Carfilzomib plus dexamethasone in patients with relapsed and refractory multiple myeloma: A retro-prospective observational study

Objective: We investigate safety and efficacy in common clinical practice of the combination of carfilzomib and dexamethasone (Kd56) approved for the ENDEAVOR trial for the treatment of relapsed or refractory multiple myeloma. Methods: We retro-prospective analyzed 75 patients in three centers in Tuscany, 48 of whom had a clinically relevant comorbidity and 50 of whom were older than 65 years, treated with a median use in the fourth line of therapy. We assessed the efficacy based on the International Myeloma Working Group criteria. Results: The overall response rate was 60%. Median PFS was 10 months in the general cohort; in patients treated for more than 1 cycle of therapy PFS was 12 months. Quality of response to Kd56 treatment was found to positively impact PFS. Refractory status to previous line of therapy or to lenalidomide or an history of exposure to pomalidomide, seemed to have no impact on survival. We also showed a low adverse events rate, with no neuropathy events, and a relatively small number of cardiovascular events above grade 3 (10%). Conclusion: Kd56 is an effective and well tolerated regimen in highly pretreated and elderly patients with a good safety profile

Characterization of Arabidopsis FPS isozymes and FPS gene expression analysis provide insight into the biosynthesis of isoprenoid precursors in seeds

Arabidopsis thaliana contains two genes encoding farnesyl diphosphate (FPP) synthase (FPS), the prenyl diphoshate synthase that catalyzes the synthesis of FPP from isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). In this study, we provide evidence that the two Arabidopsis short FPS isozymes FPS1S and FPS2 localize to the cytosol. Both enzymes were expressed in E. coli, purified and biochemically characterized. Despite FPS1S and FPS2 share more than 90% amino acid sequence identity, FPS2 was found to be more efficient as a catalyst, more sensitive to the inhibitory effect of NaCl, and more resistant to thermal inactivation than FPS1S. Homology modelling for FPS1S and FPS2 and analysis of the amino acid differences between the two enzymes revealed an increase in surface polarity and a greater capacity to form surface salt bridges of FPS2 compared to FPS1S. These factors most likely account for the enhanced thermostability of FPS2. Expression analysis of FPS::GUS genes in seeds showed that FPS1 and FPS2 display complementary patterns of expression particularly at late stages of seed development, which suggests that Arabidopsis seeds have two spatially segregated sources of FPP. Functional complementation studies of the Arabidopsis fps2 knockout mutant seed phenotypes demonstrated that under normal conditions FPS1S and FPS2 are functionally interchangeable. A putative role for FPS2 in maintaining seed germination capacity under adverse environmental conditions is discussed

DP118 | REAL-WORLD ANALYSIS OF MINIMAL RESIDUAL DISEASE IN TRANSPLANT-ELIGIBLE NEWLY DIAGNOSED MULTIPLE MYELOMA PATIENTS: A DECADE OF SINGLE-CENTER EXPERIENCE

