CAR-T from cord blood in a patient with Ph+ acute lymphoblastic leukemia relapsing after hematopoietic stem cell transplantation.

While there is intense interest in the production of allogeneic CAR-T cells from umbilical cord units, little is known about the reactivity and persistence of CAR-T cells of umbilical origin. We report the case of a patient at our hematological center with multiple relapsing Ph+ B-ALL, notably a Blinatunomab non-responder, who underwent therapy with Brexucabtagene Autoleucel following relapse on Ponatinib post-allogeneic hematopoietic stem cell transplantation. The patient achieved a rapid CAR-T expansion and durable remission presenting in good clinical conditions 6 months post-CAR-T infusion, without manifestations of graft-versus-host disease. The case report provides insight into the reactivity and persistence of CAR-T cells of umbilical origin, confirming the potential promise of allogeneic umbilical cord-derived CAR-T cells.

Unlocking Predictive Power: Quantitative Assessment of CAR-T Expansion with Digital Droplet Polymerase Chain Reaction (ddPCR).

Flow cytometry (FCM) and quantitative PCR (qPCR) are conventional methods for assessing CAR-T expansion, while digital droplet PCR (ddPCR) is emerging as a promising alternative. We monitored CAR-T transcript expansion in 40 B-NHL patients post-infusion of CAR-T products (axi-cel; tisa-cel; and brexu-cel) with both His-Tag FCM and ddPCR techniques. Sensitivity and predictive capacity for efficacy and safety outcomes of ddPCR were analyzed and compared with FCM. A significant correlation between CAR-T counts determined by FCM and CAR transcripts assessed by ddPCR (p < 0.001) was observed. FCM revealed median CD3+CAR+ cell counts at 7, 14, and 30 days post-infusion with no significant differences. In contrast, ddPCR-measured median copies of CAR-T transcripts demonstrated significant lower copy numbers in tisa-cel recipients compared to the other products at day 7 and day 14. Patients with a peak of CAR transcripts at day 7 exceeding 5000 copies/microg gDNA, termed "good CAR-T expanders", were more likely to achieve a favorable response at 3 months (HR 10.79, 95% CI 1.16-100.42, p = 0.036). Good CAR-T expanders showed superior progression-free survival at 3, 6, and 12 months compared to poor CAR-T expanders (p = 0.088). Those reaching a peak higher than 5000 copies/microg gDNA were more likely to experience severe CRS and ICANS. DdPCR proves to be a practical method for monitoring CAR-T expansion, providing quantitative information that better predicts both treatment outcomes and toxicity.

Inflammation and acute cardiotoxicity in adult hematological patients treated with CAR-T cells: results from a pilot proof-of-concept study.

AIMS: Chimeric Antigen Receptor-T (CAR-T) cell infusion is a rapidly evolving antitumor therapy; however, cardiovascular (CV) complications, likely associated with cytokine release syndrome (CRS) and systemic inflammation, have been reported to occur. The CARdio-Tox study aimed at elucidating incidence and determinants of cardiotoxicity related to CAR-T cell therapy. METHODS: Patients with blood malignancies candidate to CAR-T cells were prospectively evaluated by echocardiography at baseline and 7 and 30 days after infusion. The study endpoints were i) incidence of cancer therapy-related cardiac dysfunction (CTRCD), CTRCD were also balanced for any grade CRS, but CTRCD occurred of Cardiology Guidelines on Cardio-Oncology (decrements of left ventricular ejection fraction (LVEF) or global longitudinal strain (GLS) and/or elevations of cardiac biomarkers (high sensitivity troponin I, natriuretic peptides) and ii), correlations of echocardiographic metrics with inflammatory biomarkers. RESULTS: Incidence of CTRCD was high at 7 days (59,3%), particularly in subjects with CRS. The integrated definition of CTRCD allowed the identification of the majority of cases (50%). Moreover, early LVEF and GLS decrements were inversely correlated with fibrinogen and interleukin-2 receptor levels (p always ≤ 0.01). CONCLUSIONS: There is a high incidence of early CTRCD in patients treated with CAR-T cells, and a link between CTRCD and inflammation can be demonstrated. Dedicated patient monitoring protocols are advised.

