Compositions and methods for increasing muscle growth

Abstract

This disclosure is in the field of anti-Activin receptor IIB (ActRIIB) antibodies. In particular, it relates to the use of said antibodies for treating muscle disorders, such as muscle wasting due to disease or disuse.

1 . An anti-ActRIIB antibody or functional fragment thereof that binds to ActRIIB between amino acids 19-134 of SEQ ID NO: 181. 
     
     
         2 . The anti-ActRIIB antibody or functional fragment thereof according to  claim 1 , which binds to ActRIIB with a K D  of 1 nM or less. 
     
     
         3 . The anti-ActRIIB antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof inhibits myostatin binding to ActRIIB. 
     
     
         4 . The anti-ActRIIB antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof inhibits myostatin induced signalling as measured by a Smad dependent reporter gene assay. 
     
     
         5 . The anti-ActRIIB antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof binds to ActRIIB with a 10-fold or greater affinity than it binds to ActRIIA. 
     
     
         6 . The antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof comprises at least one complementarity determining region having at least 95% identity to at least one of the CDRs recited in SEQ ID NOs: 9, 18-28, 37, 51, 65, 71-75 or 79. 
     
     
         7 . The antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof comprises at least one complementarity determining region having at least 95% identity to CDR3 recited in SEQ ID NOs: 37. 
     
     
         8 . The antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof comprises a VH polypeptide sequence having at least 95% sequence identity to at least one of the sequences of SEQ ID NOs: 99-112. 
     
     
         9 . The antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof comprises a VL polypeptide sequence having at least 95% sequence identity to at least one of the sequences of SEQ ID NOs: 85-98. 
     
     
         10 . The antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof comprises a VH polypeptide sequence having at least 95% sequence identity to at least one of the sequences of SEQ ID NOs: 99-112 and a VL polypeptide sequence having at least 95% sequence identity to at least one of the sequences of SEQ ID NOs: 85-98. 
     
     
         11 . The antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof comprises: a heavy chain variable region CDR1 comprising the amino acid sequence of SEQ ID NOs: 9; a heavy chain variable region CDR2 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 18-28; a heavy chain variable region CDR3 comprising the amino acid sequence of SEQ ID NO: 37; a light chain variable region CDR1 comprising the amino acid sequence of SEQ ID NOs: 51; a light chain variable region CDR2 comprising the amino acid sequence of SEQ ID NOs: 65; and a light chain variable region CDR3 comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 71-79. 
     
