Peripheral Blood Stem Cell Research Articles

Digital whole-slide imaging of changes in amyloid after peripheral blood stem cell transplantation in patients with amyloid light-chain amyloidosis.

Peripheral blood stem cell transplantation (PBSCT) has made amyloid light-chain (AL) amyloidosis treatable. After PBSCT, hematological complete remission (HCR) can be achieved, leading to improved renal prognosis. The purpose of this study was to evaluate whether whole slide imaging of biopsy samples shows a post-treatment reduction in amyloid deposits in patients with AL amyloidosis. Patients were divided into three groups: Group A (n = 8), not eligible for PBSCT and treated with other therapies; Group B (n = 11), treated with PBSCT and achieved HCR; and Group C (n = 5), treated with PBSCT but did not achieve HCR. Clinical findings and amyloid deposition in glomeruli, interstitium, and blood vessels were compared before and after treatment using digital whole-slide imaging. Proteinuria and hypoalbuminemia improved more in Group B than in the other groups, and in Group B, amyloid deposition improved more in the glomeruli than in the interstitium and blood vessels. The long-term renal and survival prognosis was better in Group B than in the other groups. PBSCT can be expected to improve long-term clinical and renal histological prognosis in patients with AL amyloidosis who achieve HCR. Amyloid disappearance from renal tissue may take a long time even after clinical HCR.

NTRK-fused central nervous system tumours: clinicopathological and genetic insights and response to TRK inhibitors

Background Neurotrophic tropomyosin receptor kinase (NTRK) gene fusions are found in 1% of gliomas across children and adults. TRK inhibitors are promising therapeutic agents for NTRK-fused gliomas because they are tissue agnostic and cross the blood–brain barrier (BBB). Methods We investigated twelve NGS-verified NTRK-fused gliomas from a single institute, Seoul National University Hospital. Results The patient cohort included six children (aged 1–15 years) and six adults (aged 27–72 years). NTRK2 fusions were found in ten cerebral diffuse low-grade and high-grade gliomas (DLGGs and DHGGs, respectively), and NTRK1 fusions were found in one cerebral desmoplastic infantile ganglioglioma and one spinal DHGG. In this series, the fusion partners of NTRK2 were HOOK3, KIF5A, GKAP1, LHFPL3, SLMAP, ZBTB43, SPECC1L, FKBP15, KANK1, and BCR, while the NTRK1 fusion partners were TPR and TPM3. DLGGs tended to harbour only an NTRK fusion, while DHGGs exhibited further genetic alterations, such as TERT promoter/TP53/PTEN mutation, CDKN2A/2B homozygous deletion, PDGFRA/KIT/MDM4/AKT3 amplification, or multiple chromosomal copy number aberrations. Four patients received adjuvant TRK inhibitor therapy (larotrectinib, repotrectinib, or entrectinib), among which three also received chemotherapy (n = 2) or proton therapy (n = 1). The treatment outcomes for patients receiving TRK inhibitors varied: one child who received larotrectinib for residual DLGG maintained stable disease. In contrast, another child with DHGG in the spinal cord experienced multiple instances of tumour recurrence. Despite treatment with larotrectinib, ultimately, the child died as a result of tumour progression. An adult patient with glioblastoma (GBM) treated with entrectinib also experienced tumour progression and eventually died. However, there was a successful outcome for a paediatric patient with DHGG who, after a second gross total tumour removal followed by repotrectinib treatment, showed no evidence of disease. This patient had previously experienced relapse after the initial surgery and underwent autologous peripheral blood stem cell therapy with carboplatin/thiotepa and proton therapy. Conclusions Our study clarifies the distinct differences in the pathology and TRK inhibitor response between LGG and HGG with NTRK fusions.

Identifying Candidates for Effective Utilization of Stored Autologous PBSCs in Salvage Transplantation for Multiple Myeloma: Who Benefits Most?

