PS1178 TREATMENT AND OUTCOME OF CHRONIC MYELOID LEUKEMIA IN CHILDREN AND ADOLESCENTS: THE INDIAN PEDIATRIC ONCOLOGY GROUP‐CML‐16–01 MULTICENTRIC STUDY

Background: Multicentric trials are infrequently reported from low and middle‐income countries (LMIC). The Indian Pediatric Oncology Group (InPOG) was established with the aim of improving outcomes in childhood cancer through collaborative research. Aims: To describe the characteristics of pediatric chronic myeloid leukemia (CML) and the long‐term outcome with frontline imatinib in a collaborative multicentric data collection study from India. Methods: An invitation to participate in the InPOG‐CML‐16–01 study was mailed to the members of the Hematology‐Oncology chapter of the Indian Academy of Pediatrics. Patients with CML, aged ≤18 years at diagnosis and diagnosed during 2003–2018 were included. Data was collected by retrospective file review. The 2006 European LeukaemiaNet criteria were used to define the disease phase and response to therapy. Institutional ethics committee clearance was obtained by the participating centres. Results: Nine centres across India consented to participate; 171 children/adolescents with CML were reported. Ten patients were excluded for inadequate data (6), older age (2) and referral to another centre (2). Of the 161 patients included for analysis, 110 (68%) were males. The mean age at diagnosis was 9.7 ± 3.5 years (range: 2.0–18.0). Splenomegaly was observed in 154 (96%). The mean size of the spleen was 12.1 ± 5.1 cm below costal margin. The median haemoglobin, total leukocyte count and platelet count were 8.8 g/dL (range: 3.7–16.9), 215.5 x10 3 /μL (range: 14.6–1049) and 365 x10 3 /μL (range: 28–1570). The baseline disease phase was chronic phase (CP), accelerated phase (AP) and blast crisis (BC) in 148 (92%), 6 (3.7%) and 7 (4.3%) patients, respectively. The mean dose of imatinib was 311.2 ± 47.8 mg/m 2 /day (range: 200–500). The source of funding was self‐financed (42%), GIPAP (25%) and others (33%). Twenty‐two (14%) patients abandoned therapy after a median duration of 6.5 months (range: 1–53). CHR at 3 months, CCyR at 12 months and MMR at 18 months were attained in 125/140 (89%), 51/55 (93%) and 65/84 (77%) patients, respectively. Two (1.4%) and 14 (9.5%) progressed to AP and BC, respectively. The median time to progression was 10 months (range: 3–64). The OS for the entire cohort was 84.4 ± 4.3% and the progression‐free survival (PFS) for patients in CP was 81.1 ± 4.8% at a median duration of 28 months (range: 1–171). Fifteen patients died (14: blast crisis; 1: pulmonary embolism). One patient underwent HSCT for BC. No centre reported major adverse events that necessitated permanent cessation of imatinib. The study represents one of the first co‐operative efforts to evaluate the outcome of pediatric CML in LMIC. The limitations include the retrospective study design, representation of selected/limited centres and heterogeneity of response assessment. Acknowledgements: Chepsy C Philip (Christian Medical College, Ludhiana); Sujata Sharma (Lokmanya Tilak Municipal Medical College & General Hospital, Mumbai), Sonali Mohapatra (All India Institute of Medical Sciences, Bhubaneswar), Yamini Krishnan (MVR Cancer Centre and Research Institute, Kozhikode) Summary/Conclusion: The PFS of 161 children/adolescents with CML from 9 centres across India was 81.1 ± 4.8%. Additional highlights included male preponderance (68%), treatment abandonment (14%) and scarcity of patients undergoing HSCT.