically be desirable to maintain a subject’s haematocrit below the relevant threshold value.

[0231] In one embodiment, the disorder is PV and the subject to be treated has a haematocrit level of more than about 49% (men) or of more than about 48% (women) (Barbui et al., Blood Cancer J. 2018 Feb; 8(2): 15).

[0232] In one embodiment, the SLN124 nucleic acid or compositions of the invention is for use or is used in a method of treatment in a subject having PV to: a) reduce the risk of thrombosis; b) reduce the level of haematocrits in the blood; c) reduce the level of haemoglobin in the blood; and / or d) reduce erythropoiesis.

[0233] In one embodiment, the use of the SLN124 nucleic acid or compositions disclosed herein reduces the risk of thrombosis in a subject treated with the inhibitor, nucleic acid or composition to the corresponding level expected in a healthy subject. Alternatively, it reduces the risk of thrombosis in a subject treated with the inhibitor, nucleic acid or composition such that the difference between the risk of thrombosis in the subject before treatment and the corresponding level expected in a healthy subject is at least temporarily reduced by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0234] In one embodiment, the use of the SLN124 or compositions disclosed herein reduces the haematocrit levels in the blood of a treated subject to less than 45%, or the corresponding level expected in a healthy subject. In one embodiment the use of the SLN124 or compositions disclosed herein reduces the haematocrit levels in the blood of a treated subject to a value in the range of about 40% to about 50% or lower, e.g. a value in the range of about 42% to about 47 % or lower, e.g. to about 45%. In one embodiment the use of the SLN124 or compositions disclosed herein reduces the haematocrit levels in the blood of a treated subject to about 42% or less when the subject is a female, and to about 45% or less when the subject is a male. In one embodiment the use of the SLN124 or compositions disclosed herein reduces the haematocrit levels in the blood of a treated subject to about 47% or less. Alternatively, the use of the SLN124 or compositions reduces the haematocrit levels in the blood of a treated subject such that the difference between the level of haematocrits in the blood in a subject before treatment and the corresponding level expected in a healthy subject is at least temporarily reduced by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0235] In one embodiment, the use of the SLN124 or compositions disclosed herein reduces the level of haemoglobin in the blood of a subject treated with the inhibitor, nucleic acid or composition to the corresponding level expected in a healthy subject. Alternatively, it reduces the level of haemoglobin in the blood of a subject treated with the inhibitor, nucleic acid or composition such that the difference between the level of haemoglobin in the blood in a subject before treatment and the corresponding level expected in a healthy subject is at least temporarily reduced by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0236] In one embodiment, the PV subject treated has a haemoglobin level of more than 16.5 g / dL (men) or of more than 16.0 g / dL (women) (Barbui et al., Blood Cancer J. 2018 Feb; 8(2): 15).

[0237] In one embodiment, a bone marrow biopsy of the PV subject treated shows hypercellu larity for age with trilineage growth (panmyelosis) including prominent erythroid, granulocytic and megakaryocytic proliferation with pleomorphic, mature megakaryocytes (differences in size) (Barbui et al., Blood Cancer J. 2018 Feb; 8(2): 15).

[0238] In one embodiment, the use of the SLN124 nucleic acid or compositions disclosed herein reduces the level of erythropoiesis in a subject treated with the SLN124 nucleic acid or composition to the corresponding level expected in a healthy subject. Alternatively, it reduces the level of erythropoiesis in a subject treated with the inhibitor, nucleic acid or composition such that the difference between the level of erythropoiesis in a subject before treatment and the corresponding level expected in a healthy subject is at least temporarily reduced by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or 95%.

[0239] In one embodiment, the PV subject is characterized by having an increased red cell mass. An “increased red cell mass” is a red cell mass which is more than 25% above mean normal predicted value (Barbui et al., Blood Cancer J. 2018 Feb; 8(2): 15).

[0240] It is evident that an appropriate dosage regimen of SLN124 or a composition thereof is necessary to achieve these outcomes. The skilled person will be able to determine the dosage regimen necessary to achieve these outcomes for a given subject.

[0241] Phlebotomy

[0242] A known treatment option for patients with PV is the frequent withdrawal of blood from a subject (phlebotomy). Phlebotomy lowers haematocrit and haemoglobin levels by removing red blood cells from the circulation and decreasing iron available for further erythropoiesis. However, each 500 ml phlebotomy removes -250 mg of iron from the body, thus leading to iron deficiency in the patients. Iron deficiency is associated with decreased quality of life through fatigue and impaired cognition. Phlebotomy is also associated with side effects linked to fluid shifts, including dizziness, nausea and vasovagal syncope.

[0243] SLN124 is shown to reduce the dependency on phlebotomy for a subject with PV. In some embodiments, the number and / or frequency of phlebotomies is reduced. The reduction of phlebotomies required may be assessed over a given period (e.g., 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 1 1 months, or 12 months).

[0244] In some embodiments, the number of phlebotomies required by a subject treated with SNL124 is reduced by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% compared to a control subject, over a given period (e.g. ,6 months). The reduction may be at least 50%.

[0245] In some embodiments, the number of phlebotomies required by a subject treated with SNL124 is reduced by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% compared to the same subject prior to treatment, over a given period (e.g. ,6 months). The reduction may be at least 50%.

[0246] The subject may be a subject who has previously required one or more phlebotomies to treat PV, e.g. one, two, three or more phlebotomies in the 6-month period prior to beginning treatment.

[0247] Combination therapies

[0248] SLN124 may also be administered in combination with other therapeutic compounds, either separately or simultaneously, e.g., as a combined unit dose. The invention also provides a composition comprising SLN124 and one or more nucleic acids according to the present invention in a physiologically / pharmaceutically acceptable excipient, such as a stabilizer, preservative, diluent, buffer, and the like.

[0249] In certain embodiments, the SLN124 nucleic acid or compositions disclosed herein are for use or are used in a method of prevention, prophylaxis, decreasing the risk of suffering from or treating PV in combination with one or several of: a) a cytoreductive therapy; b) phlebotomy; c) a hepcidin agonist; d) a hepcidin mimetic, such as PTG300; e) aspirin; and f) an anticoagulant. Without wishing to be bound by theory, it will be appreciated that phlebotomy may still be required in certain subjects treated with SLN124, even though the dependency (e.g., number and / or frequency) has been reduced as a result of SLN124. For example, subjects with high baseline haematocrit levels may require phlebotomy (although reduced in number) after treatment with SLN124.