Unselected donor-derived hematopoietic stem cells boost for Chimeric Antigen Receptor T-cell associated hematotoxicity.

Hematological toxicity following Chimeric Antigen Receptor-T therapy in a patient with a prior allogeneic stem cell transplantation was resolved by the infusion of unselected donor-derived stem cell boost. Due to the donor's lymphocytes, the patient experienced a well-controlled flare-up of acute graft versus host disease.

Risk factors for hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation in a letermovir-exposed CMV-free population receiving PTCy.

Hemorrhagic cystitis (HC) is a highly impacting complication in allogeneic hematopoietic stem cell transplantation (HSCT), occurring in 12%-37% of patients. The impact of transplant- and patient-specific variables has been described, with a possible role for JCV and BKV, which may be cooperating with cytomegalovirus (CMV). Here, we analyze 134 letermovir-exposed, CMV-free patients, treated with the same cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis, describing risk factors for HC. The overall incidence of HC was 23%. Patients with HLA mismatched transplant, higher comorbidity score, and receiving three alkylating agents with TBF (thiotepa, busulfan, and fludarabine) conditioning regimen had a higher risk of HC in multivariate analysis (OR: 4.48, 6.32, and 1.32, respectively). A HC-score including male gender, TBF conditioning, and HLA-mismatch stratifies the risk of HC in the first 100 days after HSCT. The role of BKV and JCV was not highly impacting in those patients, suggesting a possible synergistic effect between CMV and JCV in causing HC. HC can be interpreted as the combination of patient-related factors, chemotherapy-related toxicities-especially due to alkylating agents-and immunological elements.

Hematopoiesis and immune reconstitution after CD19 directed chimeric antigen receptor T-cells (CAR-T): A comprehensive review on incidence, risk factors and current management.

Impaired function of hematopoiesis after treatment with chimeric antigen T-cells (CAR-T) is a frequent finding and can interest a wide range of patients, regardless of age and underlying disease. Trilinear cytopenias, as well as hypogammaglobulinemia, B-cell aplasia, and T-cell impairment, can severely affect the infectious risk of CAR-T recipients, as well as their quality of life. In this review, we provide an overview of defects in hematopoiesis after CAR-T, starting with a summary of different definitions and thresholds. We then move to summarize the main pathogenetic mechanisms of cytopenias, and we offer insight into cytomorphological aspects, the role of clonal hematopoiesis, and the risk of secondary myeloid malignancies. Subsequently, we expose the major findings and reports on T-cell and B-cell quantitative and functional impairment after CAR-T. Finally, we provide an overview of current recommendations and leading experiences regarding the management of cytopenias and defective B- and T-cell function.

The CD4/CD8 ratio of infused CD19-CAR-T is a prognostic factor for efficacy and toxicity.

CD4+ and CD8+ chimeric antigen receptor T cells (CAR-T) play different roles in the in vivo anti-tumour response, but the role of the CD4+ /CD8+ ratio among infused CAR-T has not been clearly defined yet. We analysed leftovers from infused anti-CD19 CAR-T bags of 31 patients with aggressive B-cell lymphomas. The median ratio was 1.44, lower for brexu-cel compared to tisa-cel and axi-cel. The CAR+CD4+ /CD8+ ratio was influenced by lactate dehydrogenase levels at apheresis, not by age, previous treatments or the CD4+ /CD8+ ratio in peripheral blood. Patients with a response at 3 months after CAR-T (M3) had a lower CAR+CD4+ /CD8+ ratio in the infused products compared to non-responders (ratio 0.74 vs. 2.47, p = 0.011). A CAR+CD4+ /CD8+ ratio higher than the cut point of 1.12 was associated with an increased risk of treatment failure at M3 (OR 23.3, p = 0.012) and M6 (OR 10, p = 0.028). The median 6-month PFS was 76% for patients with a ratio lower than 1.12% vs. 31% for the others. The prognostic role of the CAR+CD4+ /CD8+ ratio was independent of the costimulatory domain (CD28 vs. 4-1BB) of the product (OR 16.41, p = 0.041). Our data indicate a crucial role for CD8+ CAR-T and the CAR+CD4+ /CD8+ ratio in predicting CAR-T efficacy.

