Welcome back to the D.I.S.C.O., FDA’s Drug Information Soundcast in Clinical Oncology, Burst Edition, brought to you by FDA’s Division of Drug Information in partnership with FDA’s Oncology Center of Excellence. Today we have a quick update on another recent FDA cancer drug approval.
On August 31, 2021, FDA approved zanubrutinib (brand name Brukinsa) for adult patients with Waldenström’s macroglobulinemia.
Zanubrutinib was investigated in ASPEN, a randomized, active control, open-label trial, comparing zanubrutinib and ibrutinib in patients with MYD88 L265P mutation Waldenström’s macroglobulinemia. Patients in Cohort 1 were randomized 1:1 to receive zanubrutinib or ibrutinib until disease progression or unacceptable toxicity. Cohort 2 enrolled patients with MYD88 wildtype or MYD88 mutation unknown Waldenström’s macroglobulinemia and received zanubrutinib.
The major efficacy outcome used to support approval was response rate defined as partial response or better as assessed by an independent review committee based on standard consensus response criteria from the International Workshop on Waldenström’s Macroglobulinemia-6. An additional efficacy outcome measure was duration of response.
Approval was based on a non-comparative assessment of response and duration of response from the zanubrutinib arms. The response rate was 77.5% in the zanubrutinib arm. Event-free duration of response at 12 months was 94.4% in the zanubrutinib arm. In Cohort 2, response as assessed by independent review committee was seen in 50%.
The most common adverse reactions reported in more than 20% of patients, including laboratory abnormalities, were neutrophil count decreased, upper respiratory tract infection, platelet count decreased, rash, hemorrhage, musculoskeletal pain, hemoglobin decreased, bruising, diarrhea, pneumonia, and cough.
Full prescribing information for these approvals can be found on the web at www.fda.gov/drugsatFDA.
Health care professionals should report serious adverse events to FDA’s MedWatch Reporting Program at www.fda.gov/medwatch.
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