Role of molecular alterations in transplantation decisions for patients with primary myelofibrosis.

The aim of our study was to analyze the potential survival benefit associated with HSCT according to clinico-biological scores which incorporate molecular data (MIPSS70 and MIPSS70+V2) to facilitate decision-making in this context.

One transplant (n=241) and one non-transplant cohorts (n=239) were used to test the hypothesis that PMF patients with higher risk molecular score benefit from HSCT. A weighted propensity score was applied to balance confounding factors with the transplanted cohort as reference.

Weighted Cox proportional hazard models and logistic regression analyses were performed. 105 non-transplanted patients could be matched to the 239 transplanted patients. Mean age in transplanted and non-transplanted matched patients was 55. 5 and 57. 9 years.

Blood cell count and DIPSS score distribution were similar in both groups. HSCT was associated with a higher 6-year OS rate in intermediate-2 (60. 1% versus 41. 5%) and high-risk DIPSS patients (44. 4% versus 6. 55%), high-risk MIPSS70 (46. 5 versus 23. 9%), high-risk (73. 2% versus 39.

7%) or very high-risk MIPSS70V2 (51. 8% versus 24%). Intermediate MIPSS70 patients have an advantage of survival with HSCT only when their MTSS were low or intermediate.

Transplanted patients had an increased mortality risk the first year but a significant benefit with HSCT after the one-year landmark was observed in higher risk patients.

This study confirms that similar to DIPSS, MIPSS70 and MIPSS70+V2 risk score in addition to MTSS can be used to determine which patients with primary myelofibrosis have survival benefit from HSCT over non-HSCT strategies.