CRISPR Dependency Screens in Primary Hematopoietic Stem Cells Identify KDM3B as a Genotype Specific Vulnerability in IDH2- and TET2-Mutant Cells.

Clonal hematopoiesis (CH) is a common premalignant state in the blood and confers an increased risk of blood cancers and all-cause mortality. Identification of therapeutic targets in CH has been hindered by the lack of an ex vivo platform amenable for studying primary hematopoietic stem and progenitor cells (HSPCs). Here, we utilize an ex vivo co-culture system of HSPCs with bone marrow endothelial cells to perform CRISPR/Cas9 screens in mutant HSPCs. Our data reveal that loss of the histone demethylase family members Kdm3b and Jmjd1c specifically reduces the fitness of Idh2- and Tet2-mutant HSPCs. Kdm3b loss in mutant cells leads to decreased expression of critical cytokine receptors including Mpl, rendering mutant HSPCs preferentially susceptible to inhibition of downstream JAK2 signaling. Our study nominates an epigenetic regulator and an epigenetically regulated receptor signaling pathway as genotype-specific therapeutic targets and provides a scalable platform to identify genetic dependencies in mutant HSPCs.

Complementary and Inducible creERT2 Mouse Models for Functional Evaluation of Endothelial Cell Subtypes in the Bone Marrow.

In the adult bone marrow (BM), endothelial cells (ECs) are an integral component of the hematopoietic stem cell (HSC)-supportive niche, which modulates HSC activity by producing secreted and membrane-bound paracrine signals. Within the BM, distinct vascular arteriole, transitional, and sinusoidal EC subtypes display unique paracrine expression profiles and create anatomically-discrete microenvironments. However, the relative contributions of vascular endothelial subtypes in supporting hematopoiesis is unclear. Moreover, constitutive expression and off-target activity of currently available endothelial-specific and endothelial-subtype-specific murine cre lines potentially confound data analysis and interpretation. To address this, we describe two tamoxifen-inducible cre-expressing lines, Vegfr3-creERT2 and Cx40-creERT2, that efficiently label sinusoidal/transitional and arteriole endothelium respectively in adult marrow, without off-target activity in hematopoietic or perivascular cells. Utilizing an established mouse model in which cre-dependent recombination constitutively-activates MAPK signaling within adult endothelium, we identify arteriole ECs as the driver of MAPK-mediated hematopoietic dysfunction. These results define complementary tamoxifen-inducible creERT2-expressing mouse lines that label functionally-discrete and non-overlapping sinusoidal/transitional and arteriole EC populations in the adult BM, providing a robust toolset to investigate the differential contributions of vascular subtypes in maintaining hematopoietic homeostasis.

Supporting Cancer Survivors Following Treatment for Non-Hodgkin's and Hodgkin's Lymphoma: A Pilot Study Assessing the Feasibility and Process Outcomes of a Nurse-Led Intervention.

OBJECTIVE: Lymphoma is the sixth most common cancer in Australia and comprises 2.8% of worldwide cancer diagnoses. Research targeting development and evaluation of post-treatment care for debilitating complications resulting from the disease and its treatment is limited. This study aimed to assess the feasibility and acceptability of a nurse-led survivorship intervention, post-treatment in Hodgkin's and non-Hodgkin's lymphoma survivors. METHODS: A single-center, prospective, 3-arm, pilot, randomized controlled, parallel-group trial was used. People with lymphoma were recruited and randomized to the intervention (ENGAGE), education booklet only, or usual care arm. Participants receiving ENGAGE received an educational booklet and were offered 3 consultations (via various modes) with a cancer nurse to develop a survivorship care plan and healthcare goals. Participant distress and intervention acceptability was measured at baseline and 12-wk. Acceptability was measured via a satisfaction survey using a 11-point scale. Feasibility was measured using participation, retention rates, and process outcomes. Data were analyzed using descriptive statistics. RESULTS: Thirty-four participants with HL and NHL were recruited to the study (11 = intervention, 11 = information only, 12 = usual care). Twenty-seven participants (79%) completed all time points from baseline to 12 wk. Seven (88%) of the 8 participants receiving ENGAGE completed all consultations using various modes to communicate with the nurse (videoconference 14/23, 61%; phone 5/23, 22%; face-to-face 4/23, 17%). Participants who completed the intervention were highly satisfied with ENGAGE. CONCLUSION: The ENGAGE intervention is feasible and highly acceptable for lymphoma survivors. These findings will inform a larger trial assessing effectiveness and cost effectiveness of ENGAGE.