Thiotepa-busulfan-fludarabine Compared to Treosulfan-based Conditioning for Haploidentical Transplant With Posttransplant Cyclophosphamide in Patients With Acute Myeloid Leukemia in Remission: A Study From the Acute Leukemia Working Party of the EBMT.

We conducted a registry analysis including adult acute myeloid leukemia (AML) patients in remission who had received thiotepa, busulfan, and fludarabine (TBF) or treosulfan-based (Treo) conditioning for haplo-hematopoietic stem cell transplant (HSCT) with posttransplant cyclophosphamide (PTCy) between 2010 and 2020. A total of 1123 patients met the inclusion criteria (968 received TBF and 155 received Treo). A 1:1 matched-pair analysis was performed on 142 TBF and 142 Treo patients. In the Treo group, 68% of patients received treosulfan at a dose ≥36 g/m2 and 54% of patients received a second alkylator (thiotepa or melphalan). We observed a trend toward increased incidence of grade II-IV acute (a) graft-versus-host disease (GVHD) at 180 days in the TBF group compared with Treo (29% versus 20%; P = 0.08), while incidence of grade III-IV aGVHD was not statistically different. Similarly, the incidence of chronic (c) GVHD was not statistically different in the 2 groups. Incidence of nonrelapse mortality at 2 years was 19% in TBF and 14% in Treo (P = 0.4). Relapse incidence at 2 years was not statistically different in the 2 groups (16% and 18% in TBF and Treo, respectively; P = 0.9). Leukemia-free survival, overall survival, and GVHD-free, relapse-free survival was 65% versus 68% (P = 0.6), 73% versus 76% (P = 0.5), and 54% versus 53% (P = 0.8) in TBF versus Treo, respectively. In conclusion, we did not find a significant difference between the 2 conditioning in the present study; Treo and TBF represent 2 valid alternative regimens for haplo-HSCT with PTCy for AML in remission.

The Role of Fecal Microbiota Transplantation in the Allogeneic Stem Cell Transplant Setting.

Microbiota changes during allogeneic hematopoietic stem cell transplantation has several known causes: conditioning chemotherapy and radiation, broad-spectrum antibiotic administration, modification in nutrition status and diet, and graft-versus-host disease. This article aims to review the current knowledge about the close link between microbiota and allogeneic stem cell transplantation setting. The PubMed search engine was used to perform this review. We analyzed data on microbiota dysbiosis related to the above-mentioned affecting factors. We also looked at treatments aimed at modifying gut dysbiosis and applications of fecal microbiota transplantation in the allogeneic stem cell transplant field, with particular interest in fecal microbiota transplantation for graft-versus-host disease (GvHD), multidrug-resistant and clostridium difficile infections, and microbiota restoration after chemotherapy and antibiotic therapy.

Prospective monitoring of chronic myeloid leukemia patients from the time of TKI discontinuation: the fate of peripheral blood CD26+ leukemia stem cells.

