P158 | DARATUMUMAB, LENALIDOMIDE AND DEXAMETHASONE IN NEWLY-DIAGNOSED MULTIPLE MYELOMA PATIENTS AGED ≥80 YEARS: A MULTICENTER RETROSPECTIVE ANALYSIS OF EFFICACY AND TOLERABILITY FROM CAMMPANIA GROUP

Daratumumab plus Lenalidomide and Dexamethasone (DRD) is currently the therapy of first choice in newly diagnosed Multiple Myeloma (MM) patients who are considered not eligible for autologous stem cell transplantation. In patients aged ≥80 years, which are characterized by intrinsic frailness and are both underrepresented and consistently selected in registration trials, there is often a concern in offering such therapy. We present a retrospective analysis from a group of 64 NDMM patients aged ≥80 years from 9 different Institutions of Campania region treated with DRD. Main characteristics of patients are summarized in the table. Initial daily dose of Lenalidomide in mg was 25=16, 15=20, 10=18, 7.5=2, 5=8. Initial weekly dose of Dexamethasone in mg was 40=10, 20=35, 10=14, 4=5. Overall response rate is 97% in 62 evaluable patients. In particular, Complete and Very Good Partial Remission rates are 30% and 43%, respectively. Significant toxicity included documented infections or FUO, present at least once in 38 patients (59%), and thrombosis in 5 cases (8%). Six patients needed transfusion support. Use of Epoietin and GCSF was necessary in 31 (48%) and 39 (61%) cases, respectively. Reduction from initial dose of Lenalidomide and Dexamethasone was necessary in 35 (55%) and 29 (45%) patients, respectively. Lenalidomide was definitely stopped in 16 patients (25%). After a median follow up of 15 months (range 1-59), 47 patients are currently on treatment. Eight patients (16%) have died, none directly from MM (4 deaths due to cardiovascular events, 1 to Covid infection, 3 related to surgery). Six patients relapsed and started second line treatment. Median Overall and Progression Free Survival (OS and PFS) are not reached and 44 months, respectively. OS projected at 12 and 30 months is 90.6% and 77.92%, respectively. Median PFS for patients ≥85 years is 36.5 months, with p not statistically significant. Of note, in our group OS at 12 months for patients <85 years is 93.3% while 1-year survival in Campania region for the whole population aged 80 years was 94.85% for year 2023 (source: ISTAT). In conclusion, DRD is a feasible combination even in very elderly patients, and there is no indication to exclude them from this therapy aprioristically. Toxicity is acceptable, but there is a significant rate of patients who need reduction of drugs dose. Results are satisfying, but given the nature of the population a long term plateau of survival curves cannot be reached.