We discovered multiple novel bispecifics that maximally activate macrophage-mediated cytotoxicity and reduce binding to healthy blood cells, including bispecifics targeting macrophage immune checkpoint molecules in combination with EGFR, TROP2, and CD71. Overall, our findings indicate that CD47 predominates over CD24 as a macrophage immune checkpoint in cancer, and that the novel bispecifics we created may be optimal immunotherapies to direct myeloid cells to eradicate solid tumors.

Especially, RNA-seq analysis and Western blotting further revealed that CXCL9/10-CXCR3 axis was markedly up-regulated and JAK/STAT1 pathway was activated upon treatment with PPAB001 plus Tecentriq. Overall, our results underscore that simultaneous blockade of CD47 and CD24 is a potential therapeutic option to improve the efficacy of anti-PD-L1 therapy mainly by resetting tumor-associated macrophages toward M1 phenotype.

Sunitinib and immune checkpoint blockers are commonly used to treat metastatic renal carcinoma with limited efficacy. The MC38-hPDL1 and MC38-hCD24-hPDL1 tumor-bearing mouse models further offer the possibility of combining 57103 with the PDL1 antagonist atezolizumab. In conclusion, 57103 is a potential candidate drug for the treatment of metastatic renal carcinoma or PDL1-overexpressing cancer.

Previously, we prepared for the first time an antibody-nitric oxide conjugate (ANC)-HN01, which showed inhibitory activity against hepatocellular carcinoma...In summary, we developed a stable and homogeneous site-specific conjugated ANC, which showed good antitumor activity and improved safety profile both in vitro and in vivo. This study provides new insight into the development of next generation of ADC candidates.

Other preclinical studies are exploring the use of chimeric antigen receptor (CAR) T cells, antibody-drug conjugates, and gene therapy to target CD24 and enhance the immune response against tumors. In summary, this review focuses on the role of CD24 in the immune system and provides evidence for CD24 as a promising immune checkpoint for cancer immunotherapy.

Monoclonal antibodies, antibody-drug conjugates (ADCs), chimeric antigen receptor (CAR) T-cell therapy, and CAR-NK cell therapy are currently available for the treatment of CD24. In this review, we summarise the existing therapeutic approaches and possible future directions targeting CD24.

Notably, an increased ratio of M1/M2 in tumor-infiltrating macrophages in the mice treated with PPAB001 suggested that the dual blockade may promote the transition of macrophages from M2 to M1. Taken together, our data supported the development of PPAB001 as a novel immunotherapeutic in the treatment of CD47 and CD24 double-positive cancers.

IMM47 monotherapy or in combination with SIRP-Fc fusion protein (IMM01) or anti-PD-1 antibodies were used to test IMM47's anti-tumor efficacy in SCID mice with Jeko-1 or MCF-7 tumor cell xenotransplantation and hPD-1 Tg C57BL/6 mice with MC38-hCD24/hPD-L1 tumor cell homologous transplantation models...Additionally, an in vivo pharmacodynamics assay of IMM47 in combination with different PD-1 antibodies revealed that IMM47 exhibits synergistic therapeutic efficacy when combined with Tislelizumab, Opdivo, and Keytruda. Our research showed that the humanized anti-CD24 mAb IMM47 had excellent anti-tumor effect. The extracellular domain's N-glycosylation alteration has no effect on IMM47's ability to bind to CD24. The in vitro assays revealed that IMM47 exhibits significant ADCC, ADCP, ADCT, and CDC activities.

IMM47 also has powerful synergistic therapeutic efficacy when combined with Tislelizumab, Opdivo and Keytruda, by blocking CD24/Siglec-10 interaction through macrophage antigen presentation with strong ADCC, ADCP, ADCT and CDC activities and with a safe profile. IMM47 binding to CD24 is independent of N-glycosylation modification of the extracellular domain.

Similarly, unstimulated CLL patients-derived NLCs provided increased phagocytosis when DEMs blockade occurred. Since high levels of CD24 were associated with worse survival in both MCL and CLL, anti-CD24-induced phagocytosis could be considered for future clinical use, particularly in association with other agents such as Rituximab.

Our data has also confirmed that IMM47 specifically binds to and induces ADCC (antibody-dependent cellular cytotoxicity) ,ADCP (antibody-dependent cellular phagocytosis), and CDC (complement-dependent cytotoxicity) against a variety of cancer cells. Taken together, our data show that targeting CD24 on tumor cells using our IMM47 antibody may serve as potent immunotherapy for multiple cancer indications.