Durable response after tisagenlecleucel in adults with relapsed/refractory follicular lymphoma: ELARA trial update.

ABSTRACT: Tisagenlecleucel is approved for adults with relapsed/refractory (r/r) follicular lymphoma (FL) in the third- or later-line setting. The primary analysis (median follow-up, 17 months) of the phase 2 ELARA trial reported high response rates and excellent safety profile in patients with extensively pretreated r/r FL. Here, we report longer-term efficacy, safety, pharmacokinetic, and exploratory biomarker analyses after median follow-up of 29 months (interquartile range, 22.2-37.7). As of 29 March 2022, 97 patients with r/r FL (grades 1-3A) received tisagenlecleucel infusion (0.6 × 108-6 × 108 chimeric antigen receptor-positive viable T cells). Bridging chemotherapy was allowed. Baseline clinical factors, tumor microenvironment, blood soluble factors, and circulating blood cells were correlated with clinical response. Cellular kinetics were assessed by quantitative polymerase chain reaction. Median progression-free survival (PFS), duration of response (DOR), and overall survival (OS) were not reached. Estimated 24-month PFS, DOR, and OS rates in all patients were 57.4% (95% confidence interval [CI], 46.2-67), 66.4% (95% CI, 54.3-76), and 87.7% (95% CI, 78.3-93.2), respectively. Complete response rate and overall response rate were 68.1% (95% CI, 57.7-77.3) and 86.2% (95% CI, 77.5-92.4), respectively. No new safety signals or treatment-related deaths were reported. Low levels of tumor-infiltrating LAG3+CD3+ exhausted T cells and higher baseline levels of naïve CD8+ T cells were associated with improved outcomes. Tisagenlecleucel continued to demonstrate highly durable efficacy and a favorable safety profile in this extended follow-up of 29 months in patients with r/r FL enrolled in ELARA. This trial was registered at www.clinicaltrials.gov as #NCT03568461.

A randomised trial of topical polaprezinc to prevent oral mucositis in patients undergoing haematopoietic stem cell transplantation (ToPaZ study).

PURPOSE: Oral mucositis (OM) is a common complication in haematopoietic stem cell transplantation (HSCT). Polaprezinc, an anti-ulcer drug, has been shown to be effective to prevent OM in several studies when administered topically and systemically. This study aimed to evaluate the effectiveness of topical polaprezinc in patients undergoing HSCT. METHODS: This was an open-label randomised clinical trial comparing polaprezinc and sodium bicarbonate mouthwashes for the prevention of severe OM in HSCT patients. Adult patients who received conditioning regimens at moderate to high risk of developing OM were included. The primary endpoint was the incidence of severe (WHO grades 3-4) OM. The secondary endpoints included duration of grades 3-4 OM, incidence and duration of grades 2-4 OM, patient-reported pain and functional limitations. RESULTS: In total, 108 patients (55 test arm and 53 control arm) were randomised. There was no difference in the incidence of grades 3 to 4 OM (35% test arm versus 36% control arm). The secondary endpoints were not significantly different. In both arms, patients reported more throat pain compared to mouth pain. CONCLUSIONS: Topical polaprezinc had no effect in the prevention of OM in HSCT patients. Further research is required to evaluate the effects of systemic polaprezinc. The OM assessment tool needs to be reviewed as throat mucositis was a main issue in this study. TRIAL REGISTRATION: ACTRN12320001188921 (Date Registered: 10th November 2020).

ANZTCT consensus position statement on ruxolitinib in steroid-refractory acute and chronic graft-versus-host disease.

This position paper provides an overview of the assessment and management of both acute and chronic graft-versus-host disease (GvHD). There is a focus on the use of ruxolitinib, a selective inhibitor of Janus kinase (JAK)1 and JAK2, for the treatment of corticosteroid-refractory and corticosteroid-dependent GvHD.

Lived Experience-Led Research Agenda to Address Early Death in People With a Diagnosis of a Serious Mental Illness: A Consensus Statement.

