Identification of cells of leukemic stem cell origin with non-canonical regenerative properties.

Despite most acute myeloid leukemia (AML) patients entering remission following chemotherapy, outcomes remain poor due to surviving leukemic cells that contribute to relapse. The nature of these enduring cells is poorly understood. Here, through temporal single-cell transcriptomic characterization of AML hierarchical regeneration in response to chemotherapy, we reveal a cell population: AML regeneration enriched cells (RECs). RECs are defined by CD74/CD68 expression, and although derived from leukemic stem cells (LSCs), are devoid of stem/progenitor capacity. Based on REC in situ proximity to CD34-expressing cells identified using spatial transcriptomics on AML patient bone marrow samples, RECs demonstrate the ability to augment or reduce leukemic regeneration in vivo based on transfusion or depletion, respectively. Furthermore, RECs are prognostic for patient survival as well as predictive of treatment failure in AML cohorts. Our study reveals RECs as a previously unknown functional catalyst of LSC-driven regeneration contributing to the non-canonical framework of AML regeneration.

Identification of a Patient Suitable for CAR-T Cell Therapy in the Outpatient Setting: A Vodcast and Case Example.

Chimeric antigen receptor T cell (CAR-T) therapies targeting the CD19 antigen have been associated with high and durable response rates in patients with diffuse large B cell lymphoma (DLBCL). CAR-T cell therapies are commonly administered in the inpatient setting due to the average onset of cytokine release syndrome within the first 3 days post infusion, but there has been growing interest in delivering CAR-T cell therapies in the outpatient setting to overcome frequent hospital bed shortages and the high cost of inpatient care. Although this approach could improve access whilst catering to patient preference, it requires a multidisciplinary approach as well as careful patient selection. Herein, Dr. Foley and Dr. Kuruvilla discuss the case of a patient presenting with the ideal profile for CAR-T cell therapy referral whilst also determining the key attributes for eligibility from a clinician's perspective. Solutions for successful outpatient management include proper education, caregiver support, and early referral to ensure a timely infusion. In conclusion, outpatient administration of CAR-T cell therapy in patients with DLBCLs should be assessed on a case-by-case basis.A vodcast feature is available for this article.

Treatment Pattern, Healthcare Resource Utilization and Symptom Burden Among Patients with Triple Class Exposed Multiple Myeloma: A Population-Based Cohort Study.

PURPOSE: This study aims to describe the treatment patterns, outcomes, health care utilization and symptom burden of triple class exposed (TCE) relapsed/refractory patents with multiple myeloma (MM) receiving a subsequent line of treatment (LOT). METHODS: This is a retrospective observational cohort study using administrative databases in Ontario, Canada. Outcomes were captured for TCE patients receiving a subsequent LOT and included: treatment regimen details, time to next treatment (TTNT), overall survival (OS), health care utilization, palliative care referral, and patient reported symptoms. RESULTS: Of the 16,777 patients diagnosed with MM between 2007-2021 in Ontario, 1358 (8%) patients were classified as TCE. Among the TCE MM patients, 489 (36%) received a subsequent LOT. The two most commonly administered therapies post TCE were carfilzomib/dexamethasone (n = 111, 22%) and pomalidomide/dexamethasone(n = 95, 19%). Median TTNT was 1.7 months (95%CI 1.2-2.4 months) and median OS 12.8 months (95%CI 10.8-16.5). Healthcare utilization was high with 276 (56%) of patients evaluated in an emergency department (ED) or admitted to hospital. There was high symptom burden as reported by patients with moderate-severe impairment in well-being, fatigue, pain and drowsiness noted in greater than 25% of the cohort. Palliative care referrals rates were low with only 10% (n = 48) patients referred to palliative care. Among the patients that died during study follow up, the majority died in hospital (n = 147,44%). CONCLUSION: Our study reports one of the largest series of real-world TCE patients published and demonstrates the poor outcomes of TCE patients receiving a subsequent LOT.

Leukemic progenitor compartment serves as a prognostic measure of cancer stemness in patients with acute myeloid leukemia.

We systematically investigate functional and molecular measures of stemness in patients with acute myeloid leukemia (AML) using a cohort of 121 individuals. We confirm that the presence of leukemic stem cells (LSCs) detected through in vivo xenograft transplantation is associated with poor survival. However, the measurement of leukemic progenitor cells (LPCs) through in vitro colony-forming assays provides an even stronger predictor of overall and event-free survival. LPCs not only capture patient-specific mutations but also retain serial re-plating ability, demonstrating their biological relevance. Notably, LPC content represents an independent prognostic factor in multivariate analyses including clinical guidelines of risk stratification. Our findings suggest that LPCs provide a robust functional measure of AML, enabling quantitative and rapid assessment of a wide range of patients. This highlights the potential of LPCs as a valuable prognostic factor in AML management.

