Long PFS of more than 7 years is achieved in 9% of myeloma patients in the era of conventional chemotherapy and of first-generation novel anti-myeloma agents: a single-center experience over 20-year period

Advances in the management of multiple myeloma (MM) have led to a significant prolongation of both progression-free (PFS) and overall survival (OS). Herein, we evaluated the characteristics of patients who achieved a PFS of at least 7 years following frontline therapy, as compared with all other patients who were treated in a single center during the same time period. Thirty-six (8.8%) patients achieved a PFS of at least 7 years (long PFS group) after frontline treatment. Long PFS patients were younger (p < 0.001) and had lower ECOG performance status (p = 0.014), higher hemoglobin (p = 0.001), and higher creatinine clearance (p < 0.001) compared with the others. More patients in the long PFS group had ISS-1 or ISS-2 disease (p = 0.002) and normal pattern of marrow infiltration (p = 0.035). No patient in the long PFS group had high-risk cytogenetics at diagnosis. Long PFS patients had received more often autologous stem cell transplantation (p = 0.001) and had achieved deeper responses. The probability of achieving long PFS (≥ 7 years) for patients who managed to be progression-free at 2, 3, and 4 years was 11.6%, 13.2%, and 15.3%, respectively. Median OS in the long PFS group has not been reached yet, while in all other patients, the median OS was 4.3 years. In conclusion, our study in an unselected patient group showed that 9% of patients with newly diagnosed myeloma experience prolonged PFS of more than 7 years in the era of conventional chemotherapy or first-generation novel agents. We anticipate that novel treatment approaches will increase the probability of achieving a prolonged relapse-free status.