TP53 and B-cell chronic lymphocytic leukemia: In the European Union, Zydelig is indicated, in combination with rituximab, for the treatment of patients with relapsed chronic lymphocytic leukemia and refractory follicular B cell non-Hodgkin lymphoma and as first line therapy in chronic lymphocytic leukemia patients with 17p deletion or TP53 mutation who are unsuitable for chemoimmunotherapy (19).