Phase 2 study of epigenetic priming with decitabine followed by cytarabine for acute myeloid leukemia in older patients.

Acute myeloid leukemia (AML) in older patients has a poor prognosis, low complete remission (CR) rates, and poor overall survival (OS). Preclinical studies have shown synergistic effects of epigenetic priming with hypomethylating agents followed by cytarabine. Based on these data, we hypothesized that an induction regimen using epigenetic priming with decitabine, followed by cytarabine would be effective and safe in older patients with previously untreated AML. Here, we conducted a phase 2 trial in which older patients with previously untreated AML received an induction regimen consisting of 1 or 2 courses of decitabine 20 mg/m2 intravenously (IV) for 5 days followed by cytarabine 100 mg/m2 continuous IV infusion for 5 days. Forty-four patients (median age 76 years) were enrolled, and CR/CRi was achieved by 26 patients (59% of all patients, 66.7% of evaluable patients). Fourteen of 21 (66.7%) patients with adverse cytogenetics achieved CR including six out of seven evaluable patients with TP53 mutations. The 4- and 8-week mortality rates were 2.3% and 9.1%, respectively, with median OS of 10.7 months. These results suggest epigenetic priming with decitabine followed by cytarabine should be considered as an option for first-line therapy in older patients with AML. This trial was registered at www.clinicaltrials.gov as # NCT01829503.

An oncolytic virus-delivered TGFß inhibitor overcomes the immunosuppressive tumor microenvironment.

While checkpoint blockade immunotherapies have widespread success, they rely on a responsive immune infiltrate; as such, treatments enhancing immune infiltration and preventing immunosuppression are of critical need. We previously generated αPD-1 resistant variants of the murine HNSCC model MEER. While entirely αPD-1 resistant, these tumors regress after single dose of oncolytic vaccinia virus (VV). We then generated a VV-resistant MEER line to dissect the immunologic features of sensitive and resistant tumors. While treatment of both tumor types induced immune infiltration and IFNγ, we found a defining feature of resistance was elevation of immunosuppressive cytokines like TGFß, which blunted IFNγ signaling, especially in regulatory T cells. We engineered VV to express a genetically encoded TGFßRII inhibitor. Inhibitor-expressing VV produced regressions in resistant tumor models and showed impressive synergy with checkpoint blockade. Importantly, tumor-specific, viral delivery of TGFß inhibition had no toxicities associated with systemic TGFß/TGFßR inhibition. Our data suggest that aside from stimulating immune infiltration, oncolytic viruses are attractive means to deliver agents to limit immunosuppression in cancer.

Metabolic reprogramming via an engineered PGC-1α improves human chimeric antigen receptor T-cell therapy against solid tumors.

BACKGROUND: Cellular immunotherapies for cancer represent a means by which a patient's immune system can be augmented with high numbers of tumor-specific T cells. Chimeric antigen receptor (CAR) therapy involves genetic engineering to 'redirect' peripheral T cells to tumor targets, showing remarkable potency in blood cancers. However, due to several resistance mechanisms, CAR-T cell therapies remain ineffective in solid tumors. We and others have shown the tumor microenvironment harbors a distinct metabolic landscape that produces a barrier to immune cell function. Further, altered differentiation of T cells within tumors induces defects in mitochondrial biogenesis, resulting in severe cell-intrinsic metabolic deficiencies. While we and others have shown murine T cell receptor (TCR)-transgenic cells can be improved through enhanced mitochondrial biogenesis, we sought to determine whether human CAR-T cells could be enabled through a metabolic reprogramming approach. MATERIALS AND METHODS: Anti-EGFR CAR-T cells were infused in NSG mice which bore A549 tumors. The tumor infiltrating lymphocytes were analyzed for exhaustion and metabolic deficiencies. Lentiviruses carrying PPAR-gamma coactivator 1α (PGC-1α), PGC-1αS571A and NT-PGC-1α constructs were used to co-transduce T cells with anti-EGFR CAR lentiviruses. We performed metabolic analysis via flow cytometry and Seahorse analysis in vitro as well as RNA sequencing. Finally, we treated therapeutically A549-carrying NSG mice with either PGC-1α or NT-PGC-1α anti-EGFR CAR-T cells. We also analyzed the differences in the tumor-infiltrating CAR-T cells when PGC-1α is co-expressed. RESULTS: Here, in this study, we show that an inhibition resistant, engineered version of PGC-1α, can metabolically reprogram human CAR-T cells. Transcriptomic profiling of PGC-1α-transduced CAR-T cells showed this approach effectively induced mitochondrial biogenesis, but also upregulated programs associated with effector functions. Treatment of immunodeficient animals bearing human solid tumors with these cells resulted in substantially improved in vivo efficacy. In contrast, a truncated version of PGC-1α, NT-PGC-1α, did not improve the in vivo outcomes. CONCLUSIONS: Our data further support a role for metabolic reprogramming in immunomodulatory treatments and highlight the utility of genes like PGC-1α as attractive candidates to include in cargo along with chimeric receptors or TCRs for cell therapy of solid tumors.