[0250] In one embodiment, a cytoreductive therapy is a therapy with hydroxyurea, hydroxycarbamide, interferon-a, pegylated interferon-a-2a, busulfan, a JAK2 inhibitor or Ruxolitinib.

[0251] Treatments that are used in combination are treatments that are administered at least twice, three times, four times, five times or more within 90 days or less, 80 days or less, 70 days or less, 60 days or less, 50 days or less, 40 days or less, 30 days or less, 20 days or less, 15 days or less, 10 days or less, 9 days or less, 8 days or less, 7 days or less, 6 days or less, 5 days or less, 4 days or less, 3 days or less, 48 hours or less, 36 hours or less, 24 hours or less, 12 hours or less, 6 hours or less, 3 hours or less, 2 hours or less, 1 hour or less, 30 minutes or less, 15 minutes or less, 10 minutes or less or 5 minutes or less from each other.

[0252] In some embodiments, the subjects for treatment are also undergoing treatment with a cytoreductive therapy (e.g. hydroxycarbamide) and / or with aspirin.

[0253] Definitions

[0254] As used herein, the terms “inhibit”, “down-regulate”, or “reduce” with respect to gene expression mean that the expression of the gene, or the level of RNA molecules or equivalent RNA molecules encoding one or more proteins or protein subunits (e.g., mRNA), or the activity of one or more proteins or protein subunits, is reduced below that observed either in the absence of the nucleic acid or conjugated nucleic acid of the invention or as compared to that obtained with an siRNA molecule with no known homology to the human transcript (herein termed non-silencing control). Such control may be conjugated and modified in an analogous manner to the molecule of the invention and delivered into the target cell by the same route. The expression after treatment with the nucleic acid of the invention may be reduced to 95%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 15%, 10%, 5% or 0% or to intermediate values, or less than that observed in the absence of the nucleic acid or conjugated nucleic acid. The expression may be measured in the cells to which the nucleic acid is applied. Alternatively, especially if the nucleic acid is administered to a subject, the level can be measured in a different group of cells or in a tissue or an organ or in a body fluid such as blood or plasma. The level of inhibition is preferably measured in conditions that have been selected because they show the greatest effect of the nucleic acid on the target mRNA level in cells treated with the nucleic acid in vitro. The level of inhibition may for example be measured after 24 hours or 48 hours of treatment with a nucleic acid at a concentration of between 0.038 nM - 10 pM, preferably 1 nM, 10 nM or 100 nM. These conditions may be different for different nucleic acid sequences or for different types of nucleic acids, such as for nucleic acids that are unmodified or modified or conjugated to a ligand or not. Examples of suitable conditions for determining levels of inhibition are described in the examples.

[0255] By nucleic acid it is meant a nucleic acid comprising one or two strands comprising nucleotides and that is able to interfere with gene expression. Inhibition may be complete or partial and result in down regulation of gene expression in a targeted manner. The nucleic acid may comprise two separate polynucleotide strands; the first strand, which may also be a guide strand; and a second strand, which may also be a passenger strand. The first strand and the second strand may be part of the same polynucleotide molecule that is self-complementary which 'folds' back to form a double-stranded molecule. The nucleic acid may be an siRNA molecule.

[0256] The nucleic acid may comprise ribonucleotides, modified ribonucleotides, deoxynucleotides, deoxyribonucleotides, or non-nucleotide analogues that are able to mimic nucleotides such that they may 'pair' with the corresponding base on the target sequence or a complementary strand. The nucleic acid may further comprise a double-stranded nucleic acid portion or duplex region formed by all or a portion of the first strand (also known in the art as a guide strand) and all or a portion of the second strand (also known in the art as a passenger strand). The duplex region is defined as beginning with the first base pair formed between the first strand and the second strand and ending with the last base pair formed between the first strand and the second strand, inclusive.

[0257] By duplex region it is meant the region in two complementary or substantially complementary oligonucleotides that form base pairs with one another, either by Watson-Crick base pairing or any other manner that allows for a duplex between oligonucleotide strands that are complementary or substantially complementary. For example, an oligonucleotide strand having 21 nucleotide units can base pair with another oligonucleotide of 21 nucleotide units, yet only 19 nucleotides on each strand are complementary or substantially complementary, such that the “duplex region” consists of 19 base pairs. The remaining base pairs may exist as 5' and 3' overhangs, or as single-stranded regions. Further, within the duplex region, 100% complementarity is not required; substantial complementarity is allowable within a duplex region. Substantial complementarity refers to complementarity between the strands such that they are capable of annealing under biological conditions. Techniques to empirically determine if two strands are capable of annealing under biological conditions are well known in the art. Alternatively, two strands can be synthesised and added together under biological conditions to determine if they anneal to one another. The portion of the first strand and second strand that form at least one duplex region may be fully complementary or are at least partially complementary to each other. Depending on the length of a nucleic acid, a perfect match in terms of base complementarity between the first strand and the second strand is not necessarily required. However, the first and second strands must be able to hybridise under physiological conditions.

[0258] “Matriptase-2” or “MT2” in the context of the present invention relates to human "Transmembrane protease serine 6" (UniProt ID Q8IU80), encoded by the gene TMPRSS6 (NCBI Gene ID: 164656).

[0259] The terms “patient,” “subject,” and “individual” may be used interchangeably and refer to a human for treatment via the methods and compositions of the invention.

[0260] As used herein, “treating” or “treatment” and grammatical variants thereof refer to an approach for obtaining beneficial or desired clinical results. The term may refer to slowing the onset or rate of development of a condition, disorder or disease, reducing or alleviating symptoms associated with it, generating a complete or partial regression of the condition, or some combination of any of the above. For the purposes of this invention, beneficial or desired clinical results include, but are not limited to, reduction or alleviation of symptoms, diminishment of extent of disease, stabilization (i.e., not worsening) of state of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, and remission (whether partial or total), whether detectable or undetectable. "Treatment" can also mean prolonging survival relative to expected survival time if not receiving treatment. A subject (e.g., a human) in need of treatment may thus be a subject already afflicted with the disease or disorder in question. The term “treatment” includes inhibition or reduction of an increase in severity of a pathological state or symptoms relative to the absence of treatment, and is not necessarily meant to imply complete or even partial cessation of the relevant disease, disorder or condition. “Treatment” of a disease, disorder or condition may be limited to reducing the extent of one or more symptom of the disease, disorder or condition.

