CD19 underexpression

CD19low resistant cells exhibited preserved B cell receptor signaling and were more sensitive to both BTK and MEK inhibition. These data demonstrate that resistance to CD19 immunotherapies can result in decreased expression of both CD19 and CD22 and can result in dependency on BTK pathways.

The phase 3 ZUMA-7 trial in second-line large B cell lymphoma demonstrated superiority of anti-CD19 CAR T cell therapy (axicabtagene ciloleucel (axi-cel)) over standard of care (SOC; salvage chemotherapy followed by hematopoietic transplantation) ( NCT03391466 ). T cell activation and B cell GES, which are associated with improved axi-cel outcome, decreased with increasing lines of therapy. These data highlight differences in resistance mechanisms to axi-cel and SOC and support earlier intervention with axi-cel.

No abstract available

In addition, the inhibitory receptor of CD47, signal regulatory protein alpha (SIRPα) is increased on macrophages from patients with follicular lymphoma who relapse or progress after frontline lenalidomide and rituximab. We show that CD47 and SIRPα were elevated in lymph node biopsies from DLBCL patients. Increased expression of SIRPα on macrophages correlated with decreased ADCP activity of tafasitamab, and CRISPR-mediated CD47 overexpression on lymphoma targets impaired tafasitamab-mediated phagocytosis, in vitro. Combination of tafasitamab and an anti-CD47 enhanced ADCP activity of in vitro generated macrophages.

CLN-978 warrants further exploration. An ongoing clinical phase 1 trial is investigating safety, pharmacokinetics, pharmacodynamics, and the initial therapeutic potential of subcutaneously administered CLN-978 in patients with non-Hodgkin's lymphoma.

In addition, the inhibitory receptor of CD47, signal regulatory protein alpha (SIRPα) is increased on macrophages from patients with follicular lymphoma who relapse or progress after frontline lenalidomide and rituximab (Marques-Piubelli et al). Conclusion Our results show increased expression of CD47-SIRPa axis in primary DLBCL samples and indicate that CD47 blockade can enhance the phagocytic potential of tumor-targeting immunotherapies such as tafasitamab. Our findings suggest that there is merit in exploring the clinical utility of combining tafasitamab with an anti-CD47 blocking antibody in lymphoma.