Persistent hematopoietic polyclonality after lentivirus-mediated gene therapy for Fabry disease.

The safety and efficacy of lentivirus-mediated gene therapy was recently demonstrated in five male patients with Fabry disease-a rare X-linked lysosomal storage disorder caused by GLA gene mutations that result in multiple end-organ complications. To evaluate the risks of clonal dominance and leukemogenesis, which have been reported in multiple gene therapy trials, we conducted a comprehensive DNA insertion site analysis of peripheral blood samples from the five patients in our gene therapy trial. We found that patients had a polyclonal integration site spectrum and did not find evidence of a dominant clone in any patient. Although we identified vector integrations near proto-oncogenes, these had low percentages of contributions to the overall pool of integrations and did not persist over time. Overall, we show that our trial of lentivirus-mediated gene therapy for Fabry disease did not lead to hematopoietic clonal dominance and likely did not elevate the risk of leukemogenic transformation.

Perceptions of Change in the Natural Environment produced by the First Wave of the COVID-19 Pandemic across Three European countries. Results from the GreenCOVID study.

Although different studies have evaluated the positive impacts of the COVID-19 pandemic and lockdown measures on reducing noise pollution and traffic levels and improving air quality, how populations have perceived such changes in the natural environment has not been adequately evaluated. The present study provides a more in-depth exploration of human population perception of enhanced natural exposure (to animal life and nature sounds) and reduced harmful exposure (by improved air quality and reduced traffic volume) as a result of the COVID-19 pandemic lockdown. The data is drawn from 3,109 unselected adults who participated in the GreenCOVID survey from April to July 2020 in England, Ireland, and Spain. The findings suggest that the positive impacts to the natural environment as a result of the lockdown have been better received by the population in Spain and Ireland, in comparison to England. Participants who resided in urban areas had better perceived improvements in nature sounds, air quality, and traffic volume compared to those in rural areas. Older populations and those with lower smoking and alcohol consumption were found to perceive this improvement the most. Furthermore, the greater perception of improvements in environmental elements was also associated with better self-perceived health and improved wellbeing. In the binary logistic regression, living in Ireland or Spain, urban areas, female gender, older age, and good overall wellbeing were associated with a greater perception of improvements in the natural environment, while the factors most associated with a greater perception of reduced harmful exposure were living in Spain, had a good self-perceived health status and older age.

Abnormal dopamine receptor signaling allows selective therapeutic targeting of neoplastic progenitors in AML patients.

The aberrant expression of dopamine receptors (DRDs) in acute myeloid leukemia (AML) cells has encouraged the repurposing of DRD antagonists such as thioridazine (TDZ) as anti-leukemic agents. Here, we access patient cells from a Phase I dose escalation trial to resolve the cellular and molecular bases of response to TDZ, and we extend these findings to an additional independent cohort of AML patient samples tested preclinically. We reveal that in DRD2+ AML patients, DRD signaling in leukemic progenitors provides leukemia-exclusive networks of sensitivity that spare healthy hematopoiesis. AML progenitor cell suppression can be increased by the isolation of the positive enantiomer from the racemic TDZ mixture (TDZ+), and this is accompanied by reduced cardiac liability. Our study indicates that the development of DRD-directed therapies provides a targeting strategy for a subset of AML patients and potentially other cancers that acquire DRD expression upon transformation from healthy tissue.

Lentivirus-mediated gene therapy for Fabry disease.

Enzyme and chaperone therapies are used to treat Fabry disease. Such treatments are expensive and require intrusive biweekly infusions; they are also not particularly efficacious. In this pilot, single-arm study (NCT02800070), five adult males with Type 1 (classical) phenotype Fabry disease were infused with autologous lentivirus-transduced, CD34+-selected, hematopoietic stem/progenitor cells engineered to express alpha-galactosidase A (α-gal A). Safety and toxicity are the primary endpoints. The non-myeloablative preparative regimen consisted of intravenous melphalan. No serious adverse events (AEs) are attributable to the investigational product. All patients produced α-gal A to near normal levels within one week. Vector is detected in peripheral blood and bone marrow cells, plasma and leukocytes demonstrate α-gal A activity within or above the reference range, and reductions in plasma and urine globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3) are seen. While the study and evaluations are still ongoing, the first patient is nearly three years post-infusion. Three patients have elected to discontinue enzyme therapy.