BACKGROUND: Minimal Residual Disease (MRD) in multiple myeloma (MM) is a recognized surrogate marker for progression-free survival (PFS) and a potential clinical trial endpoint. MRD negativity is associated with improved survival, regardless of disease setting, assessment method, cytogenetic risk, or assay sensitivity. METHODS: We conducted a single-center, retrospective real-life analysis of 185 newly diagnosed MM patients eligible for ASCT, treated at AOU Careggi from Feb 2013 to Dec 2023. Patients received VTD induction until Dec 2021, then Dara-VTD per CASSIOPEIA protocol. Lenalidomide maintenance was introduced from Nov 2018. MRD was assessed on bone marrow samples using 2nd-generation 8-color flow cytometry (sensitivity 10⁻⁵) at two key time points: post-induction and post-ASCT/pre-maintenance. RESULTS: Median age was 58 (range 32–69), M/F: 97/88. High-risk (HiR) cytogenetic abnormalities [del(17p), t(4;14), t(14;16), gain/amp(1q)] were present in 33% (n=61). 141 patients (76%) received VTD induction regimen, whereas 44 (24%) were treated with Dara-VTD. Most patients (80%) underwent single ASCT; 20% received tandem ASCT due to HiR status. Lenalidomide maintenance was administered to 59% (n=109). Post-induction, the overall response rate was 99.4%, with ≥VGPR in 82% and ≥CR in 27%. MRD negativity was achieved in 40.5% (n=75), increasing from 37% (VTD) to 52% (Dara-VTD). Pre-maintenance, 55% reached ≥CR, and MRD- was observed in 70.8% overall (67% VTD vs 81% Dara-VTD). After a median follow-up of 63 months, median PFS (mPFS) was 71 months. MRD- status correlated with improved mPFS both post-induction (92.3 vs 56.6 months, p=0.01) and pre-maintenance (98 vs 46 months, p<0.001). Among patients with ≥VGPR, MRD negativity was associated with longer PFS (88 vs 52 months, p=0.01). In HiR patients, MRD negativity conferred a PFS benefit, aligning their outcomes with standard-risk patients (85 vs 35 months for HiR MRD+, p<0.001). Bone marrow re-assessment ≥12 months from the prior was available in 52 patients on maintenance therapy. Among these, 44 showed a sustained MRD-, while 8 converted to MRD+. Median PFS was significantly shorter in those who lost MRD- (NR in MRD- vs 44 in MRD loss vs 43 months in patients with persistent MRD+, p<0.001). CONCLUSIONS: Our real-world study confirms MRD as a strong early predictor of PFS, underscores the prognostic value of sustained MRD negativity, and highlights its favorable impact, particularly in high-risk patients

Real-life experience with pomalidomide plus low-dose dexamethasone in patients with relapsed and refractory multiple myeloma: A retrospective and prospective study

14nononeBackground and Objectives: The treatment of Myeloma after the second relapse is still challenging. The aim of the study was to investigate the outcomes of the POM-DEX regimen in real clinical practice. Materials and Methods: We retrospectively and prospectively analyzed 121 patients with MM treated with POM-DEX in three Italian sites in Tuscany. We assessed the efficacy based on IMWG Uniform Response Criteria in 106 patients who had received at least two courses of the POM-DEX regimen. The median time from diagnosis to use of POM-DEX was 65 months. POM-DEX median use was in the fourth-line therapy. 63.6% were exposed to lenalidomide or thalidomide, 40.5% to bortezomib or carfilzomib or ixazomib, 5.8% to mAbs in the immediately preceding line of therapy. Results: ORR was 43.4%. Median PFS and OS were 8.5 and 14 months. Eighty-nine patients received more than two courses: their median PFS and OS were 11 and 16 months. When used as the third line of therapy, median PFS and OS were 9 and 20 months and, when patients received POM-DEX for more than two courses, median PFS and OS were 14.5 and 22.5 months. Conclusions: POM-DEX is effective in RRMM, regardless of the latest exposure to IMiDs, PIs, and mAbs in the previous line of therapy.noneDel Giudice M.L.; Gozzetti A.; Antonioli E.; Orciuolo E.; Ghio F.; Ciofini S.; Candi V.; Fontanelli G.; Attucci I.; Formica G.; Bocchia M.; Galimberti S.; Petrini M.; Buda G.Del Giudice, M. L.; Gozzetti, A.; Antonioli, E.; Orciuolo, E.; Ghio, F.; Ciofini, S.; Candi, V.; Fontanelli, G.; Attucci, I.; Formica, G.; Bocchia, M.; Galimberti, S.; Petrini, M.; Buda, G

Measuring elastase, proteinase 3 and cathepsin G activities at the surface of human neutrophils with fluorescence resonance energy transfer substrates

