Luspatercept improved anemia and transfusion burden in patients with myelofibrosis with anemia, according to a phase II study.
Francesco Passamonti, MD, of University of Milan Statale, Italy, presented the results at the Annual Meeting of the Society of Hematologic Oncology.
The open-label ACE-536-MF-001 study included four patient cohorts grouped by transfusion dependance and stable ruxolitinib treatment.
The patients were assigned to four cohorts including the following:
- Cohort 1: no transfusion-dependence or ruxolitinib
- Cohort 2: transfusion-dependent but no ruxolitinib
- Cohort 3A: transfusion-dependent with ruxolitinib
- Cohort 3B: transfusion-dependent with ruxolitinib
Patients received luspatercept 1.0 mg/kg subcutaneously with titration up to 1.75 mg/kg in 21-day cycles. Response was assessed at day 169 and patients showing clinical benefit could continue treatment.
All patients were followed for three or more years after their last dose of luspatercept. In the intention-to-treat (ITT) group of 95 patients, 54.7% had primary myelofibrosis and 74.7% were at least two years from their initial diagnosis.
The mean duration of luspatercept was 42.8 weeks. Twenty-eight of the 95 patients discontinued luspatercept on day 169 because of lack of clinical benefit.
During the primary treatment period the anemia response rate was 13.6% in cohort 1, 9.5% in cohort 2, 14.3% in cohort 3A, and 26.3% in cohort 3B. About half of patients in cohort 2 (47.6%) and cohort 3B (50.0%) achieved 50% or greater reduction in transfusion burden. A mean hemoglobin increase of at least 1.5 g/dL occurred in 27.3% of cohort 1 and 50.0% of cohort 3A.
About half (47.4%) of all patients had a treatment-related adverse event. The most common adverse event was hypertension, which was reported in 17.9% of patients; 5.3% of patients had grade 3 or worse hypertension.
Serious treatment-related adverse events occurred in 3.2% of patients, one of which resulted in drug discontinuation. Nine patients died, but none of the deaths were related to the study drug.
In August, the US Food and Drug Administration approved luspatercept as a first-line treatment of anemia in adults with lower-risk myelodysplastic syndromes who may require transfusion.
Gerds AT, Harrison C, Kiladjian J-J, et al. Safety and efficacy of luspatercept for the treatment of anemia in patients with myelofibrosis: results from the ACE-536-MF-001 study. MPN-404. Presented at the Eleventh Annual Meeting of the Society of Hematologic Oncology. September 6-9, 2023; Houston, Texas.