Hypoxia drives CD39-dependent suppressor function in exhausted T cells to limit antitumor immunity.

CD8+ T cells are critical for elimination of cancer cells. Factors within the tumor microenvironment (TME) can drive these cells to a hypofunctional state known as exhaustion. The most terminally exhausted T (tTex) cells are resistant to checkpoint blockade immunotherapy and might instead limit immunotherapeutic efficacy. Here we show that intratumoral CD8+ tTex cells possess transcriptional features of CD4+Foxp3+ regulatory T cells and are similarly capable of directly suppressing T cell proliferation ex vivo. tTex cell suppression requires CD39, which generates immunosuppressive adenosine. Restricted deletion of CD39 in endogenous CD8+ T cells resulted in slowed tumor progression, improved immunotherapy responsiveness and enhanced infiltration of transferred tumor-specific T cells. CD39 is induced on tTex cells by tumor hypoxia, thus mitigation of hypoxia limits tTex suppression. Together, these data suggest tTex cells are an important regulatory population in cancer and strategies to limit their generation, reprogram their immunosuppressive state or remove them from the TME might potentiate immunotherapy.

HLA Factors versus Non-HLA Factors for Haploidentical Donor Selection.

When multiple haploidentical donors are available for transplantation, those of younger generations are generally selected over those of older generations. However, it is unclear who is the optimal donor when selecting candidates from within a generation, such as father versus mother, son versus daughter, or brother versus sister. Although traditionally male donors are favored over female donors, particularly for male recipients, and significant associations of individual HLA mis(matches) on outcomes are being increasingly recognized, the hierarchy of factors for donor selection is indeterminate. To assess whether HLA factors take precedence over non-HLA factors and to isolate the influence of specific characteristics on outcomes, we analyzed 412 patients stratified by donor relationship: child donor (son [n = 202] versus daughter [n = 96]), parent (father [n = 28] versus mother [n = 29]), and sibling (noninherited maternal [NIMA; n = 29] versus paternal [NIPA; n = 28] mismatched). Among siblings, NIMA mismatch was associated with a lower risk of acute graft-versus-host disease (aGVHD); B-leader mismatch was associated with high nonrelapse mortality (NRM), poor progression-free survival, and a trend toward poor overall survival (OS), whereas A-mismatch was associated with lower aGVHD. Among parent donors, the relationship did not impact any outcome; B-leader mismatch was associated with higher NRM and a trend toward poor OS, whereas A-mismatch was associated with lower NRM and improved progression-free survival and OS. Among child donors, no individual HLA mismatch was predictive of any outcome, and daughter donors were not associated with any adverse outcomes in multivariate analyses. Our data suggest that certain HLA factors may be more significant in some cases and should be given priority over simply selecting a donor based on relationship/sex.

Second primary malignancies in patients with haematological cancers treated with lenalidomide: a systematic review and meta-analysis.