     
         12 . An anti-ActRIIB antibody or functional fragment thereof comprising:
 (a) a heavy chain variable region CDR1 of SEQ ID NO: 1; a heavy chain variable region CDR2 of SEQ ID NO: 15; a heavy chain variable region CDR3 of SEQ ID NO: 29; a light chain variable region CDR1 of SEQ ID NO: 43; a light chain variable region CDR2 of SEQ ID NO: 57; and a light chain variable region CDR3 of SEQ ID NO: 71,   (b) a heavy chain variable region CDR1 of SEQ ID NO: 2 a heavy chain variable region CDR2 of SEQ ID NO: 16; a heavy chain variable region CDR3 of SEQ ID NO: 30; a light chain variable region CDR1 of SEQ ID NO: 44; a light chain variable region CDR2 of SEQ ID NO: 58; and a light chain variable region CDR3 of SEQ ID NO: 72,   (c) a heavy chain variable region CDR1 of SEQ ID NO: 3; a heavy chain variable region CDR2 of SEQ ID NO: 17; a heavy chain variable region CDR3 of SEQ ID NO: 31; a light chain variable region CDR1 of SEQ ID NO: 45; a light chain variable region CDR2 of SEQ ID NO: 59; and a light chain variable region CDR3 of SEQ ID NO: 73,   (d) a heavy chain variable region CDR1 of SEQ ID NO: 4; a heavy chain variable region CDR2 of SEQ ID NO: 18; a heavy chain variable region CDR3 of SEQ ID NO: 32; a light chain variable region CDR1 of SEQ ID NO: 46; a light chain variable region CDR2 of SEQ ID NO: 60; and a light chain variable region CDR3 of SEQ ID NO: 74,   (e) a heavy chain variable region CDR1 of SEQ ID NO: 5; a heavy chain variable region CDR2 of SEQ ID NO: 19; a heavy chain variable region CDR3 of SEQ ID NO: 33; a light chain variable region CDR1 of SEQ ID NO: 47; a light chain variable region CDR2 of SEQ ID NO: 61; and a light chain variable region CDR3 of SEQ ID NO: 75,   (f) a heavy chain variable region CDR1 of SEQ ID NO: 6; a heavy chain variable region CDR2 of SEQ ID NO: 20; a heavy chain variable region CDR3 of SEQ ID NO: 34; a light chain variable region CDR1 of SEQ ID NO: 48; a light chain variable region CDR2 of SEQ ID NO: 62; and a light chain variable region CDR3 of SEQ ID NO: 76,   (g) a heavy chain variable region CDR1 of SEQ ID NO: 7; a heavy chain variable region CDR2 of SEQ ID NO: 21; a heavy chain variable region CDR3 of SEQ ID NO: 35; a light chain variable region CDR1 of SEQ ID NO: 49; a light chain variable region CDR2 of SEQ ID NO: 63; and a light chain variable region CDR3 of SEQ ID NO: 77,   (h) a heavy chain variable region CDR1 of SEQ ID NO: 8; a heavy chain variable region CDR2 of SEQ ID NO: 22; a heavy chain variable region CDR3 of SEQ ID NO: 36; a light chain variable region CDR1 of SEQ ID NO: 50 a light chain variable region CDR2 of SEQ ID NO: 64; and a light chain variable region CDR3 of SEQ ID NO: 78,   (i) a heavy chain variable region CDR1 of SEQ ID NO: 9; a heavy chain variable region CDR2 of SEQ ID NO: 23; a heavy chain variable region CDR3 of SEQ ID NO: 37; a light chain variable region CDR1 of SEQ ID NO: 51; a light chain variable region CDR2 of SEQ ID NO: 65; and a light chain variable region CDR3 of SEQ ID NO: 79,   (j) a heavy chain variable region CDR1 of SEQ ID NO: 10; a heavy chain variable region CDR2 of SEQ ID NO: 24; a heavy chain variable region CDR3 of SEQ ID NO: 38; a light chain variable region CDR1 of SEQ ID NO: 52; a light chain variable region CDR2 of SEQ ID NO: 66; and a light chain variable region CDR3 of SEQ ID NO: 80,   (k) a heavy chain variable region CDR1 of SEQ ID NO: 11; a heavy chain variable region CDR2 of SEQ ID NO: 25; a heavy chain variable region CDR3 of SEQ ID NO: 39; a light chain variable region CDR1 of SEQ ID NO: 53; a light chain variable region CDR2 of SEQ ID NO: 67; and a light chain variable region CDR3 of SEQ ID NO: 81,   (l) a heavy chain variable region CDR1 of SEQ ID NO: 12; a heavy chain variable region CDR2 of SEQ ID NO: 26; a heavy chain variable region CDR3 of SEQ ID NO: 40; a light chain variable region CDR1 of SEQ ID NO: 54; a light chain variable region CDR2 of SEQ ID NO: 68; and a light chain variable region CDR3 of SEQ ID NO: 82,   (m) a heavy chain variable region CDR1 of SEQ ID NO: 13; a heavy chain variable region CDR2 of SEQ ID NO: 27; a heavy chain variable region CDR3 of SEQ ID NO: 41; a light chain variable region CDR1 of SEQ ID NO: 55; a light chain variable region CDR2 of SEQ ID NO: 69; and a light chain variable region CDR3 of SEQ ID NO: 83, or   (n) a heavy chain variable region CDR1 of SEQ ID NO: 14; a heavy chain variable region CDR2 of SEQ ID NO: 28; a heavy chain variable region CDR3 of SEQ ID NO: 42; a light chain variable region CDR1 of SEQ ID NO: 56; a light chain variable region CDR2 of SEQ ID NO: 70; and a light chain variable region CDR3 of SEQ ID NO: 84.   
     
     
         13 . The antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment comprises a full length heavy chain amino acid sequence having at least 95% sequence identity to at least one sequence selected from the group consisting of SEQ ID NOs:146-150 and 156-160. 
     
     
         14 . The antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment comprises a full length light chain amino acid sequence having at least 95% sequence identity to at least one sequence selected from the group consisting of SEQ ID NOs:141-145 and 151-155. 
     
