Bone marrow graft versus peripheral blood graft in haploidentical hematopoietic stem cells transplantation: a retrospective analysis in1344 patients of SFGM-TC registry.

The use of peripheral blood (PB) or bone marrow (BM) stem cells graft in haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide (PTCy) for graft-versus-host disease (GVHD) prophylaxis remains controversial. Moreover, the value of adding anti-thymoglobulin (ATG) to PTCy is unknown. A total of 1344 adult patients received an unmanipulated haploidentical transplant at 37 centers from 2012 to 2019 for hematologic malignancy. We compared the outcomes of patients according to the type of graft, using a propensity score analysis. In total population, grade II-IV and III-IV acute GVHD (aGVHD) were lower with BM than with PB. Grade III-IV aGVHD was lower with BM than with PB + ATG. All outcomes were similar in PB and PB + ATG groups. Then, in total population, adding ATG does not benefit the procedure. In acute leukemia, myelodysplastic syndrome and myeloproliferative syndrome (AL-MDS-MPS) subgroup receiving non-myeloablative conditioning, risk of relapse was twice greater with BM than with PB (51 vs. 22%, respectively). Conversely, risk of aGVHD was greater with PB (38% for aGVHD II-IV; 16% for aGVHD III-IV) than with BM (28% for aGVHD II-IV; 8% for aGVHD III-IV). In this subgroup with intensified conditioning regimen, risk of relapse became similar with PB and BM but risk of aGVHD III-IV remained higher with PB than with BM graft (HR = 2.0; range [1.17-3.43], p = 0.012).

CAR-NK Cells: A Chimeric Hope or a Promising Therapy?

Immunotherapy with chimeric antigen receptor-engineered T cells (CAR-T) has revolutionized the treatment landscape of relapsed/refractory B-cell malignancies. Nonetheless, the use of autologous T cells has certain limitations, including the variable quality and quantity of collected effector T cells, extended time of cell processing, limited number of available CAR cells, toxicities, and a high cost. Thanks to their powerful cytotoxic capabilities, with proven antitumor effects in both haploidentical hematopoietic stem cell transplantation and adoptive cell therapy against solid tumors and hematological malignancies, Natural Killer cells could be a promising alternative. Different sources of NK cells can be used, including cellular lines, cord blood, peripheral blood, and induced pluripotent stem cells. Their biggest advantage is the possibility of using them in an allogeneic context without major toxic side effects. However, the majority of the reports on CAR-NK cells concern preclinical or early clinical trials. Indeed, NK cells might be more difficult to engineer, and the optimization and standardization of expansion and transfection protocols need to be defined. Furthermore, their short persistence after infusion is also a major setback. However, with recent advances in manufacturing engineered CAR-NK cells exploiting their cytolytic capacities, antibody-dependent cellular cytotoxicity (ADCC), and cytokine production, "off-the-shelf" allogeneic CAR-NK cells can provide a great potential in cancer treatments.

[Allogeneic CAR-NK cells: A promising alternative to autologous CAR-T cells - State of the art, sources of NK cells, limits and perspectives]. / Les CAR-NK allogéniques : une alternative prometteuse aux CAR-T autologues ­ État de la question, sources de cellules NK, limites et perspectives.

Immunotherapy with chimeric antigen receptor engineered-T cells (CAR-T) has revolutionized the landscape of treatment of relapsed or refractory B-cell. However, the use of autologous T cells has limitations: variable quality of collected effector T cells, duration of the process sometimes incompatible with uncontrolled hemopathy, limited number of available CAR cells, sometimes fatal toxicities, extremely high cost. Natural Killer (NK) cells are an interesting alternative to T cells. NK cells are very powerful cytotoxic effectors that have demonstrated an anti-tumor effect after haploidentical hematopoietic stem cells transplantation or in adoptive cell therapy against a number of solid or hematological tumors. Mainly, they can be used in allogeneic situations without causing major toxic side effects. The sources of NK cells are multiple: cell line, cord blood, peripheral blood, induced pluripotent stem cells. Recent advances in manufacturing engineered CAR-NK cells make it possible to promote antibody-dependent cell-mediated cytotoxicity (ADCC), as well as the activation and persistence of these cells, notably via the cytokine Il-15. The majority of the reports on CAR-NK cells concern pre-clinical or early clinical trials. However, the many advantages of "off-the-shelf" allogeneic CAR-NK cells provide great potential in cancer treatments.

Sinusoidal Obstruction Syndrome in Critically Ill Patients in the Era of Defibrotide: A Retrospective Multicenter Study.

Sinusoidal obstruction syndrome (SOS) is a life-threatening liver complication of high- dose chemotherapy. Defibrotide is the only available therapeutic option approved for SOS. The prognosis of SOS in patients requiring intensive care unit (ICU) admission remains unknown. The primary objective of this study was to assess the outcome of SOS patients in ICU. This retrospective study was conducted between 2007 and 2019 in 13 French ICUs. Seventy-one critically ill adult patients with SOS defined according to European Society for Blood and Marrow Transplantation criteria and treated with defibrotide were included. The main reasons for ICU admission were respiratory failure and acute kidney injury. Mechanical ventilation, vasopressors, and renal replacement therapy were required in 59%, 52%, and 49% of patients, respectively. Twenty-three percent of patients experienced a bleeding event during defibrotide treatment. Hospital mortality was 54%, mainly related to multiorgan failure. Older age (hazard ratio [HR], 1.02; 95% confidence interval [CI], 1.00 to 1.04), mechanical ventilation (HR, 1.99; 95% CI, 1.00 to 3.99), renal replacement therapy (HR, 2.55; 95% CI, 1.32 to 4.91) were independent predictors of hospital mortality. Defibrotide prophylaxis (HR, 0.35; 95% CI, 0.13 to 0.92) was associated with better outcomes. Critically ill patients with SOS have a high mortality rate in the ICU, especially if organ support is required. Additional studies assessing the impact of defibrotide prophylaxis are warranted.