Up-front autologous stem cell transplant in peripheral T-cell lymphoma patients achieving complete response after first-line treatment: A multicentre real-world analysis.

We conducted a retrospective, multicentre study to compare consolidation therapy with or without first-line autologous stem cell transplant (ASCT) for peripheral T-cell lymphoma (PTCL) patients in a real-world setting. We enrolled 347 PTCL patients who achieved complete response after first-line treatment. Of these, 257 received consolidation chemotherapy (non-ASCT group) and 90 received ASCT (ASCT group). Clinical outcomes were comparable between ASCT and non-ASCT groups. After propensity score matching, the 2-year cumulative incidence of treatment-related mortality and relapse remained similar between groups (1.9% vs. 2.0%, p = 0.985; 24.7% vs. 47.1%, p = 0.021). However, significant differences emerged in progression-free survival and overall survival probabilities. Within the T-cell lymphoma subgroup, ASCT patients exhibited favourable outcomes compared to non-ASCT patients: 2-year progression-free survival (73.4% vs. 50.8%, p = 0.024) and overall survival (92.1% vs. 73.5%, p = 0.021). Notably, no significant differences were observed for patients with NK/T-cell lymphoma. These real-world data suggest that up-front ASCT is a safe and effective consolidation option for PTCL patients in remission, particularly those with T-cell lymphoma.

Allogeneic haematopoietic stem cell transplantation for adult T-lymphoblastic lymphoma: A real-world multicentre analysis in China.

In this multicentre, real-world study, we aimed to identify the clinical outcomes and safety of allogeneic haematopoietic stem cell transplantation (allo-HSCT) in T-lymphoblastic lymphoma (T-LBL). A total of 130 Ann Arbor stage III or IV T-LBL patients (>16 years) treated with allo-HSCT across five transplant centres were enrolled. The 2-year cumulative incidence of disease progression, the probabilities of progression-free survival (PFS), overall survival (OS) and non-relapse mortality (NRM) after allo-HSCT were 21.0%, 69.8%, 79.5% and 9.2% respectively. Patients with central nervous system (CNS) involvement had a higher cumulative incidence of disease progression compared with those without CNS involvement (57.1% vs. 18.9%, HR 3.78, p = 0.014). Patients receiving allo-HSCT in non-remission (NR) had a poorer PFS compared with those receiving allo-HSCT in complete remission (CR) or partial remission (49.2% vs. 72.7%, HR 2.21, p = 0.041). Particularly for patients with bone marrow involvement and achieving CR before allo-HSCT, measurable residual disease (MRD) positivity before allo-HSCT was associated with a poorer PFS compared with MRD negativity (62.7% vs. 86.8%, HR 1.94, p = 0.036). On multivariate analysis, CNS involvement at diagnosis and receiving allo-HSCT in NR were associated with disease progression. Thus, our real-world data suggested that allo-HSCT appeared to be an effective therapy for adult T-LBL patients with Ann Arbor stage III or IV disease.

Recent infection with SARS-CoV-2 in donors was associated with a higher incidence of acute graft-versus-host disease in recipients undergoing allogeneic haematopoietic stem cell transplantation.

The global pandemic has resulted in the common occurrence of SARS-CoV-2 infection in the population. In the post-pandemic era, it is imperative to understand the influence of donor SARS-CoV-2 infection on outcomes after allogeneic haematopoietic stem cell transplantation (allo-HSCT). We retrospectively analysed allo-HSCTs from donors with mild SARS-CoV-2 infection or early recovery stage (ERS) (group 1, n = 65) and late recovery stage (group 2, n = 120). Additionally, we included allo-HSCT from donors without prior SARS-CoV-2 infection as group 0 (n = 194). Transplants from donors with different SARS-CoV-2 infection status had comparable primary engraftment and survival rates. However, group 1 had higher incidences of acute graft-versus-host disease (aGvHD), grade II-IV (41.5% vs. 28.1% in group 0 [p = 0.014] and 30.6% in group 2 [p = 0.067]) and grade III-IV (22.2% vs. 9.6% [p = 0.004] in group 0 and 12.2% in group 2 [p = 0.049]). Conversely, the risk of aGvHD in group 2 was similar to that in group 0 (p > 0.5). Multivariable analysis identified group 1 associated with grade II-IV (hazard ratio [HR] 2.307, p = 0.010) and grade III-IV (HR 2.962, p = 0.001) aGvHD, which yielded no significant risk factors for survival. In conclusion, we preliminarily demonstrated donors in the active infection state or ERS of mild SARS-CoV-2 infection were associated with higher incidences of aGvHD in transplants from related donors.

