Background Outcomes in blast phase CML (CML-BP) are historically dismal. We sought to analyse the characteristics, prognostic factors and survival outcomes in patients with CML-BP in the TKI era. Methods All patients with CML-BP (n=477) were treated with a TKI at some point during the course of their CML. Cox proportional hazard models identified characteristics which predicted for survival. Overall survival (OS) and failure free survival (FFS) were assessed. Optimal cut off points for specific parameters, were identified using CART (classification and regression tree). Results Median age was 53 years (range, 16 to 84); 64% were male. Eighty percent were initially diagnosed in chronic phase CML (CML-CP) median 41 months (0.7 to 298 months) before transformation to CML-BP. De-novo CML-BP occurred in 71 patients. Seventy two percent patients received TKI therapy prior to CML-BP. Initial therapy for CML-BP included, TKI alone (35%), TKI with chemotherapy (46%) and non-TKI therapies (19%). The median OS was 12 months and median FFS was 5 months. In multivariate analysis, myeloid immunophenotype, prior TKI, age ≥58 years, LDH ≥1227 IU/L, platelet count <102 K/μL, no stem cell transplantation (SCT), blast phase from CP/AP and presence of chromosome 15 aberrations predicted for a significantly increased risk of death. Achievement of major hematologic response and/or complete cytogenetic response to first line treatment predicted for better survival. Combination of TKI with intensive chemotherapy followed by stem cell transplant confer the best outcome. Conclusions Patients with CML-BP continue to pose a therapeutic challenge, have dismal outcomes and require newer treatment approaches.

Long term outcomes and mutations in patients with mantle cell lymphoma (MCL) who discontinued ibrutinib have not been described. Using deep targeted next generation sequencing, we performed somatic mutation profiling from 15 MCL patients (including 5 patients with paired samples; before and after progression on ibrutinib). We identified 80 patients with MCL who discontinued ibrutinib therapy for various reasons. Median follow-up after ibrutinib discontinuation was 38 months. The median duration on ibrutinib was 7·6 months. Forty-one (51%) patients discontinued ibrutinib due to disease progression/transformation, 20 (25%) for intolerance, 7 (9%) due to patient choice, 5 (6%) for stem cell transplant, 4 (5%) due to second cancers and 3 (4%) other causes. The median survival after ibrutinib was 10 and 6 months for disease progression and transformation, respectively, and 25 months for patients with ibrutinib intolerance. Overall, BTK mutations were observed in 17% patients after progression on ibrutinib. Notably, TP53 alterations were observed after progression in 75% patients. Among the 4 patients with blastoid transformation, 3 (75%) had NSD2 mutations (co-existing with TP53). Ibrutinib-refractory MCL patients had a short survival. Demonstration of TP53 and NSD2 mutations in patients who developed blastoid transformation and ATM and TP53 mutations in patients who progressed, opens the door for future investigations in ibrutinib-refractory MCL.