[0261] As used herein, the terms "preventing" and grammatical variants thereof refer to an approach for preventing the development of, or altering the pathology of, a condition, disease or disorder. Accordingly, "prevention" may refer to prophylactic or preventive measures with respect to severity of condition. “Prophylaxis” in contrast, refers to preventing the onset of a disease or condition. For the purposes of this invention, beneficial or desired clinical results include, but are not limited to, prevention or slowing of symptoms, progression or development of a disease, whether detectable or undetectable. A subject (e.g., a human) in need of prevention may thus be a subject not yet afflicted with the disease or disorder in question. The term “prevention” includes slowing the onset of disease relative to the absence of treatment, and is not necessarily meant to imply permanent prevention of the relevant disease, disorder or condition. Thus “preventing” or “prevention” of a condition may in certain contexts refer to reducing the risk of developing the condition, or preventing or delaying the development of symptoms associated with the condition.

[0262] As used herein, an "effective amount," "therapeutically effective amount" or "effective dose" is an amount of a composition (e.g., a therapeutic composition or agent) that produces at least one desired therapeutic effect in a subject, such as preventing or treating a target condition or beneficially alleviating a symptom associated with the condition.

[0263] As used herein, the term “pharmaceutically acceptable salt” refers to a salt that is not harmful to a patient or subject to which the salt in question is administered. It may be a salt chosen, e.g., among acid addition salts and basic salts. Examples of acid addition salts include chloride salts, citrate salts and acetate salts (e.g., sodium chloride, sodium citrate, sodium acetate, potassium chloride, potassium citrate and potassium acetate). Examples of basic salts include salts wherein the cation is selected from alkali metal cations, such as sodium or potassium ions, alkaline earth metal cations, such as calcium or magnesium ions, as well as substituted ammonium ions, such as ions of the type N(R1)(R2)(R3)(R4)+, wherein R1, R2, R3and R4independently will typically designate hydrogen, optionally substituted C1 -6-alkyl groups or optionally substituted C2-6-alkenyl groups. Examples of relevant C1 -6-alkyl groups include methyl, ethyl, 1 -propyl and 2-propyl groups. Examples of C2-6-alkenyl groups of possible relevance include ethenyl, 1 -propenyl and 2-propenyl. Other examples of pharmaceutically acceptable salts are described in “Remington’s Pharmaceutical Sciences”, 17th edition, Alfonso R. Gennaro (Ed.), Mark Publishing Company, Easton, PA, USA, 1985 (and more recent editions thereof), in the “Encyclopaedia of Pharmaceutical Technology”, 3rd edition, James Swarbrick (Ed.), Informa Healthcare USA (Inc.), NY, USA, 2007, and in J. Pharm. Sci. 66: 2 (1977). A "pharmaceutically acceptable salt" retains qualitatively a desired biological activity of the parent compound without imparting any undesired effects relative to the compound. Examples of pharmaceutically acceptable salts include acid addition salts and base addition salts. Acid addition salts include salts derived from nontoxic inorganic acids, such as hydrochloric, nitric, phosphorous, phosphoric, sulfuric, hydrobromic, hydroiodic and the like, or from nontoxic organic acids such as aliphatic mono- and di-carboxylic acids, phenylsubstituted alkanoic acids, hydroxy alkanoic acids, aromatic acids, aliphatic and aromatic sulfonic acids and the like. Base addition salts include salts derived from alkaline earth metals, such as sodium, potassium, magnesium, calcium and the like, as well as from nontoxic organic amines, such as N, N'-dibenzylethylenediamine, N-methylglucamine, chloroprocaine, choline, diethanolamine, ethylenediamine, procaine and the like. The term "pharmaceutically acceptable carrier" includes any of the standard pharmaceutical carriers. Pharmaceutically acceptable carriers for therapeutic use are well known in the pharmaceutical art, and are described, for example, in Remington's Pharmaceutical Sciences, Mack Publishing Co. (A. R. Gennaro edit. 1985). For example, sterile saline and phosphate- buffered saline at slightly acidic or physiological pH may be used. Exemplary pH buffering agents include phosphate, citrate, acetate, tris / hydroxymethyl)aminomethane (TRIS), N- Tris(hydroxymethyl)methyl-3-aminopropanesulphonic acid (TAPS), ammonium bicarbonate, diethanolamine, histidine, which is a preferred buffer, arginine, lysine, or acetate or mixtures thereof. The term further encompasses any agents listed in the US Pharmacopeia for use in animals, including humans. A "pharmaceutically acceptable carrier" includes any and all physiologically acceptable, i.e., compatible, solvents, dispersion media, coatings, antimicrobial agents, isotonic and absorption delaying agents, and the like. In certain embodiments, the carrier is suitable for intravenous, intramuscular, subcutaneous, parenteral, spinal or epidermal administration (e.g., by injection or infusion). Depending on selected route of administration, the nucleic acid may be coated in a material or materials intended to protect the compound from the action of acids and other natural inactivating conditions to which the nucleic acid may be exposed when administered to a subject by a particular route of administration.

[0264] The term “solvate” in the context of the present invention refers to a complex of defined stoichiometry formed between a solute ( / n casu, a nucleic acid compound or pharmaceutically acceptable salt thereof according to the invention) and a solvent. The solvent in this connection may, for example, be water or another pharmaceutically acceptable, typically small-molecular organic species, such as, but not limited to, acetic acid or lactic acid. When the solvent in question is water, such a solvate is normally referred to as a hydrate.

[0265] The invention will now be described with reference to the following non-limiting Figures and Examples.

[0266] Brief Description of the Figures

[0267] Figure 1 shows a Swimmer plot for all participants at the time of data cut-off

[0268] Figure 2 shows the mean (± SD) hepcidin levels in Cohort 1 (3 mg / kg; n=4) and 2 (6 mg / kg; n=8) after exposure to SLN124 from Day 1 predose to Day 127 of treatment. Error bars represent + / - 1 SD. Cohort 1 is represented by the bottom line (from day 15 onwards) and Cohort 2 as the top line (from day 15 onwards).

