Allogeneic stem cell transplantation in patients with multiple myeloma-single center experience

The standard of care in multiple myeloma (MM) consists of induction chemotherapy followed by autologous stem cell transplant (autoSCT), but this setting doesn't present curative potential. Despite advances in new, efficient, and targeted drugs, allogeneic transplant (aloSCT) remains the modality with curative potential in MM. With the knowledge of high mortality and morbidity related to the treatment in comparison to treatment with novel drugs, there is no consensus in the indication of aloSCT in MM, also the choice of ideal patients profiting from this method is difficult. Therefore, we performed a retrospective unicentric study of 36 unselected consecutive patients transplanted for MM in the University Hospital in Pilsen between the years 2000-2020 in order to define possible variables influencing survival. The median age of the patients was 52 years (38-63) and the distribution of MM subtypes was standard. The majority of the patients were transplanted in the relapse setting, 3 (8.3%) patients in the 1st line setting, and in 7 (19%) patients elective auto-alo tandem transplant was performed. 18 patients (60% of patients with available cytogenetics (CG) had high-risk disease. 12 (33.3%) patients were transplanted with chemoresistant disease (at least PR not reached). With a median follow-up of 85 months, we observed median overall survival (OS) of 30 months (range 10-60) and median progression-free survival (PFS) of 15 months (11-175). 1- and 5-year Kaplan Meier survival probabilities for OS were 55% and 30.5% respectively. During the follow-up, 27 (75%) patients died, 11 (35%) due to treatment-related mortality (TRM), and 16 patients (44%) due to a relapse. 9 (25%) patients were still alive, 3 (8.3%) of them with complete remission (CR), and 6 (16.7%) patients with relapse/progression. Altogether 21 (58%) of the patients relapsed/progressed with a median of 11 months (3-175). Incidence of clinically significant acute graft versus host disease (aGvHD gr. >II) was low (8.3%) and extensive chronic GvHD (cGvHD) developed in 4 patients (11.1%). Univariant analysis proved marginal statistical significance in disease status before aloSCT (chemosensitive × chemoresistant) for OS, favoring patients with the chemosensitive disease (HR 0.43, 95% CI 0.18-1.01, p=0.05), there was no significant impact of high-risk cytogenetics (CG) on survival. No other analyzed parameter was found to be significant. Our findings support the conclusion that aloSCT is able to overcome high-risk CG and that aloSCT still remains a valid treatment choice with acceptable toxicity in well-selected high-risk patients with curative potential, even though often with active disease, but not derogating the quality of life significantly.