Mesenchymal stromal cells plus basiliximab improve the response of steroid-refractory acute graft-versus-host disease as a second-line therapy: a multicentre, randomized, controlled trial.

BACKGROUND: For patients with steroid-refractory acute graft-versus-host disease (SR-aGVHD), effective second-line regimens are urgently needed. Mesenchymal stromal cells (MSCs) have been used as salvage regimens for SR-aGVHD in the past. However, clinical trials and an overall understanding of the molecular mechanisms of MSCs combined with basiliximab for SR-aGVHD are limited, especially in haploidentical haemopoietic stem cell transplantation (HID HSCT). METHODS: The primary endpoint of this multicentre, randomized, controlled trial was the 4-week complete response (CR) rate of SR-aGVHD. A total of 130 patients with SR-aGVHD were assigned in a 1:1 randomization schedule to the MSC group (receiving basiliximab plus MSCs) or control group (receiving basiliximab alone) (NCT04738981). RESULTS: Most enrolled patients (96.2%) received HID HSCT. The 4-week CR rate of SR-aGVHD in the MSC group was obviously better than that in the control group (83.1% vs. 55.4%, P = 0.001). However, for the overall response rates at week 4, the two groups were comparable. More patients in the control group used ≥ 6 doses of basiliximab (4.6% vs. 20%, P = 0.008). We collected blood samples from 19 consecutive patients and evaluated MSC-derived immunosuppressive cytokines, including HO1, GAL1, GAL9, TNFIA6, PGE2, PDL1, TGF-ß and HGF. Compared to the levels before MSC infusion, the HO1 (P = 0.0072) and TGF-ß (P = 0.0243) levels increased significantly 1 day after MSC infusion. At 7 days after MSC infusion, the levels of HO1, GAL1, TNFIA6 and TGF-ß tended to increase; however, the differences were not statistically significant. Although the 52-week cumulative incidence of cGVHD in the MSC group was comparable to that in the control group, fewer patients in the MSC group developed cGVHD involving ≥3 organs (14.3% vs. 43.6%, P = 0.006). MSCs were well tolerated, no infusion-related adverse events (AEs) occurred and other AEs were also comparable between the two groups. However, patients with malignant haematological diseases in the MSC group had a higher 52-week disease-free survival rate than those in the control group (84.8% vs. 65.9%, P = 0.031). CONCLUSIONS: For SR-aGVHD after allo-HSCT, especially HID HSCT, the combination of MSCs and basiliximab as the second-line therapy led to significantly better 4-week CR rates than basiliximab alone. The addition of MSCs not only did not increase toxicity but also provided a survival benefit.

Clinical characteristics and outcomes of allogeneic hematopoietic stem cell transplantation recipients with coronavirus disease 2019 caused by the Omicron variant: a prospective, observational cohort study.

We aimed to describe the clinical characteristics, particularly the occurrence and risk factors of severe/critical illness, in allogeneic hematopoietic stem cell (allo-HSCT) recipients infected with coronavirus disease 2019 (COVID-19) caused by Omicron variant in an observational prospective study (n = 311). The median time from allo-HSCT to COVID-19 diagnosis was 8.5 months (range 0.8-106.1) months. Four patients (1.3%) were reported to be asymptomatic during Omicron variant infection, and 135 (43.4%) patients showed lower respiratory tract disease. Thirty-four (10.9%) patients were categorized into serious infection (severe illness n = 25; critical illness n = 9) and the median duration from COVID-19 diagnosis to serious infections was 6 days (range, 0-29) days. Thirteen (4.2%) and 6 (1.9%) patients required intensive care unit care and invasive mechanical ventilation, respectively. Receiving more than 1 type of immunosuppressive therapies at COVID-19 diagnosis was associated with severity and persistence of infection. Six patients (1.9%) died after diagnosis of COVID-19 infection. The 4-week probability of overall survival after COVID-19 diagnosis was 98.7%, which was 100% and 88.2% for non-serious and serious infection group (P < 0.001), respectively. Thus, we observed a relatively low serious infection and mortality rate in allo-HSCT recipients infected with COVID-19 caused by Omicron variant.

