Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia caused by monoclonal IgM autoantibodies that bind to red blood cells and trigger hemolysis through activation of the classical complement pathway. Cold agglutinins are produced by a clonal population of lymphocytes recognized by the WHO as a low grade lymphoproliferative disorder. Traditional therapy relied on B-cell-targeted immunosuppression with rituximab which mainly yielded partial responses in about half of the patients. The combination of rituximab with fludarabine or bendamustine significantly increased and prolonged response rates, though with a substantial infectious risk. Sutimlimab, the first C1s complement inhibitor, has shown efficacy in rapidly and sustainably increasing hemoglobin levels, reducing hemolysis, and significantly improving quality of life. However, the drug does not act on the B-cell clone and does not decrease the cold agglutinins. Therefore, several unmet needs remain, including identifying patients who can discontinue sutimlimab while maintaining remission, developing combination strategies effective against cold-induced symptoms, and improving infection prevention and control of hemolytic flares. This perspective article briefly recapitulates the pathophysiology of CAD, outlines the evolution of its treatment landscape, and focuses on the role of sutimlimab-its clinical positioning, therapeutic benefits, and management considerations-offering insights into optimizing care for patients with this challenging condition.

Large scale sequencing efforts have defined up to 27 diagnostic entities in B-ALL, leaving few samples without subtype assignment. Extended genomic and transcriptomic profiling in routine diagnostics broadens the sample collection and holds the potential to identify novel B-ALL subtypes. By analyzing an aggregated set of 4,857 B-ALL patients from three cohorts, we identified a novel group of twenty cases (age 18-66 years, median: 34 years) characterized by a previously undescribed IGH::FENDRR rearrangement exclusive to this subtype (n=17/20), KRAS p.A146T/V/P mutations (n=17/20 vs. n=86/4,857; p<0.001) and distinct DNA-methylation/gene expression profiles, including overexpression of the lncRNA FENDRR and the transcription factor FOXF1 ('FOXF1/FENDRR') as well as JAK/STAT and RAS signaling signatures. A gene expression machine learning classifier identified FOXF1/FENDRR cases in two independent cohorts with high accuracy. Patients treated according to GMALL/GRAALL protocols showed very poor chemotherapy response with n=8/13 having induction failure or MRD ≥10-3 and n=8/12 remaining MRD positive after 1st consolidation / salvage. MRD-stratified intensification including blinatumomab (n=10) and/or allogenic stem cell transplantation (n=12) resulted in ongoing molecular remission in 13/16 cases. FOXF1/FENDRR patients represent a novel B-ALL subtype which might benefit from early immunotherapeutic treatment or targeted interventions.

Iron is an essential element for most cellular processes and recent evidence highlighted its role in regulating the function of hematopoietic stem cells (HSCs). Abnormal iron levels impact HSC quiescence and self-renewal, however, the mechanism by which iron overload (IO) influences HSC function is still unknown. Here, we show that intracellular IO impairs mitochondrial fitness and bioenergetics, inducing metabolic rewiring. In thalassemic mice, as a model of chronic IO, HSCs accumulate mitochondria with elevated reactive oxygen species (mtROS), low membrane potential and reduced oxidative phosphorylation (OXPHOS). Mitochondrial defects are confirmed in other two models of IO, sickle cell disease and iron-loaded wild-type mice, and in vivo iron reduction rescues HSC mitochondria. IO HSCs are highly proliferating and in presence of damaged mitochondria rely on glycolysis for energy production. Notably, restoration of mitochondrial function by targeting in vivo mtROS improved the quiescence and self-renewal of IO HSCs. Our results unravel the critical interplay between iron, ROS and mitochondrial activity in HSCs, revealing that IO shapes HSC metabolic programs.

FLT3-ITD mutation is associated with poor prognosis in acute myeloid leukemia (AML), yet its kinase-independent mechanisms remain unclear. To investigate kinase-independent immunosuppressive mechanisms in FLT3-ITD AML, we integrated single-cell RNA sequencing from two public datasets and multiparameter flow cytometry data from 104 primary patient samples, identifying profound CD8+ T cell exhaustion as a hallmark of the FLT3-ITD immune microenvironment. Mechanistically, FLT3-ITD acts as a mutation-specific scaffold that assembles a ternary complex with PKCι and STAT1, as demonstrated by co-immunoprecipitation and intracellular colocalization. This complex enables PKCι-mediated phosphorylation of STAT1 specifically at serine 727 (S727), driving CD276 transcription independent of the canonical tyrosine 701 (Y701) site. Chromatin immunoprecipitation, electrophoretic mobility shift, promoter-reporter assays, and phosphosite-mutant constructs confirmed that S727 phosphorylation is necessary and sufficient for CD276 transactivation. Multiplex immunohistochemistry of patient bone marrow validated co-elevation of pS727-STAT1 and CD276 in FLT3-ITD blasts, accompanied by CD8+ T cell depletion. Functionally, CD276 upregulation induced profound CD8+ T cell exhaustion, characterized by reduced cytotoxicity, impaired proliferation, diminished IFN-γ production and elevated inhibitory checkpoints expression. Targeting CD276 restored CD8+ T cell function by 1.2-1.7-fold (cytotoxicity), 1.4-1.7-fold (proliferation), 1.5-1.8-fold (IFN-γ secretion) and 25.4%-67.6% (checkpoints expression) in ex vivo co-culture. In patient-derived xenograft models, co-treatment with FLT3i (quizartinib) and CD276-targeting agents led to 72.9%-80.4% tumor burden reduction and enhanced CD8+ T cell function, outperforming quizartinib monotherapy. These findings define a scaffolded PKCι-pS727-STAT1 signaling axis that promotes immune evasion in FLT3-ITD AML, supporting combined FLT3 and CD276 targeting as a promising translational strategy in this aggressive leukemia subtype.

The therapeutic landscape for relapsed or refractory large B-cell lymphoma (R/R LBCL) has undergone rapid and profound change, driven by cellular therapies, bispecific antibodies, and next-generation antibody-drug conjugates (ADCs). These advances have redefined historical standards while exposing persistent gaps in trial design, biological insight, and therapeutic sequencing. Recent randomized studies show that ADC- and bispecific-anchored regimens can outperform legacy chemotherapy comparators, yet interpretation is hindered by geographic heterogeneity, selective enrollment, and a proliferation of trials lacking contemporary control arms.Next-generation approaches including bispecific-ADC combinations, dual-target CAR-T constructs, and strategies explicitly designed to circumvent antigen escape are poised to challenge long-standing therapeutic hierarchies and may broaden curative potential to patients who are ineligible for, or relapse after, CAR-T. The field now stands at an inflection point where therapeutic innovation is advancing faster than the evidence infrastructure required to guide practice. Delivering durable, equitable benefit will require control arms aligned with current CAR-T standards, harmonized eligibility criteria, prospective molecular profiling, and adaptive trial platforms capable of evolving with the standard of care.As ADCs and bispecifics move earlier in treatment and diffuse into community practice, the central challenge is no longer the development of active therapies alone, but the creation of biologically rational, accessible, and interpretable pathways that make chemotherapy-free cure a realistic and universal goal for patients with R/R LBCL.