Background/Objectives: High-dose chemotherapy (HD-CHT) followed by autologous stem cell transplantation (ASCT) remains the gold standard for eligible multiple myeloma (MM) patients, even amidst evolving therapeutic options. Clinical trials have demonstrated ASCT's efficacy in MM, including its potential as salvage therapy after prolonged remission. Peripheral blood stem cells (PBSCs) are now the primary source of hematopoietic stem cells for ASCT. Collecting additional PBSCs post-initial myeloablative conditioning is challenging, leading many centers to adopt the practice of collecting and storing excess PBSCs during initial therapy to support tandem transplants or salvage treatments. The use of salvage ASCT may diminish in the face of novel, highly effective treatments like bispecific antibodies and cellular therapies for relapsed/refractory MM (RRMM). Despite available stored PBSC grafts, salvage ASCTs are underutilized due to various factors, including declining performance status and therapy-related comorbidities. A cost utilization analysis from 2013 revealed that roughly 70% of patients had unused PBSC products in prolonged cryopreservation, costing a significant portion of total ASCT expenses. The average cost for collecting, cryopreserving, and storing PBSCs exceeded $20,000 per person, with more than $6700 spent on unused PBSCs for a second ASCT. A more recent analysis from 2016 underscored the declining need for salvage ASCT, with less than 10% of patients using stored PBSC grafts over a decade. Methods: To address the dilemma of whether backup stem cells remain necessary for myeloma patients, the study investigated strategies to reduce the financial burden of PBSC collection, processing, and storage. It evaluated MM patients undergoing frontline ASCT from January 2012 to June 2022, excluding those with planned tandem transplants and those who had a single ASCT with no stored cells. Discussion: Among the 240 patients studied, the median age at PBSC collection was 61. Notably, only 7% underwent salvage ASCT, with nearly 90% of salvage ASCT recipients being ≤ 61 years old at the time of initial ASCT. The study revealed a decreasing trend in salvage ASCT use with increasing age, suggesting that PBSC collection for a single transplant among elderly patients (>60 years old) could be a cost-effective alternative. Most transplant centers aimed to collect 10 × 106 CD34 + cells/kg, with patients over 65 often requiring multiple collection days. Shifting towards single-transplant collections among the elderly could reduce costs and resource requirements. Additionally, the study recommended implementing strategies for excess PBSC disposal or repurposing on the collection day to avoid additional storage costs. In summary, the decreasing utilization of salvage ASCT in MM, alongside financial considerations, underscores the need for revised stem cell collection policies. Conclusions: The study advocates considering single-transplant PBSC collections for elderly patients and efficient management of excess PBSCs to optimize resource utilization.

Low-dose anti-thymocyte globulin plus low-dose posttransplant cyclophosphamide-based regimen for prevention of graft-versus-host disease in haploidentical peripheral blood stem cell transplantation for pediatric patients with hematologic malignancies.

The low-dose anti-thymocyte globulin (ATG) plus low-dose post transplantation cyclophosphamide (PTCy) -based (low-dose ATG/PTCy-based) regimen had a promising activity in preventing of graft-versus-host disease (GVHD) in adult patients. However, its efficacy in pediatric patients remain to be defined. Here, we presented the findings from 35 pediatric patients undergoing haploidentical peripheral blood stem cell transplantation (haplo-PBSCT) with the new regimen for GVHD prophylaxis. The cumulative incidences (CIs) of grades II-III and III-IV acute GVHD (aGVHD) were 34% (95% CI, 17-48%) and 11% (95% CI, 0-21%) within 180 days post-transplantation, respectively. The CIs of chronic GVHD (cGVHD) and moderate-to-severe cGVHD within 2 years were 26% (95% CI, 7-41%) and 12% (95% CI, 0-25%), respectively. The 2-year probabilities of overall survival, relapse-free survival, and graft-versus-host disease and relapse-free survival were 89% (95% CI, 78-100%), 82% (95% CI, 68-98%) and 59% (95% CI, 43-80%), respectively. The CIs of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) reactivation by day 180 were 37% (95% CI, 19-51%) and 20% (95% CI, 6-32%) respectively. These results strongly advocate for the efficacy of the low-dose ATG/PTCy-based regimen as a robust strategy for GVHD prevention in haplo-PBSCT for pediatric patients.

Clonal Hematopoiesis and Therapy-Related Myeloid Neoplasms After Autologous Transplant for Hodgkin Lymphoma.