Clinical manifestations, prognostic factors, and outcomes of adenovirus pneumonia after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Severe pneumonia is one of the most important causes of mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Adenovirus (ADV) is a significant cause of severe viral pneumonia after allo-HSCT, and we aimed to identify the clinical manifestations, prognostic factors, and outcomes of ADV pneumonia after allo-HSCT. METHODS: Twenty-nine patients who underwent allo-HSCT at the Peking University Institute of Hematology and who experienced ADV pneumonia after allo-HSCT were enrolled in this study. The Kaplan-Meier method was used to estimate the probability of overall survival (OS). Potential prognostic factors for 100-day OS after ADV pneumonia were evaluated through univariate and multivariate Cox regression analyses. RESULTS: The incidence rate of ADV pneumonia after allo-HSCT was approximately 0.71%. The median time from allo-HSCT to the occurrence of ADV pneumonia was 99 days (range 17-609 days). The most common clinical manifestations were fever (86.2%), cough (34.5%) and dyspnea (31.0%). The 100-day probabilities of ADV-related mortality and OS were 40.4% (95% CI 21.1%-59.7%) and 40.5% (95% CI 25.2%-64.9%), respectively. Patients with low-level ADV DNAemia had lower ADV-related mortality and better OS than did those with high-level (≥ 106 copies/ml in plasma) ADV DNAemia. According to the multivariate analysis, high-level ADV DNAemia was the only risk factor for intensive care unit admission, invasive mechanical ventilation, ADV-related mortality, and OS after ADV pneumonia. CONCLUSIONS: We first reported the prognostic factors and confirmed the poor outcomes of patients with ADV pneumonia after allo-HSCT. Patients with high-level ADV DNAemia should receive immediate and intensive therapy.

A predictive model of herpes zoster after allogeneic hematopoietic stem cell transplantation: VZV reactivation following antiviral prophylaxis discontinuation.

Herpes zoster (HZ) refers to the rash appearing on dermatomes due to varicella zoster virus (VZV) reactivation. The incidence of HZ is significantly higher in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients than in non-HSCT recipients. Although acyclovir prophylaxis is routinely administered to every allo-HSCT recipient for 1 year after transplantation, some individuals eventually develop late-onset HZ after completing prophylaxis. Little information is known about the clinical features of HZ after prophylactic antiviral treatment discontinuation, and an effective predictive model of late-onset HZ needs to be established. A total of 3366 patients who had received allo-HSCT from 2012 to 2017 were included in our study, among whom 201 developed HZ after 1 year (late-onset HZ). We designed a nested case-control study to identify potential predictors of late-onset HZ. Finally, we established a predictive model using binary logistic regression analysis. Age (p < .001), use of immunosuppressants at +1 year (p < .001), CD4-CD8 ratio at +1 year (p < .001), certain mental disorders (depression, anxiety, insomnia and adjustment disorder) (p < .001), engraftment time of neutrophils (p < .001), and CD8+ cell count at +30 days (p < .001) were independent predictors of late-onset HZ. A risk grading system was established based on regression coefficients. Discrimination and calibration analysis indicated that the model had good performance. We also identified several predictive factors of the incidence of HZ-related complications. This is the first scoring system for predicting the incidence of late-onset HZ after allo-HSCT. This model can be applied to identify individuals at high risk of late-onset HZ in the early period after receiving allo-HSCT.

Persistent high sepsis-induced coagulopathy and sequential organ failure assessment scores can predict the 28-day mortality of patients with sepsis: A prospective study.

BACKGROUND: The performance of the sepsis-induced coagulopathy (SIC) and sequential organ failure assessment (SOFA) scores in predicting the prognoses of patients with sepsis has been validated. This study aimed to investigate the time course of SIC and SOFA scores and their association with outcomes in patients with sepsis. METHODS: This prospective study enrolled 209 patients with sepsis admitted to the emergency department. The SIC and SOFA scores of the patients were assessed on days 1, 2, and 4. Patients were categorized into survivor or non-survivor groups based on their 28-day survival. We conducted a generalized estimating equation analysis to evaluate the time course of SIC and SOFA scores and the corresponding differences between the two groups. The predictive value of SIC and SOFA scores at different time points for sepsis prognosis was evaluated. RESULTS: In the non-survivor group, SIC and SOFA scores gradually increased during the first 4 days (P < 0.05). In the survivor group, the SIC and SOFA scores on day 2 were significantly higher than those on day 1 (P < 0.05); however, they decreased on day 4, dropping below the levels observed on day 1 (P < 0.05). The non-survivors showed higher SIC scores on days 2 (P < 0.05) and 4 (P < 0.001) than the survivors, whereas no significant differences were found between the two groups on day 1 (P > 0.05). The performance of SIC scores on day 4 for predicting mortality was more accurate than that on day 2, with areas under the curve of 0.749 (95% confidence interval [CI]: 0.674-0.823), and 0.601 (95% CI: 0.524-0.679), respectively. The SIC scores demonstrated comparable predictive accuracy for 28-day mortality to the SOFA scores on days 2 and 4. Cox proportional hazards models indicated that SIC on day 4 (hazard ratio [HR] = 3.736; 95% CI: 2.025-6.891) was an independent risk factor for 28-day mortality. CONCLUSIONS: The time course of SIC and SOFA scores differed between surviving and non-surviving patients with sepsis, and persistent high SIC and SOFA scores can predict 28-day mortality.

