Patent Publication Number: US-2023142696-A1

Title: Reconstituted HDL Formulation

Description:
TECHNICAL FIELD 
     The present invention relates to reconstituted high density lipoprotein formulations, and in particular to formulations with suitable stability and biological properties for pharmaceutical use. 
     BACKGROUND ART 
     High-density lipoproteins (HDLs) form a range of lipoprotein particles found in normal serum. Mature HDL particles are present in the form of a globular structure containing proteins and lipids. Within the outer layer of these particles are the more polar lipids, phospholipids and free cholesterol, all having charged groups orientated outwards, towards the aqueous environment. The more hydrophobic lipids, such as esterified cholesterol and triglycerides, reside in the core of the particle. Newly formed or nascent HDL particles lack the lipid and are discoidal in shape. Protein components are embedded in the outer layer. The main protein component is apolipoprotein A-I (Apo A-I) with smaller amounts of Apo A-II, Apo A-IV, Apo CIII, Apo D, Apo E and Apo J. Various other proteins reside on the HDL particle, such as lecithin-cholesterol acetyl transferase, PAF acetylhydrolase and paraoxonase. HDLs are characterized by high density (&gt;1.063 g/ml) and small size (Stoke&#39;s diameter=5 to 17 nm). 
     Efforts have been made to develop artificial HDLs that can be infused into the bloodstream of patients to mimic the biological effects of naturally-occurring HDLs. These artificial particles are generally referred to as “reconstituted HDL” (rHDL), or sometimes as HDL mimetics or synthetic HDL particles. The artificial particles contain components of the natural particles, in particular Apo A-I and lipids. For example, WO 2012/000048 describes rHDL comprising Apo A-I, phosphatidylcholine (PC) and a small amount of sodium cholate. WO 2012/109162 describes rHDL comprising Apo A-I, sphingomyelin (SM) and phosphatidylglycerol (e.g. 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DPPG)). 
     It is convenient for rHDL formulations to be lyophilized (freeze-dried) before use. Lyophilization is a commonly used method for preparing solid protein pharmaceuticals. However, this process generates a variety of freezing and drying stresses, such as concentration of the solubilized protein, formation of ice crystals, pH changes, etc. All of these stresses can denature proteins to various degrees. Thus, stabilizers are often required in a protein formulation to protect protein stability both during freezing and drying processes. In order to maintain the stability of rHDL formulations during lyophilization, stabilizers like sugars and sugar alcohols have been used. For example, U.S. Pat. No. 5,089,602 discloses plasma-derived lipoproteins that are stabilized with 10% sucrose or a mixture of 10% sucrose and 5% mannitol. WO 2012/000048 discloses sugar and sugar alcohol stabilizers used at a concentration from about 65 to 85 g/L of rHDL formulation (equivalent to about 6.5 to 8.5% w/w). WO 2012/109162 discloses sucrose and mannitol as stabilizers, used in a mixture at 4% w/w and 2% w/w respectively. An investigation into the manufacturing and shelf stability of rHDL was carried out in Kim et al, Biotechnology and Bioprocess Engineering 16, 785-792 (2011). Here, rHDL with an Apo A-I:soybean PC ratio of 1:150 could not be sufficiently stabilized with 1 or 5% sucrose, whereas 10% sucrose was described as optimal. 
     The rHDL formulations of these documents are intended for infusion therapy, but high sugar concentrations in infusion products may cause or exacerbate renal problems. This is a particular problem in the target patient population for rHDL, because these patients are often renally impaired. 
     Therefore, an object of the present invention was to provide alternative or improved rHDL formulations compared to these previous formulations. In particular, the inventors sought stable rHDL formulations with reduced renal toxicity. 
     This problem is solved by the formulation according to claim  1 . Further preferred embodiments are defined in the dependent claims. 
     Surprisingly, it has been found that the rHDL formulation of claim  1  shows good long-term stability. By containing less lyophilization stabilizer than previous formulations, the formulation also presents less risk of renal toxicity. The low lyophilization stabilizer concentration may also allow the rHDL to perform better in functional assays of rHDL function. The inventors have also found that amino acids, particularly proline, are useful lyophilization stabilizers for rHDL formulations. 
     SUMMARY OF THE INVENTION 
     The invention provides an rHDL formulation comprising an apolipoprotein, a lipid and a lyophilization stabilizer, wherein the ratio between the apolipoprotein and the lipid is from about 1:20 to about 1:120 (mol:mol). 
     Preferably, the lyophilization stabilizer is present in a concentration from about 1.0% to about 6.0% (w/w of rHDL, formulation), e.g. from 1.0, 1.1, 1.2 or 1.3 to 5.5, 5.6, 5.7, 5.8, 5.9, or 6.0. This low amount of lyophilization stabilizer may reduce the risk of renal toxicity. It is also particularly suitable for patients receiving contrast agents during acute coronary syndrome therapy (ACS), since these agents may compete with lyophilization stabilizer for clearance in the kidneys. In a preferred embodiment, the lyophilization stabilizer is present in a concentration from about 1.0% to less than 6.0% e.g. from about 1.0% to 5.9%. Preferably the lyophilization stabilizer is present in a concentration from about 3.0 to less than 6.0%, e.g. from about 3.0 to 5.9%. More preferably, the lyophilization stabilizer is present in a concentration from about 4.0 to 5.5%, particularly 4.3 to 5.3%, more particularly 4.3 to 5.0%, and most preferably 4.6 to 4.8% (w/w). Such formulations show good stability and low renal toxicity. 
     Alternatively, or in addition, it is preferred for the ratio between the apolipoprotein and the lyophilization stabilizer to be from about 1:1 to about 1:3 (w:w). In particular, the ratio between the apolipoprotein and the lyophilization stabilizer is from about 1:1 to about 1:2.4 (w:w), e.g. less than 1:2 (w:w). The inventors have found that these formulations remain stable showing few or no changes in the size distribution of lyophilized samples, even after storage for several months. However, in some embodiments, the ratio between the apolipoprotein and the lyophilization stabilizer may be less than this, e.g. from about 1:1 to about 1:7, and in particular from about 1:1 to about 1:5 (w:w). 
