Real-World Data on Clinical Features, Outcomes, and Prognostic Factors in Multiple Myeloma from Miyazaki Prefecture, Japan

The prognosis of multiple myeloma (MM) has improved with the introduction of novel agents. These data are largely derived from clinical trials and might not reflect real-world patient outcomes accurately. We surveyed real-world data from 284 patients newly diagnosed with MM between 2010 and 2018 in Miyazaki Prefecture. The median follow-up period was 32.8 months. The median age at diagnosis was 71 years, with 68% of patients aged >65 years. The International Staging System (ISS) stage at diagnosis was I in 18.4% of patients, II in 34.1%, and III in 47.5%. Bortezomib-containing regimens were preferred as initial treatment; they were used in 147 patients (51.8%). In total, 80% of patients were treated with one or more novel agents (thalidomide, lenalidomide, or bortezomib). Among 228 patients who were treated with novel agents as an initial treatment, the overall response rate (partial response (PR) or better) to initial treatment was 78.4%, and the median time to next treatment (TTNT) was 11.6 months. In the multivariate analysis, PR or better responses to initial treatment were independently favorable prognostic factors for TTNT. The median survival time after initial therapy for patients with novel agents was 56.4 months and 3-year overall survival (OS) was 70.4%. In multivariate analysis, ISS stage I/II disease and PR or better response to initial treatment, and autologous stem cell transplantation (ASCT) were identified as independent prognostic factors for overall survival (OS).