Outcomes of haploidentical haematopoietic stem cell transplantation for adolescent and young adults with acute myeloid leukaemia.

We aimed to identify the efficacy of haploidentical related donor (HID) haematopoietic stem cell transplantation (HSCT) in adolescent and young adults (AYAs) with acute myeloid leukaemia (AML) in a large cohort. Consecutive AML AYAs (15-39 years old, n = 599) receiving HID HSCT in complete remission (CR) were included. The 3-year cumulative incidence of measurable residual disease occurrence, relapse and non-relapse mortality after HID HSCT was 28.6% (95% CI: 25.0-32.2), 11.6% (95% CI: 9.0-14.2) and 6.7% (95% CI: 4.7-8.7) respectively. The 3-year probability of event-free survival, leukaemia-free survival (LFS) and overall survival (OS) after HID HSCT was 60.7% (95% CI: 56.9-64.8), 81.7% (95% CI: 78.7-84.9) and 85.6% (95% CI: 82.8-88.4) respectively. In multivariable analysis, AML risk category at diagnosis and comorbidity burdens before HID HSCT were independently associated with LFS and OS. Compared to the older adults (≥ 40 years, n = 355) with AML receiving HID HSCT in CR during the same time period, AYAs have a lower incidence of non-relapse mortality and higher probabilities of LFS and OS. Thus, we firstly confirmed the safety and efficacy of HID HSCT in AYAs with AML-CR.

Predicting short-term and long-term mortalities from sepsis in patients who receive allogeneic haematopoietic stem cell transplantation.

Patients who receive allogeneic haematopoietic stem cell transplantation (allo-HSCT) may develop sepsis, which result in a highly intensive care unit admission rate and mortality. Therefore, short-term and long-term prognostic models for sepsis after allo-HSCT are urgently needed. We enrolled patients receiving allo-HSCT who developed sepsis after allo-HSCT at Peking University People's Hospital between 2012 and 2021, including 287 patients who received allo-HSCT in 2018-2021 in the derivation cohort, and 337 patients in 2012-2017 in the validation cohort. Multivariate logistic regression analysis was used to identify prognostic factors, and these identified factors were incorporated into two scoring models. Seven independent factors (acute graft-versus-host disease (GVHD), chronic GVHD (cGVHD), total bilirubin, lactate dehydrogenase (LDH) and organ dysfunction [renal, lung and heart]) were included in the 6-month prognostic model, and six factors (cGVHD, C-reactive protein, LDH, organ dysfunction [lung, neurologic and coagulation]) were included in the 14-day prognostic model. The area under the receiver operating characteristic curves, calibration plots and decision curve analysis demonstrated the robust predictive performance of the models, better than the Sequential Organ Failure Assessment score. Early identification of patients with high risk of 6-month and 14-day death may allow clinicians to provide timely treatments and improve the therapeutic effects.

Time-dependent analysis of the impact on early cytomegalovirus reactivation of HLA mismatch and acute graft-versus-host disease after allogeneic hematopoietic cell transplantation from related donors in acquired aplastic anemia.

Cytomegalovirus (CMV) reactivation is an important issue in allogeneic hematopoietic cell transplantation (HCT). The incidence of early CMV reactivation is notably high in HLA-mismatched HCT. However, the interactions between HLA mismatch and acute graft-versus-host disease (aGvHD), a time-dependent event, make it methodologically challenging to evaluate the independent impact on CMV reactivation of the two variables. We retrospectively analyzed 355 patients with acquired aplastic anemia who received related donor transplants using a unified antithymocyte globulin-based platform. Patients were divided into group 1 (6/6 HLA match), group 2 (1-2/6 HLA allelic mismatch), and group 3 (3/6 HLA allelic mismatch). The impact of covariates was analyzed through two models: (1) time-dependent Cox and (2) dynamic landmarking analysis. The time-dependent Cox model showed that the HLA mismatch of 3/6 alleles (hazard ratio (HR) =1.852, P = .004) and aGvHD (HR = 1.009, P = .019) were independent risk factors for CMV reactivation. With the dynamic landmarking analysis, a higher HLA disparity correlated to increased early CMV reactivation (HR = 1.606, P = .001) at all time points. Developing aGvHD following HCT was generally associated with a higher incidence of CMV reactivation (HR = 1.623, P = .013), though its impact decreased with successive later landmark time points. In conclusion, our data suggest that the higher HLA disparity and aGvHD increases susceptibility to early CMV reactivation. In particular, the dynamic landmarking analysis demonstrated the time-varying effect of aGvHD on CMV reactivation, and HLA mismatch showed a profound impact over time following HCT.