BACKGROUND: Lenalidomide has been standard therapy for multiple myeloma and other haematological malignancies for more than a decade. Previous meta-analyses identified an association between lenalidomide and second primary malignancies (SPM) in patients with multiple myeloma. However, newer randomised controlled trials using lenalidomide for other indications have not reported an increased incidence of SPM. The aim of this study was to investigate the risk of developing SPM with lenalidomide use in all disease settings. METHODS: We did a systematic review of randomised controlled trials that reported SPM in patients treated with lenalidomide. PubMed, Embase, CENTRAL, Europe PubMed Central, and ClinicalTrials.gov were searched from Jan 1, 2004, to March 18, 2022. Randomised controlled trials with at least one lenalidomide group and one non-lenalidomide group were selected, regardless of the disease setting. Studies with a median follow-up of less than 12 months were excluded. Summary data were extracted by two reviewers (KS and KL) independently and verified by a third reviewer (JF). We then conducted a meta-analysis to assess the risk ratio (RR) of SPM with lenalidomide use across various disease subtypes using a random-effects model. We chose random effects for the primary analysis because of anticipated heterogeneity between different diseases, but we used fixed effects for stratified meta-analysis of multiple myeloma studies. Risk of bias was assessed with the PROTECT tool. The study was registered with PROSPERO, CRD42021257508. FINDINGS: Our search yielded 9078 studies, and 38 trials that included 14 058 patients were eligible for meta-analysis after screening, 18 of which were in multiple myeloma. The RR across all malignancies was 1·16 (95% CI 0·96-1·39). However, there was heterogeneity across indications (p=0·020). The RR when lenalidomide was used for multiple myeloma was 1·42 (1·09-1·84). There was no increase in SPM in lymphoma or chronic lymphocytic leukaemia (0·90 [0·76-1·08]) and myelodysplastic syndrome (0·96 [0·23-3·97]) trials. In the setting of multiple myeloma, lenalidomide increased both solid and haematological SPM, both in the no-transplantation and post-transplantation settings. From the 38 trials, 21 (55%) had low risk of bias, 12 (32%) had unclear risk of bias, and five (13%) had high risk of bias. INTERPRETATION: Based on the current data, lenalidomide-induced SPM seem to occur exclusively in patients with multiple myeloma. Thus, lenalidomide can be used for other indications without the major concern of a therapy-related neoplasm. In the multiple myeloma setting, lenalidomide is an effective drug, but patients should be monitored both for haematological and solid tumour SPM. This monitoring includes patients that have not received autologous haematopoietic stem-cell transplantation. Further investigations are needed to improve understanding on why lenalidomide only promotes SPM in patients with multiple myeloma. FUNDING: None.

Fully murine CD105-targeted CAR-T cells provide an immunocompetent model for CAR-T cell biology.

The modeling of chimeric antigen receptor (CAR) T cell therapies has been mostly focused on immunodeficient models. However, there are many advantages in studying CAR-T cell biology in an immunocompetent setting. We generated a fully murine CAR targeting CD105 (endoglin), a component of the TGFß receptor expressed on the surface of certain solid tumors and acute leukemias. CD105-targeted CAR-T cells can be grown from various murine backgrounds, tracked in vivo by congenic marks, and be activated by CD105 in isolation or expressed by tumor cells. CD105-targeted CAR-T cells were toxic at higher doses but proved safe in lower doses and modestly effective in treating wild-type B16 melanoma-bearing mice. CAR-T cells infiltrating the tumor expressed high levels of exhaustion markers and exhibited metabolic insufficiencies. We also generated a human CD105 CAR, which was efficacious in treating human melanoma and acute myeloid leukemia in vivo. Our work details a new murine model of CAR-T cell therapy that can be used from immunologists to further our understanding of CAR-T cell biology. We also set the foundation for further exploration of CD105 as a possible human CAR-T cell target.

Tumor microenvironmental signals reshape chromatin landscapes to limit the functional potential of exhausted T cells.

Response rates to immunotherapy in solid tumors remain low due in part to the elevated prevalence of terminally exhausted T cells, a hypofunctional differentiation state induced through persistent antigen and stress signaling. However, the mechanisms promoting progression to terminal exhaustion in the tumor remain undefined. Using the low-input chromatin immunoprecipitation sequencing method CUT&RUN, we profiled the histone modification landscape of tumor-infiltrating CD8+ T cells throughout differentiation. We found that terminally exhausted T cells had unexpected chromatin features that limit their transcriptional potential. Terminally exhausted T cells had a substantial fraction of active chromatin, including active enhancers enriched for bZIP/AP-1 transcription factor motifs that lacked correlated gene expression, which was restored by immunotherapeutic costimulatory signaling. Reduced transcriptional potential was also driven by an increase in histone bivalency, which we linked directly to hypoxia exposure. Enforced expression of the hypoxia-insensitive histone demethylase Kdm6b was sufficient to overcome hypoxia, increase function, and promote antitumor immunity. Our study reveals the specific epigenetic changes mediated by histone modifications during T cell differentiation that support exhaustion in cancer, highlighting that their altered function is driven by improper costimulatory signals and environmental factors. These data suggest that even terminally exhausted T cells may remain competent for transcription in settings of increased costimulatory signaling and reduced hypoxia.

Time from diagnosis to treatment is associated with survival in patients with acute myeloid leukaemia: An analysis of 55 985 patients from the National Cancer Database.

Acute myeloid leukaemia (AML) is conventionally thought of as a medical emergency. However, several studies on the association of time from diagnosis to treatment with survival did not have concordant results. Here we analyse 55 985 AML patients from the National Cancer Database, and we show that in patients less than 60 years old a five-day delay in chemotherapy initiation leads to worse long-term survival. The difference is small [hazard ratio (HR) 1.05, 95% confidence interval (CI) 1.01-1.09 in multivariate analysis] but statistically significant. This study raises the issue of power to detect small differences in retrospective studies.

