Management of relapsed/refractory myeloma in resource constrained setting: Median age (years) age (years) immunoglobulin subtype Hb (G/dL) serum creatininee GFR mL/minute serum albumin (g/dL) serum LDHP platelets counts circulating plasma cells cytogenetics hypercalcemia co-morbidities diabetes hypertension hypothyroidism F/H of malignancy

Abstract

Background: Treatment of relapse/refractory multiple myeloma (MM) is complex and requires consideration of disease, patients related factors and front-line treatment used. We aimed to assess the efficacy and safety of salvage regimens in symptomatic MM patients. Methods: We evaluated records of relapse/refractory MM patients treated between 2014 and 2019. One hundred ninety-five patients received salvage therapy, another 61 (21.8%) asymptomatic patients with biochemical progression were kept on close follow up. Primary outcome was progression free survival (PFS). Response and toxicity to treatment and overall survival (OS) were secondary outcome measures. Results: Patients median age was 59.5 years (range; 23-84 years) and 65.7% were males. Among 176 (90.3%) evaluable patients; 98(55.6%) responded; complete response (CR)-19(10.8%), very good partial response (VGPR)-14(7.9%), and partial response (PR) 65(36.9%). Median PFS was superior for complete responders; 31.2 versus 8.2 months, P < .005. Median PFS for refractory myeloma was 5.09 months compared to 11.4 months for nonrefractory myeloma, P < .001. Median PFS was 6.70 months for those with clinical relapse versus 9.50 months for biochemical relapse (P = .62). Median OS was not reached. Circulating plasma cells > 5%, thrombocytopenia, refractory disease were predictors of inferior PFS. Most common grade 3/4 treatment-related adverse events were thrombocytopenia (5.7%), anemia (7.5%), and febrile neutropenia (5.2%). About 10(2.4%) patients required change of therapy due to adverse reactions. Conclusion: Achievement of CR in symptomatic, relapsed myeloma was associated with superior PFS. Careful observation for asymptomatic patients with biochemical relapse is a reasonable approach. Newer novel molecules for those with refractory disease are needed.