Zubair, Abba

Abstract Background Red blood cell (RBC) transfusion may be lifesaving, however transfusion-transmitted infections (TTI) and transfusion-associated graft-versus-host disease (TA-GVHD) still pose a threat despite current donor selection and testing requirements. Amustaline (S-303)/glutathione (GSH) pathogen reduction (PR) is designed to inactivate infectious microbes and leukocytes in RBCs. The RedeS study evaluates the safety and efficacy of amustaline/GSH PR-RBCs compared to conventional RBCs in a broad spectrum of patients requiring acute and/or repeated RBC transfusion support. Methods RedeS is a Phase 3, prospective, multi-center, randomized, double-blind, active-controlled, parallel-design study, with a 6-month extension option to evaluate patients requiring repeated transfusions including red cell exchange (RCE).Eligible subjects will be stratified according to site, baseline bleeding status and participation in the extension period. The study arms include a transfusion period of 28-days for anemia with any bleeding or non-bleeding patients or a 28-day+6-month extension for non-bleeding patients with chronic anemia requiring repeated simple transfusions, or for patients with sickle cell disease (SCD) expected to receive three RCE procedures. The study will seek to enroll 600-800 subjects in the overall safety analysis, including ~140 repeatedly-transfused subjects in the 6-month extension including up to 30 subjects receiving three RCE procedures. The primary safety endpoints are the proportion of patients with any treatment-emergent adverse events (TEAEs) related to study RBC transfusion through 28 days after the last study transfusion, and the proportion of patients with treatment-emergent antibodies with confirmed specificity to PR-RBCs. The primary efficacy endpoint is the hemoglobin (Hb) increment in subjects who are non-bleeding at baseline, adjusted for the grams of Hb transfused and averaged over multiple transfusions. With 352 evaluable transfused non-bleeding subjects (176 per treatment group) from either arm, the study will have 80% power to demonstrate non-inferiority, defined as a Hb increment treatment difference of no more than 15% of the Control group mean, assuming a Control arm coefficient of variation of 50%. Discussion RedeS will characterize the safety of amustaline/GSH PR-RBCs and is designed to demonstrate the non-inferiority of PR-RBCs to conventional RBCs with respect to Hb increment, a common pragmatic clinical assessment of RBC transfusion effectiveness.

Abstract Background Sickle cell disease (SCD) is a hemoglobinopathy with limited treatment options. Genetic modification of the patient's own hematopoietic stem cells (HSCs) offers an avenue to curative therapy using the patient's own cells. Many challenges exist in collecting sufficient numbers of starting material for manufacturing, beginning with the pre‐mobilization optimization of the patient to the mobilization, collection, and post‐collection phases. Study Design and Methods A working group within the Cellular Therapy Subcommittee of the American Society for Apheresis Clinical Applications Committee describes the challenges associated with apheresis collection of the starting material for gene therapy (GT) product manufacturing for patients with SCD and discusses potential strategies for overcoming these challenges. Results and Discussion Patients must undergo automated red blood cell exchange (RCE) to lower hemoglobin S in a relatively short window of time before apheresis collection of HSCs. The risks and benefits of transfusion as well as the logistics of providing adequate and appropriate blood products must be considered. Limited agents are available for mobilization of HSCs into the peripheral blood for collection and the timing of administration is short. Each collection cycle consists of RCE followed by at least three mobilization and apheresis collection events in addition to collecting backup cells. More than one cycle is typically needed to collect enough cells for GT drug product manufacturing. Optimization of patient factors and apheresis instrument parameters leads to better collection yields. Early and frequent ongoing coordination with all stakeholders involved is critical to developing personalized treatment plans for patients.

The contributions of mesenchymal stem cells (MSCs) to tumour growth and stroma formation are poorly understood. Tumour cells can transfer genetic information and modulate cell signalling in other cells through the release of extracellular vesicles (EVs). We examined the contribution of EV‐mediated inter‐cellular signalling between bone marrow MSCs and tumour cells in human cholangiocarcinoma, highly desmoplastic cancers that are characterized by tumour cells closely intertwined within a dense fibrous stroma. Exposure of MSCs to tumour cell–derived EVs enhanced MSC migratory capability and expression of alpha‐smooth muscle actin mRNA, in addition to mRNA expression and release of CXCL‐1, CCL2 and IL‐6. Conditioned media from MSCs exposed to tumour cell–derived EVs increased STAT‐3 phosphorylation and proliferation in tumour cells. These effects were completely blocked by anti‐IL‐6R antibody. In conclusion, tumour cell–derived EVs can contribute to the generation of tumour stroma through fibroblastic differentiation of MSCs, and can also selectively modulate the cellular release of soluble factors such as IL‐6 by MSCs that can, in turn, alter tumour cell proliferation. Thus, malignant cells can “educate” MSCs to induce local microenvironmental changes that enhance tumour cell growth.