Aberrations on TP53, either as deletions of chromosome 17p (del17p) or mutations, are associated with poor outcome in multiple myeloma (MM), but conventional detection methods currently in use underestimate their incidence, hindering an optimal risk assessment and prognostication of MM patients. We have investigated the altered status of TP53 gene by SNPs array and sequencing techniques in a homogenous cohort of 143 newly diagnosed MM patients, evaluated both at diagnosis and at first relapse: single-hit on TP53 gene, either deletion or mutation, detected both at clonal and sub-clonal level, had a minor effect on outcomes. Conversely, the coexistence of both TP53 deletion and mutation, which defined the so-called double-hit patients, was associated with the worst clinical outcome (PFS: HR 3.34 [95% CI: 1.37–8.12] p = 0.008; OS: HR 3.47 [95% CI: 1.18–10.24] p = 0.02). Moreover, the analysis of longitudinal samples pointed out that TP53 allelic status might increase during the disease course. Notably, the acquisition of TP53 alterations at relapse dramatically worsened the clinical course of patients. Overall, our analyses showed these techniques to be highly sensitive to identify TP53 aberrations at sub-clonal level, emphasizing the poor prognosis associated with double-hit MM patients.
Multiple myeloma (MM) is a plasma cell (PC) disorder characterized by skeletal involvement at the time of diagnosis. Recently, cell-free DNA (cfDNA) has been proven to recapitulate the heterogeneity of bone marrow (BM) disease. Our aim was to evaluate the prognostic role of cfDNA at diagnosis according to disease distribution, and to investigate the role of the MM microenvironment inflammatory state in supplying the release of cfDNA. A total of 162 newly diagnosed MM patients were screened using 18F-FDG PET/CT and assessed by ultra low-pass whole genome sequencing (ULP-WGS). High cfDNA tumor fraction (ctDNA) levels were correlated with different tumor mass markers, and patients with high ctDNA levels at diagnosis were more likely to present with metabolically active paraskeletal (PS) and extramedullary (EM) lesions. Moreover, we demonstrated that microenvironment cancer-associated fibroblast (CAFs)-mediated inflammation might correlate with high ctDNA levels. Indeed, a high cfDNA TF level at diagnosis predicted a poorer prognosis, independent of R-ISS III and 1q amplification; the inclusion of >12% ctDNA in the current R-ISS risk score enables a better identification of high-risk patients. ctDNA can be a reliable and less invasive marker for disease characterization, and can refine patient risk.
Clonal hematopoiesis of indeterminate potential (CHIP) refers to the phenomenon where a hematopoietic stem cell acquires fitness-increasing mutation(s), resulting in its clonal expansion. CHIP is frequently observed in multiple myeloma (MM) patients, and it is associated with a worse outcome. High-throughput amplicon-based single-cell DNA sequencing was performed on circulating CD34+ cells collected from twelve MM patients before autologous stem cell transplantation (ASCT). Moreover, in four MM patients, longitudinal samples either before or post-ASCT were collected. Single-cell sequencing and data analysis were assessed using the MissionBio Tapestri® platform, with a targeted panel of 20 leukemia-associated genes. We detected CHIP pathogenic mutations in 6/12 patients (50%) at the time of transplant. The most frequently mutated genes were TET2, EZH2, KIT, DNMT3A, and ASXL1. In two patients, we observed co-occurring mutations involving an epigenetic modifier (i.e., DNMT3A) and/or a gene involved in splicing machinery (i.e., SF3B1) and/or a tyrosine kinase receptor (i.e., KIT) in the same clone. Longitudinal analysis of paired samples revealed a positive selection of mutant high-fitness clones over time, regardless of their affinity with a major or minor sub-clone. Copy number analysis of the panel of all genes did not show any numerical alterations present in stem cell compartment. Moreover, we observed a tendency of CHIP-positive patients to achieve a suboptimal response to therapy compared to those without. A sub-clone dynamic of high-fitness mutations over time was confirmed.
In recent years, liquid biopsy has emerged as a promising alternative to the bone marrow (BM) examination, since it is a minimally invasive technique allowing serial monitoring. Circulating multiple myeloma cells (CMMCs) enumerated using CELLSEARCH® were correlated with patients’ prognosis and measured under treatment to assess their role in monitoring disease dynamics. Forty-four MM and seven smouldering MM (SMM) patients were studied. The CMMC medians at diagnosis were 349 (1 to 39,940) and 327 (range 22–2463) for MM and SMM, respectively. In the MM patients, the CMMC count was correlated with serum albumin, calcium, β2-microglobulin, and monoclonal components (p < 0.04). Under therapy, the CMMCs were consistently detectable in 15/40 patients (coMMstant = 1) and were undetectable or decreasing in 25/40 patients (coMMstant = 0). High-quality response rates were lower in the coMMstant = 1 group (p = 0.04), with a 7.8-fold higher risk of death (p = 0.039), suggesting that continuous CMMC release is correlated with poor responses. In four MM patients, a single-cell DNA sequencing analysis on residual CMMCs confirmed the genomic pattern of the aberrations observed in the BM samples, also highlighting the presence of emerging clones. The CMMC kinetics during treatment were used to separate the patients into two subgroups based on the coMMstant index, with different responses and survival probabilities, providing evidence that CMMC persistence is associated with a poor disease course.
