Selinexor Plus Ruxolitinib for Treatment-Naïve Patients With Myelofibrosis

The treatment combination of selinexor plus ruxolitinib is effective in treatment-naïve patients with myelofibrosis (MF), according to a study presented at the 2023 American Society of Clinical Oncology Annual Meeting.

In this phase 1/2, open-label study, lead investigator Harris Ali and colleagues evaluated the safety and efficacy of selinexor at 40 mg and 60 mg once weekly plus ruxolitinib per standard of care in 28-day cycles. They assessed safety, spleen/symptom response, survival, and hemoglobin levels. The population of interest comprised individuals who had baseline assessment and were treated to at least week 24 (W24) or discontinued before W24. The analysis included 22 patients.

As of December 21, 2022, 10 participants received selinexor 40 mg and 14 participants received selinexor 60 mg over a median treatment duration of 28 weeks. The most common adverse events (AEs) observed (60 mg/40 mg) were nausea (79%/70%; majority grade 1-2), anemia (79%/50%), and fatigue (57%/60%). Grade ≥3 AEs included anemia (50%/40%), thrombocytopenia (29%/10%), and neutropenia (7%/20%). AEs were reversible with dose modifications. Overall, the analysis showed that 64% (14/22) of patients achieved spleen volume reduction (SVR) at W24, with 79% of patients achieving SVR in the 60 mg versus the 40 mg group. The investigators noted that the 60 mg group achieved a deeper median SVR response compared with the 40 mg group at W24 (49% vs 31%).

“Encouraging activity with [the] 60 mg selinexor [plus] ruxolitinib combination was observed in TSS50, SVR, and hemoglobin levels overall, as well as in key subgroups, including males, patients started on low-dose ruxolitinib (≤15 mg), and patients with larger baseline spleen size,” the researchers concluded.

Source: Ali H, Kishtagari A, Maher KR, et al. Selinexor (SEL) plus ruxolitinib (RUX) in JAK inhibitor (JAKi) treatment-naïve patients with myelofibrosis: updated results from XPORT-MF-034. Abstract #7063. Published for the 2023 ASCO Annual Meeting; June 2-6, 2023; Chicago, Illinois.