Addition of anti-thymocyte globulin to standard graft-versus-host disease prophylaxis versus standard treatment alone in patients with haematological malignancies undergoing transplantation from unrelated donors: final analysis of a randomised, open-label, multicentre, phase 3 trial.

BACKGROUND: Previous trials testing prevention strategies for chronic graft versus host disease (GVHD) have measured its cumulative incidence. In this trial of anti-thymocyte globulin, we measured treatment-independence at a long-term timepoint as the primary endpoint. METHODS: This was a randomised, open-label, multicentre, phase 3 trial done at ten centres in Canada and one in Australia. Eligible patients had a haematological malignancy (leukaemia, myelodysplastic syndrome, or lymphoma), were between 16 and 70 years of age, eligible for transplantation with a Karnofsky score of at least 60, and received an unrelated donor (fully matched or one-locus mismatched at HLA-A, HLA-B, HLA-C, or DRB1 loci) graft following myeloablative or non-myeloablative-reduced intensity conditioning. Patients were randomly assigned to receive anti-thymocyte globulin 4·5 mg/kg plus standard GVHD prophylaxis (cyclosporine or tacrolimus plus methotrexate or mycophenolate) or standard GVHD prophylaxis alone. The primary endpoint, freedom from immunosuppressive therapy without resumption at 12 months, was previously reported. Here we report on the prespecified 24-month analysis. Analyses were per-protocol, excluding those patients who did not proceed to transplantation. This trial is registered as ISRCTN 29899028 and NCT01217723, status completed. FINDINGS: Between June 9, 2010, and July 8, 2013, we recruited and randomly assigned 203 eligible patients to receive anti-thymocyte globulin (n=101) or no additional treatment (n=102) along with standard GVHD prophylaxis. 7 (3%) patients did not receive a transplant and were excluded from the analysis. 38 (38%) of 99 evaluable patients in the anti-thymocyte globulin plus GVHD prophylaxis group were free from immunosuppressive therapy at 24 months compared with 18 (19%) of 97 patients in the standard GVHD prophylaxis group (adjusted odds ratio [OR] 3·49 [95% CI 1·60­7·60]; p=0·0016). At 24 months, the cumulative incidence of relapse was 16·3% (95% CI 8·9­23·7) in the anti-thymocyte globulin plus GVHD prophylaxis group compared with 17·5 (9·9­25·1) in the standard GVHD prophylaxis group (p=0·73) and non-relapse mortality was 21·2% (95% CI 13·2­29·2) versus 31·3% (21·9­40·7; p=0·15). The cumulative incidence of chronic GVHD at 24 months was 26·3% (95% CI 17·5­35·1) in the anti-thymocyte globulin group and 41·3% (31·3­51·3) in the standard GVHD prophylaxis group (p=0·032). Overall survival at 24 months was 70·6% (95% CI 60·6­78·6) in the anti-thymocyte globulin plus GVHD prophylaxis group compared with 53·3% (42·8­62·8) in the standard GVHD prophylaxis group (adjusted hazard ratio [HR] 0·56, 95% CI [0·35­0·90]; p=0·017). Symptoms of chronic GVHD by the Lee Scale were more prevalent in the standard GVHD prophylaxis group, with scores of 13·27 (SD 10·94) in the anti-thymocyte globulin plus GVHD prophylaxis group and 20·38 (SD 14·68) in the standard GVHD prophylaxis group (p=0·040). Depressive symptoms were more prominent in the standard GVHD prophylaxis group, the mean Center for Epidemiological Studies Depression scale (CES-D) scores were 10·40 (SD 9·88) in the anti-thymocyte globulin group and 14·62 (SD 12·26) in the standard GVHD prophylaxis group (p=0·034). Serious adverse events (CTCAE grade 4 or 5) occurred in 38 (38%) patients in the anti-thymocyte globulin group and in 49 (51%) in the standard GVHD prophylaxis group, the most common being infection and GVHD. One patient in the anti-thymocyte globulin plus GVHD prophylaxis group died of Epstein-Barr virus hepatitis, but no deaths were attributable to anti-thymocyte globulin. INTERPRETATION: The results of this prespecified 24-month analysis suggest that pretreatment with anti-thymocyte globulin provides clinically meaningful benefits when added to standard GVHD prophylaxis in patients undergoing unrelated donor transplantation, including decreases in use of immunosuppressive therapy, chronic GVHD and its symptoms, depressive symptoms, and improved overall survival. Anti-thymocyte globulin should be included in the preparative regimens of patients with haematological malignancies selected for unrelated donor transplantation. FUNDING: Canadian Institutes of Health Research and Sanofi.