     The invention also provides an rHDL formulation comprising an apolipoprotein, a lipid and a lyophilization stabilizer, wherein the lyophilization stabilizer comprises an amino acid. Preferably the amino acid is proline. The inventors have found that amino acids are good lyophilization stabilizers for rHDL formulations, particularly when in a mixture with low amounts of other stabilizers. 
     The invention also provides the aforementioned rHDL formulation for preventing or treating a disease, disorder or condition in a human. Suitably, the disease, disorder or condition is responsive to prophylactic or therapeutic administration of the rHDL formulation. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Within the context of the present invention, the term “reconstituted HDL (rHDL) formulation” means any artificially-produced lipoprotein formulation or composition that is functionally similar to, analogous to, corresponds to, or mimics, high density lipoprotein (HDL), typically present in blood plasma. rHDL formulations include within their scope “HDL mimetics” and “synthetic HDL particles”. 
     Within the context of the present invention, the term “lyophilization stabilizer” means a substance that stabilizes protein during lyophilization. Such lyophilization stabilizers are well known in the art and are reviewed in, for example, Wang (2000) International Journal of Pharmaceuticals 203:1-60. A preferred lyophilization stabilizer for use in the invention comprises a sugar, a sugar alcohol, an amino acid, or a mixture thereof. For example, the inventors have found that disaccharides such as sucrose are particularly suitable sugars for use as the lyophilization stabilizer. Other disaccharides that may be used include fructose, trehalose, maltose and lactose. In addition to disaccharides, trisaccharides like raffinose and maltotriose may be used. Larger oligosaccharides may also be suitable, e.g. maltopentaose, maltohexaose and maltoheptaose. Alternatively, monosaccharides like glucose, mannose and galactose may be used. These mono-, di-, tri- and larger oligo-saccharides may be used either alone or in combination with each other. As noted above, lyophilization stabilizers that are sugar alcohols may also be used. These sugar alcohols may also be used either alone or in combination. A particular sugar alcohol for use in the invention is mannitol. Other sugar alcohols that may be used include inositol, xylitol, galactitol, and sorbitol. Other polyols like glycerol may also be suitable. Amino acids that may be used as lyophilization stabilizers include proline, glycine, serine, alanine, and lysine. Modified amino acids may also be used, for example 4-hydroxyproline, L-serine, sodium glutamate, sarcosine, and y-aminobutyric acid. The inventors have found that proline is a particularly suitable amino acid for use as a lyophilization stabilizer. 
     In particular embodiments, the lyophilization stabilizer comprises a mixture of a sugar and a sugar alcohol. For example, a mixture of sucrose and mannitol may be used. The sugar and the sugar alcohol may be mixed in any suitable ratio, e.g. from about 1:1 (w:w) to about 3:1 (w:w), and in particular about 2:1 (w:w). Ratios less than 2:1 are particularly envisaged, e.g. less than 3:2. Typically, the ratio is greater than 1:5, e.g. greater than 1:2 (w:w). In some embodiments the formulation comprises less than 4% sucrose and 2% mannitol (w/w of rHDL formulation), for example 3% sucrose and 2% mannitol. In some embodiments the formulation comprises 4% sucrose and less than 2% mannitol. In some embodiments the formulation comprises less than 4% sucrose and less than 2% mannitol e.g. about 1.0% to 3.9% sucrose and about 1.0% to 1.9% (w/w) mannitol. 
     In particular embodiments, the lyophilization stabilizer comprises a mixture of a sugar and an amino acid. For example, a mixture of sucrose and proline may be used. The sugar and the amino acid may be mixed in any suitable ratio, e.g. from about 1:1 to about 3:1 (w:w), and in particular about 2:1 (w:w). Ratios less than 2:1 are particularly envisaged, e.g. less than 3:2 (w:w). Typically, the ratio is greater than 1:5, e.g. greater than 1:2 (w:w). Preferably the amino acid is present in a concentration of from about 1.0 to about 2.5% e.g. from 1.0, 1.2, or 1.3 to 2.0, 2.1, 2.2, 2.3, 2.4, or 2.5% (w/w of rHDL formulation). In some embodiments the formulation comprises 1.0% sucrose and 2.2% proline, or 3.0% sucrose and 1.5% proline, or 4% sucrose and 1.2% proline. The amino acid may be added to the sugar to maintain an isotonic solution. Solutions with an osmolality of greater than 350 mosmol/kg are typically hypertonic, while those of less than 250 mosmol/kg are typically hypotonic. Solutions with an osmolality of from 250 mosmol/kg to 350 mosmol/kg are typically isotonic. 
     In particular embodiments, the lyophilization stabilizer comprises a mixture of a sugar alcohol and an amino acid. The lyophilization stabilizer may comprise a mixture of a sugar, a sugar alcohol, and an amino acid. 
     The apolipoprotein may be any apolipoprotein which is a functional, biologically active component of naturally-occurring HDL or of a reconstituted high density lipoprotein/rHDL. Typically, the apolipoprotein is either a plasma-derived or recombinant apolipoprotein such as Apo A-I, Apo A-II, Apo A-V, pro-Apo A-I or a variant such as Apo A-I Milano. Preferably, the apolipoprotein is Apo A-I. More preferably the Apo A-I is either recombinantly derived comprising a wild type sequence or the Milano sequence or alternatively it is purified from human plasma. The apolipoprotein may be in the form of a biologically-active fragment of apolipoprotein. Such fragments may be naturally-occurring, chemically synthetized or recombinant. By way of example only, a biologically-active fragment of Apo A-I preferably has at least 50%, 60%, 70%, 80%, 90% or 95% to 100% or even greater than 100% of the lecithin-cholesterol acyltransferase (LCAT) stimulatory activity of Apo A-I. 
     In the present invention the molar ratio of apolipoprotein:lipid is typically from about 1:20 to about 1:120, and preferably from about 1:20 to about 1:100, more preferably from about 1:20 to about 1:75 (mol:mol), and in particular from 1:45 to 1:65. This range includes molar ratios such as about 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, 1:55, 1:60, 1:65, 1:70, 1:75, 1:80, 1:85, 1:90, 1:95 and 1:100. A particularly advantageous ratio of apolipoprotein:lipid is from 1:40 to 1:65 (mol:mol). This ensures that the rHDL formulation according to the present invention comprises a lipid at a level which does not cause liver toxicity. 
