In the field of biological therapy, a major hurdle is the need for a platform technology that enables high
bioavailability and long therapeutic
exposure of a biological therapy in the setting of localized
disease. Classical approaches result in problematic trade-offs such as
toxicity and off-target side effects. The present disclosure provides compounds comprising
follistatin domain 1 (FSD1) of
follistatin (FST) which are able to bind biological structures, such as the
extracellular matrix, through heparan sulfates, without bearing the undesirable neutralizing effects on
activin A,
myostatin, and GDF11 activities of e.g. full-length
follistatin. The invention relates to fusion proteins or conjugated proteins, and compositions thereof, constructs or vectors encoding thereof, medical uses thereof and methods for biological therapy.