Impact of early reduction in paraprotein on survival in transplant ineligible myeloma: Lesson from a tertiary cancer center in rural India

Abstract

Introduction: The impact of rapid reduction in paraprotein levels, with induction chemotherapy in myeloma, on treatment outcomes is less clear. There are very few studies in transplant ineligible patients treated with novel agents, correlating an early reduction in paraprotein with survival duration. Methods: In this retrospective analysis of newly diagnosed multiple myeloma, ineligible for stem cell transplant, paraprotein levels at baseline and 3 months were noted with percentage reduction. Survival analysis was performed with Kaplan-Meier curves and Cox proportional hazard model. Results: Among a total of 121 patients, 42 (35%), 29 (24%), and 50 (41%) had paraprotein reduction of 100%, 90%-99%, and <90%, respectively from baseline levels at 3 months. Patients with complete disappearance of paraprotein (100% reduction) when compared against those with <100% reduction at 3 months had a trend toward higher overall survival (OS) (3-year OS of 81% vs. 69%, hazard ratio [HR] = 0.54, P = 0.182). However, the progression-free survival (PFS) was significantly higher when these two groups were compared (median PFS of 51 vs. 17 months, HR = 0.33, P ≤ 0.001). When patients with ≥90% reduction were compared with <90% reduction at 3 months, there was significant improvement in both OS and PFS (3-year OS of 80% vs. 48%, HR = 0.24, P = 0.001, median PFS of 38 vs. 14 months, HR = 0.13, P < 0.001). Conclusions: Achieving a faster and deeper reduction in paraprotein as early as 3 months could lead to significant improvement in PFS.