Bruton’s tyrosine kinase inhibitor zanubrutinib-based regimens in relapsed/refractory primary diffuse large B-cell lymphoma of the central nervous system

Patients with relapsed/refractory primary central nervous system lymphoma (R/R PCNSL) usually have a poor prognosis and limited treatment options. We respectively reviewed 38 patients with R/R PCNSL treated with zanubrutinib-based regimens in our center. The overall response rate, complete response rate and disease control rate were 76.3%, 47.4% and 92.1%, respectively. The median progression-free survival (PFS) was 31.0 months, the median overall survival (OS) was not reached. Unitivariate analysis by Cox's proportional hazards model revealed that overall response (vs. no response, HR = 0.18, 95%CI:0.07,0.48, p = 0.001), long duration of zanubrutinib (≥6months vs 2-5 months, HR = 0.20, 95%CI:0.06,0.63, p = 0.006) were independent factors for prolonged PFS. The log-rank analysis indicated a prolongation of PFS among patients exhibiting a higher Tumor mutational burden (TMB, ≥14.75muts/Mb) following zanubrutinib-based treatment (p = 0.016). Our data showed promising efficacy with tolerable safety of zanubrutinib-based therapies in patients with R/R PCNSL. Long duration of zanubrutinib may be associated with prolonged PFS.