T-cell clones of uncertain significance. When is the rogue clone dangerous?

T cell large granular lymphocyte clones that persist over time and that exhibit molecular and immunophenotypic features closely resembling those of T-cell Large Granular Lymphocyte Leukemia (T-LGLL) may be detectable in individuals who lack any clinical or laboratory features supporting a diagnosis of T-cell malignancy. This condition represents a potential precursor state termed T cell clones of uncertain significance (T-CUS). T-CUS represents the even more benign extreme of the wide spectrum of clonal T- large granular lymphocyte proliferations, emphasizing the need for an appropriate multiparametric diagnostic assessment that avoids misdiagnosis of T-cell neoplasia. This approach should overcome the numerical cut-offs as the sole criteria to differentiate the benign condition from the related malignancies. In particular, genomic aberrancies might prospectively identify individuals who are at risk of progression to full blown T-cell malignancy. We herein discuss the significance of these T cell clones in both healthy and disease states suggesting molecular assays for tracking early steps of disease.

Belantamab mafodotin in triple-refractory multiple myeloma patients: A retro-prospective observational study in Italy.

Belantamab mafodotin is the first-in-class antibody-drug conjugates targeting B-cell maturation antigen to have demonstrated effectiveness in triple-class refractory multiple myeloma (TCR-MM) patients. We performed a retrospective study including 78 TCR patients, with at least four prior lines of therapy (LOTs), who received belantamab mafodotin within named patient program and expanded access program in Italy between 2020 and 2022. Median age was 65 years (range 42-86 years), ECOG performance status was ≥1 in 45% of patients. Overall, a clinical benefit was obtained in 36 out of 74 evaluable patients (49%), with 43%, 28%, and 13.5% achieving at least partial response, very good partial response, and complete response, respectively. After a median follow-up of 12 months (range 6-21 months), median duration of response, progression-free survival (PFS), and overall survival (OS) were 14, 5.5, and 12 months, respectively. Age >70 years, good performance status and response were associated with longer PFS and OS. Keratopathy occurred in 58% of patients (G3 2.5%), corneal symptoms in 32% (G3 1.2%) and a reduction in visual acuity in 14%. Grade 3 thrombocytopenia occurred in 9% of patients. Only 3% of patients discontinued belantamab mafodotin because of side effects. This real-life study demonstrated significant and durable responses of belantamab in TCR-MM patients with four prior LOTs, otherwise ineligible for novel immunotherapies.

Elotuzumab plus pomalidomide and dexamethasone in relapsed/refractory multiple myeloma: Extended follow-up of a multicenter, retrospective real-world experience with 321 cases outside of controlled clinical trials.

The ELOQUENT-3 trial demonstrated the superiority of the combination of elotuzumab, pomalidomide, and dexamethasone (EloPd) in terms of efficacy and safety, compared to Pd in relapsed/refractory multiple myeloma (RRMM), who had received at least two prior therapies, including lenalidomide and a proteasome inhibitor. The present study is an 18-month follow-up update of a previously published Italian real-life RRMM cohort of patients treated with EloPd. This revised analysis entered 319 RRMM patients accrued in 41 Italian centers. After a median follow-up of 17.7 months, 213 patients (66.4%) experienced disease progression or died. Median progression-free survival (PFS) and overall survival (OS) were 7.5 and 19.2 months, respectively. The updated multivariate analysis showed a significant reduction of PFS benefit magnitude both in advanced International Staging System (ISS) (II and III) stages and previous exposure to daratumumab cases. Instead, advanced ISS (II and III) stages and more than 2 previous lines of therapy maintained an independent prognostic impact on OS. Major adverse events included grade three-fourths neutropenia (24.9%), anemia (13.4%), lymphocytopenia (15.5%), and thrombocytopenia (10.7%), while infection rates and pneumonia were 19.3% and 8.7%, respectively. A slight increase in the incidence of neutropenia and lymphocytopenia was registered with longer follow-up. In conclusion, our real-world study still confirms that EloPd is a safe and possible therapeutic choice for RRMM. Nevertheless, novel strategies are desirable for those patients exposed to daratumumab.

A real-world retrospective-prospective analysis of efficacy and safety of combined ixazomib, lenalidomide, and dexamethasone in relapsed/refractory multiple myeloma: The northern Italy experience.

