Inhibition of AXL Signaling in Anti-Metastatic Therapy

Abstract

Compositions and methods are provided for alleviating cancer in a mammal by administering a therapeutic dose of a pharmaceutical composition that inhibits activity of AXL protein activity, for example by competitive or non-competitive inhibition of the binding interaction between AXL and its ligand GAS6.

1 . A soluble AXL variant polypeptide, wherein said polypeptide lacks the AXL transmembrane domain and comprises at least one amino acid modification relative to the wild-type AXL sequence, and wherein said change increases the affinity of the AXL polypeptide binding to GAS6. 
     
     
         2 - 3 . (canceled) 
     
     
         4 . The soluble AXL variant polypeptide of  claim 1 , wherein said soluble AXL variant polypeptide comprises at least one amino acid modification at position 19, 23, 26, 27, 32, 33, 38, 44, 61, 65, 72, 74, 78, 79, 86, 87, 88, 90, 92, 97, 98, 105, 109, 112, 113, 116, 118, or 127 of the wild-type AXL sequence (SEQ ID NO: 1) or a combination thereof. 
     
     
         5 . The soluble AXL variant polypeptide of  claim 1 , wherein said soluble AXL variant polypeptide comprises at least one amino acid modification selected from the group consisting of 1) A19T, 2) T23M, 3) E26G, 4) E27G or E27K 5) G32S, 6) N33S, 7) T381, 8) T44A, 9) H61Y, 10) D65N, 11) A72V, 12) S74N, 13) Q78E, 14) V79M, 15) Q86R, 16) D87G, 17) D88N, 18) 190M or 190V, 19) V92A, V92G or V92D, 20) 197R, 21) T98A or T98P, 22) T105M, 23) Q109R, 24) V112A, 25) F113L, 26) H116R, 27) T118A, 28) G127R or G127E, and 29) G129E and a combination thereof. 
     
     
         6 - 16 . (canceled) 
     
     
         17 . The soluble AXL variant polypeptide of  claim 1 , wherein the polypeptide is a fusion protein comprising an Fc domain. 
     
     
         18 . The soluble AXL variant polypeptide of  claim 1 , wherein said soluble AXL variant polypeptide has an affinity of at least about 1×10 −8  M, 1×10 −9  M, 1×10 −10  M, 1×10 −11  M or 1×10 −12  M for GAS6. 
     
     
         19 . The soluble AXL variant polypeptide of  claim 1 , wherein said soluble AXL variant polypeptide exhibits an affinity to GAS6 that is at least about 10-fold stronger or at least about 20 fold stronger than the affinity of the wild-type AXL polypeptide. 
     
     
         20 - 21 . (canceled) 
     
     
         22 - 33 . (canceled) 
     
     
         34 . A method of treating, reducing, or preventing the metastasis or invasion of a tumor in a mammalian patient, the method comprising:
 administering to said patient an effective dose of the soluble AXL variant polypeptide of  claim 1 .   
     
     
         35 . The method of  claim 34 , wherein said tumor is a tumor selected from the group consisting of an ovarian tumor, a breast tumor, a lung tumor, a liver tumor, a colon tumor, a gallbladder tumor, a pancreatic tumor, a prostate tumor, and glioblastoma. 
     
     
         36 - 37 . (canceled) 
     
     
         38 . A method of determining the ability of a tumor to undergo invasion or metastasis in a subject, said method comprising:
 detecting the level of AXL activity in a biological sample from a subject with a tumor; and   comparing the level of the AXL activity in the biological sample to predetermined level,   wherein an increase over the predetermined level is indicative of a predisposition of the tumor to invasion or metastasize.   
     
     
         39 - 42 . (canceled) 
     
     
         43 . The method of  claim 38 , wherein said biological sample is selected from the group consisting of a tissue sample, a tumor tissue sample, a blood sample, a serum sample, a cerebrospinal fluid (CSF) sample, an ascites fluid sample, and a cell culture sample.