[Response rates to first-line treatment in eligible patients to autologous stem transplantation in Chile].

Background: The treatment of choice of newly diagnosed multiple myeloma (NDMM) is an induction with proteasome inhibitors followed autologous stem cell transplantation (HSCT). Since 2013, the treatment of these patients in the public system is based on CTD (cyclophosphamide, thalidomide, and dexamethasone). Aim: To evaluate the response rates achieved with CTD, and the results of HSCT in patients with NDMM in the public setting. Material and Methods: Data from patients considered as candidates for HSCT from different centers of the National Adult Antineoplastic Drug Program (PANDA, for its acronym in Spanish), diagnosed between 2013 and 2017, was analyzed. The response to treatment of first and second lines of treatment was evaluated, in addition to the results of HSCT. An optimal Response was defined as the sum of strict complete remission, complete remission and very good partial response (sCR, CR and VGPR). Results: One hundred and seventy-seven patients were analyzed, 54% women, and 53% with IgG multiple myeloma. Information about the international staging system was retrieved in 127 patients (71%). Seventeen percent were ISS I, 22% in ISS II and 32% ISS III. CTD was used as first treatment in 106 patients (60%), and cyclophosphamide, bortezomib and dexamethasone (CyBorD) in 13 (7%). As first line, CTD had an overall response of 50.9%, and CyBorD of 76.9%. Thirty patients were treated with bortezomib as second line treatment. Forty patients (22%) underwent HSCT. The 5-year Overall Survival (OS) in transplanted patients and non-transplanted patients was 100 and 62% respectively (p < 0.01). Conclusions: The response rate achieved by CTD in these patients is suboptimal. The response to CyBorD was better.