[0269] Figure 3 shows the mean ferritin (pig / L) levels in cohorts 1 (Day 1 to 239) and 2 (Day 1 to 127). Error bars represent + / - 1 SD. Cohort 1 is represented by the bottom line (from day 15 onwards) and Cohort 2 by the top line (from day 15 onwards). Figure 4 shows the mean ferritin levels in patients with low baseline ferritin (<20ug / L) or high baseline ferritin (>20ug / L). Error bars represent + / - 1 SD. Baseline ferritin > 20pg / L represented by top line and baseline ferritin < 20pg / L represented by bottom line.

[0270] Figure 5 shows the mean Haemoglobin (g / dL) per cohort. Error bars represent + / - 1 SD.

[0271] Figure 6 shows the mean haematocrit (Het) for cohort 1 and 2 up to Day 127 of the study. Error bars represent + / - 1 SD.

[0272] Figure 7 shows the change from mean baseline haematocrit Het (%) in all cohorts. Error bars represent + / - 1 SD. Cohort 1 is represented by the bottom line and Cohort 2 by the top line.

[0273] Figure 8 shows the mean Het for subjects with low Het Baseline (Het < 45%) compared with subjects with high baseline Het (Het >45%) up to Day 127 of the study. Error bars represent + / - 1 SD. “Het >45% at baseline” is represented by the top line and “Het < 45% at baseline” is represented by the bottom line.

[0274] Figure 9 shows the mean Het for subjects on cytoreductives compared to subjects not on concomitant cytoreductives up to Day 127 of the study. Error bars represent + / - 1 SD.

[0275] Figure 10 shows a swimmer plot for all participants at a later time of data cut-off than in Figure 1 .

[0276] Figure 11 shows Mean (± SEM) hepcidin levels in all cohorts after exposure to SLN124 from Day 1 predose to Day 232 of treatment.

[0277] Figure 12 shows Mean (SEM) ferritin (ug / L) levels in all cohorts after exposure to SLN124 from Day 1 predose to Day 232 of treatment.

[0278] Figure 13 shows Mean (SEM) change in Hemoglobin (g / dL) from baseline in all cohorts after exposure to SLN124 from Day 1 predose to Day 232 of treatment.

[0279] Figure 14 shows change from mean baseline Het (%) in all cohorts after exposure to SLN124 from Day 1 predose to Day 232 of treatment.

[0280] Figure 15 shows the mean Serum Iron levels (umol / L) levels in Cohort 1 (3 mg / kg), 2 (6 mg / kg), and 3 (9mg / kg) after exposure to SLN124 from Day 1 predose to Day 232 of treatment.

[0281] Figure 16 shows the mean Transferrin Saturation (%) levels in Cohort 1 (3 mg / kg), 2 (6 mg / kg), and 3 (9mg / kg) after exposure to SLN124 from Day 1 predose to Day 232 of treatment.

[0282] Figure 17 shows the mean Platelet (1 OAg / L) levels in Cohort 1 (3 mg / kg), 2 (6 mg / kg), and 3 (9mg / kg) after exposure to SLN124 from Day 1 predose to Day 232 of treatment. Figure 18 shows the mean whole blood cell (WBC) (1 OAg / L) levels in Cohort 1 (3 mg / kg), 2 (6 mg / kg), and 3 (9mg / kg) after exposure to SLN124 from Day 1 predose to Day 232 of treatment.

[0283] EXAMPLE 1 : Scope of the Clinical Study

[0284] The present invention is derived from the clinical data available to date for applicant’s SLN124- 004 clinical study using SLN124 (“divesiran”) for the treatment of polycythaemia vera (PV). Study SLN124-004 is a Phase 1 / 2, multicentre study with an open-label dose escalation phase followed by a randomised, double-blind phase. Twenty-one (21 ) subjects with PV have been enrolled across 3 ascending dose cohorts of Phase 1 in the SLN124-004 study, since recruitment first began. Five subjects were enrolled and treated in Cohort 1 at 3 mg / kg, 8 subjects were enrolled and treated with SLN124 in Cohort 2 at 6 mg / kg and 6 subjects were enrolled and treated with SLN124 in Cohort 3 at 9 mg / kg. Subjects are planned to receive a total of 4 doses of SLN124 every 6 weeks. At the time of data cut off, 4 of the 5 subjects in Cohorts 1 and 3 out of the 8 subjects in Cohort 2 had completed treatment and all follow-up visits as per protocol. All other participants are currently in their respective treatment or follow up periods. The data in Examples 2 & 3 presented herein represents all data points for 16 of the 21 patients currently enrolled. Examples 4 to 7 represents data points for all 21 patients enrolled in the study.

[0285] Participants enrolled on the study all have a confirmed diagnosis of PV as defined by WHO 2016 guidelines. All subjects were eligible to participate in the study by meeting all the eligibility criteria with no exceptions. Of note, one participant in cohort 1 had pernicious anaemia and one participant in cohort 2 had splenomegaly.

[0286] Concomitant medication of note was the anti-anaemia preparations in one participant in cohort 1. There are eleven participants on hydroxycarbamide (hydroxyurea) and fifteen on acetylsalicylic acid consistent with the treatment algorithm for PV patient management. At this point in time, the only cytoreductive used was hydroxycarbamide.

[0287] As part of the management of the disease and in accordance with the eligibility criteria, all participants had at least 3 phlebotomies in the 6 months prior to screening or at least 5 phlebotomies 12 months prior to screening (Table 1 ). Table 1 Summary of number of phlebotomies 6 months prior to screening. Participants with less than the required 3 phlebotomies 6 months prior to screening would have had at least 5 phlebotomies in the prior 12 months.

[0288] EXAMPLE 2: Effect of SLN124 on Phlebotomies

[0289] SLN124 was administered 4 times during the study, on day 1 , 43, 85 and 127. Dosing could be delayed if patients had a haematocrit (Het) of less than 37% or due to a safety event.

[0290] The phase 1 primary endpoint for efficacy (ongoing) is to compare the number of phlebotomies at three different periods. Period 1 , 6 months prior to screening to day 1 ; period 2, day 1 to day 169 and period 3, day 169 to day 239 (EoS visit). Figure 1 summarizes in a swimmer plot the number of phlebotomies during each of the periods.

