Baseline Characteristics Of Patients With Chronic Myeloid Leukemia In a Prospective Observational Study (SIMPLICITY)

Oral BCR-ABL tyrosine kinase inhibitors (TKIs), including imatinib (IM), dasatinib (DAS) and nilotinib (NIL), have improved survival in chronic-phase chronic myeloid leukemia (CP-CML). Few data are available that compare TKIs in daily clinical practice across multiple regions.

SIMPLICITY is an ongoing observational cohort study of adult patients with newly diagnosed CP-CML receiving first-line treatment with IM, DAS or NIL in the USA and Europe (Eu) outside of clinical trials (NCT01244750). The primary objective is to assess effectiveness of these TKIs in clinical practice. The study includes three ‘prospective’ cohorts of patients treated with IM, DAS or NIL since 2010 (the study opened after first-line approval of all three TKIs) and a ‘historical’ cohort treated with IM since 2008. Preliminary baseline demographics are presented for prospective cohorts.

860 prospective patients (Eu: 32%, USA: 68%) were enrolled through June 20, 2013, receiving IM (n=399), DAS (n=229) or NIL (n=232). Median age at initiation of first-line TKI was 56 years, with significant differences in pairwise comparisons between DAS and IM and NIL and IM (Table). Demographics were consistent across cohorts. Only 30% of patients had Hasford or Sokal scores recorded. ECOG performance status (PS) was available in 54% of patients. The number of baseline comorbidities per patient (mean: 3.2 + 2.7) was balanced across cohorts; 51% of patients presented with ≥3 comorbidities. Patients in the IM cohort had a higher prevalence of gastrointestinal comorbidities (P=.006 and .007 for DAS vs IM and NIL vs IM, respectively), and the NIL cohort had a higher prevalence of musculoskeletal comorbidities than the DAS cohort (P=.015). The proportions of patients with cardiovascular comorbidities were 38%, 36% and 42% in the DAS, NIL and IM cohorts, respectively, consisting primarily of hypertension (31%) and hyperlipidemia (17%) (P>.05 across cohorts). Coronary artery disease was present in 9%, cardiac arrhythmias in 6%, myocardial infarction in 3% and peripheral arterial disease in 2% of patients. The proportion of patients with diabetes was 10%. Clinicians reported effectiveness as the most common reason for TKI selection; familiarity and cost were also cited as reasons for IM selection (P<.001 vs DAS and NIL). Comorbidities were not drivers of TKI selection in this analysis.

This is the first report from the prospective cohorts of SIMPLICITY. Demographics were consistent across cohorts. Overall, the SIMPLICITY population is older with potentially more comorbidities than patients enrolled in first-line clinical trials with restrictive inclusion criteria (NEJM 2003 348 994; NEJM 2010 362 2260; NEJM 2010 362 2251). Initial TKI selection does not appear to be driven by baseline comorbidity, rather by perceived effectiveness, cost and familiarity. Hasford/Sokal scores were not recorded in the majority of patients prior to starting first-line TKI therapy. Outcomes data are being collected across cohorts that will inform about a multi-region population treated outside clinical trials.

Cortes:Ariad: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Teva: Consultancy, Honoraria, Research Funding. Hehlmann:Novartis: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding. Gambacorti-Passerini:Bristol-Myers Squibb: Consultancy; Pfizer: Honoraria, Research Funding. Goldberg:Bristol-Myers Squibb: Honoraria, Research Funding, Speakers Bureau; Novartis Oncology: Honoraria, Research Funding, Speakers Bureau; Ariad: Honoraria, Research Funding, Speakers Bureau. Khoury:Bristol-Myers Squibb: Honoraria; Pfizer: Honoraria; Ariad: Honoraria; Teva: Honoraria. Mauro:Novartis Oncology: Consultancy, Honoraria, Research Funding; Ariad: Consultancy, Honoraria, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Speakers Bureau. Michallet:Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Astellas: Consultancy, Honoraria, Research Funding; MSD: Consultancy, Honoraria, Research Funding; Genzyme: Consultancy, Honoraria, Research Funding. Paquette:Ariad: Consultancy; Incyte: Consultancy, Honoraria; Novartis: Consultancy. Foreman:ICON Clinical Research: Employment, My employer ICON Clinical Research receives research funding from pharmaceutical companies including manufacturers of CML drugs Other. Mohamed:Bristol-Myers Squibb: Employment. Zyczynski:Bristol-Myers Squibb: Employment. Hirji:Bristol-Myers Squibb: Employment. Davis:Bristol-Myers Squibb: Employment.