INTRODUCTION: Ixazomib, lenalidomide, and dexamethasone (IRd) have been approved for the treatment of relapsed/refractory multiple myeloma (RRMM) based on the results of the TOURMALINE-MM1. OBJECTIVES AND METHODS: We conducted a retrospective-prospective analysis of 106 RRMM patients (pts) treated with IRd in 21 centers in Northern Italy, with the aim to evaluate the efficacy and safety of IRd in real life. RESULTS: At IRd initiation, 34% of pts were aged ≥75 (median 72.5), 8.5% had an ECOG performance status ≥2, 54.7% of evaluable pts carried high-risk cytogenetic abnormalities [del17p and/or t(4;14) and/or t(14;16) and/or 1 g gain/amp], 60.2% had received ≥2 prior lines of therapy (pLoT), 57.5% were lenalidomide (Len)-exposed (including both Len-sensitive and Len-refractory pts), and 22% were Len-refractory. Main G ≥3 adverse events (AEs) were thrombocytopenia (16%) and neutropenia (12.3%). G ≥3 non-hematologic AEs included infections (9.4%) and GI toxicity (diarrhea 5.7%, hepatotoxicity 2.8%), VTE, skin rash, and peripheral neuropathy were mainly G1-2. The overall response rate was 56.4% (≥VGPR 30%). With a median follow-up of 38 m, median PFS (mPFS) was 16 m and the 1-year OS rate was 73%. By subgroup analysis, an extended PFS was observed for pts achieving ≥VGPR (mPFS 21.2 m), time from diagnosis to IRd ≥5 years (26.2 m), 1 pLoT (34.4 m), Len-naïve (NR), age ≥70 (20 m). In pts exposed to Len, non-refractory in any prior line and immediately prior to IRd, mPFS was 16 and 18 m, respectively. An inferior PFS was seen in Len-refractory pts (4.6 m). By multivariate analysis, independent predictors of PFS were age ≥70 (HR 0.6), time from diagnosis ≥5 years (HR 0.32), refractoriness to Len in any prior line (HR 3.33), and immediately prior (HR 4.31). CONCLUSION: IRd might be effective and safe in RRMM pts with an indolent disease, in early lines of treatment, and who proved Len-sensitive, independent of age, and cytogenetic risk.

When Waldenström macroglobulinemia hits the kidney: Description of a case series and management of a "rare in rare" scenario.

BACKGROUND: Renal injury related to Waldenström macroglobulinemia (WM) occurs in approximately 3% of patients. Kidney biopsy is crucial to discriminate between distinct histopathological entities such as glomerular (amyloidotic and non-amyloidotic), tubulo-interstitial and non-paraprotein mediated renal damage. In this context, disease characterization, management, relationship between renal, and hematological response have been poorly explored. We collected clinical, genetic and laboratory data of seven cases of biopsy-proven renal involvement by WM managed at our academic center and focused on three cases we judged paradigmatic discussing their histopathological patterns, clinical features, and therapeutic options. CASE: In this illustrative case series, we confirm that serum creatinine levels and 24 h proteinuria are parameters that when altered should prompt the clinical suspicion of WM-related renal involvement, even if at present there are not precise cut-off levels recommending the execution of a renal biopsy. In our series AL Amyloidosis (n = 3/7) and tubulo-interstitial infiltration by lymphoma cells (n = 3/7) were the two more represented entities. BTKi did not seem to improve renal function (Case 1), while bortezomib-based regimens demonstrated a beneficial activity on the hematological and organ response, even when used as second-line therapy after chemoimmunotherapy (Case 3) and also with coexistence of anti-MAG neuropathy (Case 2). In case of poor response to bortezomib, standard chemoimmunotherapy (CIT), such as rituximab-bendamustine, represents an effective option (Case 1, 6, and 7). In our series, CIT generates durable responses more frequently in cases with amyloidogenic renal damage (Case 1, 5, and 7). CONCLUSION: In this illustrative case series, we confirm that serum creatinine levels and 24 h proteinuria are parameters that when altered should prompt the clinical suspicion of WM-related renal involvement, even if at present there are not precise cut-off levels recommending the execution of a renal biopsy. Studies with higher numerosity are needed to better clarify the pathological and clinical features of renal involvement during WM and to determine the potential benefit of different therapeutic regimens according to the histopathological subtypes.

