Outcomes after First Rescue Treatment in Patients with Relapsed or Refractory Multiple Myeloma in Colombia

Abstract

Background Proteasome inhibitors (PIs) are approved for treating newly diagnosed and relapsed multiple myeloma (MM) in Colombia. This propensity score matching (PSM) analysis using data from the real-world, was designed to establish the role PIs (bortezomib or carfilzomib) at first relapsed or refractory MM. The primary endpoint was overall response rate (ORR) and secondary endpoint included was overall survival (OS). Moreover, an analysis of OS was done regarding response attained. On Behalf of RENEHOC-GRIMMCO (Colombian Registry for Hemato-Oncological Diseases and Colombian Mieloma Múltiple study group).

Methods PSM by nearest neighbor analysis to evaluate the role of PIs used at first relapse in multiple myeloma of patients belonging to RENEHOC registry, between 2010 and 2020.

Results 390 patients were identified in the first relapse of the Colombian registry, 269 patients with PI and 121 patients without PI. One hundred and ten patients were included in each group after PSM. Patients were matched for age, ISS, extramedullary disease, and use of lenalidomide to define the influence of this immunomodulatory drug in the PI group. A difference was found in the use of lenalidomide because only 1 patient was treated with PI and lenalidomide concomitantly (0.91%) compared to 31 patients in the group without PI (28.18%), (p <0, 0001).

Regarding ORR, no differences were found between the 2 groups 38.18% in PIs vs 37.27% in non-PIs group (p = 0.801). A trend towards better OS was found in the PIs group with a median of 58 months versus 39 months (p = 0.179). Overall survival in patients who achieved at least PR was better compared to those who did not reach 79 months versus 32 months in non-responders (p = 0.0001).

Conclusion In this study, we found that the use of PI has a tendency to improve overall survival in real-world in MM patients when used in the first relapse and that this effect could possibly be enhanced with the combination with lenalidomide. Regardless of the treatment used, better responses are associated with better survival.