Donor chimerism was restored with hypomethylating agent (HMA) treatment among some patients with myelofibrosis (MF) who relapsed after allogeneic hematopoietic cell transplantation (alloHCT), according to a small retrospective published in the journal Transplantation and Cellular Therapy.
These data suggest that HMA “is an option for patients in the future,” the researchers wrote in their report. “By promoting restoration of donor chimerism and clearance of pre-alloHCT somatic mutations, HMAs offer a capable therapeutic strategy for improving outcomes in this challenging patient population.”
In the single-center, retrospective study, the researchers analyzed data from the electronic health records of 12 patients with MF who relapsed after alloHCT between 2020 and 2023 and were subsequently treated with an HMA.
The median age of the cohort was 61 years and 33% of patients had primary MF, 41.7% had post-essential thrombocythemia MF, and 25.0% had post-polycythemia vera MF.
There were 92% of patients with disease classified as intermediate-2/high-risk by the Dynamic International Prognostic Scoring System (DIPSS) and 83% were considered high or very high risk by the Molecular International Prognostic Scoring System (MIPSS70+). There were 66.7%, 25.0%, and 16.7% of patients with JAK2, MPL, or CALR driver mutations, respectively, at diagnosis.
After transplantation, 99.9% of patients achieved donor chimerism at day 30 and 96.6% at day 100. Patients relapsed after alloHCT within a median of 282.5 days (range, 96-2388 days). The median donor chimerism before initiating an HMA was 57.82%.