PF-06664178

PF-06664178 is an antibody-drug conjugate (ADC) developed by Pfizer for the treatment of advanced or metastatic solid tumors. It consists of a humanized IgG1 monoclonal antibody targeting Trop-2 (tumor-associated calcium signal transducer 2), which is overexpressed in various cancers and associated with tumor aggressiveness and drug resistance. The antibody is conjugated to the cytotoxic payload Aur0101, an auristatin microtubule inhibitor, via a linker at the C-terminus of the heavy chain. The mechanism involves selective delivery of Aur0101 to Trop-2-expressing tumor cells, resulting in tubulin inhibition and cell death. Clinical development was discontinued after phase 1 due to dose-limiting toxicities (notably neutropenia, skin rash, mucosal inflammation) and modest antitumor activity[1][4][5][10].