Luspatercept Appears Safe and Effective for Treating Anemia in Patients With Myelofibrosis

The safety and efficacy of luspatercept is favorable for treating anemia in patients with myelofibrosis, according to a study by lead author Aaron Thomas Gerds and colleagues that will be presented at the 2023 American Society of Clinical Oncology Annual Meeting.

Patients were stratified into 4 cohorts based on transfusion dependence (TD) and stable ruxolitinib treatment. Cohort 1 patients had no TD and did not receive ruxolitinib, cohort 2 patients had TD and did not receive ruxolitinib, cohort 3A patients had no TD and received ruxolitinib, and cohort 3B patients had TD and received ruxolitinib. All patients received subcutaneous luspatercept 1.0 mg/kg (1.33 mg/kg for patients in the cohort 3B expansion) with titration up to 1.75 mg/kg in 21-day cycles.

The study’s key end point was anemia response from baseline without transfusion or free of red blood cell transfusion. The secondary outcomes were duration of response, transfusion frequency, change in Hgb level, and symptom response.

Over an average treatment duration of 42.8 weeks, the results showed that cohort 3B had the highest anemia response rate at 26.3% (95% CI, 13.4-43.1), with patients transfusion-independent during the primary treatment period and 31.6% (95% CI, 17.5-48.7) of patients transfusion-independent during the entire treatment period. Half of the patients in cohort 3B saw a reduced transfusion burden during the primary treatment period; more than 21% achieved mean Hgb increase ≥1.5 g/dL from baseline throughout the entire treatment period, and nearly 16% achieved a 50% or more reduction in symptom score from baseline. However, researchers also noted that 47.4% of patients had at least 1 treatment-related adverse event, most frequently hypertension. A total of 9 patients died during treatment from postprocedural hemorrhage, pneumonia, intracranial hemorrhage, septic shock, ischemic stroke, multiple organ dysfunction syndrome, renal failure, pneumonitis, and myelofibrosis, but no deaths were linked to the study drug.

“In [patients] with MF, the safety profile of luspatercept was consistent with previous studies, and efficacy results showed promising improvements in anemia and transfusion burden in all cohorts.”

Source: Gerds AT, Harrison C, Kiladjian JJ, et al. Safety and efficacy of luspatercept for the treatment of anemia in patients with myelofibrosis: results from the ACE-536-MF-001 study. Abstract #7016. Published for the 2023 ASCO Annual Meeting; June 2-6, 2023; Chicago, Illinois.