The present invention is directed to combination therapies for the treatment of cancer and pathogen related diseases, said combination therapies comprising: (1) molecules capable of binding to PD-1 or a natural ligand of PD-1 such as diabodies, scFv, antibodies , TandAb, etc.)； and (2) molecules capable of mediating targeted transformation and killing of target cells (eg, cancer cells or pathogen-infected cells, etc.) expressing disease antigens (eg, diabodies, BiTe, bispecific antibodies, CAR, etc.) Administration). In particular, the present invention is directed to a first epitope binding site which is capable of immunospecifically binding to the epitope of a cell surface molecule of an effector cell, the molecule capable of mediating the targeted conversion killing of the target cell； That is, the embodiment relates to an embodiment that is a bispecific binding molecule comprising a second epitope binding site capable of immunospecifically binding to a cancer antigen or a disease antigen such as a pathogen associated antigen. The invention is also directed to pharmaceutical compositions comprising one or more of the above-described molecules. [Selected figure] Figure 8A.本発明は、癌及び病原体関連疾患の治療のための併用療法を対象とし、上記併用療法は：（１）ＰＤ‐１又はＰＤ‐１の天然リガンドに結合できる分子（例えばダイアボディ、ｓｃＦｖ、抗体、ＴａｎｄＡｂ等）；及び（２）疾患抗原を発現する標的細胞（例えば癌細胞又は病原体感染細胞等）の標的転換殺滅を仲介できる分子（例えばダイアボディ、ＢｉＴｅ、二重特異性抗体、ＣＡＲ等）の投与を含む。本発明は特に、上記標的細胞の上記標的転換殺滅を仲介できる上記分子が、エフェクタ細胞の細胞表面分子のエピトープに免疫特異的に結合できる第１のエピトープ結合部位と、上記標的細胞のエピトープ（即ち癌抗原又は病原体関連抗原等の疾患抗原）に免疫特異的に結合できる第２のエピトープ結合部位とを含む、二重特異性結合分子である、実施形態に関する。本発明はまた、１つ又は複数の上記分子を含む医薬組成物も対象とする。【選択図】 図８Ａ