[0291] The number of phlebotomies for the 16 participants 6 months prior to dosing were 59 while the number of phlebotomies for the period between day 1 (first dose administration) and day 169 (6 weeks after the last dose administration) was 2 with 9 / 16 participants having completed that period. For the last analysis period, from D169 to Day 239 (EoS visit), only 4 participants had completed that period and only 1 phlebotomy had been indicated at the time of the data cutoff. Table 2 shows the rate of phlebotomies at the different assessment periods. While these are incomplete data sets, it is noticeable that there was a decrease in the need of phlebotomies after treatment with SLN124. Table 2 Number of phlebotomies and rate at the three different evaluation periods of the study. 6 months prior to dosing, dosing to day 169 and day 169 to day 239.

[0292] ND = Not determined

[0293] EXAMPLE 3: Effects of SLN124 on Iron and Erythropoiesis markers

[0294] Assessment of SLN124 function is assessed by monitoring biomarkers or iron metabolism and erythroid function such as hepcidin, serum iron, transferrin saturation (TSAT), ferritin, haemoglobin, MCV, red blood cell number, reticulocyte number and Haemotocrit.

[0295] Mechanistically, SLN124 will lead to induction of hepcidin. Figure 2 shows the mean data for cohorts 1 and 2 at the data cut-off. The data is shown up to day 127 showing that hepcidin was elevated after treatment often from an undetectable baseline to within the normal range (2 - 20nM, Nemeth and Ganz, 2021 ). In cohort 1 , for the mean baseline level is 0.68nM + / - 0.60. Mean hepcidin was elevated by day 8 to 4.38nM + / - 0.83 and maintained at those levels till day 127 after which it lowered to a mean hepcidin of 2.30nM + / - 0.59 by day 239 or EoS (with 3 / 4 participants data available). In cohort 2, mean hepcidin levels at baseline were 0.20nM + / - 0.12 and on the basis of 8 participants, on day 8 mean hepcidin was elevated to 2.24nM + / - 0.83 and by day 22 to 7.69nM + / - 2.39. On day 127, the mean hepcidin level remained elevated (N=5) to 4.63 + / - 1.44. Finally, cohort 3 has data for three participants to day 15. Mean baseline hepcidin was 0.075 nM + / - 0.0, with day 8 0.69 nM + / - 0.34 and day 15 2.96nM + / - 1 .74. In all cases, hepcidin was elevated after the administration of SLN124 (Table 3).

[0296] Table 3 Mean Hepcidin (nM) and standard deviation for cohorts 1 , 2 and 3 during the phase 1 portion of the study.

[0297] SD= Standard Deviation, NA= Not available, NE= Not estimated

[0298] Interestingly, the mean hepcidin baseline was very low in participants who were iron deficient based on serum iron levels (< 8mmol / L) and ferritin (<20ug / L) and within the normal range for participants with normal iron levels, yet in all cases by day 8 SLN124 had induced mean hepcidin levels between 6 to 12-fold from baseline (Table 4).

[0299] Table 4 Hepcidin (nM) and standard deviation for Day 1 and Day 8 in cohorts 1 , 2 and 3 during the phase 1 portion of the study and hepcidin fold change from baseline to Day 8.

[0300] One of the key features of most PV patients on presentation is their iron deficiency which is exacerbated by repeated phlebotomies. This means that in general, serum iron, TSAT and ferritin are all low. The baseline data for serum iron, TSAT and ferritin confirmed that in most cases the participants in the study were iron deficient at baseline with the notable exceptions of one patient in each of cohorts 1 and 2 (Table 5). The consequence of this, is that a small effect on serum iron and TSAT was observed as a result of the iron restriction generated by hepcidin presence. In the patients with normal serum iron and TSAT, the effect was more noticeable and consistent with the observations made in the SLN124-003 study in healthy volunteers (Porter et al., 2023).

[0301] Table 5 Mean levels of serum iron, TSAT and Ferritin at baseline for each cohort. SLN124 leads to iron retention, which in conjunction with a decrease in phlebotomies, is expected to result in an increase in ferritin levels (a measure of iron stores in the body).

[0302] Figure 3 shows the mean effect on ferritin after treatment with SLN124 on cohorts 1 and 2 up to day 127. Changes in mean ferritin levels were seen in both patients with low baseline ferritin (<20ug / L) or patient with high ferritin (>20ug / L) at baseline, representing improvement in iron deficient status (Figure 4).

[0303] Iron restriction as induced by SLN124 leads to microcytic red blood cells and lowers the production of haemoglobin. Haemoglobin is reduced in cohort 1 on day 127 by 1 .34 g / dL (10% from baseline) and more strongly in cohort 2 by 1.78 g / dL (12.37% from baseline) (Table 6, Figure 5). For cohort 1 with the most complete data set, return to baseline was observed by Day 211 of the study or 84 days after the last dose. In the phase 1 portion of the study Mean Corpuscular Volume (MCV) was followed to ascertain the effect of SLN124 in RBC morphology. Table 7 shows that at baseline in general all cohorts had a similar MCV which decreased in the treatment phase in cohorts 1 and 2 with the nadir taking place on Day 169 for cohort 1 . Cohort 1 had a decrease on Day 127 (mean MCV 83.6 fL+ / - 25.4) as compared to baseline mean MCV 88.0 fL + / - 20.7. In cohort 2, Day 127, n= 5 (78.6 fL + / - 5.9) can be compared to Day 1 n= 8 (83.5 fL + / - 12.6). A decrease was observed in both cohorts.

[0304] Table 6 Mean Haemoglobin (g / dL) per cohort. Table 7 Mean MCV (fL) per cohort

[0305] Study markers looking at predecessors of red blood cells and red blood cells were investigated.

