Multicenter, Prospective and Retrospective Observational Cohort Study of Ponatinib in Patients with CML in Italy: Interim Analysis of the OITI Trial

Background. Ponatinib is a third-generation tyrosine kinase inhibitor indicated for adult patients with resistant or intolerant chronic phase (CP), accelerated phase (AP) or blast phase (BP) chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia, or for those carrying the T315I mutation. In the real-world setting, there is a paucity of data regarding the use of ponatinib. The goal of the Observational study of Iclusig® (ponatinib) Treatment in patients with CML in Italy (OITI) is to evaluate treatment patterns and outcomes, including the safety and efficacy of ponatinib, in patients with CML treated in hematology centers in Italy since January 2015, when ponatinib became commercially available. Methods. This ongoing, non-interventional study includes patients aged ≥18 years with CP, AP or BP CML who initiated ponatinib treatment in routine clinical practice across 40 centers (academic and hospital settings) as of October 2018. The study population consists of a prospective cohort, including patients who started treatment with ponatinib after site activation during the ongoing enrolment period; a retrospective cohort, including patients who started treatment with ponatinib but who died or were lost to follow-up prior to site activation; and a retrospective/prospective cohort, including patients who started treatment with ponatinib prior to site activation and are still on treatment. Demographic, efficacy and safety data are collected from patient medical charts at study entry and at routine care visits. The primary endpoint is complete cytogenetic response (CCyR) rate in patients with CP CML 6 months after starting ponatinib treatment. Here, the first interim analysis after ≥6 months' observation is presented for the retrospective and retrospective/prospective cohorts. Results. At time of data analysis (02 July 2019), 56 patients (53 CP, 1 AP and 2 BP CML) had been enrolled across 21 Italian centers. Twenty-eight (50.0%) patients had received ponatinib as second-line (2L) treatment and 33.9% received ponatinib in third-line (3L). Twenty (35.7%) patients had a history of cardiovascular events and 23 (41.1%) had a history of hypertension. Among patients with CP, AP and BP CML, median age at study entry was 59.1, 33.7 and 48.5 years, respectively; among 37 evaluable patients, 12 (32.4%), 1 (2.7%) and 1 (2.7%) patient(s) had a confirmed BCR-ABL1 mutation. Of evaluable patients, 4 (10.8%) had the T315I mutation. The star