BI 770371

In recent years, immunotherapies have driven significant clinical progress and increased hopes for patients suffering from various types of cancer.

BI 770371 is an IgG1 mAb that recognizes both the V1 and V2 variants of SIRPα. In many cancer types, CD47 forms a potent ‘don’t eat me’ signaling complex with SIRPα that triggers a cascade of events that enables cancer cells to avoid detection by the innate immune system and inhibits the ability of macrophage cells to fight cancer. By blocking the interaction between SIRPα and cluster of differentiation 47 (CD47), SIRPα antagonism enhances innate immunity and restores the immune function of myeloid cells in the tumor microenvironment.


As part of the global collaboration and license agreement between OSE Immunotherapeutics and Boehringer Ingelheim, Boehringer Ingelheim is evaluating BI 770371 as monotherapy and in combination with ezabenlimab, a PD1 inhibitor (BI 754091) in an open-label, dose escalation/dose expansion Phase 1 clinical trial (NCT05327946) conducted in Canada, USA and Japan in patients with advanced solid tumors.

The first clinical results of BI 770371 presented at ESMO (European Society for Medical Oncology) 2023 conference (Madrid, Abstract #697P) showed that adverse events were manageable during the on-treatment period, Maximal Tolerated Dose (MTD) has not been reached.

The BI 770371 development program will extend the therapeutic potential of selective SIRPα antagonists in various diseases or disorders, covering the most prevalent allelic variants of SIRPα, V1 SIRPα and V2 SIRPα expressed on myeloid cells.

Boehringer Ingelheim is also evaluating BI 765063 (formerly OSE-172) in different combinations with patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) or hepatocellular carcinoma (HCC) in a Phase 1b trial conducted in the United States, Europe and Asia (NCT05249426).

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