Dr Jain on Baseline Differences Across Different Donor Types in Myelofibrosis

Tania Jain, MBBS, director, Adult Chimeric Antigen Receptor T-cell Therapy Program for Hematological Malignancies, Sidney Kimmel Comprehensive Cancer Center, assistant professor of oncology, Johns Hopkins Medicine, discusses notable differences in baseline characteristics and donor sequencing, according to a retrospective study of patient outcomes following blood or marrow transplant in 4 common donor types of myelofibrosis.

This real-world retrospective study compared the outcomes of 4 common donor types in myelofibrosis. Data from 1057 adult patients who underwent a first allogenic stem cell transplant (allo-SCT) using a peripheral blood graft between 2013 and 2019 for chronic phase myelofibrosis were obtained from the CIBMTR and the CIBMTR is a working group of over 500 BMT centers. Patients had either a matched sibling donor (MSD), matched unrelated (MUD) donor, mismatched unrelated donor (MMUD), or a haploidentical donor (HD) with posttransplant cyclophosphamide.

Notable differences were observed at baseline in the study population, Jain begins. As expected, a majority of MSD, MUD and MMUD patients were White, she says. Specifically, about 40% of HD donors were of non-White ethnicities. This demographic breakdown is relevant to note, as recently published data have shown a difference in transplant outcomes in patients of non-White ethnicities, Jain explains. This discrepancy may not be solely attributable to socioeconomic factors, and could be influenced by biological factors, she says.

Furthermore, sequencing donor selection in clinic is different than that of clinical trials, Jain continues. Typically, MSDs are the preferred donor option for patients with myelofibrosis. If no MSDs can be identified, the search will expand to MUD, followed by the other 2 donor types. However, research has shown that it takes longer to identify a HD vs a MSD, Jain reports. This practical limitation often results in a longer delay in transplant for patients waiting for an MMUD or HD, she states.

Findings from the study showed that HD and posttransplant cyclophosphamide is a viable alternative to MUD for patients requiring allo-SCT who cannot find a MSD. These results indicate that this delay in transplant is not necessary for these patients, Jain says. Additionally, HDs are more readily available, and may be more affordable for some patients, she concludes.