Actriib proteins and variants and uses therefore relating to utrophin induction for muscular dystrophy therapy

Abstract

In certain aspects, the present invention provides compositions and methods for inducing utrophin expression in muscle with an ActRIIB protein as therapy for muscular dystrophy. The present invention also provides methods of screening compounds that modulate activity of an ActRIIB protein and/or an ActRIIB ligand.

1 - 52 . (canceled) 
     
     
         53 . A method for treating a DMD or BMD patient, the method comprising administering to the patient an effective amount of an antibody or antigen-binding fragment thereof that binds to ActRIIB, and wherein the patient has elevated levels of serum CK-MM relative to the norm for patients with the same disease state. 
     
     
         54 . The method of  claim 53 , wherein the patient has DMD 
     
     
         55 . The method of  claim 53 , wherein the patient has BMD. 
     
     
         56 . The method of  claim 53 , wherein administration of the antibody or antigen-binding fragment thereof increases sarcolemmal strength of muscle fibers in the patient. 
     
     
         57 . The method of  claim 56 , wherein utrophin expression is increased in the patient's skeletal or cardiac muscle. 
     
     
         58 . The method of  claim 53 , wherein the method further comprises evaluating a marker for muscle degeneration and selecting a dose level or frequency based on the level of the marker for muscle degeneration, wherein the marker for muscle degeneration is serum CK-MM. 
     
     
         59 . The method of  claim 53 , wherein the method comprises administering an effective amount of an antibody that binds to ActRIIB. 
     
     
         60 . The method of  claim 53 , wherein the method comprises administering an effective amount of an antigen-binding fragment that binds to ActRIIB. 
     
     
         61 . The method of  claim 53 , wherein the antibody is humanized. 
     
     
         62 . The method of  claim 53 , wherein the antibody is a monoclonal antibody.