The invention relates to molecules inhibiting biologically active compounds and further comprising moieties specifically cleavable by a
reagent produced by a target
cell. The invention relates to inhibitors that bind, inhibit, suppress, neutralize, or decrease activity of a biologically
active agent. Inhibitors comprise at least one
moiety that bind, inhibit, suppress, neutralize, or decrease activity of a biologically
active agent and at least one
moiety that can be cleaved specifically by a
reagent produced by target cells. The cleavage deactivates the inhibitor. Following cleavage, the
active agent is liberated into the
local environment. Administration of the inhibitor alone or together with the active agent suppress the compound's activity until it reaches the proximity of a target
cell. Targeted specific release enables the agent concentration in specific site to reach levels that have desired therapeutic effects without
systemic toxicity.