The neutrophil serine proteases (NSPs) elastase, proteinase 3 and cathepsin G are multifunctional proteases involved in pathogen destruction and the modulation of inflammatory processes. A fraction of secreted NSPs remains bound to the external plasma membrane, where they remain enzymatically active. This protocol describes the spectrofluorometric measurement of NSP activities on neutrophil surfaces using highly sensitive Abz-peptidyl-EDDnp fluorescence resonance energy transfer (FRET) substrates that fully discriminate between the three human NSPs. We describe FRET substrate synthesis, neutrophil purification and handling, and kinetic experiments on quiescent and activated cells. These are used to measure subnanomolar concentrations of membrane-bound or free NSPs in low-binding microplates and to quantify the activities of individual proteases in biological fluids like expectorations and bronchoalveolar lavages. the whole procedure, including neutrophil purification and kinetic measurements, can be done in 4-5 h and should not be longer because of the lifetime of neutrophils. Using this protocol will help identify the contributions of individual NSPs to the development of inflammatory diseases and may reveal these proteases to be targets for therapeutic inhibitors.Alexander von Humboldt FoundationGerman Research CouncilVaincre la MucoviscidoseFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Proteases & Vectorisat Pulm Fac Med, INSERM, U618, F-37032 Tours, FranceMax Planck Inst Neurobiol, Dept Neuroimmunol, D-82152 Planegg Martinsried, GermanyUniv Tours, F-37032 Tours, FranceUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biofis, BR-0404420 São Paulo, BrazilINSERM, U921, F-37032 Tours, FranceUniversidade Federal de São Paulo, Escola Paulista Med, Dept Biofis, BR-0404420 São Paulo, BrazilWeb of Scienc

P169 | REAL-WORLD MINIMAL RESIDUAL DISEASE ANALYSIS IN TRANSPLANT-INELIGIBLE MULTIPLE MYELOMA PATIENTS TREATED WITH DARA-VMP VS. DARA-RD IN THE RANDOMIZED PHASE IV REAL MM TRIAL

Introduction. Daratumumab-bortezomib-melphalan-prednisone (D-VMP) and daratumumab-lenalidomide-dexamethasone (D-Rd) are standard-of-care regimens for newly diagnosed multiple myeloma (NDMM) patients (pts) ineligible for transplant (NTE). No prospective randomized trial compared D-VMP vs D-Rd, and data on the feasibility of minimal residual disease (MRD) assessment in real-life NTE settings are limited. Methods. REAL-MM is a randomized, multicenter, phase IV trial (NCT03829371), comparing D-VMP vs D-Rd in a real-life population of NTE NDMM pts. The study is actively enrolling. NTE NDMM pts (age ≥65 or with comorbidities) are being randomized 1:1 to D-VMP vs D-Rd and enrolled regardless of performance status and comorbidities. Stratification is based on IMWG frailty score and cytogenetic (CG) risk [high risk (HR)=del(17p) and/or t(14;16) and/or t(4;14)]. MRD is assessed by next-generation-flow in pts achieving ≥ very good partial response (VGPR) at +6, +12 months from randomization and yearly thereafter until +60 months. The primary endpoint of the trial is progression-free survival; the current preliminary analysis focuses on clinical response, MRD negativity (MRD-) rates and safety in the first year after randomization. Results At data cut-off (December 12, 2024), 163 pts were randomized (D-VMP n=81; D-Rd n=82). We excluded from the analysis 43 pts with < 1 year of follow-up, focusing on 120 pts (D-VMP n=61; D-Rd n=59) randomized before December 31, 2023. Baseline characteristics were balanced in D-VMP vs D-Rd arms: median age was 75 (IQR 72-78) vs 76 years (IQR 74-79); 34% vs 37% were frail; 25% vs 22% had HR CG. After a median follow-up of 14 months, ORR was 85% vs 78% (p=0.35) and ≥ VGPR rates were 67% and 59% (p=0.45). MRD- rates were 18% and 19% at 6 months (p=1.00), and 34% vs 27% at 12 months (p=0.43). Among HR CG pts, 12 months MRD- rates were 27% vs 38% (p=0.69) and among frail pts 29% vs 14% (p=0.28). No safety concerns emerged. The most frequent grade 3-4 adverse events were thrombocytopenia (13%) and neutropenia (8%) with D-VMP and neutropenia (28%) and infections (8%) with D-Rd. Conclusions. This preliminary descriptive analysis confirms the applicability of MRD assessment in a real-life NTE NDMM population, including 36% of frail patients. High MRD- rates were observed at 12 months in both arms, including HR CG and frail patients, supporting the use of daratumumab-based combinations in this setting. No new safety data emerged