Characteristics and outcomes of COVID-19 in patients with plasma cell dyscrasias during the first Omicron wave in Beijing since December 2022: a retrospective study at a National Clinical Research Center for Hematologic Disease.

The wave of coronavirus disease 2019 (COVID-19) with Omicron variant reached its first peak in Beijing, China in December 2022. We delineated characteristics and factors associated with adverse outcome of patients with plasma cell dyscrasias (PCDs) and COVID-19 during the first month of the wave. A total of 104 patients with a median age of 65 years were included in the study, with multiple myeloma (74%, n=77) and primary Immunoglobulin light chain amyloidosis (16.3%, n=17) being the two most common disease. Overall, severe or critical COVID-19 was developed in 18 (17.3%) patients, with a total all-cause mortality rate of 4.8% (n=5). The vaccination coverage was 41% and 48.1%, before and during the upsurge of Omicron, respectively, calling for the improvement of vaccination in PCD patients. Multivariable analysis revealed that age was the only independent risk factors (OR=1.14, 95% CI: 1.06-1.26, p = 0.002) associated with the development of severe or critical disease. Among patients with severe or critical group, low levels of albumin (HR=18.29; 95% CI: 1.82-183.44, p = 0.013) and high levels of lactic dehydrogenase (LDH) (HR=0.08; 95% CI: 0.01-0.65, p = 0.018) were associated with longer time to negative conversion of COVID-19.

Autologous hematopoietic stem cell transplantation improves survival outcomes in peripheral T-cell lymphomas: a multicenter retrospective real-world study.

The aim of this study is to evaluate the survival benefit of consolidative autologous hematopoietic stem cell transplantation (ASCT) in patients with peripheral T-cell lymphomas (PTCL). In this retrospective study, the ASCT group underwent consolidative ASCT after first-line therapy at 14 transplantation centers in China between January 2001 and December 2019. Data were collected over the same time frame for the non-ASCT group from the database of lymphoma patient records at Peking University Cancer Hospital & Institute. A total of 120 and 317 patients were enrolled in the ASCT and non-ASCT groups, respectively, and their median ages were 43 years and 51 years, respectively. In the ASCT group, 101 patients had achieved complete remission (CR) and 19 patients had achieved partial remission at the time of ASCT. The median follow-up time was 40.2 months and 68 months, and the 3-year overall survival (OS) rate was 80.6% and 48.9% (p < 0.001) for the ASCT and non-ASCT groups, respectively. The beneficial effect of ASCT for OS remained even after propensity score-matched (PSM) analysis (81.6% vs 68.3%, p = 0.001). Among the 203 patients who were aged ≤ 65 years and achieved CR, ASCT conferred a significant survival benefit (3-year progression-free survival [PFS]: 67.4% vs 47.0%, p = 0.004; 3-year OS: 84.0% vs 74.1%, p = 0.010), and this was also maintained after PSM analysis (3-year PFS: 66.6% vs 48.4%, p = 0.042; 3-year OS: 84.8% vs 70.5%, p = 0.011). Consolidative ASCT improved the survival outcome of PTCL patients, even those who achieved CR after first-line therapy.

An Fc-muted bispecific antibody targeting PD-L1 and 4-1BB induces antitumor immune activity in colorectal cancer without systemic toxicity.