Autologous stem cell transplant in older patients (age ≥ 65) with newly diagnosed multiple myeloma: A systematic review and meta-analysis.

OBJECTIVE: While autologous stem cell transplant (ASCT) is a standard of care for newly-diagnosed younger patients with multiple myeloma, its role in older patients remains controversial. We conducted a systematic review and meta-analysis of observational studies and randomized controlled trials (RCTs) assessing the efficacy and toxicity of ASCT in older patients (age ≥ 65 years) with newly-diagnosed myeloma. METHODS: We searched Medline, Embase, and the Cochrane database through February 2, 2018. The primary outcome was overall survival; secondary outcomes included progression-free survival, response rates and toxicity. The Grading of Recommendations Assessment, Development and Evaluation criteria (GRADE) method was used to assess certainty in evidence. RESULTS: Of 8614 abstracts screened, six observational studies and two RCTs were included in the systematic review. For overall survival, pooled observational data favored ASCT (Hazard Ratio [HR] 0.44, 95% Confidence Interval [CI] 0.34-0.58, p < .0001), while the impact of the RCT data was uncertain (HR 0.94, 95% CI 0.25-3.54, p = .93). Observational data showed higher complete response rates with ASCT (odds ratio 5.06, 95% CI 2.60-9.88, p < .0001). Progression free survival benefit from the RCTs was uncertain (HR 1.05, 95% CI 0.36-3.12, p = .93). Data were insufficient to pool for toxicity. CONCLUSION: For older patients with newly diagnosed multiple myeloma, ASCT may improve the overall survival and complete response rates based upon observational data although the quality of this evidence is very low. The role of ASCT in improving overall survival based upon RCT data remains uncertain with low quality of evidence. Our study highlights the urgent need for well-conducted studies to understand the role of ASCT in older patients.

Identification of Chemotherapy-Induced Leukemic-Regenerating Cells Reveals a Transient Vulnerability of Human AML Recurrence.

Despite successful remission induction, recurrence of acute myeloid leukemia (AML) remains a clinical obstacle thought to be caused by the retention of dormant leukemic stem cells (LSCs). Using chemotherapy-treated AML xenografts and patient samples, we have modeled patient remission and relapse kinetics to reveal that LSCs are effectively depleted via cell-cycle recruitment, leaving the origins of relapse unclear. Post-chemotherapy, in vivo characterization at the onset of disease relapse revealed a unique molecular state of leukemic-regenerating cells (LRCs) responsible for disease re-growth. LRCs are transient, can only be detected in vivo, and are molecularly distinct from therapy-naive LSCs. We demonstrate that LRC features can be used as markers of relapse and are therapeutically targetable to prevent disease recurrence.

A phase 1 trial evaluating thioridazine in combination with cytarabine in patients with acute myeloid leukemia.

We completed a phase 1 dose-escalation trial to evaluate the safety of a dopamine receptor D2 (DRD2) antagonist thioridazine (TDZ), in combination with cytarabine. Thirteen patients 55 years and older with relapsed or refractory acute myeloid leukemia (AML) were enrolled. Oral TDZ was administered at 3 dose levels: 25 mg (n = 6), 50 mg (n = 4), or 100 mg (n = 3) every 6 hours for 21 days. Intermediate-dose cytarabine was administered on days 6 to 10. Dose-limiting toxicities (DLTs) included grade 3 QTc interval prolongation in 1 patient at 25 mg TDZ and neurological events in 2 patients at 100 mg TDZ (gait disturbance, depressed consciousness, and dizziness). At the 50-mg TDZ dose, the sum of circulating DRD2 antagonist levels approached a concentration of 10 µM, a level noted to be selectively active against human AML in vitro. Eleven of 13 patients completed a 5-day lead-in with TDZ, of which 6 received TDZ with hydroxyurea and 5 received TDZ alone. During this period, 8 patients demonstrated a 19% to 55% reduction in blast levels, whereas 3 patients displayed progressive disease. The extent of blast reduction during this 5-day interval was associated with the expression of the putative TDZ target receptor DRD2 on leukemic cells. These preliminary results suggest that DRD2 represents a potential therapeutic target for AML disease. Future studies are required to corroborate these observations, including the use of modified DRD2 antagonists with improved tolerability in AML patients. This trial was registered at www.clinicaltrials.gov as #NCT02096289.