     In other embodiments, the molar ratio of apolipoprotein:lipid may be in a range from about 1:80 to about 1:120. For example, the ratio may be from 1:100 to 1:115, or from 1:105 to 1:110. In these embodiments, the molar ratio may be for example from 1:80 to 1:90, from 1:90 to 1:100, or from 1:100 to 1:110. In a preferred embodiment the rHDL formulation according to the present invention comprises additionally a detergent in order to further stabilize the rHDL particles. The detergent may be any ionic (e.g. cationic, anionic, zwitterionic) detergent or non-ionic detergent, inclusive of bile acids and salts thereof, suitable for use in rHDL formulations. Ionic detergents may include bile acids and salts thereof, polysorbates (e.g. PS80), 3-[(3-Cholamidopropyl)dimethylammonio]-1-propane-sulfonate-(CHAPS), 3-[(3-Cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonate (CHAPSO), cetyl trimethyl-ammonium bromide, lauroylsarcosine, tert-octyl phenyl propanesulfonic acid and 4′-amino-7-benzamido-taurocholic acid. 
     Bile acids are typically dihydroxylated or trihydroxylated steroids with 24 carbons, including cholic acid, deoxycholic acid, chenodeoxycholic acid or ursodeoxycholic acid. Preferably, the detergent is a bile salt such as a cholate, deoxycholate, chenodeoxycholate or ursodeoxycholate salt. A particularly preferred detergent is sodium cholate. The concentration of the detergent, in particular of sodium cholate, is preferably 0.3 to 1.5 mg/mL. The bile acid concentration can be determined using various methods including colorimetric assay (for example, see Lerch et. al., 1996, Vox Sang. 71:155-164; Sharma, 2012, Int. J. Pharm Biomed. 3(2), 28-34; &amp; Gallsäuren test kit and Gallsauren-Stoppreagens (Trinity Biotech)). In some embodiments of the invention the rHDL formulation comprises cholate levels of 0.5 to 1.5 mg/ml, as determined by colorimetric assay and a lyophilization stabilizer in a concentration from about 4.0 to 5.5%, particularly 4.3 to 5.3%, more particularly 4.3 to 5.0%, and most preferably 4.6 to 4.8% (w/w). In particular embodiments the lyophilization stabilizer is sucrose. Such formulations show good stability and low renal and liver toxicity. 
     The ratio between the apolipoprotein and the lyophilization stabilizer is usually adjusted so this ratio is from about 1:1 to about 1:7 (w:w). More preferably, the ratio is from about 1:1 to about 1:3, in particular about 1:1.1 to about 1:2. In specific embodiments the rHDL formulations thus have ratios of 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2 (w:w). It is however contemplated that for particular embodiments where there are low amounts of protein (e.g. &lt;20mg/mL) that the ratio between the apolipoprotein and the lyophilization stabilizer can be extended to as much as about 1:7 (w:w), e.g. about 1:4.5 (w:w). 
     Suitably, the apolipoprotein is at a concentration from about 5 to about 50 mg/ml. This includes 5, 8, 10, 15, 20, 25, 30, 35, 40, 45 and 50 mg/ml and any ranges between these amounts. The apolipoprotein is, preferably, at a concentration from about 25 to 45 mg/ml. In other embodiments, the apolipoprotein may be at a concentration of from about 5 to 20 mg/ml, e.g. about 8 to 12 mg/ml. 
     The lipid may be any lipid which is a functional, biologically active component of naturally occurring HDL or of reconstituted high density lipoprotein (rHDL). Such lipids include phospholipids, cholesterol, cholesterol-esters, fatty acids and/or triglycerides. Preferably, the lipid is at least one charged or non-charged phospholipid or a mixture thereof. 
     In a preferred embodiment the rHDL formulation according to the present invention comprises a combination of a detergent and a non-charged phospholipid. In an alternative preferred embodiment the rHDL formulation comprises a charged phospholipid but no detergent at all. In a further preferred embodiment the rHDL formulation comprises charged and non-charged lipids as well as a detergent. 
     As used herein, “non-charged phospholipids”, also called neutral phospholipids, are phospholipids that have a net charge of about zero at physiological pH. Non-charged phospholipids may be zwitterions, although other types of net neutral phospholipids are known and may be used. “Charged phospholipids” are phospholipids that have a net charge at physiological pH. The charged phospholipid may comprise a single type of charged phospholipid, or a mixture of two or more different, typically like-charged phospholipids. In some examples, the charged phospholipids are negatively charged glycophospholipids. 
     The formulation according to the present invention may also comprise a mixture of different lipids, such as a mixture of several non-charged lipids or of a non-charged lipid and a charged lipid. Examples of phospholipids include phosphatidylcholine (lecithin), phosphatidic acid, phosphatidylethanolamine (cephalin), phosphatidylglycerol (PG), phosphatidylserine (PS), phosphatidylinositol (PI) and sphinogomyelin (SM) or natural or synthetic derivatives thereof. Natural derivatives include egg phosphatidylcholine, egg phosphatidylglycerol, soy bean phosphatidylcholine, hydrogenated soy bean phosphatidylcholine, soy bean phosphatidylglycerol, brain phosphatidylserine, sphingolipids, brain sphingomyelin, egg sphingomyelin, galactocerebroside, gangliosides, cerebrosides, cephalin, cardiolipin and dicetylphospate. Synthetic derivatives include dipalmitoylphosphatidylcholine (DPPC), didecanoyl-phosphatidylcholine (DDPC), dierucoylphosphatidylcholine (DEPC), dimyristoylphosphatidylcholine (DLPC), palmitoyl-oleoylphosphatidylcholine (PMPC), palmitoylstearoyl-phosphatidylcholine (PSPC), dioleoylphosphatidyl-ethanolamine (DOPE), dilauroylphosphatidylglycerol (DLPG), distearoylphosphatidylglycerol (DSPG), dioleoyl-phosphatidylglycerol (DOPG), palmitoyloleoylphosphatidyl-glycerol (POPG), dimyrstolyphosphatidic acid (DMPA), dipalmitoylphosphatidic acid (DPPA), distearoyl-phosphatidic acid (DSPA), dipalmitoylphosphatidylserine (DPPS), distearoylphosphatidylethanolamine (DSPE), di-oleoylphosphatidylethanolamine (DOPE), dioleoyl-phosphatidylserine (DOPS), dipalmitoylsphingomyelin (DPSM) and distearoylsphingomyelin (DSSM). The phospholipid can also be a derivative or analogue of any of the above phospholipids. Best results could be obtained with phosphatidylcholine. In another embodiment the lipids in the formulation according to the present invention are sphingomyelin and a negatively charged phospholipid, such as phosphatidylglycerol (e.g. DPPG). A mixture of sphingomyelin and phosphatidylglycerol (particularly DPPG) is specifically envisaged for use in the invention. In these embodiments, the sphingomyelin and the phosphatidylglycerol may be present in any suitable ratio, e.g. from 90:10 to 99:1 (w:w), typically 95:5 to 98:2 and most typically 97:3. 