BACKGROUND: Resistance to immune checkpoint inhibitor (ICI) therapy narrows the efficacy of cancer immunotherapy. Although 4-1BB is a promising drug target as a costimulatory molecule of immune cells, no 4-1BB agonist has been given clinical approval because of severe liver toxicity or limited efficacy. Therefore, a safe and efficient immunostimulatory molecule is urgently needed for cancer immunotherapy. METHODS: HK010 was generated by antibody engineering, and the Fab/antigen complex structure was analyzed using crystallography. The affinity and activity of HK010 were detected by multiple in vitro bioassays, including enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), flow cytometry, and luciferase-reporter assays. Humanized mice bearing human PD-L1-expressing MC38 (MC38/hPDL1) or CT26 (CT26/hPDL1) tumor transplants were established to assess the in vivo antitumor activity of HK010. The pharmacokinetics (PK) and toxicity of HK010 were evaluated in cynomolgus monkeys. RESULTS: HK010 was generated as an Fc-muted immunoglobulin (Ig)G4 PD-L1x4-1BB bispecific antibody (BsAb) with a distinguished Fab/antigen complex structure, and maintained a high affinity for human PD-L1 (KD: 2.27 nM) and low affinity for human 4-1BB (KD: 493 nM) to achieve potent PD-1/PD-L1 blockade and appropriate 4-1BB agonism. HK010 exhibited synergistic antitumor activity by blocking the PD-1/PD-L1 signaling pathway and stimulating the 4-1BB signaling pathway simultaneously, and being strictly dependent on the PD-L1 receptor in vitro and in vivo. In particular, when the dose was decreased to 0.3 mg/kg, HK010 still showed a strong antitumor effect in a humanized mouse model bearing MC38/hPDL1 tumors. Strikingly, HK010 treatment enhanced antitumor immunity and induced durable antigen-specific immune memory to prevent rechallenged tumor growth by recruiting CD8+ T cells and other lymphocytes into tumor tissue and activating tumor-infiltrating lymphocytes. Moreover, HK010 not only did not induce nonspecific production of proinflammatory cytokines but was also observed to be well tolerated in cynomolgus monkeys in 5 week repeated-dose (5, 15, or 50 mg/kg) and single-dose (75 or 150 mg/kg) toxicity studies. CONCLUSION: We generated an Fc-muted anti-PD-L1x4-1BB BsAb, HK010, with a distinguished structural interaction with PD-L1 and 4-1BB that exhibits a synergistic antitumor effect by blocking the PD-1/PD-L1 signaling pathway and stimulating the 4-1BB signaling pathway simultaneously. It is strictly dependent on the PD-L1 receptor with no systemic toxicity, which may offer a new option for cancer immunotherapy.

Development and validation of a mortality predicting scoring system for severe aplastic anaemia patients receiving haploidentical allogeneic transplantation.

Haploidentical allogeneic haematopoietic stem cell transplantation (haplo-HSCT) is a significant alternative treatment for severe aplastic anaemia (SAA). To improve this process by modifying the risk stratification system, we conducted a retrospective study using our database. 432 SAA patients who received haplo-HSCT between 2006 and 2020 were enrolled. These patients were divided into a training (n = 288) and a validation (n = 144) subset randomly. In the training cohort, longer time from diagnosis to transplantation, poorer Eastern Cooperative Oncology Group (ECOG) status and higher haematopoietic cell transplantation-specific comorbidity index (HCT-CI) score were independent risk factors for worse treatment-related mortality (TRM) in the final multivariable model. The haplo-HSCT scoring system was developed by these three parameters. Three-year TRM after haplo-HSCT were 6% [95% confidence interval (CI), 1-21%], 21% (95% CI, 7-40%), and 47% (95% CI, 20-70%) for the low-, intermediate-, and high-risk group, respectively (P < 0·0001). In the validation cohort, the haplo-HSCT scoring system also separated patients into three risk groups with increasing risk of TRM: intermediate-risk [hazard ratio (HR) 2·45, 95% CI, 0·92-6·53] and high-risk (HR 11·74, 95% CI, 3·07-44·89) compared with the low-risk group (P = 0·001). In conclusion, the haplo-HSCT scoring system could effectively predict TRM after transplantation.

A humanized 4-1BB-targeting agonistic antibody exerts potent antitumor activity in colorectal cancer without systemic toxicity.