Higher levels of free plasma mitochondrial DNA are associated with the onset of chronic GvHD.

Toll-like receptor-9 (TLR9) responsive B cells have previously been associated with the onset of extensive chronic graft-versus-host disease (cGvHD). We hypothesized that the onset of cGvHD associated with a higher level of plasma-free mitochondrial DNA (mtDNA), a putative TLR9 agonist. Plasma cell-free mtDNA levels were measured in 39 adult patients post-HSCT with and without cGvHD. mtDNA was isolated from plasma and quantified by Q-PCR amplification. We correlated B cell responsiveness to CpG-DNA, a prototypical TLR9 agonist, and previously identified cGVHD biomarkers with mtDNA levels. Free plasma mtDNA were elevated in patients post-HSCT without cGvHD compared to normal non-HSCT adults. There was a significantly higher level of free plasma mtDNA associated with the onset of cGvHD (3080 ± 1586 versus 1834 ± 1435 copies/µL; p = 0.02) compared to 6 months post-HSCT controls. Free mtDNA levels post-HSCT correlated with B cell responsiveness to CpG-DNA and known cGvHD biomarkers: CXCL10 (p = 0.003), ICAM-1 (p = 0.007), CXCL9 (p = 0.03), sCD25 (p = 0.05) and sBAFF (p = 0.05), and percentage of CD21low B cells. Plasma levels of free mtDNA are increased in cGvHD and may represent an endogenous inflammatory stimulus for TLR9 expressing B cells.

Acute myeloid leukaemia disrupts endogenous myelo-erythropoiesis by compromising the adipocyte bone marrow niche.

Acute myeloid leukaemia (AML) is distinguished by the generation of dysfunctional leukaemic blasts, and patients characteristically suffer from fatal infections and anaemia due to insufficient normal myelo-erythropoiesis. Direct physical crowding of bone marrow (BM) by accumulating leukaemic cells does not fully account for this haematopoietic failure. Here, analyses from AML patients were applied to both in vitro co-culture platforms and in vivo xenograft modelling, revealing that human AML disease specifically disrupts the adipocytic niche in BM. Leukaemic suppression of BM adipocytes led to imbalanced regulation of endogenous haematopoietic stem and progenitor cells, resulting in impaired myelo-erythroid maturation. In vivo administration of PPARγ agonists induced BM adipogenesis, which rescued healthy haematopoietic maturation while repressing leukaemic growth. Our study identifies a previously unappreciated axis between BM adipogenesis and normal myelo-erythroid maturation that is therapeutically accessible to improve symptoms of BM failure in AML via non-cell autonomous targeting of the niche.

CD56bright natural killer regulatory cells in filgrastim primed donor blood or marrow products regulate chronic graft-versus-host disease: the Canadian Blood and Marrow Transplant Group randomized 0601 study results.

Randomized trials have conclusively shown higher rates of chronic graft-versus-host disease with filgrastim-stimulated apheresis peripheral blood as a donor source than unstimulated bone marrow. The Canadian Blood and Marrow Transplant Group conducted a phase 3 study of adults who received either filgrastim-stimulated apheresis peripheral blood or filgrastim-stimulated bone marrow from human leukocyte antigen-identical sibling donors. Because all donors received the identical filgrastim dosing schedule, this study allowed for a controlled evaluation of the impact of stem cell source on development of chronic graft-versus-host disease. One hundred and twenty-one evaluable filgrastim-stimulated apheresis peripheral blood and filgrastim-stimulated bone marrow patient donor products were immunologically characterized by flow cytometry and tested for their association with acute and chronic graft-versus-host disease within 2 years of transplantation. The immune populations evaluated included, regulatory T cells, central memory and effector T cells, interferon γ positive producing T cells, invariate natural killer T cells, regulatory natural killer cells, dendritic cell populations, macrophages, and activated B cells and memory B cells. When both filgrastim-stimulated apheresis peripheral blood and filgrastim-stimulated bone marrow were grouped together, a higher chronic graft-versus-host disease frequency was associated with lower proportions of CD56bright natural killer regulatory cells and interferon γ-producing T helper cells in the donor product. Lower CD56bright natural killer regulatory cells displayed differential impacts on the development of extensive chronic graft-versus-host disease between filgrastim-stimulated apheresis peripheral blood and filgrastim-stimulated bone marrow. In summary, while controlling for the potential impact of filgrastim on marrow, our studies demonstrated that CD56bright natural killer regulatory cells had a much stronger impact on filgrastim-stimulated apheresis peripheral blood than on filgrastim-stimulated bone marrow. This supports the conclusion that a lower proportion of CD56bright natural killer regulatory cells results in the high rate of chronic graft-versus-host disease seen in filgrastim-stimulated apheresis peripheral blood. clinicaltrials.gov Identifier: 00438958.

