Targeting Bruton's tyrosine kinase for the treatment of B cell associated malignancies and autoimmune diseases: Preclinical and clinical developments of small molecule inhibitors

B cell receptor (BCR) signaling plays a key role in B cell development and function. Aberrant BCR signaling has been confirmed as a central driver for the pathogenesis of various B cell malignancies. Bruton's tyrosine kinase (BTK) is a vital component of BCR signaling and exhibits overexpression in various B cell leukemias and lymphomas. Inhibiting BTK has been proved as an efficient way for B cell malignancy intervention. Remarkable achievements have been made in the pursuit of selective BTK inhibitors, represented by the success of the irreversible BTK inhibitors, ibrutinib and acalabrutinib. Constantly emerging agents exhibiting superior efficacy and safety in preclinical and clinical studies provide promising therapeutics for the treatment of B cell malignancies.