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Introduction: Despite extensive research, comprehensive characterization of leukaemic stem cells (LSC) and information on their immunophenotypic differences from normal haematopoietic stem cells (HSC) is lacking. Herein, we attempted to unravel the immunophenotypic (IPT) characteristics and heterogeneity of LSC using multiparametric flow cytometry (MFC) and single‐cell sequencing. Materials and Methods: Bone marrow aspirate samples from patients with acute myeloid leukaemia (AML) were evaluated using MFC at diagnostic and post induction time points using a single tube‐10‐colour‐panel containing LSC‐associated antibodies CD123, CD45RA, CD44, CD33 and COMPOSITE (CLL‐1, TIM‐3, CD25, CD11b, CD22, CD7, CD56) with backbone markers that is, CD45, CD34, CD38, CD117, sCD3. Single‐cell sequencing of the whole transcriptome was also done in a bone marrow sample. Results: LSCs and HSCs were identified in 225/255 (88.2%) and 183/255 (71.6%) samples, respectively. Significantly higher expression was noted for COMPOSITE, CD45RA, CD123, CD33, and CD44 in LSCs than HSCs (p < 0.0001). On comparing the LSC specific antigen expressions between CD34+ (n = 184) and CD34‐ LSCs (n = 41), no difference was observed between the groups. More than one sub‐population of LSC was demonstrated in 4.4% of cases, which further revealed high concordance between MFC and single cell transcriptomic analysis in one of the cases displaying three LSC subpopulations by both methods. Conclusion: A single tube‐10‐colour MFC panel is proposed as an easy and reproducible tool to identify and discriminate LSCs from HSCs. LSCs display both inter‐ and intra‐sample heterogeneity in terms of antigen expressions, which opens the facets for single cell molecular analysis to elucidate the role of subpopulations of LSCs in AML progression. [ABSTRACT FROM AUTHOR]

Purpose: The use of [177Lu]Lu-PSMA-617 radioligand therapy has become increasingly recognized as a viable therapeutic approach for patients in the advanced stages of metastatic castration-resistant prostate cancer (mCRPC). However, there is limited data regarding its effectiveness and safety in earlier lines. This study aims to present our institution's experience with [177Lu]Lu-PSMA-617 as a first-line systemic therapy for mCRPC. Methods: We collected and analyzed data from consecutive mCRPC patients who underwent first-line treatment with [177Lu]Lu-PSMA-617 at our center from 2015 to 2023. The various outcome measures included best prostate-specific antigen-response rate (PSA-RR) (proportion of patients achieving a ≥ 50% decline in PSA); objective radiographic response rate (ORR) (proportion of patients achieving complete or partial radiographic responses); radiographic progression-free survival (rPFS) (measured from treatment initiation until radiographic progression or death from any cause); overall survival (OS) (measured from treatment initiation until death from any cause); and adverse events. Results: Forty treatment-naïve mCRPC patients with PSMA-positive disease on [68Ga]Ga-PSMA-11 PET/CT were included (median age: 68.5 years, range: 45–78; median PSA: 41 ng/mL, range: 1-3028). These patients received a median cumulative activity of 22.2 GBq (range: 5.55–44.4) [177Lu]Lu-PSMA-617 over 1–6 cycles at 8–12 week intervals. A ≥ 50% decline in PSA was observed in 25/40 (62.5%) patients (best PSA-RR). Radiographic responses were evaluated for thirty-eight patients, with thirteen showing partial responses (ORR 34.2%). Over a median follow-up of 36 months, the median rPFS was 12 months (95% confidence interval, CI: 9–15), and the median OS was 17 months (95% CI: 12–22). Treatment-emergent grade ≥ 3 anemia, leucopenia, and thrombocytopenia were noted in 4/40 (10%), 1/40 (2.5%), and 3/40 (7.5%) patients, respectively. Conclusion: The findings suggest that [177Lu]Lu-PSMA-617 is a safe and effective option as a first-line treatment in mCRPC. Further trials are needed to definitively establish its role as an upfront treatment modality in this setting. [ABSTRACT FROM AUTHOR]