     The formulation according to the present invention typically has a lyophilization stabilizer concentration from about 1.0% to about 6.0% e.g. from 1.0, 1.1, 1.2 or 1.3% to 5.5, 5.6, 5.7, 5.8, 5.9, or 6.0%, preferably from about 1.0% to less than 6.0%, e.g. from about 1.0% to 5.9% (w/w of rHDL formulation). Preferably from about 3.0% to less than 6.0%, e.g. from about 3.0% to 5.9%, preferably from about 4.0 to 5.9%, preferably, from about 4.0% to 5.5%, preferably 4.3 to 5.3%, preferably 4.3 to 5.0%, and most preferably from 4.6 to 4.8% (w/w) and in said formulation the ratio between the apolipoprotein and the lipid is preferably from about 1:20 to about 1:75, more preferably from about 1:45 to about 1:65 (mol:mol). The lyophilization stabilizer is preferably a sugar (e.g. sucrose), optionally in combination with a sugar alcohol such as mannitol or sorbitol, or an amino acid such as proline. 
     In a preferred embodiment, the rHDL formulation according to the present invention has a pH in the range of 6 to 8, preferably within the range of 7 to 8. Even more preferably the pH is in the range of 7.3 to 7.7. 
     In a preferred embodiment of the present invention, the formulation is lyophilized. Due to the presence of lyophilization stabilizer, preferably of sucrose, sucrose and mannitol, or sucrose and proline, in combination with the apolipoprotein:lipid ratio, the lyophilisation yields in a stable powder having a long shelf life. This powder may be stored, used directly or after storage as a powder or used after rehydration to form the reconstituted high density lipoprotein formulation. 
     The invention may be used for large scale production of reconstituted high density lipoprotein. The lyophilized product may be prepared for bulk preparations, or alternatively, the mixed protein/lipid solution may be apportioned in smaller containers (for example, single dose units) prior to lyophilization, and such smaller units may be used as sterile unit dosage forms. The lyophilized formulation can be reconstituted in order to obtain a solution or suspension of the protein-lipid complex, that is the reconstituted high density lipoprotein. The lyophilized powder is rehydrated with an aqueous solution to a suitable volume. Preferred aqueous solutions are water for injection (WFI), phosphate-buffer saline or a physiological saline solution. The mixture can be agitated to facilitate rehydration. Preferably, the reconstitution step is conducted at room temperature. 
     It is well known to the person skilled in the art how to obtain a solution comprising the lipid, and the apolipoprotein, such as described in WO 2012/000048. 
     In one preferred embodiment, the invention provides a method of producing a rHDL formulation including the step of adding the lyophilization stabilizer to the solution comprising the lipid, and the apolipoprotein until a concentration of from about 1.0% to about 6.0% (w/w of rHDL formulation) is reached, e.g. from 1.0, 1.1, 1.2 or 1.3 to 5.5, 5.6, 5.7, 5.8, 5.9, or 6.0. In a preferred embodiment, the lyophilization stabilizer is added until a concentration from about 1.0% to less than 6.0% e.g. from about 1.0% to 5.9% is reached. Preferably lyophilization stabilizer is added until a concentration from about 3.0 to less than 6.0%, e.g. from about 3.0 to 5.9% is reached. More preferably the lyophilization stabilizer is added until a concentration from about 4.0 to 5.5%, particularly 4.3 to 5.3%, more particularly 4.3 to 5.0%, and most preferably 4.6 to 4.8% (w/w) is reached. The solution may already contain stabilizer. 
     In preferred embodiments the solution additionally includes a detergent such as sodium cholate. In a preferred embodiment the rHDL formulation is manufactured by combining Apo A-I purified from plasma, with phosphatidylcholine (PC) in the presence of sodium cholate and sucrose at a concentration from about 1.0% to about 6.0%, preferably from about 1.0% to less than 6.0% w/w to produce disc shaped, non-covalently associated particles (MW approximately 144 kDa). 
     In particular embodiments the rHDL formulation is comprised of an Apo A-I (recombinant or purified from plasma) and phoshatidylcholine stabilized by cholate and sucrose at a concentration from about 1.0% to about 6.0% w/w, preferably from about 1.0% to less than 6.0%. In particular embodiments the cholate levels are from about 0.5 to about 1.5 mg/mL. Preferably the recombinant Apo A-I comprises either a wild type sequence or the Milano sequence (which when expressed forms dimers). 
     The lyophilized rHDL formulation of the present invention may be formed using any method of lyophilization known in the art, including, but not limited to, freeze drying, i.e. the apolipoprotein/lipid-containing solution is subjected to freezing followed by reduced pressure evaporation. 
     The lyophilized rHDL formulations that are provided can retain substantially their original stability characteristics for at least 2, 4, 6, 8, 10, 12, 18, 24, 36 or more months. For example, lyophilized rHDL formulations stored at 2-8° C. or 25 ° C. can typically retain substantially the same molecular size distribution as measured by HPLC-SEC when stored for 6 months or longer. Particular embodiments of the rHDL formulation can be stable and suitable for commercial pharmaceutical use for at least 6 months, 12 months, 18 months, 24 months, 36 months or even longer when stored at 2-8° C. and/or room temperature. 
     The rHDL formulation according to the present invention may be used in preventing or treating a disease, disorder or condition in a human. Suitably, the disease, disorder or condition is responsive to prophylactic or therapeutic administration of the rHDL formulation according to the present invention. Examples of such diseases, disorders or conditions include atherosclerosis; cardiovascular disease (e.g. acute coronary syndrome (ACS) such as angina pectoris and myocardial infarction); or diseases, disorders or conditions such as diabetes that predispose to ACS; hypercholesterolaemia (e.g. elevated serum cholesterol or elevated LDL cholesterol) and hypocholesterolaemia resulting from reduced levels of high-density lipoprotein (HDL), such as being symptomatic of Tangier disease. 
