T-cell prolymphocytic leukaemia in a patient with chronic myeloid leukaemia receiving nilotinib: first documented report

Since the introduction of imatinib, the first oral tyrosine kinase inhibitor (TKI) targeting the Philadelphia Chromosome, the prognosis in chronic myelogenous leukaemia (CML) has dramatically improved.1 Although there have been multiple reports demonstrating a T/Natural Killer (NK) cell monoclonal lymphocytosis with the use of dasatinib and some studies showing a small increased risk of second malignancies with the use of TKIs in CML, an association between nilotinib and rare haematological malignancies has not been established.2–6 Herein, we report the first case of T-cell prolymphocytic leukaemia (T-PLL) occurring in a patient with CML in sustained deep-molecular response after nilotinib therapy. A patient in her 60s (age) was diagnosed with chronic phase CML in 2008. The karyotype at diagnosis showed the classic Philadelphia chromosome (46,XX,t(9;22)(q34;q11)). Real-time quantitative polymerase chain reaction (RT qPCR) for BCR-ABL1 detected an e14a2 transcript type. She was started on first-line nilotinib 400 mg two times a day as part of the Evaluating Nilotinib Efficacy and Safety in Clinical Trials-Newly Diagnosed Patients (ENESTnd) trial (a randomised controlled trial comparing nilotinib at two doses of 300 mg two times a day and 400 mg two times a day, with imatinib 400 mg once a day). She achieved optimal response at 3 months of treatment as per the 2013 European Leukaemia Net (ELN) guidelines and 5-log reduction (MR5; RT qPCR for …