The present invention is directed to bispecific molecules (e.g., diabodies, bispecific antibodies, trivalent binding molecules, etc.) that possess at least one epitope-binding site that is immunospecific for an epitope of PD-1 and at least one epitope-binding site that is immunospecific for an epitope of CTLA-4 (i.e., a “PD-1 x CTLA-4 bispecific molecule”). The PD-1 x CTLA-4 bispecific molecules of the present invention are capable of simultaneously binding to PD-1 and to CTLA-4, particularly as such molecules are arrayed on the surfaces of human cells. The invention is directed to pharmaceutical compositions that contain such PD-1 x CTLA-4 bispecific molecules, and to methods involving the use of such bispecific molecules in the treatment of cancer and other diseases and conditions. The present invention also pertains to methods of using such PD-1 x CTLA-4 bispecific molecules to stimulate an immune response.本發明涉及雙特異性分子(例如，雙抗體、雙特異性抗體、三價結合分子等)，其具有對於PD-1的表位免疫特異性的至少一個表位-結合位點和對於CTLA-4的表位免疫特異性的至少一個表位-結合位點(即，“PD-1 x CTLA-4雙特異性分子”)。本發明的PD-1 x CTLA-4雙特異性分子能夠同時結合PD-1和結合CTLA-4，尤其當這類分子排列在人細胞的表面上時。本發明涉及藥物組合物，其包含這類PD-1 x CTLA-4雙特異性分子，並且涉及包括這類雙特異性分子在治療癌症和其他疾病和病況中的用途的方法。本發明也涉及使用這類PD-1 x CTLA-4雙特異性分子刺激免疫應答的方法。