The constitutive activation of STAT3 gene and its mutations are at the crossroad between LGL leukemia and autoimmune disorders.

Type T Large Granular Lymphocyte Leukemia (T-LGLL) is a chronic disorder characterized by the abnormal proliferation of clonal cytotoxic T cells. The intriguing association of T-LGLL with autoimmune and inflammatory diseases, the most prominent example being rheumatoid arthritis, raises questions about the underlying pathophysiologic relationships between these disorders which share several biological and clinical features, most notably neutropenia, which is considered as a clinical hallmark. Recent progress in molecular genetics has contributed to a better understanding of pathogenetic mechanisms, thus moving our knowledge in the field of LGL leukemias forward. Focusing on the constitutive activation of STAT3 pathway and the well-established role of STAT3 mutations in T-LGLL, we herein discuss whether the T cell clones occurring in comorbid conditions are the cause or the consequence of the immune-inflammatory associated events. Overall, this review sheds light on the intricate relationships between inflammation and cancer, emphasizing the importance of the STAT3 gene and its activation in the pathophysiology of these conditions. Gaining a deeper understanding of these underlying mechanisms seeks to pave the way for the development of novel targeted therapies for patients affected by inflammation-related cancers.

Elotuzumab plus pomalidomide and dexamethasone in relapsed/refractory multiple myeloma: a multicenter, retrospective, real-world experience with 200 cases outside of controlled clinical trials.

In the ELOQUENT-3 trial, the combination of elotuzumab, pomalidomide and dexamethasone (EloPd) proved to have a superior clinical benefit over pomalidomide and dexamethasone with a manageable toxicity profile, leading to its approval for the treatment of patients with relapsed/refractory multiple myeloma (RRMM) who have received at least two prior therapies, including lenalidomide and a proteasome inhibitor. We report here a real-world experience of 200 cases of RRMM treated with EloPd in 35 Italian centers outside of clinical trials. In our dataset, the median number of prior lines of therapy was two, with 51% of cases undergoing autologous stem cell transplant and 73% having been exposed to daratumumab. After a median follow-up of 9 months, 126 patients had stopped EloPd, most of them (88.9%) because of disease progression. The overall response rate was 55.4%, a finding in line with the pivotal trial results. Regarding adverse events, the toxicity profile in our cohort was similar to that in the ELOQUENT-3 trial, with no significant differences between younger (<70 years) and older patients. The median progression-free survival was 7 months, which was shorter than that observed in ELOQUENT-3, probably because of the different clinical characteristics of the two cohorts. Interestingly, International Staging System stage III disease was associated with worse progression-free survival (hazard ratio=2.55). Finally, the median overall survival of our series was shorter than that observed in the ELOQUENT-3 trial (17.5 vs. 29.8 months). In conclusion, our real-world study confirms that EloPd is a safe and possible therapeutic choice for patients with RRMM who have received at least two prior therapies, including lenalidomide and a proteasome inhibitor.

Pro-inflammatory cells sustain leukemic clonal expansion in T-cell large granular lymphocyte leukemia.

T-cell large granular lymphocyte leukemia (T-LGLL) is a chronic lymphoproliferative disorder characterized by the clonal expansion of T-cell large granular lymphocytes (T-LGL). Immunophenotypic and genotypic features contribute to discriminate symptomatic (CD8+ STAT3-mutated T-LGLL) from clinically indolent patients, this latter group including CD8+ wildtype (wt), CD4+ STAT5B-mutated and wt cases. T-LGL lymphoproliferation is sustained both by somatic gain-offunction mutations (i.e., STAT3 and STAT5B) and by pro-inflammatory cytokines, but little information is available on the activity of T-LGLL non-leukemic cells. In this study, we characterized pro-inflammatory cells in the peripheral blood of T-LGLL patients and analyzed their role in supporting the leukemic growth. In symptomatic patients we found that cell populations not belonging to the leukemic component showed a discrete pro-inflammatory pattern. In particular, CD8+ STAT3-mutated cases showed a skewed Th17/Treg ratio and an abnormal distribution of monocyte populations characterized by increased intermediate and non-classical monocytes. We also demonstrated that monocytes released high levels of interleukin-6 after CCL5 stimulation, a chemokine specifically expressed only by leukemic LGL. Conversely, in asymptomatic cases an altered distribution of monocyte populations was not detected. Moreover, T-LGLL patients' monocytes showed abnormal activation of signaling pathways, further supporting the different pathogenic role of monocytes in patients in discrete clinical settings. Altogether, our data contribute to deepening the knowledge on the different cell subtypes in T-LGLL, focusing particularly on non-leukemic cell populations and thus offering the rationale for new therapeutic strategies.