Importance: People with serious mental illness (SMI), defined as a diagnosis of schizophrenia spectrum disorder, bipolar disorder, or disabling major depressive disorder) die approximately 10 to 25 years earlier than the general population. Objective: To develop the first-ever lived experience-led research agenda to address early mortality in people with SMI. Evidence Review: A virtual 2-day roundtable comprising 40 individuals convened on May 24 and May 26, 2022, and used a virtual Delphi method to arrive at expert group consensus. Participants responded to 6 rounds of virtual Delphi discussion via email that prioritized research topics and agreement on recommendations. The roundtable was composed of individuals with lived experience of mental health and/or substance misuse, peer support specialists, recovery coaches, parents and caregivers of people with SMI, researchers and clinician-scientists with and without lived experience, policy makers, and patient-led organizations. Twenty-two of 28 (78.6%) of the authors who provided data represented people with lived experiences. Roundtable members were selected by reviewing the peer-reviewed and gray literature on early mortality and SMI, direct email, and snowball sampling. Findings: The following recommendations are presented in order of priority as identified by the roundtable participants: (1) improve the empirical understanding of the direct and indirect social and biological contributions of trauma on morbidity and early mortality; (2) advance the role of family, extended families, and informal supporters; (3) recognize the importance of co-occurring disorders and early mortality; (4) redefine clinical education to reduce stigma and support clinicians through technological advancements to improve diagnostic accuracy; (5) examine outcomes meaningful to people with an SMI diagnosis, such as loneliness and sense of belonging, and stigma and their complex relationship with early mortality; (6) advance the science of pharmaceuticals, drug discovery, and choice in medication use; (7) use precision medicine to inform treatment; and (8) redefine the terms system literacy and health literacy. Conclusions and Relevance: The recommendations of this roundtable are a starting point for changing practice and highlighting lived experience-led research priorities as an option to move the field forward.

Restoring bone marrow niche function rejuvenates aged hematopoietic stem cells by reactivating the DNA Damage Response.

Aging associated defects within stem cell-supportive niches contribute towards age-related decline in stem cell activity. However, mechanisms underlying age-related niche defects, and whether restoring niche function can improve stem cell fitness, remain unclear. Here, we sought to determine whether aged blood stem cell function can be restored by rejuvenating their supportive niches within the bone marrow (BM). We identify Netrin-1 as a critical regulator of BM niche cell aging. Niche-specific deletion of Netrin-1 induces premature aging phenotypes within the BM microenvironment, while supplementation of aged mice with Netrin-1 rejuvenates aged niche cells and restores competitive fitness of aged blood stem cells to youthful levels. We show that Netrin-1 plays an essential role in maintaining active DNA damage responses (DDR), and that aging-associated decline in niche-derived Netrin-1 results in DNA damage accumulation within the BM microenvironment. We show that Netrin-1 supplementation is sufficient to resolve DNA damage and restore regenerative potential of the aged BM niche and blood stem cells to endure serial chemotherapy regimens.

Australia and New Zealand Transplant and Cellular Therapies (ANZTCT) position statement: COVID-19 management in patients with haemopoietic stem cell transplant and chimeric antigen receptor T cell.

Patients with post-haemopoietic stem cell transplant or chimeric antigen receptor T -cell (CAR-T) therapy face a significant risk of morbidity and mortality from coronavirus disease 2019 because of their immunosuppressed state. As case numbers in Australia and New Zealand continue to rise, guidance on management in this high-risk population is needed. Whilst we have learned much from international colleagues who faced high infection rates early in the pandemic, guidance relevant to local health system structures, medication availability and emerging therapies is essential to equip physicians to manage our patients optimally.

Loss, adaptation and growth: The experiences of creative arts therapists during the Covid-19 pandemic.

