P-372: Treatment of multiple myeloma in the public health system in Brazil: results of 9 years of treatment

Introduction: Brazil lacks national statistics on epidemiological, clinical aspects and treatment results in multiple myeloma (MM). Furthermore, bortezomib was only incorporated into the Brazilian public system (SUS) in September 2020, until then patients were treated with CTd and those ineligible with MPT. At the Hospital Universitário de Brasília (HUB) we follow patient with MM with the aim of developing national data to better understand the disease, patients and treatment results.

Methods: In this single-center retrospective study, patients with new diagnose MM were consecutively included from November 2014 to May 2024. We evaluated clinical data (age, sex, diagnosis, prognosis, regimens, lines, transplant eligibility, response) and calculated progression-free survival (PFS) and overall survival (OS).

Results: We included 91 patients. The median age was 63.1 years, 61% were men, 59% IgG, 25% IgA and 14% light chain, 62% had kappa chain restriction, 61% underwent FLC at diagnosis (36% rate above 100), 60% had anemia, 26% hypercalcemia, 30% Cr >2, 79% bone lesions, 37% plasmacytoma and 22% more than 60% marrow infiltration. No patient underwent FISH and 41% did not have ISS calculated due to unavailability of B2-microglobulin, but 20% had elevated LDH. The clinical stage was advanced in the majority (82% DS III and 52% ISS III). Due to their age plus comorbidity, 31% were ineligible for ASCT. The most used 1st line treatments were CTd (46%), VCd (20%), MPT (15%), VMP (7%), MPT (4%) and VTd (3%). Bortezomib was used in the first line in 30%. The median number of cycles was 6. Response to 1L was 4% CR, 32% VGPR, 48% PR, 3% stable disease, and 14% disease progression. 54% of eligible patients underwent ASCT (77% at 1L) and 82% maintenance after ASCT, preferably with biweekly bortezomib, since lenalidomide was not incorporated into SUS. The median number of rescue treatments was 1 (0-8). For all patients, median PFS and OS were respectively 57 months (5-year PFS 43%) and 111.9 months (5-year OS 71%) (111.9 months ASCT-ineligible and 161.1 months ASCT-eligible). For transplant-eligible patients median PFS was significantly longer in patients who received ASCT (median 68.2 months vs. 23.8 months, p< 0.001). The same for patients treated with CTd (median 65.9 months vs. 23.8 months, p=0.0002) and there was a trend in patients treated with VCd or VTd before ASCT (median PFS not reached in 105 months vs. 14 months, p=0.0877). At 50-months, PFS with MPT and VMP were 51% vs 38%. First line with CTd, VMP, VCd/VTd and VMP, resulted in 60-month OS of 68%, 75%, 68% and 66%, respectively. OS was significantly higher in patients that proceeded to ASCT after CTd or VTD/VCd.

Conclusions: There has been a substantial improvement in survival amongst MM in SUS that can be in part attributed to the incorporation of the proteasome inhibitor in the induction, rescue, and maintenance. ASCT remains an important factor improving survival.