BACKGROUND: Colorectal cancer (CRC) is one of the most common malignancies and the patient survival rate remains unacceptably low. The anti-programmed cell death-1 (PD-1)/programmed cell death ligand 1 (PD-L1) antibody-based immune checkpoint inhibitors have been added to CRC treatment regimens, however, only a fraction of patients benefits. As an important co-stimulatory molecule, 4-1BB/CD137 is mainly expressed on the surface of immune cells including T and natural killer (NK) cells. Several agonistic molecules targeting 4-1BB have been clinically unsuccessful due to systemic toxicity or weak antitumor effects. We generated a humanized anti-4-1BB IgG4 antibody, HuB6, directed against a unique epitope and hypothesized that it would promote antitumor immunity with high safety. METHODS: The antigen binding specificity, affinity and activity of HuB6 were determined by enzyme-linked immunosorbent assay (ELISA), surface plasmon resonance (SPR), biolayer interferometry (BLI) and flow cytometry. The antitumor effects were evaluated in humanized mice bearing syngeneic tumors, and possible toxicity was evaluated in humanized mice and cynomolgus monkeys. RESULTS: HuB6 showed high specificity and affinity for a binding epitope distinct from those of other known 4-1BB agonists, including utomilumab and urelumab, and induced CD8 + T, CD4 + T and NK cell stimulation dependent on Fcγ receptor (FcγR) crosslinking. HuB6 inhibited CRC tumor growth in a dose-dependent manner, and the antitumor effect was similar with urelumab and utomilumab in humanized mouse models of syngeneic CRC. Furthermore, HuB6 combined with an anti-PD-L1 antibody significantly inhibited CRC growth in vivo. Additionally, HuB6 induced antitumor immune memory in tumor model mice rechallenged with 4 × 106 tumor cells. Toxicology data for humanized 4-1BB mice and cynomolgus monkeys showed that HuB6 could be tolerated up to a 180 mg/kg dose without systemic toxicity. CONCLUSIONS: This study demonstrated that HuB6 should be a suitable candidate for further clinical development and a potential agent for CRC immunotherapy.

Comparable clinical outcomes of haploidentical hematopoietic stem cell transplantation in patients with hepatitis-associated aplastic anemia and non-hepatitis-associated aplastic anemia.

Hepatitis-associated aplastic anemia (HAAA), a rare subtype of aplastic anemia (AA), is defined as bone marrow failure occurring after acute hepatitis. Severe HAAA requires immunosuppressive therapy (IST) or hematopoietic stem cell transplantation (HSCT) as lifesaving treatment. The outcomes of HAAA patients who underwent haploidentical hematopoietic stem cell transplantation (haplo-HSCT) have not been systematically evaluated. We retrospectively compared the characteristics of 15 patients with HAAA and 60 non-hepatitis-associated aplastic anemia (non-HAAA) patients, all 75 of whom underwent haplo-HSCT in our hospital between January 2006 and October 2021. The median ages of the patients were 18 years old (range, 3-36) for HAAA patients and 13 years (range, 2-45) for non-HAAA patients (p = 0.693). The median time for neutrophil engraftment was 14 days (range, 11-22) in the HAAA group and 12 days (range, 10-21) in the non-HAAA group (p = 0.363). At the time of analysis, 15 HAAA patients and 58 non-HAAA patients were alive, and their median follow-up times were 37 (range, 3-87) months and 31 (range, 2-110) months (p = 0.347), respectively. There were no significant differences in the three-year overall survival (OS) rates (100% vs. 96.7 ± 0.33%, P = 0.638) or liver event-free survival (LEFS) (80.0 ± 0.17% vs. 76.7 ± 0.19%, P = 0.747) between the two groups. Despite the small number of HAAA patients due to the rarity of the disease, these results, such as the similar incidence rates of 3-year OS and fewer liver events than expected, suggest that haplo-HSCT is a feasible treatment for HAAA a when there are no human leukocyte antigen (HLA)-matched donors available and has a low risk of transplant-related mortality and complications.

A modified conditioning regimen based on low-dose cyclophosphamide and fludarabine for haploidentical hematopoietic stem cell transplant in severe aplastic anemia patients at risk of severe cardiotoxicity.

Severe cardiotoxicity is a fatal complication during high-dose cyclophosphamide (Cy)-based conditioning in hematopoietic stem cell transplant (HSCT) for severe aplastic anemia (SAA). This study aimed to evaluate the feasibility and efficacy of a modified conditioning regimen in haploidentical HSCT (haplo-HSCT) for severe-cardiotoxic-risk SAA patients. This BuCylow Flu conditioning utilized busulfan (Bu, 3.2 mg/kg for 2 days), low-dose Cy (100 mg/kg), fludarabine (150 mg/m2 ), and rabbit antithymocyte globulin (rATG, 10 mg/kg). Compared to BuCy conditioning using high-dose Cy of 200 mg/kg, Bu of 3.2 mg/kg for 2 days, and rATG of 10 mg/kg, the incidence of severe cardiotoxicity of BuCylow Flu conditioning was significantly decreased (2.17% vs 12.80%, p = .032). The engraftment rates (100% for neutrophil and 84.44% for platelet) were favorable. The probabilities of 100-day transplant-related mortality were similar in the BuCylow Flu and the BuCy group (8.75% vs 10.53%, p = .671). Both 1-year overall survival (88.79% vs 84.66%, p = .357) and 1-year failure-free survival (84.78% vs 81.70%, p = .535) were comparable. The BuCylow Flu group had higher rates of cytomegalovirus and Epstein-Barr virus reactivation. In conclusion, the BuCylow Flu provided reduced severe cardiotoxicity, and achieved favorable engraftment and survival. Our results suggest BuCylow Flu conditioning can be a feasible alternative for haplo-HSCT recipients at risk of severe cardiotoxicity.

