At Good Therapeutics we are developing protein-based drugs with regulated, context-dependent activity. Our new drugs can "sense" their local environment and respond by changing from an inactive form to an active one. Unlike protease-activated therapeutics, the mechanism is reversible. The active form of the drug can change back to the inactive form when it is no longer in the presence of the activating signal. Our technology is based on allosteric control of protein activity – a type of regulation that is widely found in nature but has yet to be applied to therapeutics.