     
         15 . An anti-ActRIIB antibody or functional fragment comprising:
 (a) the variable light chain sequence of SEQ ID NO: 85 and variable heavy chain sequence of SEQ ID NO: 99;   (b) the variable light chain sequence of SEQ ID NO: 86 and variable heavy chain sequence of SEQ ID NO: 100;   (c) the variable light chain sequence of SEQ ID NO: 87 and variable heavy chain sequence of SEQ ID NO: 101;   (d) the variable light chain sequence of SEQ ID NO: 88 and variable heavy chain sequence of SEQ ID NO: 102;   (e) the variable light chain sequence of SEQ ID NO: 89 and variable heavy chain sequence of SEQ ID NO: 103;   (f) the variable light chain sequence of SEQ ID NO: 90 and variable heavy chain sequence of SEQ ID NO: 104;   (g) the variable light chain sequence of SEQ ID NO: 91 and variable heavy chain sequence of SEQ ID NO: 105;   (h) the variable light chain sequence of SEQ ID NO: 92 and variable heavy chain sequence of SEQ ID NO: 106;   (i) the variable light chain sequence of SEQ ID NO: 93 and variable heavy chain sequence of SEQ ID NO: 107;   (j) the variable light chain sequence of SEQ ID NO: 94 and variable heavy chain sequence of SEQ ID NO: 108;   (k) the variable light chain sequence of SEQ ID NO: 95 and variable heavy chain sequence of SEQ ID NO: 109;   (l) the variable light chain sequence of SEQ ID NO: 96 and variable heavy chain sequence of SEQ ID NO: 110;   (m) the variable light chain sequence of SEQ ID NO: 97 and variable heavy chain sequence of SEQ ID NO: 111; or   (n) the variable light chain sequence of SEQ ID NO: 98 and variable heavy chain sequence of SEQ ID NO: 112.   
     
     
         16 . An anti-ActRIIB antibody or functional fragment comprising:
 (a) the heavy chain sequence of SEQ ID NO: 146 and light chain sequence of SEQ ID NO: 141;   (b) the heavy chain sequence of SEQ ID NO: 147 and light chain sequence of SEQ ID NO: 142;   (c) the heavy chain sequence of SEQ ID NO: 148 and light chain sequence of SEQ ID NO: 143;   (d) the heavy chain sequence of SEQ ID NO: 149 and light chain sequence of SEQ ID NO: 144;   (e) the heavy chain sequence of SEQ ID NO: 150 and light chain sequence of SEQ ID NO: 145;   (f) the heavy chain sequence of SEQ ID NO: 156 and light chain sequence of SEQ ID NO: 151;   (g) the heavy chain sequence of SEQ ID NO: 157 and light chain sequence of SEQ ID NO: 152;   (h) the heavy chain sequence of SEQ ID NO: 158 and light chain sequence of SEQ ID NO: 153;   (i) the heavy chain sequence of SEQ ID NO: 159 and light chain sequence of SEQ ID NO: 154; or   (j) the heavy chain sequence of SEQ ID NO: 160 and light chain sequence of SEQ ID NO: 155.   
     
     
         17 . An anti-ActRIIB antibody or functional fragment thereof that binds to ActRIIB between amino acids 19-134 of SEQ ID NO: 181, wherein the antibody or functional fragment thereof cross-blocks or is cross-blocked from binding to ActRIIB by at least one antibody or functional fragment thereof of  claim 16 . 
     
     
         18 . An anti-ActRIIB antibody or functional fragment thereof that binds to ActRIIB between amino acids 19-134 of SEQ ID NO: 181, wherein the antibody or functional fragment thereof cross-blocks or is cross-blocked by at least one antibody of  claim 17  from binding to ActRIIB. 
     
     
         19 . An antibody according to  claim 1  which binds to an epitope comprising or consisting of:
 (a) amino acids 78-83 of SEQ ID NO: 181 (WLDDFN—SEQ ID NO:188); 
 (b) amino acids 76-84 of SEQ ID NO: 181 (GCWLDDFNC—SEQ ID NO:186); 
 (c) amino acids 75-85 of SEQ ID NO: 181 (KGCWLDDFNCY—SEQ ID NO:190); 
 (d) amino acids 52-56 of SEQ ID NO: 181 (EQDKR—SEQ ID NO:189); 
 (e) amino acids 49-63 of SEQ ID NO: 181 (CEGEQDKRLHCYASW—SEQ ID NO:187); or 
 (f) amino acids 78-83 of SEQ ID NO: 181 (WLDDFN) and amino acids 52-56 of SEQ ID NO: 181 (EQDKR). 
 
     
     
         20 . The antibody or functional fragment thereof of  claim 17 , wherein cross-blocking or binding is detected in a BIAcore assay or an ELISA. 
     
     
         21 . The anti-ActRIIB antibody or functional fragment thereof according to  claim 1 , wherein said antibody or functional fragment thereof is of the IgG1 isotype. 
     
     
         22 . The anti-ActRIIB antibody or functional fragment thereof according to  claim 1 , which has altered effector function through mutation of the Fc region. 
     
     
         23 . An isolated polynucleotide sequence encoding an antibody or functional fragment thereof according to  claim 1 . 
     
     
         24 . An isolated polynucleotide sequence according to  claim 23 , comprising one or more of SEQ ID NOs: 113-140 or 161-180. 
     
     
         25 . A cloning or expression vector comprising one or more isolated polynucleotide sequences according to  claim 23 . 
     
