Most patients with early-stage classical Hodgkin lymphoma (cHL) are treated with doxorubicin, bleomycin, vinblastine, and dacarbazine with or without radiation therapy, although studies are now evaluating the incorporation of novel agents paired with abbreviated chemotherapy. We present the efficacy and safety of brentuximab vedotin (BV) and nivolumab in combination with doxorubicin and dacarbazine (AN+AD) in patients with early-stage cHL. In this phase 2 study, patients with non-bulky (<10 cm) Ann Arbor stage I or II cHL received 4 cycles of AN+AD. The primary endpoint was complete response (CR) rate at end of treatment (EOT) by investigator. At the time of this analysis, 154 patients received ≥1 dose of AN+AD. The objective response rate at EOT was 96% (95% CI, 91.7-98.6), and the CR rate was 92% (95% CI, 86.0-95.4). In the favorable (n=56) and unfavorable (n=97) subgroups, CR rates were 95% (95% CI, 85.1-98.9) and 91% (95% CI, 83.1-95.7), respectively. The proportion of patients with duration of CR of at least 2 years was 96% (95% CI, 90.9-98.4). At a median follow-up of 27.9 months, the estimated 2-year PFS rate was 97% (95% CI, 92.0-98.8). Any-grade and grade ≥3 treatment-emergent adverse events occurred in 99% and 44% of patients, respectively; no events of febrile neutropenia were reported. Any-grade treatment-emergent immune-mediated adverse events occurred in 22% of patients. One disease-related death was reported after the safety reporting period. Results from this study support the use of BV and nivolumab in combination with limited chemotherapy in patients with non-bulky, early-stage cHL. ClinicalTrials.gov: NCT03646123.

Intestinal Enterococcus domination has been associated with an increased risk of mortality from acute graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (allo-HCT), a curative-intent treatment for patients with hematologic malignancies. In this study, we investigated interactions between Enterococcus and the intestinal epithelium as a mechanism to aggravate GVHD. We observed that endogenous intestinal Enterococcus outgrowth was associated with increased GVHD mortality and major histocompatibility complex class II (MHC-II) expression by intestinal epithelial cells in the colon in an MHC-disparate mouse model of GVHD. Monocolonization of nontransplanted gnotobiotic mice with Enterococcus faecalis was sufficient to induce colonic MHC-II expression. Conversely, select species within the genus Enterococcus, as well as a consortium of 4 anaerobic commensal bacteria including Blautia producta, did not affect colonic MHC-II expression in gnotobiotic mice. In addition, E faecalis colonization induced inflammatory responses in CD4+ T cells and natural killer cells from the colonic lamina propria, the 2 main sources of interferon gamma production that drives MHC-II expression in nonprofessional antigen-presenting cells. We further explored the potential therapeutic benefit of establishing colonization resistance against E faecalis through administration of a lantibiotic-producing B producta strain after allo-HCT. Colonization of transplanted mice with a consortium of commensal bacteria containing the lantibiotic-producing B producta strain prevented intestinal Enterococcus domination after transplantation and improved GVHD survival. Our results demonstrate a potential mechanism by which Enterococcus aggravates GVHD through increased MHC-II expression in the intestinal epithelium. Targeting the Enterococcus-epithelium-MHC-II axis thus presents a therapeutic opportunity to prevent lethal GVHD.

NUTM1 rearrangement defines a significant subset of B-cell acute lymphoblastic leukemia (B-ALL), particularly in infants lacking KMT2A rearrangements, yet its underlying molecular characteristics remain poorly understood. Here, we establish that NUTM1-rearranged (NUTM1-r) leukemia is a discrete entity characterized by a unique transcriptional and epigenetic landscape, notably featuring global DNA hypomethylation, irrespective of the 5' fusion partner. Functional interrogation of NUTM1 fusions reveals a dual oncogenic role: they drive commitment toward the B-lymphoid lineage while concurrently conferring potent leukemic stem cell properties. Strikingly, expression of a representative fusion, BRD9-NUTM1, is sufficient to induce serially transplantable B-cell progenitor, prepro-B-like leukemia in vivo, faithfully recapitulating the key molecular and immunophenotypic features of human NUTM1-r B-ALL. Mechanistically, NUTM1 fusions establish an aberrant chromatin state, marked by global enhancement of H3K27 acetylation and the creation of distinctive open chromatin regions that co-opt both B-lineage and stemness-related transcriptional programs, including those involving NF-κB and posterior HoxA genes. In stark contrast to resistant KMT2A-rearranged leukemias, NUTM1-r leukemic cells exhibit a profound sensitivity to chemotherapy. This vulnerability is mechanistically linked to the leukemia's dependence on active transcription. Our findings delineate the unique molecular profile of NUTM1-r leukemias, revealing specific vulnerabilities that rationalize their favorable clinical outcomes and suggest opportunities for modified therapeutic strategies.