Since the outbreak of the COVID-19 pandemic in March 2020, mental health professionals have been called upon to cope with various challenges, including the shift to telehealth without prior training, overload in the workplace, increased risk of infection, and personal stressors relating to the pandemic. This article presents the qualitative findings of a larger international mixed-method study that explored the experiences of creative arts therapists around the globe during the first year of the pandemic (Feniger-Schaal et al., 2022). Twenty creative arts therapists were interviewed between July 2020 and March 2021. Transcriptions of the interviews were qualitatively analyzed through reflexive thematic analysis. Three main themes were identified: an experience of processing the losses caused by the pandemic, a restorative orientation that focused on adaptations the therapists made, and innovations that lead to personal and professional growth. Artistic engagement and creativity were found to be a resource when coping with losses and helped therapists adapt to the shift to tele-creative arts therapies (tele-CAT). Although this shift can lead to advances in the field of creative arts therapies, it requires further consideration, including the need for ethical guidelines, specific training, the development of digital methods that support the creative process, and dedicated supervision for therapists. The findings also point to the importance of psychological support to mitigate the burden therapists experience during stressful events.

Allogeneic haemopoietic cell transplant services in Australia and New Zealand in the first year of the COVID-19 pandemic: a report from Australia and New Zealand transplant and cellular therapies.

BACKGROUND: The COVID-19 pandemic has caused major disruption to health systems, with allogeneic haemopoietic cell transplant (alloHCT) services a particularly vulnerable area. Ongoing provision of alloHCT has required dynamic responses at national and local levels. In Australia and New Zealand (ANZ), a high reliance on unrelated donors from overseas registries has posed an additional challenge. AIMS: To describe the impact of COVID-19 on alloHCT services in ANZ in the first year of the pandemic. METHODS: Data from the national alloHCT patient and unrelated donor registries were extracted for a 2-year time frame. Comparisons were made between a pre-pandemic period of 1 March 2019 to 29 February 2020 and the corresponding dates during the pandemic, 1 March 2020 to 28 February 2021. RESULTS: There was a 13% decrease in the number of allogeneic transplants, a reversal of steady increases in previous years, with the largest decrease in unrelated donor transplants. Local donors supplied a greater proportion of unrelated stem cell products. With a switch to universal cryopreservation, the time from request of a product to infusion increased by a median of 25.5 days for overseas products and 14 days for local products. There was a significant increase in the number of products collected but not used. CONCLUSIONS: A strong public health response and coordinated transplant community activities allowed for safe provision of alloHCT in ANZ; however, our data suggest that the timely delivery of allogeneic transplants was affected by the COVID-19 pandemic. Continued dedicated efforts are required to minimise further impacts.

Engineering a niche supporting hematopoietic stem cell development using integrated single-cell transcriptomics.

Hematopoietic stem cells (HSCs) develop from hemogenic endothelium within embryonic arterial vessels such as the aorta of the aorta-gonad-mesonephros region (AGM). To identify the signals responsible for HSC formation, here we use single cell RNA-sequencing to simultaneously analyze the transcriptional profiles of AGM-derived cells transitioning from hemogenic endothelium to HSCs, and AGM-derived endothelial cells which provide signals sufficient to support HSC maturation and self-renewal. Pseudotemporal ordering reveals dynamics of gene expression during the hemogenic endothelium to HSC transition, identifying surface receptors specifically expressed on developing HSCs. Transcriptional profiling of niche endothelial cells identifies corresponding ligands, including those signaling to Notch receptors, VLA-4 integrin, and CXCR4, which, when integrated in an engineered platform, are sufficient to support the generation of engrafting HSCs. These studies provide a transcriptional map of the signaling interactions necessary for the development of HSCs and advance the goal of engineering HSCs for therapeutic applications.

Shifting to tele-creative arts therapies during the COVID-19 pandemic: An international study on helpful and challenging factors.

The COVID-19 pandemic has led to an unprecedented shift to online treatment. For the creative arts therapies (CATs) - a healthcare profession that involves the intentional use of the visual art, drama, music, dance, and poetry within a therapeutic relationship - this shift has been highly consequential for practice. This study examined (a) how the COVID-19 pandemic has impacted clinical practice in the CATs, and (b) the features characterizing online practice in an international sample of 1206 creative arts therapists aged 22-86 (92% female). It aimed to identify changes in the use of the arts in therapy, resources that contributed to the delivery of therapy, and the role of therapists' creative self-efficacy in adapting to these changes. Respondents completed close and open-ended questions providing examples of what does and does not work in online practice. The results indicate that creative self-efficacy plays a meaningful role in buffering the impact of therapists' computer comfort on their perceived difference in online clinical practice; confidence in one's abilities positively contributed to their adaptation to online practice. The qualitative analysis yielded four main categories: the challenges of tele-CATs, continuing the therapeutic process through tele-CATs, adaptations for tele-CATs, and future directions. Overall, the results present a timely report on the inevitable transition of the CATs to online practice.