     rHDL formulations according to the present invention may be administered by any route of administration known in the art. Preferably, rHDL formulations are administered parenterally, such as by intravenous (IV) infusion or injection. In preferred embodiments the rHDL formulation comprises Apo A-I (recombinant or purified from plasma) which has been reconstituted to form particles suitable for IV infusion. 
     The administered dosage of the rHDL formulation may be in the range of from about 1 to about 120 mg/kg body weight. Preferably, the dosage is in the range of from about 5 to about 80 mg/kg inclusive of 8 mg/kg, 10 mg/kg, 12 mg/kg, 20 mg/kg, 30 mg/kg, 40 mg/kg, 50 mg/kg, 60 mg/kg, and 70 mg/kg dosages. Alternatively delivery can be achieved by fixed dosages of rHDL, that is, in an amount independent of patient body weight. Preferred fixed dosages include 0.1-15 g, 0.5-12 g, 1-10 g, 2-9 g, 3-8 g, 4-7 g or 5-6 g of apolipoprotein. Particularly preferred fixed dosages include 1-2 g, 3-4 g, 5-6 g or 6-7 g of apolipoprotein. Non-limiting examples of specific fixed dosages include 0.25 g, 0.5 g, 1.0 g, 1.7 g, 2.0 g, 3.4 g, 4.0 g, 5.1 g, 6.0 g, 6.8 g and 8.0 g of apolipoprotein. Accordingly, a vial preferably comprises the lyophilized rHDL formulation with a protein content of 0.25 g, 0.5 g, 1, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8 or 10 g per vial. More preferably the protein content is either 0.5, 1, 2, 4, 6, 8, or 10 g per vial. 
     The invention also provides an apolipoprotein kit comprising one or more unit doses of the apolipoprotein formulation disclosed herein and one or more other kit components. 
     Suitably, the kit is for prophylactically or therapeutically treating a disease, disorder or condition in a human, as hereinbefore described. 
     Non-limiting examples of one or more other kit components include instructions for use; vials, containers or other storage vessels containing each of the unit doses; delivery devices such as needles, catheters, syringes, tubing and the like; and/or packaging suitable for safely and conveniently storing and/or transporting the kit. Preferably the instructions for use are a label or package insert, wherein the label or package insert indicates that the apolipoprotein formulation may be used to treat a disease or condition such as cardiovascular disease by administering a fixed dose amount to a human subject in need thereof. 
     A ‘package insert’ refers to instructions included in commercial packages of the apolipoprotein formulations, that contains information about the indications, usage, dosage, administration, contraindications and/or warnings concerning the use of such apolipoprotein formations. 
     For the purposes herein, a ‘vial’ refers to a container which holds an apolipoprotein formulation. The vial may be sealed by a stopper pierceable by a syringe. Generally, the vial is formed from a glass material. The apolipoprotein formulation in the vial can be in various states including liquid, lyophilized, frozen etc. The fixed dosage apolipoprotein formulation is preferably stable as turbidity is a preferred measure. A turbidity level of below about 5, 10, 15, 20, or 30 NTU can generally be considered a stable dosage apolipoprotein formulation. Turbidity measurements can be taken by incubating the apolipoprotein formulations over time periods such as 0 hr, 2 hr, 4hr, 6 hr, 12 hr, 18 hr, 24 hr, 36 hr, 72 hr, 7 days and 14 days at storage temperatures such as room temperature or 2 to 8° C. 
     Preferably the apolipoprotein formulation is considered to be stable as a liquid when it is stored for 14 days at room temperature and exhibits a turbidity of less than about 15 NTU. 
     The kit may facilitate administration of the apolipoprotein formulation by a health professional or self-administration by a patient or caregiver. 
     As used herein, the term “comprising” encompasses “including” as well as “consisting” e.g. a formulation or to a component of a formulation that is described as “comprising” X may consist exclusively of X or may include something additional e.g. X+Y. 
     The term “about” in relation to a numerical value x means, for example, x+10%. 
     The word “substantially” does not exclude “completely” e.g. a composition which is “substantially free” from Y may be completely free from Y. Where necessary, the word “substantially” may be omitted from the definition of the invention. 
     Where the invention provides a process involving multiple sequential steps, the invention can also provide a process involving less than the total number of steps. The different steps can be performed at very different times by different people in different places (e.g. in different countries). 
     Unless specifically stated, a process comprising a step of mixing two or more components does not require any specific order of mixing. Thus components can be mixed in any order. Where there are three components then two components can be combined with each other, and then the combination may be combined with the third component, etc. 
     Various embodiments of the invention are described herein. It will be appreciated that the features specified in each embodiment may be combined with other specified features, to provide further embodiments. In particular, embodiments highlighted herein as being suitable, typical or preferred may be combined with each other (except when they are mutually exclusive). 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS: 
         FIG.  1   : Molecular size distribution of formulations containing 5 to 10% w/w sucrose. 
         FIG.  2 A : Direct comparison of molecular size distribution of formulations containing 4 and 7.5% w/w sucrose. 
         FIG.  2 B : Molecular size distribution of formulations containing 1, 2, 3, 4 and 7.5% (w/w) sucrose. 
         FIG.  2 C : Molecular size distribution of formulations containing sucrose and proline and 7.5% sucrose. 
         FIGS.  3 A and  3 B : LCAT activity for 4 to 10% w/w sucrose formulations. 
         FIG.  3 C : LCAT activity for 1, 2, 3, 4 and 7.5% w/w sucrose formulations. 
         FIG.  3 D : LCAT activity for formulations containing sucrose and proline. 
         FIG.  4 A to  4 B : Impact of sucrose concentration on cholesterol efflux. 
         FIG.  4 C : Impact of formulations containing sucrose and proline on cholesterol efflux. 
         FIGS.  5 A to  5 H : Turbidity of formulations with different sucrose concentrations and formulations containing sucrose and proline. 
         FIG.  6   : Picture of lyo cakes with different sucrose concentration. 
         FIG.  7   : Picture of lyo cakes with different sucrose concentrations and sucrose and proline. 
     