A prospective study of the use of central venous catheters in patients newly diagnosed with acute myeloid leukemia treated with induction chemotherapy.

PURPOSE: Central venous catheters (CVCs) are widely used in acute myeloid leukemia (AML) patients. Complications associated with CVCs are frequently encountered and contribute to morbidity and mortality. Prospective studies investigating and comparing complications of different types of CVCs in AML patients and their effects on the quality of life are limited. METHODS: We conducted a prospective observational study and evaluated the complications associated with the use of CVCs in adult AML patients during induction chemotherapy and evaluated quality of life outcomes as reported by the patients during and after their hospitalization. RESULTS: Fifty newly diagnosed patients with AML (median age, 59 years) who received intensive induction chemotherapy were enrolled in the study. Twenty-nine patients (58%) had a peripherally inserted central catheters (PICCs) placed and 21 (42%) patients received a Hickmann tunneled central catheter (TCC). Three percent of cases developed catheter-related thrombosis in PICCs and no thrombosis in TCCs. Catheter-related bloodstream infection was diagnosed in 8% of patients. CVC occlusion occurred in 44 patients (88%). The total number of occlusion events was 128; 97% of patients with PICCs and 76% of patients with TCCs (p = 0.003). All patients reported that the use of CVC simplified their course of treatment. Most patients reported similar restrictions in activity associated with TCCs and PICCs. CONCLUSION: The present study demonstrates that thrombosis and catheter-related bloodstream infections remain important complications of CVCs in AML patients. Occlusion rates were higher with the use of PICCs and the use of CVCs impacted the quality of life.

Outcomes of Patients With Acute Myeloid Leukemia Who Relapse After 5 Years of Complete Remission.

Leukemia relapse 5 years after achieving first complete remission (CR1) is uncommon in patients with acute myeloid leukemia (AML). In this study, we evaluated the outcomes of AML patients with late relapse at our institution and reviewed the literature for these patients. The study cohort consisted of nine AML patients with late relapse. The median interval between CR1 and AML relapse was 6.1 years (range: 5.116.2 years). At relapse, the karyotype was different from the initial AML diagnosis in 50% of patients. At the time of AML relapse, seven patients received induction chemotherapy and two patients received hypomethylating agents with an overall CR rate of 66%. The median time to relapse after achieving second CR (CR2) was 16.5 months [95% confidence interval (CI): 9.4, NA]. The median overall survival after first relapse was 28.6 months (95% CI: 7.3, 3.466.5 months). Despite initial CR after reinduction therapy, relapse rates are still high, suggesting that alternative strategies for postremission therapies are warranted in CR2. These approaches include the use of allogeneic hematogenic cell transplantation and the use of newly approved AML agents as maintenance therapy in nontransplant eligible patients.

EZH2 Supports Osteoclast Differentiation and Bone Resorption Via Epigenetic and Cytoplasmic Targets.

Key osteoclast (OCL) regulatory gene promoters in bone marrow-derived monocytes harbor bivalent histone modifications that combine activating Histone 3 lysine 4 tri-methyl (H3K4me3) and repressive H3K27me3 marks, which upon RANKL stimulation resolve into repressive or activating architecture. Enhancer of zeste homologue 2 (EZH2) is the histone methyltransferase component of the polycomb repressive complex 2, which catalyzes H3K27me3 modifications. Immunofluorescence microscopy reveals that EZH2 localization during murine osteoclastogenesis is dynamically regulated. Using EZH2 knockdown and small molecule EZH2 inhibitor GSK126, we show that EZH2 plays a critical epigenetic role in OCL precursors (OCLp) during the first 24 hours of RANKL activation. RANKL triggers EZH2 translocation into the nucleus where it represses OCL-negative regulators MafB, Irf8, and Arg1. Consistent with its cytoplasmic localization in OCLp, EZH2 methyltransferase activity is required during early RANKL signaling for phosphorylation of AKT, resulting in downstream activation of the mTOR complex, which is essential for induction of OCL differentiation. Inhibition of RANKL-induced pmTOR-pS6RP signaling by GSK126 altered the translation ratio of the C/EBPß-LAP and C/EBPß-LIP isoforms and reduced nuclear translocation of the inhibitory C/EBPß-LIP, which is necessary for transcriptional repression of the OCL negative-regulatory transcription factor MafB. EZH2 in multinucleated OCL is primarily cytoplasmic and mature OCL cultured on bone segments in the presence of GSK126 exhibit defective cytoskeletal architecture and reduced resorptive activity. Here we present new evidence that EZH2 plays epigenetic and cytoplasmic roles during OCL differentiation by suppressing MafB transcription and regulating early phases of PI3K-AKT-mTOR-mediated RANKL signaling, respectively. Consistent with its cytoplasmic localization, EZH2 is required for cytoskeletal dynamics during resorption by mature OCL. Thus, EZH2 exhibits complex roles in supporting osteoclast differentiation and function. © 2019 American Society for Bone and Mineral Research.

