According to Lucia Masarova and colleagues, the median therapy duration of ruxolitinib—a JAK inhibitor used in patients with advanced-phase myelofibrosis (MF)—is about three years. The researchers examined patients who had been treated with ruxolitinib for three years or more, and reported that 40% of patients who received ruxolitinib for ≥3 years survived to 10 years post-initiation.
In their report, featured at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting, the researchers specified that “age remains the major predictive factor of survival despite long ruxolitinib therapy.”
The retrospective study included a total of 131 patients who had received ruxolitinib for three or more years. The primary measures of the analysis were the associations between clinical characteristics and therapy details and the overall survival (OS) rate at treatment initiation and in the years following.
According to the abstract, among 62 patients with ≥28 gene sequencing data available, 19, 24, and 19 patients had zero, one, and ≥2 mutations, respectively, beyond JAK2, MPL, CALR. The median time to treatment initiation from presentation and MF diagnosis was four and 11 months, respectively. The median duration of ruxolitinib therapy was 76 months (95% confidence interval, 56–88).
Notably, the factors associated with OS in univariate analysis were age over 65 years, neutrophils percentage, blasts percentage, and Eastern Cooperative Oncology Group (ECOG) performance status below two. However, only age over 65 years and neutrophil percentage remained significant in multivariate analysis.
Overall, the authors presented their data as supportive of ruxolitinib therapy in patients with advanced phases of MF over the long-term.