Methods and compositions using fgf23 variant polypeptides

Abstract

The present disclosure is directed to methods, kits and compositions for preventing or treating age-related conditions or metabolic disorders. The fusion polypeptides of the disclosure include FGF23 or an active fragment thereof. In one embodiment, the fusion polypeptide comprises (a) a polypeptide comprising fibroblast growth factor 23 (FGF23), or a functionally active variant or derivative thereof, wherein FGF23 has a mutation at one or more of the positions Q156, C206 and C244; and (b) either a modified Fc fragment having decreased affinity for Fc-gamma-receptor and/or increased serum half-life, or a polypeptide comprising at least one extracellular subdomain of a Klotho protein, or a functionally active variant or derivative thereof and, optionally (c) a linker. The Klotho fusion proteins are useful in the treatment and prevention of a variety of age-related conditions and metabolic disorders. In another embodiment, the fusion polypeptide comprises a FGF (such as FGF23), or a functionally active variant or derivative thereof; and a modified Fc fragment, or a functionally active variant or derivative thereof In various embodiments of the fusion polypeptides, FGF23 has mutations which decrease aggregation and protease-mediated cleavage.

What is claimed is: 
     
         1 . A fusion polypeptide comprising: (a) a polypeptide comprising fibroblast growth factor 23 (FGF23), or a functionally active variant or derivative thereof, wherein FGF23 has a mutation as described herein; and (b) a fusion partner as described herein, or a functionally active variant or derivative thereof; and, optionally (c) a linker. 
     
     
         2 . The fusion polypeptide of  claim 1 , wherein the polypeptide of (a) is operatively linked to the N-terminus of the polypeptide of (b). 
     
     
         3 . The fusion polypeptide of  claim 1 , wherein the polypeptide of (b) is operatively linked to the N-terminus of the polypeptide of (a). 
     
     
         4 . The fusion polypeptide of  claim 1 , wherein the polypeptide of (a) and the polypeptide of (b) are connected by a polypeptide linker. 
     
     
         5 . The fusion polypeptide of  claim 4 , wherein the polypeptide linker comprises an amino acid sequence selected from the group consisting of: SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, and SEQ ID NO: 18. 
     
     
         6 . The fusion polypeptide of  claim 4 , wherein the polypeptide linker comprises at least 1 and up to about 30 repeats of an amino acid sequence selected from the group consisting of: SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, and SEQ ID NO: 18. 
     
     
         7 . The fusion polypeptide of  claim 4 , wherein the polypeptide of (a) is connected by a peptide bond to the N-terminus of said polypeptide linker, and the polypeptide of (b) is connected by a peptide bond to the C-terminus of said polypeptide linker. 
     
     
         8 . The fusion polypeptide of  claim 4 , wherein the polypeptide of (a) is connected by a peptide bond to the C-terminus of said polypeptide linker, and the polypeptide of (b) is connected by a peptide bond to the N-terminus of said polypeptide linker. 
     
     
         9 . The fusion polypeptide of  claim 1 , wherein the extracellular subdomain of the Klotho protein is a KL-D1 domain or a KL-D2 domain. 
     
     
         10 . The fusion polypeptide of  claim 1 , wherein the polypeptide of (a) comprises at least two extracellular subdomains of the Klotho protein. 
     
     
         11 . The fusion polypeptide of  claim 10 , wherein the at least two extracellular subdomains of the Klotho protein are at least two KL-D1 domains in tandem repeats. 
     
     
         12 . The fusion polypeptide of  claim 10 , wherein the at least two extracellular subdomains of the Klotho protein are at least two KL-D2 domains in tandem repeats. 
     
     
         13 . The fusion polypeptide of  claim 10 , wherein the at least two extracellular subdomains of Klotho protein comprise a KL-D1 domain and a KL-D2 domain. 
     
     
         14 . The fusion polypeptide of  claim 1 , wherein the polypeptide of (a) is the extracellular domain of the Klotho protein. 
     
     
         15 . The fusion polypeptide of  claim 1 , further comprising a signal peptide. 
     
     
         16 . The fusion polypeptide of  claim 15 , wherein the signal peptide is the Klotho signal peptide. 
     
     
         17 . The fusion polypeptide of  claim 15 , wherein the signal peptide is the IgG signal peptide. 
     
     
         18 . The fusion polypeptide of  claim 1  that specifically binds to a fibroblast growth factor receptor. 
     
     
         19 . The fusion polypeptide of  claim 1 , wherein the Klotho protein is alpha-Klotho. 
     
     
         20 . The fusion polypeptide of  claim 1 , wherein the Klotho protein is beta-Klotho. 
     
     
         21 . The fusion polypeptide of  claim 19 , wherein the fibroblast growth factor is fibroblast growth factor-23 (FGF23) or a fibroblast growth factor-23 variant (R179Q). 
     
     
         22 . The fusion polypeptide of  claim 20 , wherein the fibroblast growth factor is fibroblast growth factor-19 or fibroblast growth factor-21. 
     
     
         23 . The fusion polypeptide of  claim 1  comprising an amino acid sequence which is 95% or more identical to the amino acid sequence of SEQ ID NO: 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, or 68. 
     
     
         24 . The fusion polypeptide of  claim 1  having the amino acid sequence of SEQ ID NO: 58, or SEQ ID NO: 68. 
     
     
         25 . The fusion polypeptide of  claim 1  comprising FcLALA. 
     
     
         26 . A pharmaceutical composition comprising the fusion polypeptide of  claim 1  and a pharmaceutically acceptable carrier. 
     
     
         27 . A nucleic acid comprising a sequence that encodes the fusion polypeptide of  claim 1 . 
     
     
         28 . A host cell containing the nucleic acid of  claim 27 . 
     
     
         29 . A vector comprising the nucleic acid of  claim 27 . 
     
     
         30 . A method for treating or preventing an age-related condition, a metabolic disorder, muscle atrophy, chronic renal disease or chronic renal failure, hyperphosphatemia, or calcinosis in an individual, comprising administering to an individual in need thereof a therapeutically effective dose of a pharmaceutical composition comprising a fusion polypeptide comprising: (a) a polypeptide comprising fibroblast growth factor 23 (FGF23), or a functionally active variant or derivative thereof as described herein; and (b) a fusion partner as described herein, or a functionally active variant or derivative thereof; and, optionally (c) a linker. 
     
     
         31 . The method of  claim 30 , wherein the age-related condition is selected from the group consisting of sarcopenia, skin atrophy, muscle wasting, brain atrophy, atherosclerosis, arteriosclerosis, pulmonary emphysema, osteoporosis, osteoarthritis, immunologic incompetence, high blood pressure, dementia, Huntington's disease, Alzheimer's disease, cataracts, age-related macular degeneration, prostate cancer, stroke, diminished life expectancy, memory loss, wrinkles, impaired kidney function, and age-related hearing loss. 
     
     
         32 . The method of  claim 30 , wherein the Klotho protein is alpha Klotho protein. 
     
     
         33 . The method of  claim 31 , wherein the age-related condition is muscle wasting, the Klotho protein is alpha Klotho protein, and the fibroblast growth factor is fibroblast growth factor 23.