Patent ID: 8541203

Claim:
A method of manufacturing an activatable binding polypeptide (ABP), the method comprising: (a) culturing a cell comprising a nucleic acid construct that encodes the ABP under conditions that lead to expression of the ABP, wherein the ABP comprises a masking moiety (MM), a cleavable moiety (CM), and an antigen binding domain (ABD) that specifically binds vascular endothelial growth factor (VEGF), (i) wherein the ABP in an uncleaved state comprises a structural arrangement from N-terminus to C-terminus as follows: MM-CM-ABD or ABD-CM-MM; (ii) wherein the MM is a peptide that inhibits binding of the ABD to the target, and wherein the MM comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 31, 32, 33, 34, 35, 36, 37 and 38; and (iii) wherein, the CM is positioned in the ABP such that, in an uncleaved state, the MM interferes with specific binding of the ABD to VEGF, and in a cleaved state the MM does not interfere or compete with specific binding of the ABD to VEGF; (b) recovering the ABP; and (c) testing the ABP for the ability to maintain an activatable phenotype while in soluble form.