This provides pharmaceutical compositions that comprise a combination of an anti-cancer agent which is an first antibody and a second antibody. In some embodiments, the first antibody is an anti-Programmed Death-1 (PD-1) antibody. In certain embodiments, the composition is a fixed dose formulation. In certain embodiments, the composition is administered as a flat-dose. The disclosure also provides a kit for treating a subject afflicted with a disease, the kit comprising a dosage of any composition disclosed herein and instructions for using the composition in any of the disclosed methods for treating a disease.