Therapy-related myeloid neoplasm (t-MN) is a life-threatening complication of autologous peripheral blood stem cell transplantation (aPBSCT) for Hodgkin lymphoma (HL). Although previous studies have reported an association between clonal hematopoiesis (CH) in the infused PBSC product and subsequent post-aPBSCT risk of t-MN in patients with non-HL, information about patients with HL treated with aPBSCT is not available. We constructed a retrospective cohort of 321 patients with HL transplanted at a median age of 34 years (range, 18-71). Targeted DNA sequencing of PBSC products performed for CH-associated or myeloid malignancy-associated genes identified pathogenic mutations in these patients. CH was identified in the PBSC product of 46 patients (14.3%) with most prominent representation of DNMT3A (n = 25), PPM1D (n = 7), TET2 (n = 7), and TP53 (n = 5) mutations. Presence of CH in the PBSC product was an independent predictor of t-MN (adjusted hazard ratio [aHR], 4.50 [95% CI, 1.54 to 13.19]). Notably all patients with TP53 mutations in the PBSC product developed t-MN, whereas none of the patients with DNMT3A mutations alone (without co-occurring TP53 or PPM1D mutations) did. Presence of TP53 and/or PPM1D mutations was associated with a 7.29-fold higher hazard of t-MN when compared with individuals carrying no CH mutations (95% CI, 1.72 to 30.94). The presence of TP53 and/or PPM1D mutations was also associated with a 4.17-fold higher hazard of nonrelapse mortality (95% CI, 1.25 to 13.87). There was no association between CH and relapse-related mortality. The presence of TP53 and/or PPM1D mutations in the PBSC product increases the risk of post-aPBSCT t-MN and nonrelapse mortality among patients with HL and may support alternative therapeutic strategies.

In-Vitro Proliferation and Enrichment of CD34+ Autologous Haematopoietic Stem Cells, Obtained from Patients with End-Stage Left Ventricular Failure

With a rising global prevalence of end-stage heart failure and a limited availability of cardiac transplantation programmes or left ventricular assist devices in many parts of the world, there is a renewed interest in potential alternative treatment options.Along with other groups, we have previously demonstrated the beneficial effect of intracoronary autologous bone marrow derived peripheral haemopoietic stem cell transplantation, to improve myocardial contractility in end-stage heart failure.We now assess the ability of these cells to expand in numbers in-vitro, to achieve enrichment of stem cell counts, using standard cell culture methods and flow- cytometric analysis.We demonstrate that with in-vitro culturing (within 3 passages post-harvest), the CD34+ stem cell fraction increases in standard culture media, across multiple samples. However, optimal culture conditions to achieve near pure stem cell populations with rapid cell proliferation, still needs to be defined.

Predictive model of the efficiency of hematopoietic stem cell collection in patients with multiple myeloma and lymphoma based on multiple peripheral blood markers.

Autologous hematopoietic stem cell transplantation (ASCT) has gained extensive application in the treatment of lymphoma and multiple myeloma (MM). Plenty of studies demonstrate that peripheral blood indicators could be considered potential predictive biomarkers for hematopoietic stem cells (HSCs) collection efficiency, including white blood cell count (WBC), monocyte count (Mono), platelet count (PLT), hematocrit, and hemoglobin levels. Currently, clinically practical predictive models based on these peripheral detection indicators to quickly, conveniently, and accurately predict collection efficiency are lacking. In total, 139 patients with MM and lymphoma undergoing mobilization and collection of ASCT were retrospectively studied. The study endpoint was successful collection of autologous HSCs. We analyzed the effects of clinical characteristics and peripheral blood markers on collection success, and screened variables to establish a prediction model. We determined the optimal cutoff value of peripheral blood markers for predicting successful stem cell collection and the clinical value of a multi-marker prediction approach. We also established a prediction model for collection efficacy. Univariate and multivariate logistic regression analyses showed that the mobilization regimen, Mono, PLT, mononuclear cell count (MNC), and peripheral blood CD34+ cell count (PB CD34+ counts) were significant predictors of successful collection of peripheral blood stem cells (PBSC). Two predictive models were constructed based on the results of multivariate logistic analyses. Model 1 included the mobilization regimen, Mono, PLT, and MNC, whereas Model 2 included the mobilization regimen, Mono, PLT, MNC, and PB CD34+ counts. Receiver operating characteristic (ROC) curve analysis showed that the PB CD34+ counts, Model 1, and Model 2 could predict successful HSCs collection, with cutoff values of 26.92 × 106/L, 0.548, and 0.355, respectively. Model 1 could predict successful HSCs collection with a sensitivity of 84.62%, specificity of 75.73%, and area under the curve (AUC) of 0.863. Model 2 could predict successful HSCs collection with a sensitivity of 83.52%, specificity of 94.17%, and AUC of 0.946; thus, it was superior to the PB CD34+ counts alone. Our findings suggest that the combination of the mobilization regimen, Mono, PLT, MNC, and PB CD34+ counts before collection has predictive value for the efficacy of autologous HSCs collection in patients with MM and lymphoma. Using models based on these predictive markers may help to avoid over-collection and improve patient outcomes.

Azacitidine combined with interferon-α for pre-emptive treatment of AML/MDS after allogeneic peripheral blood stem cell transplantation: A prospective phase II study.