A real-life study of daratumumab-bortezomib-dexamethasone (D-VD) in lenalidomide exposed/refractory multiple myeloma patients: a report from the Triveneto Myeloma Working Group.

Treatment of lenalidomide refractory (Len-R) multiple myeloma (MM) patients still represents an unmet clinical need. In the last years, daratumumab-bortezomib-dexamethasone (D-VD) combination was extensively used in this setting, even though only a small fraction of Len-R patients was included in the pivotal trial. This real-life study aimed to evaluate the efficacy and safety of the D-VD regimen in a cohort that exclusively enrolled Len exposed or refractory MM patients. The study cohort included 57 patients affected by relapsed/refractory MM. All patients were previously exposed to Len, with 77.2% being refractory. The overall response rate (ORR) was 79.6% with 43% of cases obtaining at least a very good partial response (VGPR). The D-VD regimen showed a favorable safety profile, with low frequency of grade 3-4 adverse events, except for thrombocytopenia observed in 21.4% of patients. With a median follow-up of 13 months, median progression-free survival (PFS) was 17 months. No significant PFS differences were observed according to age, ISS, LDH levels, type of relapse, and high-risk FISH. Len exposed patients displayed a PFS advantage as compared to Len refractory patients (29 vs 16 months, p = 0.2876). Similarly, patients treated after Len maintenance showed a better outcome as compared to patients who had received a full-dose Len treatment (23 vs 13 months, p = 0.1728). In conclusion, our real-world data on D-VD combination showed remarkable efficacy in Len-R patients, placing this regimen as one of the standards of care to be properly taken into account in this MM setting.

Predictors of unsustained measurable residual disease negativity in patients with multiple myeloma.

ABSTRACT: The prognostic impact of achieving and in particular maintaining measurable residual disease (MRD) negativity in multiple myeloma is now established; therefore, identifying among MRD-negative patients the ones at higher risk of losing MRD negativity is of importance. We analyzed predictors of unsustained MRD negativity in patients enrolled in the FORTE trial (NCT02203643). MRD was performed by multiparameter flow cytometry (sensitivity of 10-5) at premaintenance and every 6 months thereafter. The cumulative incidence (CI) of MRD resurgence and/or progression was analyzed in MRD-negative patients. A total of 306 of 474 (65%) MRD-negative patients were analyzed. After a median follow-up of 50.4 months from MRD negativity, 185 of 306 (60%) patients were still MRD negative and progression free, 118 (39%) lost their MRD-negative status, and 3 patients (1%) died without progression. Amp1q vs normal (4-year CI, 63% vs 34), ≥2 concomitant high-risk cytogenetic abnormalities vs 0 (4-year CI, 59% vs 33%), circulating tumor cells at baseline (high vs low at 4-year CI, 62% vs 32%), and time-to-reach MRD negativity postconsolidation vs preconsolidation (4-year CI, 46% vs 35%) were associated with a higher risk of unsustained MRD negativity in a multivariate Fine-Gray model. During the first 2 years of maintenance, patients receiving carfilzomib-lenalidomide vs lenalidomide alone had a lower risk of unsustained MRD negativity (4-year CI, 20% vs 33%).

Impact of minimal residual disease standardised assessment by FDG-PET/CT in transplant-eligible patients with newly diagnosed multiple myeloma enrolled in the imaging sub-study of the FORTE trial.

