This study determined whether 85 patients with multiple myeloma (MM) double-refractory to primary induction therapy with triplet regimens had a homogenous prognosis. The overall response rate (ORR) after the second-line therapy was 51%. Patients who proceeded to immediate autologous stem cell transplantation (ASCT) had better ORR than those who received conventional therapies (62% vs. 31%). The ORR for patients who had ASCT directly after the frontline therapy was higher than for those treated with other regimens as the second line therapy (91% vs. 45%) and offered ASCT as the third-line therapy (91% vs. 55%). The median progression-free survival (PFS) after the second-line therapy and median overall survival were 21.6 months and 35.6 months, respectively. ASCT after the second line treatment (HR = 0.24) was an independent predictor of PFS. Eligible patients with primary refractory MM achieve the most benefit from ASCT, also performed immediately after first line induction therapy.
Keywords: Double-refractory multiple myeloma; prognosis; survival; treatment response.