This prospective clinical study aimed to evaluate the efficacy and safety of the pre-emptive treatment modality of azacitidine in combination with interferon-α (IFN-α) in AML/MDS patients post-transplantation. Forty-seven patients aged 17-62 were enrolled with 14 patients having completed the planned 12 cycles. Following initiation, 72.3% responded positively after the first cycle, peaking at 77.2% by the fifth cycle. Notably, 24 patients maintained sustained responses throughout a median follow-up of 1050 days (range, 866-1234). Overall survival, leukaemia-free survival and event-free survival probabilities at 3 years were 69.5%, 60.4% and 35.7% respectively. Cumulative incidences of relapse and non-relapse mortality were 36.5% and 4.3% respectively. Multivariate analysis identified that receiving pre-emptive treatment for fewer than six cycles and the absence of chronic graft-versus-host disease after intervention was significantly associated with poorer clinical outcomes. The combination of azacitidine with IFN-α was well-tolerated with no observed severe myelotoxicity, and the majority of adverse events were reversible and manageable. In conclusion, the use of azacitidine in conjunction with IFN-α as pre-emptive therapy is a safe and effective treatment to prevent disease progression in AML/MDS patients with MRD positivity post-allo-HSCT.

Chondral regeneration in femoroacetabular lesions is favoured using peripheral blood stem cells with hyaluronan-based scaffold and micro-drilling: A prospective cohort study.

To determine whether intra-articular injections of peripheral blood stem cells (PBSC) with hyaluronan (HA)-based scaffold improve articular cartilage regeneration in chondral injuries caused by mixed-femoroacetabular impingement syndrome (FAIS) over a period longer than 24 months post-hip arthroscopy. In this prospective cohort study, patients with mixed-FAIS and chondral injury ≥ IIIB according to the International Cartilage Regeneration and Joint Preservation Society grade or III/IV of Konan/Haddad classification underwent intra-articular injection of PBSC with an HA-based scaffold and micro-drillings during hip arthroscopy. The degree of chondral repair was measured at baseline and 5 years using the International Cartilage Repair Society morphologic score system (MSS) as the primary outcome. Pain was measured at baseline and 5 years using the Visual Analogue Scale for Pain (VAS Pain), and hip functionality was measured at baseline (presurgery), 6 months, 1 year, and 5 years using the Hip Outcome Score (HOS). The largest diameter of injury, median follow-up, side effects, complications, and improvements were described. T-test, ANOVA with multiple comparisons, and statistical power were estimated. From initially 34 cases, 25 patients were enrolled. The median follow-up was 5.1 ± 0.3 years. One patient (4%) reported a few side effects with filgrastim administration. No infection, tumours, or synovitis was reported. The largest diameters in zones two, three, and four were 12.4 ± 3.1 mm (n = 8), 13.5 ± 2.8 mm (n = 14), and 11.4 ± 1.9 mm (n = 3), respectively. Ninety-two percent (23/25) of patients improved their outcomes. The MSS and HOS increased from 3.8 ± 1.1 to 9.6 ± 1.5 pts (p < 0.001) and from 65.5 ± 13.0 to 93.9 ± 2.4 pts (p < 0.001), respectively. The VAS-Pain decreased from 5.3 ± 0.7 to 1.3 ± 0.6 mm (p < 0.001). The obtained a posteriori power-size was 0.99. The intervention suggests a favourable impact on articular cartilage regeneration and clinical outcomes for hip chondral lesions in mixed-FAIS injuries after a median follow-up of 5.1 ± 0.3 years. Level IV.

A retrospective study on the efficacy of pegfilgrastim-filgrastim combination regimen in the mobilization for autologous stem cell transplantation in lymphoma patients

BackgroundThe high mobilization failure rate with the mobilization strategy of combining chemotherapy and filgrastim (rhG-CSF) in autologous hematopoietic stem cell transplantation (auto-HSCT) in lymphomas is one of the unresolved issues. Whether the combination of polyethylene glycol filgrastim [pegfilgrastim (PEG-FIL), PEG-rhG-CSF] and filgrastim (FIL) improves the mobilization success rate and the timing of combination therapy has not been studied. Methods107 lymphoma patients who received auto-HSCT were retrospectively enrolled and divided into groups of PEG+FIL and FIL. The group of PEG+FIL received pegfilgrastim (9 mg) on the third day of the chemotherapy, followed by filgrastim (10 μg/kg/day) based on the counts of peripheral blood stem cells (PBSC). The group of FIL received filgrastim 10 μg /kg/day depending on the number of PBSCs. ResultsThe incidence of neutropenic fever in the group of PEG+FIL was significantly lower than in the group of FIL. The mean recovery time of leukocytes at autologous stem cell transplantation was significantly shorter in the group of PEG+FIL than in the group of FIL. Compared to the groups of FIL, the group of PEG+FIL had lower hospitalization costs. We found that the combination therapy is more recommended for patients with a bone marrow hematopoietic area of less than 30 %. Filgrastim is best administered 5–6 days after pegfilgrastim administration. ConclusionsCompared to conventional filgrastim mobilization, the combination of pegfilgrastim and filgrastim schedule has high efficacy, non-inferior safety, and superior health economic benefits during auto-HSCT.

