Liu, Lawrence

Importance Obesity is a risk factor associated with multiple myeloma (MM) and its precursor, monoclonal gammopathy of unknown significance (MGUS). However, it is unclear how cumulative exposure to obesity affects the risk of MGUS progression to MM. Objective To determine the association of cumulative exposure to excess body mass index (EBMI), defined as BMI (calculated as weight in kilograms divided by height in meters squared) greater than 25, with risk of MGUS progression to MM. Design, Setting, and Participants This cohort study included patients with MGUS, including immunoglobin G, immunoglobin A, or light chain MGUS, from the nationwide US Veterans Health Administration database from October 1, 1999, to December 31, 2021. A published natural language processing–assisted model was used to confirm diagnoses of MGUS and progression to MM. Data were analyzed from February 12 to November 4, 2024. Exposures Cumulative EBMI was calculated by area under the curve of measured BMI subtracting the reference BMI at 25 during the first 3 years after MGUS diagnosis. Main Outcomes and Measures The main outcome was progression from MGUS to MM. Multivariable Fine-Gray time-to-competing-event analyses, with death as the competing event, were used to determine associations. Results The cohort included 22 429 patients with MGUS (median [IQR] age, 70.5 [63.5-77.9] years; 21 613 [96.4%] male), with 8329 Black patients (37.1%) and 14 100 White patients (62.9%). There were 4862 patients (21.7%) with reference range BMI (18.5 to <25), 7619 patients (34.0%) with BMI 25 to less than 30, and 8513 patients (38.0%) with BMI 30 or greater at the time of MGUS diagnosis. Compared with reference range BMI at MGUS diagnosis, patients with BMI 25 to less than 30 (adjusted hazard ratio [aHR], 1.17; 95% CI, 1.03-1.34) or 30 or greater (aHR, 1.27; 95% CI, 1.09-1.47) at MGUS diagnosis had higher risk of progression to MM. In patients with reference range BMI at MGUS diagnosis, each 1-unit increase of EBMI per year was associated with a 21% increase in progression risk (aHR, 1.21; 95% CI, 1.04-1.40). However, for patients with BMI 25 or greater at MGUS diagnosis, the incremental risk associated with cumulative EBMI exposure was not statistically significant. Conclusions and Relevance This cohort study found that, for patients with BMI 18.5 to less than 25 at the time of MGUS diagnosis, cumulative exposure to BMI 25 or greater was associated with an increased risk of progression. These findings suggest that for these patients, maintaining a healthy and stable weight following MGUS diagnosis may prevent progression to MM.

Abstract Idecabtagene vicleucel (ide-cel) was the first chimeric antigen receptor T-cell therapy to gain US Food and Drug Administration approval for patients with relapsed/refractory multiple myeloma (RRMM). The clinical outcomes of standard of care (SOC) ide-cel in racially and ethnically diverse populations have been understudied. This study pooled data from 207 patients with RRMM (28% patients of racial and ethnic minority groups) treated with SOC ide-cel across 11 institutions to examine racial and ethnic differences in the incidence of toxicities and adverse events, response to ide-cel, and survival. This study included 22 (11%) Hispanic, 36 (17%) non-Hispanic Black, and 149 (72%) non-Hispanic White patients with RRMM. Compared with Hispanic and non-Hispanic White patients, non-Hispanic Black patients had higher median levels of C-reactive protein (1.0, 0.8, and 3.5 mg/dL, respectively; P = .02) and baseline ferritin (362.0 vs 307.0 vs 680.5, respectively; P = .08) and were more likely to develop cytokine release syndrome (77%, 85%, and 97%, respectively; P = .04). Although best overall response rate was lower among Hispanic patients (59%) than among non-Hispanic Black (86%) and White patients (86%; P = .01), there were no racial and ethnic differences in progression-free or overall survival. We provide, to our knowledge, the first and largest investigation of clinical outcomes of SOC ide-cel by race and ethnicity. Despite differences in safety and response to ide-cel, our findings encourage the use of ide-cel in all patients with RRMM. These findings should be confirmed in larger samples of diverse patients with RRMM, with longer follow-up time.