    
    
     EXAMPLES 
     Example 1 
     Preparation of the Samples 
     To make the samples for the following experiments, sodium cholate (New Zealand Pharmaceuticals) was dissolved in buffer (10 mM NaCl, 1 mM EDTA, 10 mM TRIS, pH 8.0) and stirred until clear. Soybean phosphatidylcholine (Phospholipid GmbH) was added to an appropriate volume of the cholate and stirred for 16 h at room temperature. The Apo A-I solution was diluted to a protein concentration of 9.0 mg/mL (determined by OD280) with 10 mM NaCl and mixed with an appropriate volume of the lipid solution to obtain protein to lipid ratio in the range of 1:45 to 1:65. The mixture was stirred at 2-8° C. for 30 min to 16 h. The HDL mimetics were prepared by cholate dialysis using 1% as a diafiltration buffer. The eluate was concentrated to a protein concentration of 33 to 38 g protein /L. Sucrose was added to obtain the desired concentration (1%, 2%, 3%, 4%, 5%, 6.5%, 7%, 10% w/w). The pH of the solution was adjusted, with 0.2 M NaOH to pH 7.50 ±0.1 after which WFI (water for injection) was added to obtain a protein concentration of 30 mg/mL. The final formulations were then sterile filtered through a 0.2+0.1 μm filter and filled into 100 mL glass vials at 1.7 g protein per vial and lyophilized. 
     In some formulations proline was added to the desired concentration. Proline maintains an isotonic formulation. 
     Example 2 
     Molecular Size Distribution 
     Particle formation was determined using HPLC-SEC and assessed by the molecular size distribution of the various formulations. Size exclusion chromatography (HPLC-SEC) was performed on a Superose 6 HR 10/30 column (GE Healthcare) with 140 mmol/1 NaCl, 10 mmol/1 Na-phosphate, 0.02% NaN3, pH7.4, with a flow rate of 0.5 ml/min. Samples of about 90  ug  protein were applied, and elution profiles were recorded at 280 nm. 
     Little difference was observed for formulations containing 5-10% w/w sucrose in the final formulation ( FIG.  1   ), indicating that formulations containing % 5% w/w sucrose did not affect particle stability after reconstitution.  FIG.  1    shows a complete chromatogram of (1) internal control, 2: 5% w/w sucrose, 3: 6.5% w/w sucrose, 4: 7.5% w/w sucrose and 5: 10% w/w sucrose. 
     In addition a direct comparison between a 7.5% w/w sucrose formulation and 4% w/w sucrose formulation demonstrated that these formulations exhibit a similar molecular size distribution ( FIG.  2 A ). 
       FIGS.  2 B and  2 C  show the results for sucrose concentrations 1, 2, 3, and 4% (w/w) and formulations comprising sucrose and proline. 
     All tested formulations are stable. The sucrose content of 4 to 7.5% w/w was optimum and did not affect the particle to stability after reconstitution. 
     Example 3 
     LCAT Activation 
     A measure of the effectiveness of the rHDL particles in various formulations was determined by measuring the LCAT activity. HDL particles are capable of sequestering cholesterol from plaques formed along artery walls or cells by interaction with the ATP-binding cassette transporter Al (ABCA1). Lecithin-cholesterol acyltransferase (LCAT), a plasma enzyme converts the free cholesterol into cholesteryl ester (a more hydrophobic form of cholesterol), which is then sequestered into the core of the HDL particle before being transported to the liver to be metabolized. If the sucrose content in the final formulation affected the efficacy of the rHDL particle, LCAT activity would decrease. 
     The lecithin-cholesterol acyltransferase (LCAT) activity esterification was assayed as described by Stokke and Norum (Scand J Clin Lab Invest. 1971; 27(1):21-7). 150 μl pooled human plasma (CSL Behring) was incubated with 10 μl rHDL sample and 150 μl PBS in the presence of 20 μl [4-14C]cholesterol (7.5 μCi/ml) for 1.5 h at 4° C. To initiate the esterification of cholesterol, half of the reaction mixture was placed at 37° C. for 30 min while the other half was further incubated at 4° C. for 30 min (to determine background noise). For both samples the cholesterol and cholesteryl ester is extraction by liquid liquid extraction with n-hexane. The cholesteryl ester was separated from unesterified cholesterol using a solid phase extraction column (SampliQ Amino, Agilent) and measured by scintillation counting. The count rate of the sample stored at 4° C. is subtracted from the count rate of the sample stored at 37° C. The same procedure is also performed with a reference sample. The LCAT activity is is expressed as % of the Reference sample. 
       FIGS.  3 A and  3 B  show LCAT activity for 4-10% w/w sucrose formulations.  FIG.  3 C  shows LCAT activity for 1-4% w/w sucrose formulations. Very little difference is seen in LCAT activity when the sucrose ranges from 5-10% w/w in the final formulation ( FIG.  3 A ), however a slight decreasing trend is evident when the sucrose is further reduced to 4% w/w ( FIG.  3 B ).  FIG.  3 D  shows LCAT activity for formulations comprising sucrose and proline. No apparent trend in LCAT activity is observed for formulations containing sucrose and proline. Thus the efficacy of the HDL particle in sucrose/proline formulations is maintained. 
     Example 4 
     Cholesterol Efflux 