     
         26 . A vector according to  claim 25 , wherein said vector comprises one or more of SEQ ID NOs: 113-140 or 161-180, or fragment thereof encoding at least one CDR region. 
     
     
         27 . An isolated host cell comprising one or more vectors according to  claim 25 . 
     
     
         28 . A process for the production of an anti-ActRIIB antibody or functional fragment thereof that binds to ActRIIB between amino acids 19-134 of SEQ ID NO: 181, comprising culturing the host cell of  claim 27  and isolating said antibody or functional fragment thereof. 
     
     
         29 . A pharmaceutical composition comprising an anti-ActRIIB antibody or functional fragment thereof of  claim 1  or a polynucleotide sequence encoding an anti-ActRIIB antibody or functional fragment thereof of  claim 1 . 
     
     
         30 . A pharmaceutical composition according to  claim 29 , further comprising a pharmaceutically acceptable diluent or carrier. 
     
     
         31 . A pharmaceutical composition according to  claim 29 , further comprising one or more additional active agents. 
     
     
         32 . A pharmaceutical composition according to  claim 31 , wherein said one or more additional active agents is selected from IGF-1, IGF-2, a variant of IGF-1 or IGF-2, an anti-myostatin antibody, a myostatin propeptide, a myostatin decoy protein that binds ActRIIB but does not activate it, a beta 2 agonist, a Ghrelin agonist, a SARM, GH agonists/mimetics and follistatin. 
     
     
         33 . A method of treatment of a disease in an individual in need thereof, comprising the step of administering an effective dose of an anti-ActRIIB antibody or functional fragment thereof that binds to ActRIIB between amino acids 19-134 of SEQ ID NO: 181, or a polynucleotide encoding an anti-ActRIIB antibody or functional fragment thereof that binds to ActRIIB between amino acids 19-134 of SEQ ID NO: 181,
 wherein the disease is selected from: a musculoskeletal disease or disorder; acute and/or chronic renal disease or failure; liver fibrosis or cirrhosis; cancer such as breast cancer; Parkinson's Disease; conditions associated with neuronal death, such as ALS, brain atrophy, or dementia and anemia; liver, kidney and pulmonary fibrosis; age-related conditions; and cancers examplified by but not restricted to rhabdomyosarcomas, bone-loss inducing cancers, hepatocellular carcinomas, and gastrointestinal cancers.   
     
     
         34 . The method of  claim 33 , wherein said musculoskeletal disease or disorder is muscle atrophy, myopathy, myotonia, a congenital myopathy, nemalene myopathy, multi/minicore myopathy and myotubular (centronuclear) myopathy, mitochondrial myopathy, familial periodic paralysis, inflammatory myopathy, metabolic myopathy, a glycogen or lipid storage disease, dermatomyositisis, polymyositis, inclusion body myositis, myositis ossificans, rhabdomyolysis and myoglobinurias; a dystrophy, Duchenne, Becker, myotonic, fascioscapulohumeral, Emery-Dreifuss, oculopharyngeal, scapulohumeral, limb girdle, Fukuyama, or a congenital muscular dystrophy, or hereditary distal myopathy; osteoporosis; a bone fracture; short stature; dwarfism; prolonged bed rest; voluntary inactivity; and/or involuntary inactivity. 
     
     
         35 . The method according to  claim 33 , wherein the individual has been pre-treated with IGF-1, IGF-2 or variants of IGF-1 or IGF-2, an anti-myostatin antibody, a myostatin propeptide, a myostatin decoy protein that binds ActRIIB but does not activate it, a beta 2 agonist, a Ghrelin agonist, a SARM, GH agonists/mimetics or follistatin. 
     
     
         36 . The method according to  claim 33 , wherein the individual has previously been refractive to treatment with IGF-1, IGF-2 or variants of IGF-1 or IGF-2, an anti-myostatin antibody, a myostatin propeptide, a myostatin decoy protein that binds ActRIIB but does not activate it, a beta 2 agonist, a Ghrelin agonist, a SARM, GH agonists/mimetics or follistatin. 
     
     
         37 . The method according to  claim 33 , wherein the individual is elderly, has spent time in a zero gravity environment or has undergone a period of inactivity. 
     
     
         38 . A method of ameliorating the muscle wasting effects of enforced inactivity or time spent in a zero gravity environment comprising administering an effective dose of an antibody or functional fragment thereof according to  claim 1  prior to said period of enforced inactivity or time spent in a zero gravity environment. 
     
     
         39 . The method according to  claim 33 , wherein the individual has a fracture to a limb or joint. 
     
     
         40 . The method according to  claim 33 , wherein the individual has undergone or is about to undergo, hip or knee replacement surgery. 
     
     
         41 . An antibody encoded by pBW522 (DSM22873) or pBW524 (DSM2287).