[0306] Table 8 depicts the mean reticulocyte counts which do not show a strong trend at present. Table 8 Mean absolute Reticulocyte counts (10E9 cells / L) after treatment with SLN124 at 3mg / kg (Cohort 1 ), 6mg / kg (Cohort 2) and 9mg / kg (Cohort 3)

[0307] Although it is known that in PV some patients can have red blood cells with short life span (Pollycove et al., 1966), a significant effect would take time to be seen since there will be a large excess of pre-dose red blood cells as compared to post-dose red blood cells. Table 9 shows the mean effects per cohorts with a similar observation as that made for the reticulocyte counts. Table 9 Mean Red blood cell count

[0308] It was also observed that SLN124 treatment was associated with limited increases in platelets but that effect does not appear to be dose dependent. Finally, a key marker for this study was the effect of SLN124 on haematocrit (Het). Table 10 and Figure 6, shows the mean effect per cohort. Cohort 1 had a maximal decrease of mean Het on Day 127 (Mean Het 40.3% + / - 2.0) compared to mean baseline (45.2% + / - 7.5); for cohort 2 a maximum decrease on Day 169 (not all data available at cut-off) was Het 42.6% + / - 3.9 compared to mean Het of 48.0% + / - 5.1 at baseline. Cohort 3 cannot yet be determined due to the lack of data at the time of cutoff. Mean haematocrit absolute values from baseline are shown in Figure 7, and suggests a potential dose response, showing that cohort 2 had a more pronounced decrease over time than cohort 1 .

[0309] Table 10 Mean haematocrit (%) per cohort. It is important to note that the baseline Het was heterogeneous with 8 / 16 (50%) having Het < 45% (range 39% to 45%) and the remaining 8 patients (50%) had Het >45% (range 46% to 56%). In cohort 1 , 1 / 4 had Het >45%; in cohort 2, 6 / 8 (75%) had Het >45% and in cohort 3, 1 / 4 had Het >45%. Data from the three cohorts was pooled to compare the effect of SLN124 on the two subpopulations and shows that SLN124 treatment controls haematocrit regardless of baseline (Figure 8). The first subpopulation analysis was between patients with low Het at baseline (Het <45%) compared to patients with a high Het at baseline (Het >45%). A small change was observed in the low Het population up to Day 169 with no phlebotomies indicated (Baseline Het 42.2% + / - 2.3 vs Day 169 Het 40.2 + / - 3.0). A larger decrease (baseline Het 50.8 % + / - 4.0 vs Day 169 Het 44.5% + / - 4.6) was observed in the high Het baseline population with these patients achieving the mean target Het <45%. A similar analysis comparing patients who had been on cytoreductives prior to entry into the study compared to those who had not had cytoreductive treatment shows that patients with baseline cytoreductives (1 1 / 16) had a decrease from mean baseline (Het 47.1 % + / - 4.8) by Day 169 (Het 43.9% + / - 4.0). When compared to the patient population with no background cytoreductives (5 / 16; baseline mean Het 46.0% + / - 6.8 vs Day 169 mean Het 41 .0 % + / - 6.0) (Figure 9), both are decreased indicating that SLN124 had the desired effect in both populations.

[0310] EXAMPLE 4: Effect of SLN124 on Phlebotomies (day 1 to day 239)

[0311] The phase 1 primary endpoint for efficacy was to compare the number of phlebotomies at three different periods: Predose, 6 months prior to screening to day 1 ; Treatment period, day 1 to day 169 and Follow-up period, Day 169 to Day 239 (EoS visit). Figure 10 summarizes in a swimmer plot the number of phlebotomies during each of the periods.

[0312] The number of phlebotomies for the 21 participants 6 months prior to dosing were 79 while the number of phlebotomies for the treatment period between Day 1 (first dose administration) and Day 169 (6 weeks after the last dose administration) was 5. For the follow-up period, from Day 169 to Day 239 (EoS visit), only 4 phlebotomies have been reported at the time of the data cut-off. Table 11 shows the rate of phlebotomies at the different assessment periods. By the nature of the status of the study, incomplete data sets, conclusions cannot be drawn. However, it is clear that there was a decrease observed in the need of phlebotomies after treatment, with a rate of phlebotomies per patient per month (phlb / pt / mo) prior to dosing of 0.63 compared to the rate in the treatment phase of 0.04 phlb / pt / mo and at follow-up of 0.05 phlb / pt / mo. Table 11 Number of phlebotomies and rate at the three different evaluation periods of the study. Six months prior to dosing, dosing to Day 169 and Day 169 to Day 239.

[0313] Note: Phlb=phlebotomies, # Pts= number of patients at a given period, Phlb / pt / mo = Number of phlebotomies per patient per month for a given period.

[0314] EXAMPLE 5: Effects of SLN124 on Hepcidin and Target Engagement (Day 1 to Day 239)

[0315] Assessment of SLN124 function was performed by monitoring biomarkers or iron metabolism and erythroid function such as hepcidin, serum iron, transferrin saturation (TSAT), ferritin, hemoglobin, MCV, red blood cell number, reticulocyte number and Hematocrit.

[0316] SLN124 is expected to down regulate TMPRSS6 expression in the liver leading to an induction of hepcidin expression and increase in systemic levels. Figure 11 shows hepcidin data, in which a clear elevation of hepcidin to within physiological levels was observed. The following results are all represented as mean (SEM) nM for hepcidin levels during study conduct. In cohort 1 , the baseline level, was 0.48 (0.40) (normal range, 2nM to 20nM; Nemeth & Ganz 2021 ). Hepcidin was elevated by Day 8 to 3.05 (1.1 1 ) and maintained until the end of the study. In cohort 2, hepcidin levels at baseline were 0.20 (0.12) and on the basis of 8 participants, on day 8 hepcidin was elevated to 2.24 (0.83) and by day 22 to 7.70 (2.40). On Day 127, hepcidin levels remained elevated to 5.07 (1.12) and remained elevated until the end of study. Finally, cohort 3 baseline hepcidin was 0.59 (0.51 ), with Day 8 3.80 (1.85). In all cases, hepcidin was elevated after the administration of SLN124. Interestingly, the mean hepcidin baseline was very low in participants who were iron deficient based on serum iron levels (< 8mmol / L) and ferritin (<20ug / L) and within the normal range for participants with normal iron levels, yet in all cases by Day 8, SLN124 had induced hepcidin levels between 6 to 1 1 -fold from baseline (Table 12). Table 12 Mean Hepcidin (nM) (Standard Error of the Mean) for cohorts 1 , 2 and 3 during the phase 1 portion of the study.

[0317] Table 13 Hepcidin (nM) (SEM) for Day 1 and Day 8 in cohorts 1 , 2 and 3 during the phase 1 portion of the study and hepcidin fold change from baseline to Day 8.

