TREATING MULTIPLE MYELOMA IN A RESOURCE-LIMITED SETTING: REAL-WORLD OUTCOMES

Abstract

Over 70% of the Brazilian population (> 150 million people) do not have access to private health care. Alkylating agents, thalidomide, and autologous stem cell transplantation (ASCT) are the mainstay of newly diagnosed multiple myeloma (NDMM) treatment in the public health care system. Therefore, real-life data from resource-limited countries are scarce and essential to optimize the incorporation of new technologies into this scenario. Describe characteristics of patients with NDMM, access to therapy, and outcomes, including overall survival (OS) and progression-free survival (PFS). Retrospective chart study including all patients with NDMM treated at Hospital das Clinicas de São Paulo Complex between 2009 and 2019. A total of 816 patients with NDMM were included. Mean age was 63 years and 55% were male. At the diagnosis, 91% of patients had bone lesions, 56% anemia, 41% hypercalcemia, and 26% presented with impaired renal function. Regarding the clinical stage, 88% were Durie Salmon III clinical stage, and 46% were ISS III stage. Median follow-up time was 5 years. A triplet regimen (cyclophosphamide, dexamethasone, and thalidomide) was the most prescribed in the frontline (446/792, 56%), followed by alkylating agent + dexamethasone regimens (281/792, 27%). Only three patients (0.4%) in this cohort received bortezomib upfront. 379 (46%) were referred to ASCT for consolidation, and 257 (25%) proceeded with it in the first-line treatment. 36% of the patients received three or more lines of therapy. Patients who underwent ASCT had fewer comorbidities by Charlson's index, lower ECOG at diagnosis, and fewer ISS stage III patients (31%) (p < 0.001 for all). Only 16% of the patients over 60 years underwent ASCT. Median time from diagnosis to transplant was ten months. Early mortality (≤ 120 days after diagnosis) was 9.7%, mainly due to infection. For the whole cohort, the overall response rate (ORR) after the first induction was 408/647 (63%), and 144 (22%) had disease progression. PFS and OS were 1.7 years (95% CI 1.6-1.9) and 3.7 years (95% CI 3.4-4.2), respectively. Median OS for patients that received ASCT was 5.9 (95%CI 5.1-7.8) years. This real-world cohort demonstrated that the available therapy in a resource-limited setting is far from the current gold standard for NDMM. Alkylating-based therapy results in suboptimal response rates, while the ASCT procedure is not timely available for all patients. In addition, poor clinical status and advanced disease may impact the choice of not using triplet regimens upfront. Early diagnosis, incorporating proteasome inhibitors and newer agents into the frontline, and ASCT availability are the major initiatives to decrease the disparity between rich and developing countries.