Multidimensional analysis of B7 homolog 3 B7-H3 RNA expression in small cell lung cancer SCLC molecular subtypes

Authors:

Carl Gay, Taofeek Owonikoko, Lauren Byers, Noura Choudhury, Sajid Ahmed, Zachary Cain, Xiaozhong Qian, Matthew Brentnall, Simon Heeke, Ming Poi, Sharon Wu, Charles Rudin

Purpose

  • B7-H3 (CD276), a transmembrane protein showing low expression in normal tissues but overexpression in SCLC and other solid tumors, is a promising target for ADCs1,2
  • We performed a multidimensional analysis of B7-H3/CD276 RNA expression in SCLC molecular subtypes, comparing expression with that of another key molecular target in SCLC, DLL33
  • We also analyzed the relationship of B7-H3 RNA expression with the expression of other immunerelated genes and gene signatures

Conclusions

  • B7-H3 showed high and consistent expression across subgroups of patients with SCLC defined by the tumor molecular subtype or prior immunotherapy use
  • The relative expression of B7-H3 was higher and less variable among molecular subtypes than for DLL3, which is another potential molecular target in this tumor type3
  • B7-H3 expression had limited association with PD-L1 expression, supporting a role as a distinct therapeutic target
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