Zanubrutinib Can Rapidly Improve Clinical Features Especially Anemia in Newly Diagnosed Waldenström Macroglobulinemia

Waldenström macroglobulinemia (WM) is a rare lymphoproliferative disease with an ambiguous clinical presentation. It is well established that bone marrow infiltration is a key component of the pathophysiology of WM, which most commonly presents as anemia. The phase III ASPEN study has already demonstrated the comparable efficacy and improved safety of zanubrutinib versus ibrutinib in patients with WM. Here, we presented a real-world study about zanubrutinib and WM in different center.

A total of 30 newly diagnosed WM patients from Ruijin Hospital and Shanghai Tenth People's Hospital was included in this retrospective study. All patients received zanubrutinib as monotherapy. The median age of the 30 patients was 65 years（range 36-85 years）with 17 patients >65 years, the ratio of male to female was 1.5:1, and all patients met the indications for treatment. The majorities of patients (24/30, 80%) presented with non-specific symptoms such as fatigue, weight loss and fever. Additionally, three patients presented with significantly enlarged lymph nodes, 2 with bleeding and 1 with Reynolds phenomenon. According to IPSS, these patients can be categorized with high-risk (26.7%, 8/30), intermediate-risk (43.3%, 13/30) and low-risk (30%, 9/30). At the time of initial diagnosis, the median level of IgM was 20.3g/L (1.3-84.8g/L), while the median haemoglobin level was 95g/L (49-149g/L). In addition, MYD88 L265P mutation was detected in 81.5% (22/27) cases. All patients were treated with zanubrutinib as monotherapy, with a median time to first treatment (TTFT) of 3.3 months (range 0.4-28.1). The median duration of zanubrutinib therapy was 15.5 months (range 1.0-57.0). Zanubrutinib was well tolerated and no patients need to discontinue treatment. Further efficacy analysis demonstrated 24 patients showing strikingly improvement about hemoglobin levels and the median response time was 3.0 months (range 0.2-12 months). A significantly reduction of IgM level was also observed in 23 patients after 3 months treatment of zanubrutinib, with a median percentage reduction of 52% (50%-94%). We concluded that zanubrutinib can rapidly improve clinical features especially anemia in the treatment of newly diagnosed WM, which will largely boost confidence of clinicians as well as patients and finally be benefit to cure this disease.

Keywords:

Waldenström macroglobulinemia, Zanubrutinib, anemia

No relevant conflicts of interest to declare.

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