Aplastic anemia triggered by the Bruton tyrosine kinase inhibitor acalabrutinib in two patients with mantle cell lymphoma - A case report.

The use of Bruton's tyrosine kinase inhibitors (BTKi) is rapidly increasing for patients with mantle cell lymphoma (MCL). Side effects reported so far are usually manageable. However, here we present two cases of life-threatening aplastic anemia (AA) upon treatment with the BTKi acalabrutinib for MCL. The first patient died of neutropenic infection secondary to AA. The second patient was successfully treated with immunosuppressive treatment but the MCL relapsed shortly thereafter. AA is a potentially fatal complication that should be considered when patients present with pancytopenia during treatment with BTKi.