Treatment-free remission after a second TKI discontinuation attempt in patients with Chronic Myeloid Leukemia re-treated with dasatinib – interim results from the DAstop2 trial
Hjalmar Flygt, Stina Söderlund, Johan Richter, Susanne Saußele, Perttu Koskenvesa, Leif Stenke, Satu Mustjoki, Andreja Dimitrijevic, Jesper Stentoft, Waleed Majeed, Lydia Roy, Dominik Wolf, Arta Dreimane, Bjørn Tore Gjertsen, Tobias Gedde‐Dahl, Erik Ahlstrand, Berit Markevärn, Henrik Hjorth‐Hansen, Jeroen J. W. M. Janssen, Ulla Olsson‐Strömberg
Abstract
Abstract Tyrosine kinase inhibitor (TKI) discontinuation in chronic myeloid leukemia (CML) has become part of routine care for patients with a sustained deep molecular response (DMR). Approximately 50% experience a molecular relapse upon TKI cessation. Most of them quickly regain DMR upon TKI resumption. Whether these patients can achieve a second treatment-free remission (TFR) remains unclear. DAstop2 (ClinicalTrials.gov ID: NCT03573596) is a prospective study including patients with a failed first TFR attempt re-treated with any TKI for ≥ one year. Upon entering the study, patients received the TKI dasatinib for additional two years. Patients with sustained DMR for ≥1 year qualified for a second TKI stop. Ninety-four patients were included between Oct 2017-Dec 2021. At the time of data analysis, 62 patients had attempted a 2 nd stop. After a median follow-up of 27 months from 2 nd stop, TFR rates were 61, 56 and 46% at 6, 12 and 24 months respectively. No progression to advanced stage disease was seen and 87% had re-achieved MR 4 within a median of 3 months from TKI re-initiation. In summary, we show that a 2 nd TFR attempt after dasatinib treatment is safe, feasible and TFR rates seem in the range of those reported in trials of a first TKI stop.