Eventos adversos a medicamentos e efetividade do tratamento em pacientes com mieloma múltiplo: coorte histórica de pacientes tratados no Sistema Único de Saúde

Abstract

Introduction: Multiple myeloma (MM) is an incurable hematologic cancer marked by clonal plasma cell proliferation and systemic complications. MM has shown increasing incidence and mortality, especially in Latin American countries such as Brazil. Treatment has advanced with the incorporation of new therapeutic agents; however, these regimens are still associated with significant adverse events (AEs), and access to emerging therapies in the public healthcare system remains unequal. Aim: The present study aimed to evaluate the factors associated with overall survival (OS) and AEs in a cohort of patients initiating treatment for MM. Methods: This is a historical cohort study conducted at a public onco-hematology center in Belo Horizonte, Brazil, including patients diagnosed with MM who initiated treatment between 2018 and 2022. Data were retrospectively collected from medical records and analyzed using Statistical Analysis System (SAS®) OnDemand for Academics. The primary outcomes were treatment-related AEs, including peripheral neuropathy, thromboembolism, cardiotoxicity, and hematologic toxicities. Secondary outcomes included OS and time to next treatment (TTNT). Variables analyzed included age, sex, comorbidities, polypharmacy, International Staging System (ISS) stage, treatment regimen, autologous stem cell transplant, and treatment response. Statistical analyses involved descriptive statistics, Kaplan-Meier (KM) survival curves with log-rank test, Cox proportional hazards models, and estimation of cumulative incidence and incidence rates of AEs during first-line treatment. Results: Most patients were male (57.1%), aged 65 or less (53.3%), with high rates of comorbidities (75.2%) and polypharmacy (58.1%). At the time of diagnosis, more than one-third (38.1%) presented with advanced disease (ISS stage III). First-line regimens included immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs). Autologous stem cell transplantation (ASCT) was performed in 28.6% of cases. A partial or very good partial response was achieved by 59.0% of patients. KM analysis estimated mean OS at 21.6 months (SD=16.4) and showed significantly reduced survival in patients without ASCT (p<0.05), indicated by Cox regression (HR=8.15; 95% CI: 1.07–62.17). AEs occurred in 83.8% of patients, and peripheral neuropathy was the most common (69.5%), particularly among patients treated with IMiDs and PIs. Conclusion: This study provides relevant real-world data on MM patients treated in the SUS. Results indicate the effectiveness of current MM treatments in Brazil, highlight the prognostic benefit of ASCT, and underscore the need for early transplantation and monitoring of toxicities.