Multinational phase 1 study of the Probody PD-L1 inhibitor pacmilimab for advanced or recurrent solid tumors

Probody therapeutics are antibody prodrugs that are activated in the tumor microenvironment by tumor-associated proteases, thereby restricting the activity to the tumor microenvironment and minimizing ‘off-tumor’ toxicity. The multinational phase 1 and first-in-human PROCLAIM-CX-072 study evaluated the Probody PD-L1 inhibitor pacmilimab in patients with advanced or recurrent solid tumors. At the recommended phase 2 dose of 10 mg/kg every 14 days pacmilimab had a low rate of immune-mediated toxicity, with signs of antitumor activity in patients not selected for high PD-L1 expression.