Dinutuximab-beta after autologous peripheral blood stem cell transplantation improved event-free survival of newly diagnosed children with high-risk neuroblastoma but overall survival remains unchanged: Saudi Arabia's multi-institutional experiences

Dinutuximab-beta after autologous peripheral blood stem cell transplantation improved event-free survival of newly diagnosed children with high-risk neuroblastoma but overall survival remains unchanged: Saudi Arabia's multi-institutional experiences

Allogeneic Hematopoietic Cell Transplant For Bone Marrow Failure or Myelodysplastic Syndrome in Dyskeratosis Congenita/Telomere Biology Disorders: Single-Center, Single-Arm, Open-Label Trial of Reduced-Intensity Conditioning Without Radiation

BackgroundDyskeratosis congenita/Telomere biology disorders (DC/TBD) often manifest as bone marrow failure (BMF) or myelodysplastic syndrome (MDS). Allogeneic hematopoietic cell transplant (alloHCT) rescues hematologic complications, but radiation and alkylator-based conditioning regimens cause diffuse whole-body toxicity and may expedite DC/TBD-specific non-hematopoietic complications. Optimization of conditioning intensity in DC/TBD to allow for donor hematopoietic cell engraftment with the least amount of toxicity remains a critical goal of the alloHCT field. Objectives/Study DesignWe report prospectively collected standard alloHCT outcomes from a single-center single-arm open-label clinical trial of bone marrow or peripheral blood stem cell alloHCT for DC/TBD-associated BMF or MDS. Conditioning was reduced intensity (RIC) including alemtuzumab 1mg/kg, fludarabine 200 mg/m2, and cyclophosphamide 50 mg/kg. A previous single-arm open-label phase II clinical trial for the same patient population conducted at the same center, differing only by inclusion of 200 centigray of total body irradiation (TBI), served as a control cohort. ResultsThe Non-TBI cohort included 10 patients (ages 1.7-65.9 years, median follow-up of 3.9 years) compared to the control TBI cohort which included 12 patients (ages 2.2-52.2 years, median follow-up of 10.5 years). Baseline characteristics differed only in total CD34+ cells received, with a median of 5.6 (Non-TBI) compared to 2.6 (TBI) x 106/kg (p=0.02; no difference in total nucleated cells). The cumulative incidence of day +100 grade II-IV acute and 4-year chronic graft-versus-host disease (GvHD) were low at 0 and 10% (Non-TBI) and 8 and 17% (TBI), respectively (acute, p=0.36; chronic, p=0.72). Primary graft failure was absent. Secondary non-neutropenic graft failure occurred in one (Non-TBI cohort). The Non-TBI cohort demonstrated delayed achievement of full donor chimerism but superior lymphocyte recovery. There was no difference in 4-year overall survival at 80% (Non-TBI) and 75% (TBI; p=0.78).MDS as an indication for alloHCT was uncommon, but overall associated with poor outcomes. There were 3 MDS patients in the Non-TBI cohort: 1 relapsed and died at day+387; 1 relapsed at day+500 and is alive 5.5 years later following salvage with a 2nd alloHCT; 1 relapsed at day+1093 and is alive at day +100 after a 2nd alloHCT. There was 1 MDS patient in the TBI cohort who achieved 100% donor myeloid engraftment without relapse but died at day+827 from a bacterial infection in the setting of immune mediated cytopenia. ConclusionElimination of TBI from the RIC regimen for DC/TBD was not associated with significant changes in rates of graft failure, GvHD, and overall survival, but was associated with delayed achievement of full donor chimerism and improved lymphocyte reconstitution. For DC/TBD-associated BMF, TBI appears to be dispensable. Optimal approaches to DC/TBD-associated MDS remain unclear. Larger cohorts are needed to better assess the unique contribution of TBI and donor CD34+ cell dose. Longer follow-up is required to assess differences in DC/TBD complications and late effects.