Background: 18F-FDG-PET/CT is the current standard technique to define minimal residual disease (MRD) outside the bone marrow (BM) in multiple myeloma (MM), recently standardised applying the Deauville scores (DS) to focal lesions (FS) and bone marrow uptake (BMS) and defining the complete metabolic response (CMR) as uptake below the liver background (DS <4). Methods: In this analysis, we aimed at confirming the role of CMR, and complementarity with BM multiparameter flow cytometry (MFC) at 10-5, in an independent cohort of newly diagnosed transplant-eligible MM patients previously enrolled in the phase II randomised FORTE trial. 109 of the 474 global patients enrolled in the trial between February 23, 2015, and April 5, 2017, who had paired PET/CT (performed at baseline [B] and preceding maintenance therapy [PM]) and MFC evaluation, were included in this analysis. Findings: At B, 93% of patients had focal lesions within the bones (FS ≥4 in 89%) and 99% increased BM uptake (BMS ≥4 in 61%). At PM, CMR was achieved in 63% of patients, which was a strong predictor for prolonged PFS in univariate analysis at landmark time PM (HR 0.40, P = 0.0065) and in Cox multivariate analysis (HR 0.31, P = 0.0023). Regarding OS, a trend in favour of CMR was present in univariate (HR 0.44, P = 0.094), and Cox multivariate model (HR 0.17, P = 0.0037). Patients achieving both PET/CT CMR and MFC negativity at PM showed significantly extended PFS in univariate (HR 0.45, P = 0.020) and multivariate analysis (HR 0.41, P = 0.015). Interpretation: We herein confirm the applicability and validity of DS criteria to define CMR and its prognostic relevance and complementarity with MFC at the BM level. Funding: Amgen, Celgene/Bristol Myers Squibb, Italian Ministry of Health (RC-2022-2773423).

Tixagevimab/Cilgavimab as pre-exposure prophylaxis against SARS-CoV-2 in patients with hematological malignancies.

The approved combination of Tixagevimab/Cilgavimab has been shown to decrease the rate of symptomatic SARS-CoV-2 infection in patients at increased risk of inadequate response to vaccination. However, Tixagevimab/Cilgavimab was tested in a few studies that included patients with hematological malignancies, even if this population has shown an increased risk of unfavorable outcomes following infection (with high rates of hospitalization, intensive care unit admission, and mortality) and poor significant immunization following vaccines. We performed a real-life prospective cohort study to evaluate the rate of SARS-CoV-2 infection following pre-exposure prophylaxis with Tixagevimab/Cilgavimab in anti-spike seronegative patients compared to a cohort of seropositive patients who were observed or received a fourth vaccine dose. We recruited 103 patients with a mean age of 67 years: 35 (34%) received Tixagevimab/Cilgavimab and were followed from March 17, 2022, until November 15, 2022. After a median follow-up of 4.24 months, the 3-month cumulative incidence of infection was 20% versus 12% in the Tixagevimab/Cilgavimab and observation/vaccine groups respectively (HR 1.57; 95% CI: 0.65-3.56; p = 0.34). In this study, we report our experience with Tixagevimab/Cilgavimab and a tailored approach to SARS-CoV-2 infection prevention in patients with hematological malignancies during the SARS-CoV-2 omicron surge.

Long-term follow-up of rituximab plus bendamustine and cytarabine in older patients with newly diagnosed MCL.

The combination of rituximab, bendamustine, and low-dose cytarabine (R-BAC) has been studied in a phase 2 prospective multicenter study from Fondazione Italiana Linfomi (RBAC500). In 57 previously untreated elderly patients with mantle cell lymphoma (MCL), R-BAC was associated with a complete remission rate of 91% and 2-year progression-free survival (PFS) of 81% (95% confidence interval [CI], 68-89). Here, we report the long-term survival outcomes, late toxicities, and results of minimal residual disease (MRD) evaluation. After a median follow-up of 86 months (range, 57-107 months), the median overall survival (OS) and PFS were not reached. The 7-year PFS and OS rates were 55% (95% CI, 41-67), and 63% (95% CI, 49-74), respectively. Patients who responded (n = 53) had a 7-year PFS of 59% (95% CI, 44-71), with no relapse or progression registered after the sixth year. In the multivariate analysis, blastoid/pleomorphic morphology was the strongest adverse predictive factor for PFS (P = .04). Patients with an end of treatment negative MRD had better, but not significant, outcomes for both PFS and OS than patients with MRD-positive (P = 0.148 and P = 0.162, respectively). There was no signal of late toxicity or an increase in secondary malignancies during the prolonged follow-up. In conclusion, R-BAC, which was not followed by maintenance therapy, showed sustained efficacy over time in older patients with MCL. Survival outcomes compare favorably with those of other immunochemotherapy regimens (with or without maintenance), including combinations of BTK inhibitors upfront. This study was registered with EudraCT as 2011-005739-23 and at www.clinicaltrials.gov as #NCT01662050.