Introduction: MGRS are new rare clinical entities, whose recognition and optimal management is evolving.Methods: To implement real‐life data, we retrospectively analysed a multicentre cohort of 60 patients with renal biopsy‐proven MGRS receiving mainly novel treatments (between 2006 and 2021) in eight Italian centres. Based on renal biopsy, patients were divided into two subgroups: AL amyloidosis (70%, n = 42) and other‐MGRS (30%, n = 18).Results: Baseline characteristics follow typical manifestations of MGRS disorders in terms of small clonal burden, laboratory and clinical features. More patients with AL amyloidosis had monotypic lambda light‐chain disease, estimated glomerular filtration rate (eGFR) ≥ 60 mL/min and nephrotic proteinuria than other‐MGRS group. The most widely used drug was bortezomib, and about one‐third of patients underwent ASCT. Overall response rate was 86% with no differences in the two subgroups. However, high‐quality hematologic responses ≥very good partial response (VGPR) were greater in AL amyloidosis than in other‐MGRS group (67% vs 28%, p = 0.015). The depth of haematological response influenced renal response, obtained in 32 (59%) of evaluable patients, similarly in the subgroups. Indeed, 75% patients with ≥ VGPR (p = 0.049) and none with stable disease (p ≤ 0.001) obtained a renal response. No association between renal response and histotypes (p = 0.9) or type of first‐line therapy (p = 0.3) was found. At a median follow‐up of 54.4 months (IQR 24.8–102.8), median progression‐free survival (PFS) was 100.1 months (95% CI 34.9–NR), and median overall survival not reached (95% CI 129.8–NR). No significant difference emerged between the two groups in terms of survival outcomes. Achieving ≥ VGPR was confirmed as the main independent predictor of prolonged PFS in the general population (HR = 0.29, p = 0.023) and AL amyloidosis group (HR 0.23; p = 0.023). Preserved renal function at diagnosis was predictive of improved PFS in the AL amyloidosis group (eGFR ≥ 60 mL/min: HR = 0.003; p = 0.018; eGFR 30–60 mL/min: HR = 0.04, p = 0.046).Conclusion: Further research is warranted to develop standardised response criteria and treatment strategies to improve MGRS management.
Modern therapies have clearly marked the history of multiple myeloma (MM), leading to undisputed advantages in terms of sustained responses and prolonged survival, while progressively improving patients' quality of life. Nonetheless, disease recurrence and resistance to available therapies underscore the importance of identifying additional treatment options, especially in hard‐to‐treat patients, or when access to cutting‐edge immunotherapies is limited. Melflufen (melphalan‐flufenamide) plus dexamethasone has been approved by the European Medicines Agency for triple‐class‐refractory MM patients after ≥ 3 prior therapies, but current data from real‐world settings are scarce. We herein report data from a single‐center experience of 17 relapsed/refractory MM patients treated with melflufen‐dexamethasone outside clinical trials between December 2021 and July 2025 in Bologna (Italy). The overall response rate was 41%. At a median follow‐up (mFU) of 8 months, mPFS was 3.7 months (95% CI 1.8–NR) in the overall population, being 9.0 months (95% CI 7.8–NR) in responders (mFU 10 months), while mOS has not been reached (95% CI 13.5–NR) either in the total population or in subgroups. Notably, 11/17 patients received subsequent therapies (seven receiving novel immunotherapeutic approaches), achieving deeper and more durable responses than those receiving conventional regimens. Grade ≥ 3 hematologic toxicities were common (35% anemia, 53% neutropenia, 53% thrombocytopenia), while grade ≥ 3 nonhematologic events were less frequent (mainly fatigue: 6%, and infections: 23.5%). No secondary primary malignancies were recorded. Collectively, our data confirmed the efficacy previously reported with melflufen–dexamethasone and its manageable safety profile, even in elderly patients likely more fragile and more heavily pretreated than those included in the trials. Overall, melflufen–dexamethasone may represent a treatment option, especially for patients refractory to novel immunotherapies or those who are not ideal candidates to receive such treatments while still preserving access to subsequent T‐cell redirecting therapies, thereby addressing a significant unmet need in this hard‐to‐treat patient population.