Despite considerable research efforts, patients with advanced-stage triple-negative breast cancer (TNBC) generally receive chemotherapy and have a poor prognosis, with few effective targeted therapy or immunotherapy options available. Now, data from a phase II study demonstrate promising activity of the PD-L1 × CTLA4 bispecific antibody KN046 (a single-domain antibody Fc-fusion protein designed to simultaneously inhibit both PD-1 and CTLA4 signalling) in this setting.

In this trial, a total of 27 women with treatment-naive locally advanced inoperable or metastatic TNBC received KN046 at one of two doses (3 or 5 mg/kg every 2 weeks) plus nab-paclitaxel at centres in China. Objective response rate (ORR) and duration of response (DOR) were the primary end points.