     Reverse cholesterol transport (ROT) is a pathway by which accumulated cholesterol is transported from the vessel wall to the liver for excretion. Cells efflux free cholesterol to lipid-poor Apo A-I via the ABCA1 pathway. The cholesterol efflux assay measures the capacity of HDL to accept cholesterol released from cells. It is anticipated that if sucrose content affected particle formation and/or integrity, differences would affect cholesterol efflux. 
     Cholesterol efflux from murine macrophage cell lines J774 and RAW 264.7 is highly responsive to cAMP stimulation, which leads to the up-regulation of ABCA1 (Bortnick et. al.,.  J Biol Chem.  2000; 275(37):28634-40). RAW264.7 cells were obtained from the American Type Culture Collection (ATCC). Cells were cultured in DMEM (Dulbecco&#39;s modified Eagle&#39;s medium, Gibco) supplemented with 10% (v/v) foetal calf serum (FCS, Gibco), 2 mM glutamine, 100 units/mL penicillin and 100 μg/mL streptomycin in a humidified CO 2  incubator at 37°. For efflux experiments, cells were seeded into 24-well plates at a density of 0.35×10 6  cells per well. The following day, cells were labeled with [1,2- 3 H]cholesterol (1 μCi/mL, GE) in DMEM supplemented with 5% (v/v) FCS. After a labelling period of 36 h, cells were washed with phosphate buffered saline (PBS) and then incubated in DMEM containing 0.2% fatty-acid-free bovine serum albumin (BSA) in the absence or presence of 0.3 mM 8-bromoadenosine 3′,5′-cyclic monophosphate sodium salt-cAMP (8Br-cAMP) for 16 h to up-regulate ABCA1. Following two washes with PBS, cells were incubated with different cholesterol acceptors in DMEM/ 0.2% fatty-acid-free BSA medium. After 5-6 h of incubation, plates were centrifuged at 500 g for 10 minutes to remove any floating cells and cellular debris. Radioactivity in cell supernatants was measured by liquid scintillation counting. Total cell-associated [ 3 H]cholesterol was determined after extraction of cells in control wells for at least 30 minutes with 0.1 M Triton X-100. Cholesterol efflux was expressed as the percentage of the radioactivity released from cells into the medium relative to the total radioactivity in cells and medium. The difference in efflux between control and 8Br-cAMP-stimulated cells was taken as a measure of ABCA1-dependent efflux. 
       FIGS.  4 A and  4 B  show that as sucrose concentration decreases from 7.5% w/w to 4% w/w the cholesterol efflux increased. No apparent difference in cholesterol efflux was observed between the proline containing formulations and the 7.5% sucrose formulation ( FIG.  4 C ). 
     Example 5 
     Turbidity 
     The term turbidity is used to describe the cloudiness or haze in a solution. Strictly, turbidity arises from the multiple scattering events of visible light by elements present in the solution. Since turbidity arises from the net scattered light, it depends on the sample path length, protein concentration and size of the protein/aggregates/particles. Given that all reduced sucrose formulations contained the same protein concentration upon reconstitution and were measured with the same path length, differences in turbidity can be attributed to differences in the size and/or number of protein/aggregates/particles resulting from the various sucrose formulations. 
     Turbidity was determined with a LED nephelometer (Hach 2100AN Turbiditimeter, Loveland, Colo.) using formacin as a standard. Results are given as relative light scattering (NTU). 
     Formulations containing 4-10% w/w sucrose produced similar turbid solutions upon reconstitution ( FIGS.  5 A &amp;  5 B ). Sucrose concentrations of less than 4% showed increased turbidity ( FIGS.  5 E and  5 G ). Based on turbidity, sucrose concentrations of 4% (w/w) and above are optimum. 
     Relative increases in the turbidity of a solution upon is storage, is often cited as an indication of aggregation in protein biopharmaceuticals.  FIGS.  5 C,  5 D,  5 F and  5 H  show that little to no increase in turbidity are seen upon storage in liquid form, thereby indicating stability of the particles. 
     Example 6 
     Lyo Cake Appearance 
     Sucrose formulations with 4% w/w and 7.5% w/w sucrose produced the most stable lyo cakes ( FIG.  6   ). 
     Sucrose formulations with 1 to 4% w/w, and formulations containing sucrose and proline, also produced stable lyo cakes ( FIG.  7   ). 
     Example 7 
     Stability of rHDL Formulations 
     The stability of lyophilized rHDL formulations (prepared as per Example 1) was examined before and after storage (protected from light) at 40 C for 12 weeks. Parameters s tested included pH, turbidity, LCAT activation, HPLC-SEC (aggregate content, % lipoprotein in single peak and its relative retention time) and cholesterol efflux (C-efflux) (Tables 1 &amp; 2). The results indicate that the formulations remain stable over the storage period. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                 t = 0 
                 t = 12 weeks 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1385.E009.09- 
                 1% 
                 2% 
                 3% 
                 4% 
                 7.5% 
                 1% 
                 2% 
                 3% 
                 4% 
                 7.5% 
               
