The purpose of this study is to evaluate the efficacy, safety, PK characteristics in subjects
with relapsed/refractory B-cell lymphoma. Furthermore, the relationship between the exposure
level of Keynatinib and its efficacy and safety, the penetration rate of keynatinib in the
Blood-Brain Barrier (BBB) and its PK characteristics in cerebrospinal fluid in R/R-PCNSL
patients, the relationship between the BTK receptor occupancy rate and the efficacy are also
evaluated.