[0318] EXAMPLE 6: Effect of SLN124 on Iron and Erythropoiesis Markers (Day 1 to Day 239)

[0319] One of the key features of most PV patients on presentation is their iron deficiency which is exacerbated by repeated phlebotomies. This means that in general, serum iron, TSAT and ferritin are all low. The baseline data for serum iron, TSAT and ferritin confirms that in most cases the participants in the study were iron deficient at baseline with the notable exceptions of one patient in each of cohorts 1 and 2 (Table 14). The consequence of this is that a small effect on serum iron and TSAT were observed as a result of the iron restriction generated by hepcidin presence. In the patients with normal serum iron and TSAT, the effect was more noticeable and consistent with the observations made in the SLN124-003 study in healthy volunteers (Porter et al, 2023). In the case of Ferritin in cohort 3, there was one patient with very high Ferritin levels at baseline (324ug / L) which drives the mean high background. This patient also had normal values for TSAT (32%) and serum iron (16mmol / L). All other patients in the cohort had a range between 2 and 13 ug / L showing the iron deficiency and consistent with expectations.

[0320] Table 14 Mean levels of serum iron, TSAT and Ferritin at baseline for each cohort.

[0321] SLN124 leads to iron retention, which in conjunction with a decrease in phlebotomies, is expected to result in an increase in ferritin levels (a measure of iron stores in the body). Figure 12 shows the mean effect on ferritin after treatment with SLN124. Cohort 3 had a higher baseline than cohorts 1 and 2 due to one patient having a baseline ferritin >300ug / L contributing to the large SEM seen.

[0322] Iron restriction as induced by SLN124 may lead to microcytic red blood cells and lower haemoglobin production. Haemoglobin is reduced in all cohorts (Table 15, Figure 13). The Mean Corpuscular Volume (MCV) was followed to ascertain the effect of SLN124 in RBC morphology (Table 16). Table 17 shows that at baseline in general all cohorts had a similar MCV which decreased in the treatment phase. The effect was similar in the cohorts and importantly shows that iron restriction was having the expected effect. Table 15 Mean Haemoglobin (g / dL) per cohort.

[0323] Table 16 Mean MCV (fL) per cohort Study markers looking at predecessors of red blood cells and red blood cells were investigated. Table 17 depicts the mean reticulocyte counts. In cohort 1 a decrease was seen from baseline to peak effect on Day 127 (a decrease of 19% in counts). In cohort 2, the effect seemed stronger and peaked on Day 211 with a decrease in cell counts of 33%. In cohort 3, despite the limited data, a decrease of 17% was observed by Day 85. Table 17 Mean absolute Reticulocyte counts (10E9 cells / L) after treatment with SLN 124 at 3mg / kg (Cohort 1 ), 6mg / kg (Cohort 2) and 9mg / kg (Cohort 3)

[0324] Although it is known that in PV some patients can have red blood cells with a short life span (Pollycove et al., 1966), a significant effect may take time to be seen given that there will be a large excess of pre-dose red blood cells as compared to post-dose red blood cells. Table 18 shows the mean effects per cohorts.

[0325] Table 18 Mean Red blood cell count

[0326] Finally, a key clinically relevant marker for this study is the effect of SLN124 on haematocrit (Het). Table 19 and Figure 14 shows the mean effect per cohort. Table 19 Mean (SEM) haematocrit (%) per cohort.

[0327] EXAMPLE 7: Study Safety Data Review

[0328] SLN124 is well-tolerated without dose-limiting toxicities. Treatment emergent adverse events (TEAEs) were recorded in 19 / 21 participants. A majority of TEAEs (83%) were grade 1 and there was no treatment related emergent adverse events (TREAEs) > grade 2. Forty-four mild, self-limiting injection site reactions were observed in 14 / 21 participants. No treatment-related serious adverse events or TEAEs led to discontinuation. The available and cumulative nonclinical and clinical data obtained from the completed studies with SLN124, and the ongoing Phase 1 SLN124-004 study is consistent with the known safety profile of SLN124 and the population under study. In addition, the risk and impact relating to administering SLN124 is considered to be low. As a result, the benefit versus risk profile of SLN124 remains positive and therefore, acceptable for the continuation of Phase 2 clinical studies.

[0329] SUMMARY

[0330] The phase 1 portion of the study had enrolled 16 patients at the time of the efficacy data cutoff. The primary efficacy endpoint compared the number of phlebotomies during three periods of the study. The first period had 59 phlebotomies for all patients 6 months prior to Day 1 predose. The second period, based on the current incomplete data set, had 2 phlebotomies between Day 1 post-dose and Day 169 (6 weeks after the last dose) and the third period (Day 169 to Day 239 or EoS visit) had 1 phlebotomy observed after the 4 patients of cohort 1 completed the phase 1 portion of the study. In the follow-up period, the number of phlebotomies was expected to increase as compared to the treatment period. However, in the healthy volunteer study (SLN124-003, Porter et al 2023), hepcidin was elevated by ~2-fold after 8 weeks. Given that in most of the patients in the SANRECO trial had a very low hepcidin baseline (as compared to healthy volunteers) and that the induction levels were not dissimilar in absolute terms, it is possible that the reduction back to baseline may be prolonged in the PV patient population. At least in the Q6W dosing regimen, hepcidin remained elevated in a consistent manner (Figure 2) suggesting that in PV, the effect of SLN124 persists for over 6 weeks. Indeed, data for hepcidin in cohort 1 (only cohort with full hepcidin data available) showed that mean hepcidin remains elevated 3.4-fold above baseline by day 239 (Table 3). When looking individually at subject 10071001 who only received 2 doses of SLN124 (on Days 1 and 43), the effect on hepcidin peaks on day 71 (6.81 nM or 28 days after the last dose received) wains by day 211 to 0.49nM (140 days after the peak or 20 weeks), yet is still 5.5- fold higher than baseline (Table 20). This suggests a long persistent effect on hepcidin. Patient P1403 (Table 20), who only received one dose of SLN124 (Day 1 ), showed an effect peaking on day 22 (7.15 nM) and by Day 127 back to baseline, indicating an effect of SLN124 on hepcidin production from peak to back to baseline of 105 days (15 weeks). These two examples show that hepcidin elevation persisted over a long period of time which also translated to the cohort level.

[0331] Table 20 Patients P1007 and P1403 hepcidin absolute values Day 1 to Day 239 of phase 1.

