Acute graft-versus-host disease (GVHD) remains a leading cause of morbidity and non-relapse mortality following allogeneic hematopoietic cell transplantation. The clinical staging of GVHD varies greatly between transplant centers and is frequently not agreed upon by independent reviewers. The lack of standardized approaches to handle common sources of discrepancy in GVHD grading likely contributes to why promising GVHD treatments reported from single centers have failed to show benefit in randomized multi-center clinical trials. We developed guidelines through international expert consensus opinion to standardize the diagnosis and clinical staging of GVHD for use in a large international GVHD research consortium. During the first year of use, the guidance was following discussion of complex clinical phenotypes by experienced transplant physicians and data managers. These guidelines increase the uniformity of GVHD symptom capture which may improve the reproducibility of GVHD clinical trials after further prospective validation.

Most cancer patients succumb to disseminated disease because conventional systemic therapies lack spatiotemporal control of their toxic effects in vivo, particularly in a complicated milieu such as bone marrow where progenitor stem cells reside. Here, we demonstrate the treatment of disseminated cancer by photoactivatable drugs using radiopharmaceuticals. An orthogonal-targeting strategy and a contact-facilitated nanomicelle technology enabled highly selective delivery and co-localization of titanocene and radiolabelled fluorodeoxyglucose in disseminated multiple myeloma cells. Selective ablation of the cancer cells was achieved without significant off-target toxicity to the resident stem cells. Genomic, proteomic and multimodal imaging analyses revealed that the downregulation of CD49d, one of the dimeric protein targets of the nanomicelles, caused therapy resistance in small clusters of cancer cells. Similar treatment of a highly metastatic breast cancer model using human serum albumin-titanocene formulation significantly inhibited cancer growth. This strategy expands the use of phototherapy for treating previously inaccessible metastatic disease.

Multiple myeloma (MM) is a plasma B-cell hematologic cancer that causes significant skeletal morbidity. Despite improvements in survival, heterogeneity in response remains a major challenge in MM. Cluster of differentiation 38 (CD38) is a type II transmembrane glycoprotein overexpressed in myeloma cells and is implicated in MM cell signaling. Daratumumab is a U.S. Food and Drug Administration-approved high-affinity monoclonal antibody targeting CD38 that is clinically benefiting refractory MM patients. Here, we evaluated [Zr]Zr-desferrioxamine (DFO)-daratumumab PET/CT imaging in MM tumor models. Daratumumab was conjugated to DFO--benzyl-isothiocyanate (DFO-Bz-NCS) for radiolabeling with Zr. Chelator conjugation was confirmed by electrospray ionization-mass spectrometry, and radiolabeling was monitored by instant thin-layer chromatography. Daratumumab was conjugated to Cyanine5 (Cy5) dye for cell microscopy. In vitro and in vivo evaluation of [Zr]Zr-DFO-daratumumab was performed using CD38 human myeloma MM1.S- (MM1.S) cells. Cellular studies determined the affinity, immunoreactivity, and specificity of [Zr]Zr-DFO-daratumumab. A 5TGM1- (5TGM1)/KaLwRij MM mouse model served as control for imaging background noise. [Zr]Zr-DFO-daratumumab PET/CT small-animal imaging was performed in severe combined immunodeficient mice bearing solid and disseminated MM tumors. Tissue biodistribution (7 d after tracer administration, 1.11 MBq/animal, = 4-6/group) was performed in wild-type and MM1.S tumor-bearing mice. A specific activity of 55.5 MBq/nmol (0.37 MBq/μg) was reproducibly obtained with [Zr]Zr-daratumumab-DFO. Flow cytometry confirmed CD38 expression (>99%) on the surface of MM1.S cells. Confocal microscopy with daratumumab-Cy5 demonstrated specific cell binding. Dissociation constant, 3.3 nM (±0.58), and receptor density, 10.1 fmol/mg (±0.64), was obtained with a saturation binding assay. [Zr]Zr-DFO-daratumumab/PET demonstrated specificity and sensitivity for detecting CD38 myeloma tumors of variable sizes (8.5-128 mm) with standardized uptake values ranging from 2.1 to 9.3. Discrete medullar lesions, confirmed by bioluminescence images, were efficiently imaged with [Zr]Zr-DFO-daratumumab/PET. Biodistribution at 7 d after administration of [Zr]Zr-DFO-daratumumab showed prominent tumor uptake (27.7 ± 7.6 percentage injected dose per gram). In vivo blocking was achieved with a 200-fold excess of unlabeled daratumumab. [Zr]Zr-DFO- and Cy5-daratumumab demonstrated superb binding to CD38 human MM cells and significantly low binding to CD38 cells. Daratumumab bioconjugates are being evaluated for image-guided delivery of therapeutic radionuclides.

Pegfilgrastim is produced by binding a 20,000-dalton polyethylene glycol molecule to granulocyte colony-stimulating factor (G-CSF), increasing the mass of the compound, and resulting in a longer-lasting form of G-CSF. This makes it more convenient to use pegfilgrastim as a single-day injection. This study was a prospective phase II single-center trial. Fifteen normal related donors received pegfilgrastim 12 mg subcutaneously to mobilize peripheral blood stem cells (PBSC) for allogeneic stem cell transplantation. Leukapheresis was planned to start 3 days after injection. All harvests were successful. Median number of leukapheresis was 2 days (range 1-3 days). There were 7/15 donors who only required single leukapheresis. The maximum concentration of white blood cells (WBC) and circulating CD34 cells occurred 3 days after pegfilgrastim injection (WBC: median 62,200/μl; CD34: median 69.76/μl). The median yield of CD34 cells was 6.78 × 10(6)/kg recipient weight. The median CD3 cells was 1.89 × 10(8)/kg recipient weight. The main adverse events were bone pain and headache. Median neutrophil and platelet engraftments in the recipients occurred on day 12 and day 13, respectively, after transplantation. PBSC mobilization with single-day injection of pegfilgrastim in normal donor is feasible. Further comparisons of this protocol to standard G-CSF for allogeneic stem cell mobilization should be conducted in future.

Multiple myeloma (MM) is a cancer of bone marrow (BM) plasma cells, which is increasingly treatable but still incurable. In 90% of MM patients, severe osteolysis results from pathological interactions between MM cells and the bone microenvironment. Delineating specific molecules and pathways for their role in cancer supportive interactions in the BM is vital for developing new therapies. Very Late Antigen 4 (VLA4, integrin α4β1) is a key player in cell–cell adhesion and signaling between MM and BM cells. We evaluated a VLA4 selective near infrared fluorescent probe, LLP2A-Cy5, for in vitro and in vivo optical imaging of VLA4. Furthermore, two VLA4-null murine 5TGM1 MM cell (KO) clones were generated by CRISPR/Cas9 knockout of the Itga4 (α4) subunit, which induced significant alterations in the transcriptome. In contrast to the VLA4+ 5TGM1 parental cells, C57Bl/KaLwRij immunocompetent syngeneic mice inoculated with the VLA4-null clones showed prolonged survival, reduced medullary disease, and increased extramedullary disease burden. The KO tumor foci showed significantly reduced uptake of LLP2A-Cy5, confirming in vivo specificity of this imaging agent. This work provides new insights into the pathogenic role of VLA4 in MM, and evaluates an optical tool to measure its expression in preclinical models.

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Alloantibodies against factor VIII (FVIII), arising in 20%-35% of severe haemophilia A patients, significantly increase both haemophilia-related mortality and the financial burden due to the high cost of bypassing agents (BAs) and immune tolerance induction (ITI).

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