Efficacy of Zanubrutinib

The effects of zanubrutinib (Zanubrutinib) were compared with the BTK inhibitor ibrutinib in a major study of 201 patients with Waldenström's macroglobulinemia (WM) who had not previously received BTK inhibitor therapy. Zanubrutinib showed similar effects to ibrutinib. After an average of 20 months of treatment, about 28% of patients who received zanubrutinib showed little sign of cancer (very good partial response), compared with 19% of patients who received ibrutinib. Beneficial effects were seen in patients who had not previously received treatment and in those whose cancer had returned or failed to respond to previous treatments.

The primary study of zanubrutinib in marginal zone lymphoma involved 66 patients whose cancer had relapsed or failed to respond to previous treatments targeting CD20. Overall, after an average of 28 months of treatment, about 68% of patients had at least a partial response, 26% had a complete response (no evidence of cancer), and 42% had a partial response. Mantle cell lymphoma (MCL) was studied in two multicenter clinical trials with a combined overall response rate of 84% in 118 patients. The duration of response is 14-18 months. Although 57% of patients experienced grade 3 and 4 adverse side effects, including anemia, pneumonitis, and neutropenia, only 8% discontinued treatment, suggesting that zanubrutinib monotherapy was well tolerated and that zanubrutinib has greater BTK selectivity, which may result in fewer off-target effects and improve the potential for combination with other targeted therapies.

Two major ongoing studies are investigating the benefits of zanubrutinib in chronic lymphocytic leukemia. In the first study, involving patients with chronic lymphocytic leukemia (CLL) or small lymphocytic leukemia whose disease had not been previously treated, zanubrutinib was compared with bendamustine plus rituximab. After an average of about 23 months of treatment, about 15% of patients who received zanubrutinib experienced death or signs of cancer progression, compared with about 30% of patients who received bendamustine plus rituximab.

In a second study, patients with chronic lymphocytic leukemiaor small lymphocytic leukemia(whose disease did not improve (refractory) or relapsed after at least one prior treatment) were compared. Zanubrutinib showed similar effects to ibrutinib. After an average of approximately 14 months of treatment, approximately 78% of patients treated with zanubrutinib and approximately 63% of patients treated with ibrutinib had a response to the disease.

The original drug of zanubrutinib has been launched in China and has been included in the medical insurance. The price of 80mg*64 capsules per box may be around 6,000 yuan. The original drug of zanubrutinib marketed overseas is relatively expensive. There are currently no generic drugs of zanubrutinib on the market.