Search

The article discusses the use of ruxolitinib after fedratinib failure in patients with myelofibrosis. It presents a case series of 14 patients who received ruxolitinib after fedratinib therapy, detailing their clinical outcomes and responses. The study highlights the potential clinical benefit of second-line ruxolitinib, achieving spleen and symptoms response in a subset of patients. The findings suggest that sequential use of ruxolitinib after fedratinib may be beneficial for selected patients, with no observed excess toxicity in the second-line setting. [Extracted from the article]

Calreticulin (CALR) mutations are detected in around 20% of patients with primary and post-essential thrombocythemia myelofibrosis (MF). Regardless of driver mutations, patients with splenomegaly and symptoms are generally treated with JAK2-inhibitors, most commonly ruxolitinib. Recently, new therapies specifically targeting the CALR mutant clone have entered clinical investigation. To collect information on efficacy and safety of ruxolitinib in CALR-mutated patients, we report a sub-analysis of the "RUX-MF" (NCT06516406) study, comprising 135 CALR-mutated and 786 JAK2-mutated ruxolitinib-treated patients. Compared to JAK2-mutated patients, CALR-mutated patients started ruxolitinib with a more severe disease (higher peripheral blast counts, lower hemoglobin levels and worse marrow fibrosis) and after a longer median time from diagnosis (2.6 versus 0.7 years, p < 0.001). At 6 months, spleen responses were numerically inferior in CALR-mutated patients, who also had significantly lower rates of symptom responses (56.1% versus 66.7%, p = 0.04)., Competing Interests: Declarations. Competing interests: Francesca Palandri reports consultancy and honoraria from Novartis, BMS, AOP, Sierra Oncology, Incyte, Telios, Abbvie, Constellation-Morphosys, Sobi and GSK. Giulia Benevolo reports honoraria from Novartis, Janssen, Amgen, Takeda, and BMS. Massimo Breccia reports honoraria from Novartis, BMS, Pfizer, Incyte and is the Editor-in Chief of Annals of Hematology. Massimiliano Bonifacio reports honoraria from Novartis, BMS, Pfizer, and Incyte. Monica Crugnola reports honoraria from Novartis and Amgen. Gianni Binotto reports honoraria from Novartis, Incyte, BMS-Celgene, and Pfizer. Roberto M. Lemoli reports honoraria from Jazz, Pfizer, AbbVie, BMS, Sanofi, and StemLine. Fabrizio Pane reports honoraria from Incyte, Novartis, Jazz, BMS-Celgene, Amgen, and Gilead. Giuseppe A. Palumbo reports consultancy and honoraria from Abbvie, AOP, AstraZeneca, BMS, Incyte, GSK, Morphosys, and Novartis., (© 2025. The Author(s).)

Background: Ruxolitinib (RUX) is a JAK1/2 inhibitor approved for the therapy of myelofibrosis (MF) based on clinical trials including only intermediate2-high risk (INT2/HIGH) patients. However, RUX is commonly used in intermediate-1 (INT1) patients, with scarce information on responses and outcome., Methods: The authors investigated the benefit of RUX in 1055 MF patients, included in the "RUX-MF" retrospective study., Results: At baseline (BL), 595 (56.2%) patients were at INT1-risk according to DIPSS (PMF) or MYSEC-PM (SMF). The spleen was palpable at <5 cm, between 5 and 10 cm, and >10 cm below costal margin in 5.9%, 47.4%, and 39.7% of patients, respectively; 300 (54.1%) were highly symptomatic (total symptom score ≥20). High-molecular-risk (HMR) mutations (IDH1/2, ASXL-1, SRSF2, EZH2, U2AF1 Q157 ) were detected in 77/167 patients. A total of 101 (19.2%) patients had ≥1 cytopenia (Hb < 10 g/dL: n.36; PLT <100 x 10 9 /L: n = 43; white blood cells <4 x 10 9 /L: n = 40). After 6 months on RUX, IWG-MRT-defined spleen and symptoms response rates were 26.8% and 67.9%, respectively. In univariate analysis, predictors of SR at 6 months were no HMR mutations odds ratio [OR], 2.0, p = .05], no cytopenia (OR, 2.10; p = .01), and blasts <1% (OR, 1.91; p = .01). In multivariate analysis, absence of HMR maintained a significant association (OR, 2.1 [1.12-3.76]; p = .01)., Conclusions: In INT1 patients, responses were more frequent and durable, whereas toxicity rates were lower compared to INT2/high-risk patients. Presence of HMR mutations, cytopenia, and peripheral blasts identified less-responsive INT1 patients, who may benefit for alternative therapeutic strategies., (© 2024 The Author(s). Cancer published by Wiley Periodicals LLC on behalf of American Cancer Society.)