Mesenchymal Stromal/Stem Cells (MSCs) are multipotent, non-hematopoietic progenitor cells with a wide range of immune modulation and regenerative potential which qualify them as a potential component of cell-based therapy for various autoimmune/chronic inflammatory ailments. Their immunomodulatory properties include the secretion of immunosuppressive cytokines, the ability to suppress T-cell activation and differentiation, and the induction of regulatory T-cells. Considering this and our interest, we here discuss the significance of MSC for the management of Graft-versus-Host-Disease (GvHD), one of the autoimmune manifestations in human. In pre-clinical models, MSCs have been shown to reduce the severity of GvHD symptoms, including skin and gut damage, which are the most common and debilitating manifestations of this disease. While initial clinical studies of MSCs in GvHD cases were promising, the results were variable in randomized studies. So, further studies are warranted to fully understand their potential benefits, safety profile, and optimal dosing regimens. Owing to these inevitable issues, here we discuss various mechanisms, and how MSCs can be employed in managing GvHD, as a cellular therapeutic approach for this disease. Preconditioning of MSCs before infusing in patients with GvHD Preconditioning of MSCs is indeed a crucial step in improving the effectiveness of stem cell therapy for GvHD. Preconditioning involves exposing MSCs to cytokines, growth factors, and/or drugs prior to transplantation. This exposure induces changes in the MSCs' behavior such as enhance the anti-inflammatory and immunomodulatory properties of MSCs, which can reduce the severity of GvHD and improving the homing of MSCs to the injured target organ helping in tissue repair. Overall, precondition makes MSCs more effective in combating GvHD. [ABSTRACT FROM AUTHOR]

Aim: To assess the safety and effectiveness of daratumumab monotherapy in Indian patients with relapsed/refractory multiple myeloma. Methods: In this prospective, multicenter, phase IV study, patients (aged ≥18 years) received intravenous daratumumab (16 mg/kg) in six cycles. Safety was the primary end point. Results: Of the 139 patients included, 121 (87.1%) experienced ≥1 treatment-emergent adverse events (TEAEs; 53 [38.1%] drug-related), 32 (23%) had ≥1 serious TEAEs (five [3.6%] drug-related) and 16 (11.5%) deaths were reported (one death [0.7%] was drug-related). Overall response rate was 26.3%; 62.7% of patients had stable disease. Median time to first response and median progression-free survival were 5.2 and 5.9 months, respectively. Functional status and well-being were improved. Conclusion: Daratumumab showed an acceptable and expected safety profile with consistent efficacy, providing a novel therapeutic option for relapsed/refractory multiple myeloma management in India. Daratumumab is a monoclonal antibody approved for the treatment of patients with relapsed/refractory multiple myeloma (RRMM). This study evaluated the outcome of daratumumab single therapy in Indian patients who were not cured with other drugs used for the same disease. 139 adult patients were included in this study from 15 institutes across India. Daratumumab (16 mg/kg) was diluted with 500 or 1000 ml of saline solution and given slowly through the intravenous route 16-times within 6 months. The study examined whether the safety profile and benefits of daratumumab reported in Indian patients were similar to those reported in the RRMM populations of other countries. The study found that most of the adverse events were not severe and could be easily treated by the study physician. 16 patients died (one might have been due to daratumumab treatment). Daratumumab treatment provided life support and recovery benefits to many patients. Daratumumab single therapy provides an appropriate and acceptable safety profile with no new adverse events and consistent benefits in RRMM patients. Clinical Trial Registration:NCT03768960 (ClinicalTrials.gov), CTRI/2019/06/019546. This study demonstrated an acceptable and expected safety profile with consistent efficacy for daratumumab monotherapy in patients with relapsed/refractory multiple myeloma, providing a novel therapeutic option for myeloma management in India. [ABSTRACT FROM AUTHOR]