[0332] Effects on markers were observed which were consistent with iron restriction induced by the increase in hepcidin elicited by SLN124. These included lowering of mean serum iron, mean TSAT, mean haemoglobin, mean MCV and mean Het while increasing mean ferritin. All these effects translated into a reduction of phlebotomies during the treatment period.

[0333] References

[0334] Nemeth, E and Ganz, T, Hepcidin-Ferroportin Interactions Controls Systemic Iron homeostasis. Int J of Mol Sci. 2021 , 22, 6493-7006.

[0335] Pollycove, M; Winchell, HS, Lawrence, JH and Kusubov N. Pattern of Erythropoiesis in Polycythemia Vera as Studies by Iron Kinetics . Blood 1966 https: / / doi.Org / 10.1182 / blood.V28.6.807.807

[0336] Porter JB, Scrimgeour A, Martinez A, James L, Aleku M, Wilson R, Muckenthaler M, Boyce M, Wilkes D, Schaeper II, Campion GV. SLN124, a GalNAc conjugated 19-mer siRNA targeting tmprss6, reduces plasma iron and increases hepcidin levels of healthy volunteers. Am J HematoL 2023;1-11. doi: 10.1002 / ajh.27015.

[0337] STEPS-0238: Barraclough N. SLN124: Preliminary Once Weekly Subcutaneous Administration Study of Embryo-Fetal Development in the Mouse. Labcorp Early Development Laboratories Ltd, Harrogate, UK. January 2024.

[0338] STEPS-0239: Sawyers J. SLN124: 29 Day Subcutaneous Administration Toxicity and Toxicokinetic Study in the Monkey. Labcorp Early Development Laboratories Ltd, Harrogate, UK. March 2024.

[0339] STEPS-0240: Gibson L. SLN124: 39-Week Subcutaneous Toxicity and Toxicokinetic Study in the Cynomolgus Monkey. Labcorp Early Development Laboratories Ltd, Harrogate, UK. March 2024.

[0340] STEPS-0250: Barraclough N. SLN124: Once Weekly Subcutaneous Administration Study of Fertility and Early Embryonic Development in the Mouse. Labcorp Early Development Laboratories Ltd, Harrogate, UK. March 2024.

Claims

Claims1 . SLN124 for use in the prevention, prophylaxis or treatment of polycythaemia vera (PV), wherein said SLN124 is administered to a human subject in need thereof at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight.

2. SLN124 for use in maintaining the haematocrit of a polycythaemia vera (PV) subject at or below a haematocrit threshold level, wherein said SLN124 is administered to a human subject in need thereof at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight.

3. SLN124 for use according to claim 2, wherein the haematocrit threshold level is about 45%.

4. SLN124 for use in reducing the dependency on phlebotomy for a polycythaemia vera (PV) subject, wherein said SLN124 is administered to a human subject in need thereof at an individual dose of from 1 mg / kg to 10mg / kg of subject body weight.

5. SLN124 for use according to claim 4, wherein SLN124 reduces the number of phlebotomies required to maintain the haematocrit of a PV subject at or below a haematocrit threshold level.

6. SLN124 for use according to claim 5, wherein the haematocrit threshold level is 45%.

7. SLN124 for use according to any one of the above claims, wherein the SLN124 is administered to a subject in need thereof at an individual dose of 1 mg / kg, 2 mg / kg, 3 mg / kg, 4 mg / kg, 5 mg / kg, 6 mg / kg, 7 mg / kg, 8 mg / kg or 9 mg / kg of subject body weight.

8. SLN124 for use according to any one of the above claims, wherein an individual dose provides SLN124 to a subject in an amount of 3mg / kg of subject body weight.

9. SLN124 for use according to any one of claims 1 -7, wherein an individual dose provides SLN124 to a subject in an amount of 6mg / kg of subject body weight.

10. SLN124 for use according to any one of claims 1 -7, wherein an individual dose provides SLN124 to a subject in an amount of 9mg / kg of subject body weight.11 . SLN124 for use according to any one of the above claims, wherein an individual dose provides SLN124 in an amount of about SLN124 in an amount of about 100 mg, about 125 mg, about 150 mg, about 175 mg, about 200 mg, about 225 mg, about 250 mg, about 275 mg, about 300 mg, about 325 mg, about 350 mg, about 375 mg, about 400 mg, about 425 mg, about 450 mg, about 475 mg, about 500 mg, about 525 mg, about 550 mg, about 575 mg, about 600 mg, about 625 mg, about 650 mg, about 675 mg, about 700 mg, about 725 mg, ab about 750 g, about 775 mg, about 800 mg,about 825 mg, about 850 mg, about 875 mg, about 900 mg, about 925 mg, about 950 mg, about 975 mg, or about 1 g.

12. SLN124 for use according to claim 11 , wherein an individual dose provides SLN124 in an amount of 150 mg, 200 mg, 250 mg, 300 mg, 350 mg, 400 mg, 450 mg, 500 mg, 550 mg, 600 mg, 650 mg, 700 mg, 750 mg, 800 mg, 850 mg, 900 mg, 950 mg or 1000 mg.

13. SLN124 for use according to claim 12, wherein an individual dose provides SLN124 in an amount of 350 mg, 400 mg, 450 mg, 500 mg, 550 mg, or 600 mg.

14. SLN124 for use according to any one of the above claims, wherein SLN124 is administered to a subject via a dosing regime comprising a plurality or course of doses.

15. SLN124 for use according to claim 14, wherein SLN124 is administered to a subject via a dosing regime of once every 2 weeks, every 3 weeks, every 4 weeks, every 5 weeks, every 6 weeks, every 7 weeks, every 8 weeks, every 9 weeks, every 10 weeks, every 11 weeks or every 12 weeks, or more.

16. SLN124 for use according to claim 14, wherein SLN124 is administered to a PV subject in need thereof about every four to six weeks.

17. SLN124 for use according to claim 14, wherein SLN124 is administered to a PV subject in need thereof about every six weeks.

18. SLN124 for use according to claim 14, wherein SLN124 is administered to a PV subject in need thereof about 1 -monthly, 2-monthly, 3-monthly, or 4-monthly.

19. SLN124 for use according to any one of the preceding claims, wherein the SLN124 is in the form of a sodium salt in water and administered by subcutaneous injection.

20. SLN124 for use according to any one of the preceding claims, wherein the condition is Jak2 positive Polycythaemia vera.

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