Introduction: In chronic myeloid leukemia (CML), about half of the patients achieving a deep and stable molecular response with tyrosine kinase inhibitors (TKIs) may discontinue TKI treatment without disease recurrence. As such, treatment-free remission (TFR) has become an ambitious goal of treatment. Given the evidence that deepness and duration of molecular response are necessary but not sufficient requisites for a successful TFR, additional biological criteria are needed to identify CML patients suitable for efficacious discontinuation. Leukemia stem cells (LSCs) are supposed to be the reservoir of the disease. Previously, we demonstrated that residual circulating CD34+/CD38-/CD26+ LSCs were still detectable in a consistent number of CML patients during TFR. Methods: CML LSCs could be easily identified by flow-cytometry as they express the CD34+/CD38-/CD26+ phenotype. In this study, we explored the role of these cells and their correlation with molecular response in a cohort of 109 consecutive chronic phase CML patients prospectively monitored from the time of TKI discontinuation. Results: After a median observation time of 33 months from TKI discontinuation, 38/109 (35%) patients failed TFR after a median time of 4 months, while 71/109 (65%) patients are still in TFR. At TKI discontinuation, peripheral blood CD26+LSCs were undetectable in 48/109 (44%) patients and detectable in 61/109 (56%). No statistically significant correlation between detectable/undetectable CD26+LSCs and the rate of TFR loss was found (p = 0.616). The incidence of TFR loss based on the type of TKI treatment was statistically significant for imatinib treatment compared to that of nilotinib (p = 0.039). Exploring the behavior of CD26+LSCs during TFR, we observed fluctuating values that were very variable between patients, and they were not predictive of TFR loss. Discussion: Up to date, our results confirm that CD26+LSCs are detectable at the time of TKI discontinuation and during TFR. Moreover, at least for the observation median time of the study, the persistence of "fluctuating" values of residual CD26+LSCs does not hamper the possibility to maintain a stable TFR. On the contrary, even patients discontinuing TKI with undetectable CD26+LSCs could undergo TFR loss. Our results suggest that factors other than residual LSCs "burden" playing an active role in controlling disease recurrence. Additional studies evaluating CD26+LSCs' ability to modulate the immune system and their interaction in CML patients with very long stable TFR are ongoing.

Determinants of frontline tyrosine kinase inhibitor choice for patients with chronic-phase chronic myeloid leukemia: A study from the Registro Italiano LMC and Campus CML.

BACKGROUND: Imatinib, dasatinib, and nilotinib are tyrosine kinase inhibitors (TKIs) approved in Italy for frontline treatment of chronic-phase chronic myeloid leukemia (CP-CML). The choice of TKI is based on a combined evaluation of the patient's and the disease characteristics. The aim of this study was to analyze the use of frontline TKI therapy in an unselected cohort of Italian patients with CP-CML to correlate the choice with the patient's features. METHODS: A total of 1967 patients with CP-CML diagnosed between 2012 and 2019 at 36 centers throughout Italy were retrospectively evaluated; 1089 patients (55.4%) received imatinib and 878 patients (44.6%) received a second-generation (2G) TKI. RESULTS: Second-generation TKIs were chosen for most patients aged <45 years (69.2%), whereas imatinib was used in 76.7% of patients aged >65 years (p < .001). There was a predominant use of imatinib in intermediate/high European long-term survival risk patients (60.0%/66.0% vs. 49.7% in low-risk patients) and a limited use of 2G-TKIs in patients with comorbidities such as hypertension, diabetes, chronic obstructive pulmonary disease, previous neoplasms, ischemic heart disease, or stroke and in those with >3 concomitant drugs. We observed a greater use of imatinib (61.1%) in patients diagnosed in 2018-2019 compared to 2012-2017 (53.2%; p = .002). In multivariable analysis, factors correlated with imatinib use were age > 65 years, spleen size, the presence of comorbidities, and ≥3 concomitant medications. CONCLUSIONS: This observational study of almost 2000 cases of CML shows that imatinib is the frontline drug of choice in 55% of Italian patients with CP-CML, with 2G-TKIs prevalently used in younger patients and in those with no concomitant clinical conditions. Introduction of the generic formulation in 2018 seems to have fostered imatinib use.

Efficacy and safety of nilotinib as frontline treatment in elderly (> 65 years) chronic myeloid leukemia patients outside clinical trials.

