Recovery of polyclonal immunoglobulins during treatment in patients ineligible for autologous stem‐cell transplantation is a prognostic marker of longer progression‐free survival and overall survival

Summary Immunoparesis is the suppression of normal polyclonal immunoglobulins and is present in most patients with newly diagnosed multiple myeloma (MM). The association of immunoparesis at diagnosis, and particularly its recovery along with treatment, with survival in patients ineligible for autologous stem‐cell transplantation (ASCT) has not been well established. This retrospective study evaluated the impact of immunoparesis in 431 patients diagnosed with MM, ineligible for ASCT, with a median overall survival of 36 months [95% confidence interval (CI): 31–40]. Immunoparesis was present in 81.2% of patients at diagnosis and was associated with a trend to a worse overall response rate (ORR: 84.8% vs. 74.9%; OR 1.88 (95% CI: 0.97–3.63), shorter progression‐free survival (PFS) [22.0 vs. 18.2 months; hazard ratio (HR) 0.775; 95%CI: 0.590–1.018; p = 0.066], and overall survival (OS) (45.9 vs. 34.2 months; HR 0.746; 95% CI: 0.551–1.010; p = 0.057). Twenty‐four per cent of patients who had immunoparesis at diagnosis recovered polyclonal immunoglobulins in the follow‐up period. Interestingly, these patients had a better ORR (96.3% vs. 68.2%; OR 12.29 (95% CI: 3.77–40.06), PFS (HR 0.703; 95CI%: 0.526–0.941; p = 0.018) and OS (HR 0.678; 95 CI%: 0.503–0.913; p = 0.011) than patients who did not recover it. In summary, restoring a healthy immune system along with first‐line treatment in patients with MM, not receiving ASCT, is associated with better outcomes.