4.2CD73 mAb combined with CTLA-4 mAb
The combination of CD73 mAb and PD-1 mAb was found to be more effective against both subcutaneous and metastatic tumors than CD73 mAb and CTLA-4 mAb[20].This may be due to the stronger antineoplastic activity of PD-1 mAb itself than CTLA-4 mAb, or the synergistic effect of CD73 mAb and PD-1 mAb on Tregs. However, CD73 mAb combined with CTLA-4 mAb still has clinical significance that cannot be ignored. CD73 mAb combined with CTLA-4 mAb significantly improved median survival in tumor metastasis model of mice[67].In melanoma, the efficacy of anti-CTLA-4 therapy can be enhanced by targeting various immunosuppressive mechanisms in tumor tissue, including CD73. CD73 antibody combined with CTLA-4 mAb has a significant inhibitory effect on melanoma growth. In the melanoma model of mice, the percentage of infiltrated CD8+T and CD4+T cells was particularly increased after the combination of the two antibodies, and the proportion of Tregs was also increased compared with that of the two antibodies alone, which may be due to the increase of CD4+T cells after the combination of the two monoclonal antibodies. At the same time, IFN -γ levels were increased in melanoma tissues of mice treated with CD73 antibody in combination with CTLA-4 antibody[43],CTLA-4 mAb is also of great clinical significance in hematologic malignancies such as AML and MDS[18],which has great potential in combination with CD73 antibody in the treatment of blood malignant diseases.