Ruxolitinib Shows Sustained Clinical, QOL Benefits in Real-World Data

Patients with myelofibrosis treated with ruxolitinib (Jakafi; Incyte) showed persistent responses in the phase 4 JAKoMo study (NCT05044026), along with fewer adverse events than in published randomized trials.1 The findings were published in the European Journal of Hematology.

Ruxolitinib, a Janus kinase (JAK) inhibitor, was initially approved more than a decade ago for the treatment of myelofibrosis and remains the standard of care.2 The development of JAK inhibitors has significantly improved the pharmacologic management of myelofibrosis, the authors of the current study explained.1 Ruxolitinib was the first JAK inhibitor approved for myelofibrosis, and published research has shown it has significant efficacy and may improve survival.

Regarding survival, outcomes were similar to those seen in clinical trials of ruxolitinib for myelofibrosis. | Image credit: fotogurmespb - stock.adobe.com

However, formal interventional trials can be limited in their generalizability, the authors noted. The JAKoMo trial, which was a long-term, noninterventional study, assessed ruxolitinib use in the routine clinical setting at 122 centers in Germany. Researchers evaluated the efficacy, safety, and quality of life (QOL) effects of ruxolitinib in 943 adult patients with primary myelofibrosis (PMF), myelofibrosis following polycythemia vera (PPV-MF), or secondary to essential thrombocythemia (PET-MF).

“JAKoMo was an observational, real-world study reflecting routine clinical usage of [ruxolitinib] employed at individual physician's discretion for [myelofibrosis] treatment in Germany,” the authors wrote. “These real-world data complement published clinical trial and expanded access results and reveal several features that differ from the clinical trial experience. Unfortunately, due to a limited data set and its focus on safety and efficacy, there was only limited data on patient details such as comorbidities collected, and, therefore, further analysis, including their influence on outcomes, may not be provided.”

Patients were eligible to be included in the study either before treatment initiation (n = 479; arm A) or after treatment initiation (n = 464; arm B) and were followed for more than 36 months. In arm A, patients demonstrated improvement from baseline to 6 months in all efficacy outcomes and in most QOL measures, and there was a 17% increase in the percentage of patients reporting normal QOL in both arms. In arm B, QOL outcomes were better at baseline than in arm A, and outcomes were generally stable over time.

Regarding survival, outcomes were similar to those seen in clinical trials, with at least three-quarters of patients surviving through the end of the study in both arms. In the JAKoMo trial, adverse events (AEs) were reported less frequently than in registrational trials, which may be related to lower ruxolitinib dosing in the real-world setting, the authors noted. Overall, sustained QOL benefits such as better general health and fatigue alleviation were seen in the real-world setting.

The study reaffirmed ruxolitinib’s efficacy in myelofibrosis, showing significant clinical and QOL benefits that were sustained in the long term. Responses were also seen quickly, generally within 6 months, and there were fewer adverse events than in clinical trials.

Limitations to the study included reliance on investigators to follow dosing recommendations according to the European Summary of Product Characteristics, as well as limited on-site monitoring of data. Therefore, there were more missing data on values such as International Prognostic Scoring System scores and molecular genetics assessments compared with interventional clinical trials. Still, the data reflect real-world use of ruxolitinib in this patient population.

“The JAKoMo study shows that real-world [ruxolitinib] treatment of [myelofibrosis] promotes significant and sustained clinical and QOL benefits, including general health improvement and alleviation of [myelofibrosis]-associated fatigue,” the authors concluded. “Maximum sustained responses were generally achieved within 6 months and were associated with fewer AEs than in randomized trials, which may reflect more conservative and personalized real-world dosing.”

References

1. Koschmieder S, Isfort S, Schulte C, et al. Final results from a large, non-interventional, phase 4 study of ruxolitinib for the treatment of myelofibrosis in clinical routine. Eur J Haematol. Published online July 6, 2025. doi:10.1111/ejh.70005

2. Pemmaraju N, Bose P, Rampal R, Gerds AT, Fleischman A, Verstovsek S. Ten years after ruxolitinib approval for myelofibrosis: a review of clinical efficacy. Leuk Lymphoma. 2023;64(6):1063-1081. doi:10.1080/10428194.2023.2196593