Autologous Peripheral Blood Stem Cell Transplantation and Timing of Local Radiation Therapy in Patients With Malignant Lymphoma: Results of the Japanese Radiation Oncology Study Group Questionnaire Survey.

Malignant lymphoma (ML) including Hodgkin's lymphoma and non-Hodgkin's lymphoma is often treated with local radiation therapy (RT) in combination with autologous hematopoietic stem cell transplantation (ASCT) to prevent relapse; however, the efficacy and optimal timing of this approach is unclear. In this study, a national survey conducted by the Japanese Radiation Oncology Study Group reviewed ML cases from 2011 to 2019 to determine whether RT should be added to ASCT, focusing on the use of autologous peripheral blood stem cell transplantation (auto-PBSCT), a predominant form of ASCT. The survey encompassed 92 patients from 11 institutes, and assessed histological ML types, treatment regimens, timing of RT relative to auto-PBSCT, and associated adverse events. The results indicated no significant differences in adverse events, including myelosuppression, based on the timing of RT in relation to auto-PBSCT. However, anemia was more prevalent when RT was administered before auto-PBSCT, and there was a higher incidence of neutropenia recovery delay in patients receiving RT after auto-PBSCT. This study provides valuable insights into the variable practices of auto-PBSCT and local RT in ML treatment, emphasizing the need for optimized timing of these therapies to improve patient outcomes and reduce complications.

Surgical treatment of appendiceal mucormycosis in an immunocompromised patient: a case report

BackgroundGastrointestinal mucormycosis is a rapidly progressing and often fatal disease, predominantly affecting immunocompromised patients. Surgical intervention, in addition to antifungal therapy, is essential. Herein, we describe the successful management of appendiceal mucormycosis in a patient with acute promyelocytic leukemia through rapid surgical intervention and antifungal therapy.Case presentationA 29-year-old woman underwent autologous peripheral blood stem cell transplantation for acute promyelocytic leukemia (APL). Subsequently, her condition relapsed, and remission induction therapy was initiated. During the immunosuppressive period, she developed a fever and severe abdominal pain. Computed tomography revealed severe edema of the ileum, cecum, and ascending colon. Despite receiving multiple antibiotics, antivirals, and antifungals, her condition showed no improvement. Consequently, she underwent exploratory laparotomy, with no bowel perforation noted, revealing severe inflammation in the ileum, cecum, and ascending colon, as well as appendiceal necrosis. Appendectomy was performed, and histopathological analysis revealed hyphae in the vessels and layers of the appendiceal wall, suggestive of mucormycosis. The patient was diagnosed with appendiceal mucormycosis, and liposomal amphotericin B was administered. Subsequent monitoring showed no recurrence of mucormycosis. Genetic analysis of the resected tissue revealed Rhizopus microspores as the causative agent.ConclusionsRapid surgical intervention and antifungal drug administration proved successful in managing appendiceal mucormycosis in a patient with APL. Early recognition and aggressive surgical intervention are imperative to improve outcomes in such patients.

Construction of a digital twin of chronic graft vs. host disease patients with standard of care

There is an unmet medical need for new clinical trials to evaluate novel therapies in chronic graft-versus-host disease (cGvHD). Disease rarity, ethical issues regarding placebo arms, time, and cost impede clinical trial conduct. Digital twin (DT) technology enables virtual clinical trial arm construction using historical data, circumventing these obstacles. We evaluated the feasibility of constructing a DT trial arm using a large database of real-world clinical trial data and performed an efficacy assessment of a standard-of-care (SOC) drug to examine agreement with literature data. We constructed a flGvHD DT cohort (cGvHD patients at first-line treatment) (2042 patients; 32 cohorts) using the Trial Accelerator™ Digital Twin platform and derived an SOC arm from this cohort (flGvHD DT SOC cohort) (438 patients; eight cohorts); we analyzed the efficacy of SOC (prednisone) (overall response rate (ORR)) at six months. Our analysis results are in agreement with literature: flGvHD DT: disease onset time: 7.58 months post-allogeneic hematopoietic cell transplantation; most used graft source: peripheral blood stem cells; flGvHD DT SOC: ORR at six months for prednisone: 52.7%. It is feasible to construct a DT cohort using existing clinical trial data; a DT SOC arm can potentially replace a control arm in clinical trials.

