Semaphorin 4D and interleukin 1beta-complement cascade axis are key drivers of disease progression in multiple myeloma

Abstract Background and aims: Myeloma bone disease (MBD) is a common and clinically significant manifestation, observed in most patients at the time of multiple myeloma (MM) diagnosis. MBD has been associated with increased morbidity due to osteolytic lesions, pathological fractures, and chronic pain; however, its impact on survival outcomes in the era of modern MM therapies remains poorly documented. The present study aims to evaluate the impact of MBD on Overall Survival (OS), Progression-Free Survival (PFS), and Time to Progression (TTP) in newly diagnosed MM (NDMM) patients. Additionally, we aimed to explore the potential association of previously reported MBD biomarkers (Sema4D, Activin-A, periostin) and markers of bone metabolism with MBD and the above clinical outcomes. We hypothesized that these biomarkers may predict disease progression, particularly in precursor/asymptomatic stages, such as Smoldering MM (SMM) and Monoclonal Gammopathy of Undetermined Significance (MGUS). We also performed a proteomic analysis in the plasma of NDMM patients to identify novel biomarkers associated with patient outcomes and propose potential therapeutic targets in the context of modern MM therapies. Methodology Plasma samples from 76 consecutive patients with NDMM were analyzed. ELISA was performed to measure Sema4D, Activin-A, and periostin levels and the LEGENDplex™ Human Bone Metabolism Panel (13-plex) was used to quantify 13 additional proteins including cytokines. To study these markers at the SMM/MGUS stage, 21 paired samples from the same patients were analyzed, along with 25 independent SMM/MGUS age- and sex-matched patients. Proteomic analysis of plasma samples for novel biomarker identification was conducted using liquid chromatography–mass spectrometry (LC-MS) in 44 NDMM patients. Results NDMM patients had median age at diagnosis 59.5 years (range 46–89) and the median follow-up duration was 2.5 years (range 1.7–3.4). Of these, 43 (56.6%) were women, and 49 (64.5%) presented with MBD. Patients with MBD did not show statistically significant differences in OS (HR: 1.32, 95% CI: 0.35 - 4.97; p=0.68), PFS (HR: 0.83, 95% CI: 0.39 - 1.75; p=0.62), or TTP (HR: 0.74, 95% CI: 0.32 - 1.71; p=0.48) compared to those without MBD, suggesting that current treatments mitigated the impact of MBD on patient outcomes. Sema4D and periostin were elevated in patients with SMM/MGUS who progressed to MM (p=0.001; p<0.0001 vs non-progressors). Notably, in NDMM patients Sema4D was predictive of PFS, with a tendency to also predict TTP (Multivariate p=0.03, HR: 3.03, 95%CI: 1.06 - 8.66 and p=0.05, HR: 3.62, 95%CI: 0.98 - 13.29, respectively), highlighting its potential role as a prognostic and therapeutic target. While periostin was significantly associated with OS in univariate analysis (p-adjusted for multiple comparisons=0.048, HR: 6.02, 95% CI: 1.60 - 22.66) this effect was not retained in the multivariate analysis, suggesting that the prognostic value may be influenced by confounding variables. Multiplate analysis showed that at the MM stage IL-1β predicted PSF (Multivariate p=0.03, HR: 5.55, 95%CI: 1.14-27.03) and osteopontin predicted OS (Multivariate p=0.02, HR: 10.82, 95%CI: 1.29 - 90.65), indicating that bone turnover and inflammation remain key pathophysiological mechanisms in MM that could be targeted by emerging therapies. Proteomic analysis identified several markers associated with MBD and patient outcomes in NDMM patients. Among these, the complement component C9 consistently predicted all outcomes, including OS (Univariate p-adjusted for multiple comparisons=0.048, HR: 0.10, 95% CI: 0.02 - 0.56; Multivariate p=0.004, HR: 0.03, 95% CI: 0.003 - 0.35), TTP (Univariate p-adjusted= 0.043, HR: 7.44, 95% CI: 1.99 - 27.86; Multivariate p=0.006, HR: 7.94, 95% CI: 1.77 - 35.57) and PFS (Univariate p-adjusted=0.043, HR: 4.60, 95% CI: 1.68 - 12.66; Multivariate p=0.010, HR: 4.88, 95% CI: 1.44 - 16.52), suggesting the potential involvement of the complement system in disease pathophysiology. Conclusions Our findings support that MBD does not significantly impact on OS, TTP and PFS in NDMM patients who receice modern therapies. This study highlights Sema4D as a promising biomarker for early prediction of MM progression and for PFS in NDMM patients. Importantly, the IL-1β–complement cascade axis emerged as a key driver of disease progression, independent of MBD, and as a potential therapeutic target in NDMM patients.