Background: Anemia is frequently present in patients with myelofibrosis (MF), and it may be exacerbated by treatment with the JAK2-inhibitor ruxolitinib (RUX). Recently, a relevant blast phase (BP) incidence has been reported in anemic MF patients unexposed to RUX., Methods: The authors investigated the incidence of BP in 886 RUX-treated MF patients, included in the "RUX-MF" retrospective study., Results: The BP incidence rate ratio (IRR) was 3.74 per 100 patient-years (3.74 %p-y). At therapy start, Common Terminology Criteria for Adverse Events grade 3-4 anemia (hemoglobin [Hb] <8 g/dL) and severe sex/severity-adjusted anemia (Hb <8/<9 g/dL in women/men) were present in 22.5% and 25% patients, respectively. IRR of BP was 2.34 in patients with no baseline anemia and reached respectively 4.22, 4.89, and 4.93 %p-y in patients with grade 1, 2, and 3-4 anemia. Considering the sex/severity-adjusted Hb thresholds, IRR of BP was 2.85, 4.97, and 4.89 %p-y in patients with mild/no anemia, moderate, and severe anemia. Transfusion-dependent patients had the highest IRR (5.03 %p-y). Progression-free survival at 5 years was 70%, 52%, 43%, and 27% in patients with no, grade 1, 2, and 3-4 anemia, respectively (p < .001). At 6 months, 260 of 289 patients with no baseline anemia were receiving ruxolitinib, and 9.2% had developed a grade 3-4 anemia. By 6-month landmark analysis, BP-free survival was significantly worse in patients acquiring grade 3-4 anemia (69.3% vs. 88.1% at 5 years, p < .001)., Conclusions: This study highlights that anemia correlates with an increased risk of evolution into BP, both when present at baseline and when acquired during RUX monotherapy. Innovative anemia therapies and disease-modifying agents are warranted in these patients., (© 2023 The Authors. Cancer published by Wiley Periodicals LLC on behalf of American Cancer Society.)

Most patients with myelofibrosis (MF) discontinue ruxolitinib (JAK1/JAK2 inhibitor) in the first 5 years of therapy due to therapy failure. As the therapeutic possibilities of MF are expanding, it is critical to identify patients predisposed to early ruxolitinib monotherapy failure and worse outcomes. We investigated predictors of early ruxolitinib discontinuation and death on therapy in 889 patients included in the "RUX-MF" retrospective study. Overall, 172 patients were alive on ruxolitinib after ≥5 years (long-term ruxolitinib, LTR), 115 patients were alive but off ruxolitinib after ≥5 yrs (short-term RUX, STR), and 123 patients died while on ruxolitinib after <5 yrs (early death on ruxolitinib, EDR). The cumulative incidence of the blast phase was similar in LTR and STR patients ( p = 0.08). Overall survival (OS) was significantly longer in LTR pts ( p = 0.002). In multivariate analysis, PLT < 100 × 10 9 /L, Hb < 10 g/dL, primary MF, absence of spleen response at 3 months and ruxolitinib starting dose <10 mg BID were associated with higher probability of STR. Assigning one point to each significant variable, a prognostic model for STR (STR-PM) was built, and three groups were identified: low (score 0-1), intermediate (score 2), and high risk (score ≥ 3). The STR-PM may identify patients at higher risk of failure with ruxolitinib monotherapy who should be considered for alternative frontline strategies.