The relationship of CD34+ dosage and platelet recovery following high dose chemotherapy and autologous CD34+ reinfusion in multiple myeloma.

Autologous hematopoietic stem cell transplantation (ASCT) is an established treatment for multiple myeloma (MM), yet the impact of transplanted CD34+ cell dose remains unresolved, especially in patients over the age of 65 years. Data was collected from 207 consecutive ASCT patients to determine the relationship between CD34+ infusion count and short-term and long-term platelet recovery. For MM patients under the age of 65 years (n=155), CD34+ dosage correlates with time to platelet engraftment (p<0.001) and platelet count at 30 days (p=0.003), but not with long-term platelet counts at 180 or 360 days from the CD34+ reinfusion. For MM patients aged 65 years or older (n=46), CD34+ dosage did not correlate with time to platelet engraftment, but did correlate with both short-term and long-term platelet counts at 30 (p<0.001), 180 (p=0.021), and 360 days (p=0.005). Exploratory regression analysis was done to explore platelet stability following the current minimum CD34+ dosage reinfusion. For MM patients under the age of 65 years, the minimum standard CD34+ dosage of 2×106cells/kg was sufficient for a timing to platelet engraftment of <21 days and short-term platelets count ≥150×109/L at 30 days. Alternatively, for MM patients aged 65 years or older, the CD34+ dosage of 2×106cells/kg was insufficient for platelet counts ≥150×109/L at 30 and only marginally attainable at 360 days suggesting that in elderly MM patients a higher CD34+ dosage may be required for platelet recovery and possibly long-term platelet stability.

Lentivector Iterations and Pre-Clinical Scale-Up/Toxicity Testing: Targeting Mobilized CD34+ Cells for Correction of Fabry Disease.

Fabry disease is a rare lysosomal storage disorder (LSD). We designed multiple recombinant lentivirus vectors (LVs) and tested their ability to engineer expression of human α-galactosidase A (α-gal A) in transduced Fabry patient CD34+ hematopoietic cells. We further investigated the safety and efficacy of a clinically directed vector, LV/AGA, in both ex vivo cell culture studies and animal models. Fabry mice transplanted with LV/AGA-transduced hematopoietic cells demonstrated α-gal A activity increases and lipid reductions in multiple tissues at 6 months after transplantation. Next we found that LV/AGA-transduced Fabry patient CD34+ hematopoietic cells produced even higher levels of α-gal A activity than normal CD34+ hematopoietic cells. We successfully transduced Fabry patient CD34+ hematopoietic cells with "near-clinical grade" LV/AGA in small-scale cultures and then validated a clinically directed scale-up transduction process in a GMP-compliant cell processing facility. LV-transduced Fabry patient CD34+ hematopoietic cells were subsequently infused into NOD/SCID/Fabry (NSF) mice; α-gal A activity corrections and lipid reductions were observed in several tissues 12 weeks after the xenotransplantation. Additional toxicology studies employing NSF mice xenotransplanted with the therapeutic cell product demonstrated minimal untoward effects. These data supported our successful clinical trial application (CTA) to Health Canada and opening of a "first-in-the-world" gene therapy trial for Fabry disease.

Sam68 Allows Selective Targeting of Human Cancer Stem Cells.

Targeting of human cancer stem cells (CSCs) requires the identification of vulnerabilities unique to CSCs versus healthy resident stem cells (SCs). Unfortunately, dysregulated pathways that support transformed CSCs, such as Wnt/ß-catenin signaling, are also critical regulators of healthy SCs. Using the ICG-001 and CWP family of small molecules, we reveal Sam68 as a previously unappreciated modulator of Wnt/ß-catenin signaling within CSCs. Disruption of CBP-ß-catenin interaction via ICG-001/CWP induces the formation of a Sam68-CBP complex in CSCs that alters Wnt signaling toward apoptosis and differentiation induction. Our study identifies Sam68 as a regulator of human CSC vulnerability.