P-364: A Large Scale Analysis of Autologous Stem Cell Transplantation for Multiple Myeloma Patients Older than 65 Years

Introduction: In Multiple Myeloma (MM) patients (pat) older than 65 yo, the value of the consolidation with autologous stem cell transplantation (auto-SCT) is not well defined. Although it is a population underrepresented in CT, SCT is used in many centers. TriNetX is a federated global health research platform that provides researchers with access to electronic medical records from healthcare organizations to conduct research studies. The aim of our study is to evaluate the safety and efficacy of auto-SCT in pat older than 65yo with MM. Thus, we have employed the data from Hospital 12 de Octubre cohort, and we have validated it with the TriNetx network in a large cohort of MM patients.

Methods: We have analyzed a cohort from our center (H12O) who have received an auto-SCT from Jan 2013 to Mar 2023. We defined two cohorts: Cohort 1, pat with > 65 yo at the time of transplantation (n=61) and Cohort 2 ≤ 65y (n=234).
Data from the last 10 yo of the TriNetx platform of 111 centers have been used with the diagnosis of symptomatic MM (CIE-10: C90.0). Cohort 1, included n=5,080; and Cohort 2 included n=10,376. We performed a matcher pair comparison of a subset of closely matched pat based on Propensity Score Matching (PSM). Key factors included in PSM were baseline population characteristics: ethnicity, sex, comorbidities (Hypertensive diseases, Ischemic heart, CKD, DM, Diseases of liver, Chronic lower respiratory diseases), treatment previous.

Results: In the H12O cohort of pat, the median age was 68 (66-74) in >65yo pat and 57 (28-65) in < 65 y pat. The older population presented greater Charlson Ind (p=0.001), polypharmacy (p= 0.04) and a another neoplasm (p=0.01). There were no differences in the type of conditioning, pre-SCT response or induction treatment.
In our center, with a median follow-up of 3.8yo (0.02-10.8) the PFS at 6y was similar in both groups: 47.3% in Cohort 1 and 54.7% in Cohort2 (HR, 1.2 95% CI, 0.7-1.9, p=0.51). The older pat required admission to the ICU more frequently (19.7% vs 9.8%, p=0.03), without an associated increase in NRM (1.6% vs 1.7%, p=0.7). We found no significant diff in the engraftment, transfusion and complications.

At TriNetX database, after the PSM, the final population was 4,927pat in each cohort. Cohort 1 with a mean age (+-SD) of 69.8 (3) and Cohort2 of 56.3 (7.4). The variables were balanced. Need of a new treat at 6yo of follow-up was 64.4 % in Cohort1 and 63.6% Cohort2 (HR, 0.9, 95%CI, 0.8-1, p=0.1). Surival at 60 days was similar between both cohorts: 98.2% in Cohort 1 and 98.9% in Cohort 2 (HR, 1.6, 95%CI, 1.1-2.3, p=0.3).The risk of any transplant complication was significantly lower in Cohort 1 vs. Cohort 2 (RR: 0.4, 95% CI, 0.3 to 0.6).


Conclusions: This large-scale study shows that ASCT in MM patient, older than 65yo have similar NRM and PFS. Additionally, the incidence of severe side effects and mortality related with ASCT was comparable between younger and older pat. Based on this results ASCT should be considered in fit pat older than 65yo.