The present invention provides methods for treating, reducing the severity, or inhibiting the growth of cancer (e.g., solid tumors). The methods of the present invention comprise administering to a subject in need thereof a therapeutically effective amount of a programmed death 1 (PD-1) antagonist (e.g., an anti-PD-1 antibody), optionally, in combination with radiation therapy. In certain embodiments, the methods comprise administering hypo-fractionated radiation in combination with an anti-PD-1 antibody or a fragment thereof to achieve a prolonged abscopal effect in tumor inhibition.
