Peripheral blasts are associated with responses to ruxolitinib and outcomes in patients with chronic‐phase myelofibrosis
Francesca Palandri, Daniela Bartoletti, Alessandra Iurlo, Massimiliano Bonifacio, Elisabetta Abruzzese, Giovanni Caocci, Elena Maria Elli, Giuseppe Auteri, Mario Tiribelli, Nicola Polverelli, Maurizio Miglino, Florian H. Heidel, Alessia Tieghi, Giulia Benevolo, Eloise Beggiato, Carmen Fava, Francesco Cavazzini, Novella Pugliese, Gianni Binotto, Costanza Bosi, Bruno Martino, Monica Crugnola, Emanuela Ottaviani, Giorgia Micucci, Malgorzata Monika Trawinska, Antonio Cuneo, Monica Bocchia, Mauro Krampera, Fabrizio Pane, Roberto M. Lemoli, Daniela Cilloni, Nicola Vianelli, Michèle Cavo, Giuseppe A. Palumbo, Massimo Breccia
Abstract
BACKGROUND: The presence of peripheral blasts (PB) is a negative prognostic factor in patients with primary and secondary myelofibrosis (MF) and PB ≥4% was associated with a particularly unfavorable prognosis. Ruxolitinib (RUX) is the JAK1/2 inhibitor most used for treatment of MF-related splenomegaly and symptoms. Its role has not been assessed in correlation with PB. METHODS: In 794 chronic-phase MF patients treated with RUX, we evaluated the impact of baseline percentage of PB on response (spleen and symptoms responses) and outcome (RUX discontinuation-free, leukemia-free, and overall survival). Three subgroups were compared: PB-0 (no PB, 61.3%), PB-4 (PB 1%-4%, 33.5%), and PB-9 (PB 5%-9%, 5.2%). RESULTS: At 3 and 6 months, spleen responses were less frequently achieved by PB-4 (P = .001) and PB-9 (P = .004) compared to PB-0 patients. RUX discontinuation-free, leukemia-free, and overall survival were also worse for PB-4 and PB-9 patients (P = .001, P = .002, and P < .001, respectively). CONCLUSIONS: Personalized approaches beyond RUX monotherapy may be useful in PB-4 and particularly in PB-9 patients.