Acute Myeloid Leukemia Following Gynecologic Cancer in the Era of Platinum-Based Chemotherapy.

OBJECTIVE: The aim of the present study was to estimate the risk of therapy-related acute myeloid leukemia (t-AML) in patients with gynecologic malignancies receiving chemotherapy using a population-based database. METHODS: The National Cancer Institute's Surveillance, Epidemiology, and End Results database was accessed, and a cohort of women diagnosed with a primary ovarian, uterine, or cervical malignancy between January 1, 1992, and December 31, 2014, who received chemotherapy was selected. Those who subsequently developed AML were identified. Standardized incidence ratio (SIR) with 95% confidence intervals (CIs) and excess risk (ER) per 10,000 persons were calculated. Median overall survival of women with t-AML was calculated following generation of Kaplan-Meier curves. RESULTS: We identified 60,130 women who met the inclusion criteria; 56.4%, 19.4%, and 24.2% were diagnosed with ovarian, cervical, and uterine cancer, respectively. A total of 79 patients (0.13%) developed t-AML. The calculated SIR was 4.41 (95% CI, 3.49-5.50). For women with ovarian, cervical, and uterine cancer, the SIRs were 4.25 (95% CI, 3.13-5.66), 5.33 (95% CI, 2.92-8.95), and 4.26, (95% CI, 2.52-6.73), respectively. The highest risk was observed among women younger than 50 years (SIR, 11.69; 95% CI, 7.56-17.25). Median interval between gynecologic cancer and t-AML diagnosis was 40 months (range, 3-218 months), whereas median OS following the diagnosis of t-AML was 4 months (95% CI, 1.52-6.48 months). CONCLUSIONS: Therapy-related AML following chemotherapy treatment for a gynecologic malignancy is a very rare late treatment-related event associated with a poor prognosis.

The Role of Semaphorin 4D in Bone Remodeling and Cancer Metastasis.

Semaphorin 4D (Sema4D; CD100) is a transmembrane homodimer 150-kDa glycoprotein member of the Semaphorin family. Semaphorins were first identified as chemorepellants that guide neural axon growth. Sema4D also possesses immune regulatory activity. Recent data suggest other Sema4D functions: inactivation of platelets, stimulation of angiogenesis, and regulation of bone formation. Sema4D is a coupling factor expressed on osteoclasts that inhibits osteoblast differentiation. Blocking Sema4D may, therefore, be anabolic for bone. Sema4D and its receptor Plexin-B1 are commonly dysregulated in cancers, suggesting roles in cancer progression, invasion, tumor angiogenesis, and skeletal metastasis. This review focuses on Sema4D in bone and cancer biology and the molecular pathways involved, particularly Sema4D-Plexin-B1 signaling crosstalk between cancer cells and the bone marrow microenvironment-pertinent areas since a humanized Sema4D-neutralizing antibody is now in early phase clinical trials in cancers and neurological disorders.

Primary Urinary Tract Lymphoma: Rare but Aggressive.

BACKGROUND: Primary urinary tract lymphoma (PUTL) is an uncommon disease with only a few case reports in the literature. MATERIALS AND METHODS: Information about 1,264 patients diagnosed between 1983 and 2013 with PUTL was extracted from the Surveillance, Epidemiology and End Results database. Kaplan-Meier curves and multivariable regression analysis were used to analyze the survival and identify prognostic factors. A comparison of nodal diffuse large B-cell lymphoma (DLBCL) with PUTL DLBCL was performed. In addition, we compared the characteristics of kidney and bladder lymphoma. RESULTS: PUTL incidence was 1 case/1,000,000 people per year. DLBCL was found to be the predominant histology. Five-year overall survival and cancer-specific survival were 49% and 58%, respectively. DLBCL histology, male gender, stage III-IV disease, and advanced age were found to be poor prognostic factors. Surgery may be beneficial. Urinary tract DLBCL has a worse prognosis than nodal DLBCL. CONCLUSION: To our knowledge, this is the largest population-based study of PUTL in the literature. The survival of patients has not improved in the era of modern therapies therefore new treatments are needed.