Methods of treating cancer using antibodies and molecules that immunospecifically bind to BTN1A1

A method of treating cancer in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of a molecule comprising an antigen binding fragment that immunospecifically binds to BTN1A1, wherein the cancer expresses PD-L1 at a level lower than or equal to a PD-L1 reference level;

• wherein the PD-L1 reference level is the average or medium expression level of PD-L1 in a population of healthy individuals;
• and wherein the antigen binding fragment comprises:
• (i) a heavy chain variable region (VH) comprising a VH complementarity-determining region (CDR) 1, a VH CDR2, and a VH CDR3 having an amino acid sequence of a VH CDR1, a VH CDR2, and a VH CDR3, respectively, of a VH having an amino acid sequence of SEQ ID NO:31;
• and
• (ii) a light chain variable region (VL) comprising a VL CDR1, a VL CDR2, and a VL CDR3 having an amino acid sequence of a VL CDR1, a VL CDR2, and a VL CDR3, respectively, of a VL having an amino acid sequence of SEQ ID NO:33.