Dual T-cell depletion with individually tailored anti-thymocyte globulin and attenuated dose of post-transplant cyclophosphamide in haploidentical peripheral stem cell transplantation

This study aimed to assess the efficacy of dual T-cell suppression using individually tailored doses of antithymocyte globulin (ATG) and attenuated dose of post-transplant cyclophosphamide (PTCy) in haploidentical hematopoietic stem cell transplantation (haplo-HSCT). We conducted a retrospective analysis of 78 adults with acute leukemia or myelodysplastic syndrome who underwent haplo-HSCT using intravenous busulfan and fludarabine conditioning. Thirty-two patients received attenuated ATG/PTCy, while 46 patients received ATG (7.5 mg/kg) as GVHD prophylaxis. The 100-day cumulative incidence of grade III-IV (9.7% vs. 32.4%, P = 0.018) acute GVHD, as well as 2-year moderate-severe chronic GVHD (13.9% vs. 43.9%, P = 0.018) in the ATG/PTCy group were significantly lower than those in the ATG group. The 2-year overall survival was comparable between the two groups. However, 2-year GVHD-free, relapse-free survival in the ATG/PTCy group was significantly higher compared to that in the ATG group (38.9% vs. 21.7%, P = 0.021). Moreover, during post-engraftment period, the ATG/PTCy group exhibited lower incidences of life-threatening bacterial (12.5% vs. 37%, P = 0.033) and viral infection (0% vs. 17.4%, P = 0.035) than the ATG group. In conclusion, the combination of individually tailored ATG and low-dose PTCy appears to be a promising strategy in haplo-HSCT.

Superiority of BM over PBSC for recipients with pre-transplant lung dysfunction in HLA-matched allogeneic HCT

Background aimsPre-transplant lung dysfunction is known to be a risk factor for non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (allo-HCT). It is unclear which cell source gives better outcomes for patients with pulmonary dysfunction. MethodsWe analyzed 3289 adult patients with standard-risk disease who had received HLA-matched allo-HCT, and compared outcomes between those who received peripheral blood stem cell (PBSC) vs. bone marrow (BM) in two cohorts based on the presence of a lung score by the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI): the Lung-scored (LS) and non-LS cohorts. ResultsIn the LS cohort, the 2-year overall survival (OS) in the BM group tended to be higher than that in the PBSC group (72.4% vs. 61.4%; P = 0.044). In the non-LS cohort, there was no significant difference between the two groups (71.7% vs. 73.2%; P = 0.13). Multivariate analyses confirmed that PBSC was significantly associated with inferior OS in the LS cohort (hazard ratio [HR], 1.66; 95% CI, 1.09-2.54; P = 0.019). On the other hand, the cell source did not affect OS in the non-LS cohort (HR, 0.92; 95% CI, 0.76-1.12; P = 0.41). We found that PBSC was associated with an increased risk of NRM in the LS cohort (HR, 2.17; 95% CI, 1.16-4.05; P = 0.016), while the cell source did not significantly affect NRM in the non-LS cohort. PBSC was not identified as a risk factor for relapse in either cohort. ConclusionsOur results suggest that BM might be beneficial for recipients with lung dysfunction in HLA-matched allo-HCT.

Single Apheresis Session on the 4th Day of Granulocyte Colony-Stimulating Factor Administration Seems Convenient to Collect Enough Peripheral Blood Stem Cells from Healthy Donors

Background: To minimize adverse events of peripheral blood stem cell (PBSC) collection in healthy donors, it is reasonable to limit the total dose of granulocyte colony-stimulating factor (G-CSF) and/or the number of apheresis days without decreasing of PBSCs yield. Therefore, we have started to collect G-CSF induced PBSCs on day 4 instead of on day 5. So, we retrospectively aimed to investigate the results of this 4-day G-CSF administration. Study Design and Methods: Seventy-six healthy donors who performed on G-CSF induced PBSCs donation consecutively between January 2020 and July 2022 were included in this study. G-CSF (filgrastim) at 2 × 5 µg/kg/day subcutaneously was applied. Apheresis started on day 4. Results: Sixty-nine (90.8%) of 76 donors provided enough PBSCs on day 4 apheresis session. Younger age (p = 0.004), higher PB CD34+ cell count on the 4th day of G-CSF (p < 0.001), and male donor (p = 0.010) were correlated with increased amounts of PBSCs yield. Univariate and multivariate logistic regression analyses to predict very good mobilizers (collected PBSCs ≥8 × 106/kg after the first apheresis) were performed. In multivariate logistic regression analyses, male sex (p = 0.004), PB CD34+ cell count ≥100/µL on the 4th day of G-CSF (p < 0.001), and glomerular filtration rate ≥115 mL/min (p = 0.031) were found to be independent predicting factors to demonstrate very good mobilizer. Conclusion: It seems that starting the apheresis on the 4th day of G-CSF administration is effective and to provide minimal G-CSF exposure in healthy donors.