Here, we report real-world evidence on the safety and efficacy of nilotinib as a first-line treatment in elderly patients with chronic phase CML, treated in 18 Italian centers. Sixty patients aged > 65 years (median age 72 years (65-84)) were reported: 13 patients were older than 75 years. Comorbidities were recorded at baseline in 56/60 patients. At 3 months of treatment, all patients obtained complete hematological response (CHR), 43 (71.6%) an early molecular response (EMR), while 47 (78%) reached a complete cytogenetic response (CCyR). At last follow-up, 63.4% of patients still had a deep molecular response (MR4 or better), 21.6% reached MR3 as best response and 11.6% persisted without MR. Most patients (85%) started the treatment at the standard dose (300 mg BID), maintained at 3 months in 80% of patients and at 6 months in 89% of them. At the last median follow-up of 46.3 months, 15 patients discontinued definitively the treatment (8 due to side effects, 4 died for unrelated CML causes, 1 for failure, 2 were lost to follow-up). One patient entered in treatment-free remission. As to safety, 6 patients (10%) experienced cardiovascular events after a median time of 20.9 months from the start. Our data showed that nilotinib could be, as first-line treatment, effective and relatively safe even in elderly CML patients. In this setting, more data in the long term are needed about possible dose reduction to improve the tolerability, while maintaining the optimal molecular response.

Impact of Covid 19 pandemic on hematopoietic stem cell transplantation activities: Report from a single center.

The current COVID-19 pandemic has placed unprecedented stress on the healthcare system, including HSCT. Several international organizations have created guidelines for managing different aspects of HSCT in the context of the pandemic. Comparing 2019 and 2020, our transplant center performed the same number of transplants. In both periods, transplants were mainly for patients with acute leukemia; thus, the urgency criteria was respected in light of pandemic restraints. Transplants by sibling donors and cord blood units remained the same, while transplants by unrelated donors were increased, in particular from European registries, and transplants by haploidentical donors were decreased. This change was made in light of the necessity of cryopreserving all apheresis products. We decided against cryopreserving bone marrow products due to the greater risk of drastic reduction in CD34 + cell count during the process. For urgent cases with only a haploidentical donor available, we opted for the use of PBSC following stimulation with G-CSF. GvHD prophylaxis was performed with PTCY on days + 3 + 5, cyclosporine with tapering from day + 100, and mycophenolic acid until day + 90 post-HSCT. Post-transplant outcomes such as graft failure, sepsis, and GVHD were not affected by the changes implemented. As a result of logistic difficulties, we halted our Car-T program from the start of the lockdown in March 2020 until September 2020. In accord with international guidelines, we were able to continue our HSCT program in the order to ensure a lifesaving treatment for patients with hematologic diseases for whom this procedure cannot be postponed.

Endothelial activation predicts disseminated intravascular coagulopathy, cytokine release syndrome and prognosis in patients treated with anti-CD19 CAR-T cells.

Cytokine release syndrome (CRS) and consumptive coagulopathy can complicate the treatment with chimeric antigen receptor T (CAR-T) cells. The modified version of the Endothelial Activation and Stress Index (mEASIX), a score derived from haematopoietic stem cell transplantation, combines platelets, C-reactive protein (CRP), and lactate dehydrogenase (LDH) and has been correlated with CRS and endothelial biomarkers. In 38 consecutive patients with aggressive lymphoproliferative disease we measured a coagulative laboratory panel at baseline and early after infusion of anti-CD19 CAR-T. The panel was investigated also in the presence of CRS graded 2 or higher, or immune effector cell-associated neurotoxicity syndrome (ICANS). Moreover, we examined the relationship between mEASIX, coagulation biomarkers, and toxicities of CAR-T cells. During CRS grade 2 or higher, we found increased prothrombin time (PT) and activated partial thromboplastin time (aPTT), fibrinogen, D-dimer, factor VIII (FVIII), and von Willebrand factor (vWF) antigen levels, and decreased platelet count and antithrombin levels. The occurrence of immune effector cell-associated neurotoxicity syndrome was associated with higher PT values, D-dimer, FVIII, and vWF levels, and decreased fibrinogen levels and platelet count. A higher mEASIX score correlated with increased aPTT values, fibrinogen, D-dimer, FVIII and vWF levels, and decreased antithrombin levels. Baseline mEASIX was predictive for consumptive coagulopathy and CRS graded 2 or higher, and for progression-free survival and overall survival.