High levels of circulating tumor cells (CTC) are a powerful predictor of poor outcomes in newly diagnosed multiple myeloma, yet the mechanistic underpinnings of this correlation remain unknown. To investigate whether CTC-related pathobiology is driven by a specific CTC subset, paired bone marrow and blood samples from patients with newly diagnosed multiple myeloma were analyzed by single-cell transcriptomics and whole-genome sequencing. This revealed that down to the individual clone level, CTC and paired bone marrow cells are transcriptionally similar, without evidence for a distinct circulating population. In contrast, bone marrow myeloma cells from patients with high CTC levels had increased proliferation and unbalanced primary genetic events, including enrichment for MAF and CCND translocations. To investigate the impact of heterogenic genomic events on CTC levels, whole-exome and bulk RNA sequencing from the Multiple Myeloma Research Foundation CoMMpass data set were analyzed and validated in our in-house data sets. Bone marrow tumor cells from patients with high CTC levels were uniformly characterized by transcriptomic signatures of proliferation. Furthermore, CTC levels were uniquely dependent on primary genomic events and high-risk secondary genomic events, including amplification 1q, deletion 1p, deletion 13q, biallelic TP53 mutations, and increased apolipoprotein B editing complex-induced mutations even in patients without MAF translocations. Finally, we developed a model that predicts the impact of genetic alterations and tumor burden on CTC levels. In sum, we reveal that CTC are the net result of tumor burden, primary translocations, and secondary genomic events, making CTC a powerful biomarker for genomics-driven high-risk disease in patients with newly diagnosed myeloma.

The use of posttransplant cyclophosphamide was initially pioneered as a means of permitting haploidentical transplantation across HLA barriers. This approach has now become a standard of care for the prevention of significant acute and chronic graft-versus-host disease (GVHD) after related and unrelated HLA-matched allogeneic peripheral blood stem cell transplant across a full spectrum of conditioning intensities. This article discusses recent advances, the mechanisms of action, and important unresolved questions in the prevention of GVHD that will help inform new prospective clinical studies.

Sickle cell disease (SCD) and β-thalassemia are devastating genetic disorders resulting from defects in the β-globin subunit of adult hemoglobin. Both disorders are ameliorated by the induction of γ-globin, a component of fetal hemoglobin (HbF). Therefore, the development of safe, effective, and widely available inducers of HbF is needed. Here, we discovered that slow cycling erythroid cells exhibit increased γ-globin expression. To understand the molecular basis of this, we screened all cyclin-dependent kinase inhibitors (CDKIs) for their ability to induce HbF using CRISPR activation. We found that overexpression of CDKN1B, which encodes p27Kip1 (but not overexpression of other CDKIs), induces γ-globin expression at the transcriptional level. CDKN1B mutants expressing proteins unable to bind/inhibit CDKs and/or cyclins revealed that γ-globin induction by p27Kip1 depends largely on the domains involved in its cell cycle function. Pharmacological inhibition and genetic reduction of CDK4/6 also result in increased HbF. In genetic rescue experiments, we show that p27Kip1 induces HbF by inhibiting CDK4/6, through a mechanism that is likely BCL11A and ZBTB7A independent. Furthermore, palbociclib, an oral CDK4/6 inhibitor, significantly increases HbF in a murine SCD model at doses that are well tolerated. Moreover, we show that HbF induction by hydroxyurea, a drug currently in use to treat SCD, may be mediated in part by CDK4/6 inhibition. Overall, our findings establish a causal relationship between CDK4/6 activity and γ-globin production and suggest that single or dual CDK4/6 inhibitors might be therapeutically beneficial for SCD and β-thalassemia.

Venous thromboembolism (VTE) remains a leading contributor to maternal morbidity and mortality during pregnancy and the immediate postpartum period. Although pregnancy is recognized as a hypercoagulable state, the molecular mechanisms underlying this prothrombotic shift remain incompletely characterized. In this study, lactoferrin was identified as an enhancer of coagulation factor XIa (FXIa) activity. Elevated plasma concentrations of lactoferrin were observed in pregnant women and found to be estrogen dependent, mediated through estrogen response elements (EREs) within the lactoferrin gene promoter. In murine models, pregnancy-induced thrombotic pathology was ameliorated by either genetic knockout of lactoferrin or pharmacological blockade using HS9, a peptide that selectively inhibits lactoferrin-mediated potentiation of FXIa. Notably, HS9 (1 mg/kg) exhibited a substantially reduced hemorrhagic profile compared with low-molecular-weight heparin. These findings identify lactoferrin as a physiological modulator of gestational hypercoagulability and implicate it as a potential therapeutic target for pregnancy-associated VTE, with the capacity to reduce thrombotic risk while preserving hemostatic integrity.