Shorter donor leukocyte telomere length is associated with poor peripheral blood stem cell mobilization induced by granulocyte colony-stimulating factor

Background/purposeInsufficient numbers of peripheral blood stem cells (PBSC) after granulocyte colony-stimulating factor (G-CSF) mobilization occurs in a significant proportion of PBSC collections, often from older age donors. Telomere length (TL) is often used as an indicator of an individual's biological age. This study aimed to investigate the relationship between donors' leukocyte TL and the outcome of G–CSF–induced PBSC mobilization in healthy unrelated donors. MethodsDonors’ leukocyte TLs and the outcome of G–CSF–induced PBSC mobilization, as assessed by pre-harvest CD34+ cell counts, were analyzed in 39 healthy PBSC donors. TL in a non-mobilized general population (n = 90) was included as a control group. G-CSF mobilization effect was categorized into three groups according to pre-harvest CD34+ cell count: poor (≤25/μL, PMD), intermediate (between 25 and 180/μL), and good (≥180/μl, GMD). ResultsLeukocyte TL of PBSC donors correlated well with pre-harvest CD34+ cell counts (r = 0.645, p < 0.001). Leukocyte TLs of PMDs (n = 8) were significantly shorter than those of GMDs (n = 9) and non-mobilization controls (p < 0.05). Moreover, all PMD TLs were below the 50th percentile, and 62.5% of PMDs had TLs below the 10th percentile of age-matched control participants. In contrast, no GMD TLs were below the 10th percentile; in fact, 33.3% (3/9) of them were above the 90th percentile. ConclusionOur results indicate that shorter donor leukocyte TL is associated with poor G–CSF–induced PBSC mobilization. TL, which represents a donor's biological age, could be a potential predictor for mobilization outcome.

Post-transplant cyclophosphamide-based graft-versus-host disease prophylaxis following mismatched unrelated donor peripheral blood stem cell (PBSC) transplantation.

6503 Background: Our prior prospective multi-center clinical trial (15-MMUD; NCT02793544) estimated 79% overall survival (OS) at one year in adult patients with hematological malignancies undergoing reduced intensity conditioning (RIC), receiving bone marrow (BM) grafts from HLA-mismatched unrelated donors (MMUD), and post-transplant cyclophosphamide (PTCy)-based graft- versus-host disease (GVHD) prophylaxis (Shaw et al, J Clin Oncol 2021). We sought to determine whether OS in adults receiving mobilized PBSC from MMUD would be comparable. Methods: We conducted a prospective, multi-center Phase II study (ACCESS; NCT04904588) to assess the impact of PTCy-based GVHD prophylaxis on OS following MMUD transplantation in adults and children with advanced hematological malignancies. The study included three strata: two for adults based on conditioning regimen intensity [myeloablative (MAC) or RIC] using PBSC, and one pediatric cohort using MAC and BM. Eligible donors were matched at 4-7/8 HLA-loci (HLA -A, -B, -C, and -DRB1) and &lt; 35 years. The primary endpoint was OS at one year following transplantation. We report the results of a planned interim analysis of the first 70 adult patients enrolled on the RIC PBSC stratum. Results: Thirteen sites enrolled 70 patients with the following demographics: median age of 65 years (range 24-77); 50% male; diagnoses: AML (53%), MDS (26%), ALL (7%), other heme malignancies (14%); and patient race/ethnicity: non-Hispanic white (48%). Donor characteristics included: median age 25y (range 18-35); male (44%); and HLA match level: 7/8: 67%; 6/8: 27%; 5/8: 6%. Conditioning regimens included fludarabine (flu) and melphalan (63%), flu/busulfan (20%), other (17%). OS at one year post HCT was 79% (95% confidence interval (CI): 68-87%). Secondary endpoints are provided in the table. Conclusions: Encouraging OS was observed at one year following MMUD PBSC in patients receiving RIC and PTCy. Notably, half of enrolled patients were people of color. OS was similar to our prior study using BM grafts. Rates of GVHD and other complications appear comparable to those in HLA-matched donor recipients, suggesting MMUD HCT could expand access to a potentially life-saving therapy. Accrual to both adult strata of ACCESS is complete, with over 200 patients in follow-up. Accrual to the pediatric stratum continues. Clinical trial information: NCT04904588 . [Table: see text]