Not all LGL leukemias are created equal.

Large Granular Lymphocyte (LGL) Leukemia is a rare, heterogeneous even more that once thought, chronic lymphoproliferative disorder characterized by the clonal expansion of T- or NK-LGLs that requires appropriate immunophenotypic and molecular characterization. As in many other hematological conditions, genomic features are taking research efforts one step further and are also becoming instrumental in refining discrete subsets of LGL disorders. In particular, STAT3 and STAT5B mutations may be harbored in leukemic cells and their presence has been linked to diagnosis of LGL disorders. On clinical grounds, a correlation has been established in CD8+ T-LGLL patients between STAT3 mutations and clinical features, in particular neutropenia that favors the onset of severe infections. Revisiting biological aspects, clinical features as well as current and predictable emerging treatments of these disorders, we will herein discuss why appropriate dissection of different disease variants is needed to better manage patients with LGL disorders.

Real-world use of carfilzomib combined with lenalidomide and dexamethasone in patients with multiple myeloma in Europe and Israel.

Clinical trials have demonstrated the efficacy and safety of carfilzomib in patients with relapsed/refractory multiple myeloma (RRMM); however, prospective real-world data are limited. This real-world, prospective, observational study evaluated carfilzomib use, effectiveness and safety in adults with RRMM. Data are presented for a subset of patients (n = 383) who received carfilzomib in combination with lenalidomide and dexamethasone (KRd). The overall response rate (ORR) was 83.6% among 360 evaluable patients. Treatment responses were better when KRd was administered at earlier therapy lines than at later lines of therapy (ORR: second line, 85.3%; third line or later, 81.0%). In patients with the anti-CD38 antibody-refractory disease, ORR was higher when KRd was administered earlier than at later therapy lines (second line/third line, 75.0%; fourth line or later, 60.0%). An ORR of 68.1% and 82.0% was achieved in the lenalidomide-refractory and not lenalidomide-refractory subgroups, respectively. KRd was consistently administered per the European label (twice weekly dose of 27 mg/m2) and the median time to discontinuation was 14.6 months. The safety profile of KRd was consistent with previous studies. These real-world data highlight the effectiveness of KRd as a treatment for patients with RRMM, including those with disease refractory to lenalidomide or anti-CD38 antibodies.

Tγδ LGLL identifies a subset with more symptomatic disease: analysis of an international cohort of 137 patients.

Tγδ large granular lymphocyte leukemia (LGLL) is a rare variant of T-cell LGLL (T-LGLL) that has been less investigated as compared with the more frequent Tαß LGLL, particularly in terms of frequency of STAT3 and STAT5b mutations. In this study, we characterized the clinical and biological features of 137 patients affected by Tγδ LGLL; data were retrospectively collected from 1997 to 2020 at 8 referral centers. Neutropenia and anemia were the most relevant clinical features, being present in 54.2% and 49.6% of cases, respectively, including severe neutropenia and anemia in ∼20% of cases each. Among the various treatments, cyclosporine A was shown to provide the best response rates. DNA samples of 97 and 94 cases were available for STAT3 and STAT5b mutation analysis, with 38.1% and 4.2% of cases being mutated, respectively. Clinical and biological features of our series of Tγδ cases were also compared with a recently published Tαß cohort including 129 cases. Though no differences in STAT3 and STAT5b mutational frequency were found, Tγδ cases more frequently presented with neutropenia (P = .0161), anemia (P < .0001), severe anemia (P = .0065), and thrombocytopenia (P = .0187). Moreover, Vδ2- cases displayed higher frequency of symptomatic disease. Overall, Tγδ cases displayed reduced survival with respect to Tαß cases (P = .0017). Although there was no difference in STAT3 mutation frequency, our results showed that Tγδ LGLL represents a subset of T-LGLL characterized by more frequent symptoms and reduced survival as compared with Tαß LGLL.