               
                 13/40° C. 
                 sucrose 
                 sucrose 
                 sucrose 
                 sucrose 
                 sucrose 
                 sucrose 
                 sucrose 
                 sucrose 
                 sucrose 
                 sucrose 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Turbidity 
                 12.4 
                 10.4 
                 8.63 
                 6.87 
                 6.06 
                 13.7 
                 11.1 
                 7.24 
                 5.41 
                 5.16 
               
               
                 LCAT- 
                 97 
                 102 
                 104 
                 110 
                 111 
                 94 
                 101 
                 100 
                 98 
                 105 
               
               
                 activation 
               
               
                 HPLC - SEC- 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
               
               
                 Aggregates 
               
               
                 HPLC-SEC - 
                 98.8 
                 99.2 
                 99.5 
                 99.6 
                 99.6 
                 99.3 
                 99.7 
                 99.6 
                 99.6 
                 99.6 
               
               
                 Lipoprotein 
               
               
                 peak 
               
               
                 C-efflux (total 
                 110 
                 95 
                 103 
                 119 
                 102 
                 109 
                 85 
                 114 
                 116 
                 84 
               
               
                 efflux) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
             
               
                   
                 TABLE 2 
               
             
            
               
                   
                   
               
               
                   
                 t = 0 
                 t = 12 weeks 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 1385.E009.14- 
                 1% sucrose/ 
                 3% sucrose/ 
                 4% sucrose/ 
                 1% sucrose/ 
                 3% sucrose/ 
                 4% sucrose/ 
               
               
                 16/40° C. 
                 2.2% proline 
                 1.5% proline 
                 1.2% proline 
                 2.2% proline 
                 1.5% proline 
                 1.2% proline 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Turbidity 
                 8.20 
                 8.48 
                 7.48 
                 8.74 
                 6.14 
                 6.12 
               
               
                 LCAT-activation 
                 104 
                 116 
                 109 
                 95 
                 103 
                 99 
               
               
                 HPLC - SEC 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
                 &lt;0.2 
               
               
                 Aggregates 
               
               
                 HPLC-SEC 
                 98.6 
                 99.4 
                 99.5 
                 99.2 
                 99.5 
                 99.7 
               
               
                 Lipoprotein peak 
               
               
                 C-efflux (total 
                 114 
                 80 
                 97 
                 120 
                 108 
                 99 
               
               
                 efflux)