Tisagenlecleucel in adult relapsed or refractory follicular lymphoma: the phase 2 ELARA trial.

Tisagenlecleucel is an autologous anti-CD19 chimeric antigen receptor-T cell therapy with clinically meaningful outcomes demonstrated in patients with relapsed/refractory (r/r) B-cell lymphoma. In a previous pilot study of tisagenlecleucel in r/r follicular lymphoma (FL), 71% of patients achieved a complete response (CR). Here we report the primary, prespecified interim analysis of the ELARA phase 2 multinational trial of tisagenlecleucel in adults with r/r FL after two or more treatment lines or who relapsed after autologous stem cell transplant (no. NCT03568461). The primary endpoint was CR rate (CRR). Secondary endpoints included overall response rate (ORR), duration of response, progression-free survival, overall survival, pharmacokinetics and safety. As of 29 March 2021, 97/98 enrolled patients received tisagenlecleucel (median follow-up, 16.59 months; interquartile range, 13.8-20.21). The primary endpoint was met. In the efficacy set (n = 94), CRR was 69.1% (95% confidence interval, 58.8-78.3) and ORR 86.2% (95% confidence interval, 77.5-92.4). Within 8 weeks of infusion, rates of cytokine release syndrome were 48.5% (grade ≥3, 0%), neurological events 37.1% (grade ≥3, 3%) and immune effector cell-associated neurotoxicity syndrome (ICANS) 4.1% (grade ≥3, 1%) in the safety set (n = 97), with no treatment-related deaths. Tisagenlecleucel is safe and effective in extensively pretreated r/r FL, including in high-risk patients.

Vascular Regulation of Hematopoietic Stem Cell Homeostasis, Regeneration, and Aging.

PURPOSE OF REVIEW: Hematopoietic stem cells (HSCs) sit at the top of the hierarchy that meets the daily burden of blood production. HSC maintenance relies on extrinsic cues from the bone marrow (BM) microenvironment to balance stem cell self-renewal and cell fate decisions. In this brief review, we will highlight the studies and model systems that define the centralized role of BM vascular endothelium in modulating HSC activity in health and stress. RECENT FINDINGS: The BM microenvironment is composed of a diverse array of intimately associated vascular and perivascular cell types. Recent dynamic imaging studies, coupled with single-cell RNA sequencing (scRNA-seq) and functional readouts, have advanced our understanding of the HSC-supportive cell types and their cooperative mechanisms that govern stem cell fate during homeostasis, regeneration, and aging. These findings have established complex and discrete vascular microenvironments within the BM that express overlapping and unique paracrine signals that modulate HSC fate. SUMMARY: Understanding the spatial and reciprocal HSC-niche interactions and the molecular mechanisms that govern HSC activity in the BM vascular microenvironment will be integral in developing therapies aimed at ameliorating hematological disease and supporting healthy hematopoietic output.

Australia and New Zealand Transplant and Cellular Therapies COVID-19 vaccination consensus position statement.

Australia and New Zealand have achieved excellent community control of COVID-19 infection. In light of the imminent COVID-19 vaccination roll out in both countries, representatives of all adult and paediatric allogeneic bone marrow transplant and cellular therapy (TCT) centres as well as representatives from autologous transplant only centres in Australia and New Zealand collaborated with infectious diseases specialists with expertise in TCT on this consensus position statement regarding COVID-19 vaccination in TCT patients in Australia and New Zealand. It is our recommendation that TCT patients, should have expedited access to high-efficacy COVID-19 vaccines given that these patients are at high risk of morbidity and mortality from COVID-19 infection. We also recommend prioritising vaccination of TCT healthcare workers and household members of TCT patients. Vaccination should not replace other public health measures in TCT patients given the effectiveness of COVID-19 vaccination in TCT patients is unknown. Furthermore, given the limited available data, prospective collection of safety and efficacy data of COVID-19 vaccination in this patient group is a priority.