Zanubrutinib Versus Ibrutinib: Which is Better for WM?

According to a story from, the biopharmaceutical company BeiGene, Ltd. recently released the results of a phase 3 clinical trial. The goal of this trial was the comparison of the company’s drug zanubrutinib (marketed as BRUKINSA) to ibrutinib as a treatment for the rare blood cancer Waldenström’s macroglobulinemia (WM). Both of these drugs are classed as BTK inhibitors. The results of this trial failed to demonstrate significantly significant superiority of one drug over the other.

About Waldenström’s Macroglobulinemia (WM)

Waldenström’s macroglobulinemia, which is also known as lymphoplasmacytic lymphoma, is a rare type of blood cancer that affects two types of B lymphocytes, including plasma cells and lymphoplasmacytoid cells. A distinct characteristic of this type of cancer is the presence of a high concentration of IgM antibodies. It is a slow progressing form of blood cancer, and many patients can lead active lives. While it cannot be cured, it is treatable; some patients are able to experience years of remission without symptoms. There are only about 1,500 new cases per year in the U.S. Although it mostly occurs due to sporadic genetic mutations, a family history increases risk. Symptoms include vision loss, headaches, enlargement of the lymph nodes, liver, and spleen, bleeding nose and gums, weight loss, fatigue, and general weakness. To learn more about WM, click here.

Study Findings

The study found that zanubrutinib and ibrutinib were effective at comparable levels without either drug carrying an overwhelming advantage over the other. However, there were some minor findings in favor of zanubrutinib. The study included 229 WM patients. The study found that the very good partial response (VGPR) rate was 28.4 percent for zanubrutinib and 19.2 percent for ibrutinib. The major response rate (partial response or better) was 77.5 percent for zanubrutinib and 77.8 percent for ibrutinib. The 12 month progression free survival rate was 89.7 percent and 87.2 percent, respectively.

Another finding that slightly favored zanubrutinib was in safety, with 58.4 percent of patients using the drug experiencing serious adverse effects versus 63.3 percent of ibrutinib users. 

Overall, the differences between the two drugs were slight. However, BeiGene plans to continue comparing the drugs in treating other forms of blood cancer, such as chronic lymphocytic leukemia.

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