Lenalidomide-based triplet regimens in first relapsed multiple myeloma patients: real-world evidence from a propensity score matched analysis.

Lenalidomide and dexamethasone (Rd)-based triplets, in particular carfilzomib-Rd (KRd) and daratumumab-Rd (DaraRd), represent a standard of care in lenalidomide-sensitive multiple myeloma (MM) patients in first relapse. Meta-analysis of randomized clinical trials (RCT), suggested better outcome with DaraRd. Trying to address this issue in clinical practice, we collected data of 430 consecutive MM patients addressed to Rd-based triplets in first relapse between January 2017 and March 2021. Overall, the most common used regimen was DaraRd, chosen in almost half of the cases (54.4%), followed by KRd (34.6%). Different triplets were used much less commonly. In an attempt to limit the imbalance of a retrospective analysis, we conducted a propensity score matching (PSM) comparison between DaraRd and KRd. After PSM, efficacy of DaraRd versus KRd was similar in terms of overall-response rate (ORR) (OR: 0.9, P=0.685) as well as of very good partial response (VGPR) or better (OR: 0.9, P=0.582). The median progression-free survival (PFS) was significantly longer for DaraRd (29.8 vs. 22.5 months; P=0.028). DaraRd was tolerated better, registering a lower rate of grade 3-4 non-hematological toxicity (OR: 0.4, P<0.001). With the limitations of any retrospective analysis, our real-life PSM comparison between DaraRd and KRd, in first-relapse MM patients, showed better tolerability and prolonged PFS of DaraRd, although with some gaps of performance, in particular of DaraRd, with respect to RCT. Carfilzomib-containing regimens, like KRd, still remain a valid second-line option in the emerging scenario of first-line daratumumab-based therapy.

A bone-based 3D scaffold as an in-vitro model of microenvironment-DLBCL lymphoma cell interaction.

About 30% of patients with diffuse large B-cell lymphoma (DLBCL) relapse or exhibit refractory disease (r/r DLBCL) after first-line immunochemotherapy. Bone marrow (BM) involvement confers a dismal prognosis at diagnosis, likely due to the interaction between neoplastic cells and a complex tumor microenvironment (TME). Therefore, we developed a 3D in-vitro model from human decellularized femoral bone fragments aiming to study the role of mesenchymal stromal cells (MSC) and the extracellular matrix (ECM) in the adaptation, growth, and drug resistance of DLBCL lymphoma cells. The 3D spatial configuration of the model was studied by histological analysis and confocal and multiphoton microscopy which allowed the 3D digital reproduction of the structure. We proved that MSC adapt and expand in the 3D scaffold generating niches in which also other cell types may grow. DLBCL cell lines adhered and grew in the 3D scaffold, both in the presence and absence of MSC, suggesting an active ECM-lymphocyte interaction. We found that the germinal center B-cell (GCB)-derived OCI-LY18 cells were more resistant to doxorubicin-induced apoptosis when growing in the decellularized 3D bone scaffold compared to 2D cultures (49.9% +/- 7.7% Annexin V+ cells in 2D condition compared to 30.7% + 9.2% Annexin V+ 3D adherent cells in the ECM model), thus suggesting a protective role of ECM. The coexistence of MSC in the 3D scaffold did not significantly affect doxorubicin-induced apoptosis of adherent OCI-LY18 cells (27.6% +/- 7.3% Annexin V+ 3D adherent cells in the ECM/MSC model after doxorubicin treatment). On the contrary, ECM did not protect the activated B-cell (ABC)-derived NU-DUL-1 lymphoma cell line from doxorubicin-induced apoptosis but protection was observed when MSC were growing in the bone scaffold (40.6% +/- 5.7% vs. 62.1% +/- 5.3% Annexin V+ 3D adherent cells vs. 2D condition). These data suggest that the interaction of lymphoma cells with the microenvironment may differ according to the DLBCL subtype and that 2D systems may fail to uncover this behavior. The 3D model we proposed may be improved with other cell types or translated to the study of other pathologies with the final goal to provide a tool for patient-specific treatment development.