The impact of pretransplant serum ferritin on haploidentical hematopoietic stem cell transplant for acquired severe aplastic anemia in children and adolescents.

Haploidentical hematopoietic stem cell transplant (haplo-HSCT) provides an important alternative for children and adolescents with acquired severe aplastic anemia (SAA) lacking matched donors. To test whether pretransplant serum ferritin (SF) represents a candidate predictor for survival and a potential biomarker for graft-versus-host disease (GvHD) in pediatric haplo-HSCT, we retrospectively evaluated 147 eligible patients with SAA who underwent haplo-HSCT. The patients were divided into the low-SF group (< 1000 ng/mL) and the high-SF group (≥ 1000 ng/mL). We found that SF ≥1000 ng/mL independently increased the risk of grade II-IV aGvHD (HR = 2.596; 95% CI, 1.304-5.167, P = 0.007) and grade III-IV aGvHD (HR = 3.350; 95% CI, 1.162-9.658, P = 0.025). Similar probabilities of transplant-related mortality at 100 days were observed in the two groups (6.19 ± 2.45% vs 8.00 ± 3.84%, P = 0.168). The two-year overall survival (85.29 ± 3.89% vs 92.00% ± 3.84%, P = 0.746) and failure-free survival (83.23% ± 4.08% vs 83.37% ± 6.27%, P = 0.915) were comparable. GvHD-/failure-free survival were 60.06 ± 5.10% and 75.56 ± 6.87%, respectively (P = 0.056). In conclusion, elevated pretransplant SF level is associated with higher incidences of grade II-IV aGvHD and grade III-IV aGvHD. However, it is not associated with worse survival after haplo-HSCT for children and adolescent patients with SAA.

Wilms' tumor gene 1 is an independent prognostic factor for pediatric acute myeloid leukemia following allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Sequential monitoring of Wilms' tumor gene 1 (WT1) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) could predict relapse in adult acute myeloid leukemia (AML). However, the prognostic role of WT1 in pediatric AML after allo-HSCT is unclear. Thus, we determined to see whether sequential monitoring of WT1 after allo-HSCT could predict relapse in AML children. METHODS: Pediatric AML patients receiving allo-HSCT from January 21, 2012 to December 20, 2018 at the Peking University Institute of Hematology were included in this study. WT1 expression level was determined by TaqMan-based reverse transcription-polymerase chain reaction. WT1 sequential monitoring was performed 1, 2, 3, 4.5, 6, 9, and 12 months post-transplantation and at 6-month intervals thereafter. The primary end point was relapse. The secondary end points included disease-free survival (DFS), overall survival (OS), and non-relapse mortality (NRM). Kaplan-Meier analysis was used for DFS and OS estimates, while competing risk analysis was used for estimating relapse and NRM. RESULTS: Of the 151 consecutive patients included, the median age was 10 years (range, 1-17). The optimal cutoff value of WT1 within 1 year after allo-HSCT to predict relapse was 0.8% (80 WT1 copies/104 ABL copies), with a sensitivity of 60% and specificity of 79%. Compared with WT1 expression < 0.8%, WT1 expression ≥0.8% indicated significantly higher 5-year cumulative incidence of relapse (CIR, 35.1% vs. 11.3%; P = 0.001), lower 5-year disease-free survival (DFS, 60.4% vs. 80.8%; P = 0.009), and lower 5-year overall survival (OS, 64.9% vs. 81.6%; P = 0.038) rates. Multivariate analyses showed that WT1 was an independent risk factor for relapse (HR 2.89; 95% confidence interval (CI), 1.25-6.71; P = 0.014). Both the CIR (5-year CIR: 8.3% vs. 11.3%; P = 0.513) and DFS (5-year DFS: 91.7% vs. 80.8%; P = 0.208) were comparable between patients achieving minimal residual disease (MRD) negativity after preemptive interferon-α (IFN-α) treatment and those without MRD after allo-HSCT, which were better than those of MRD-positive patients without preemptive therapies. CONCLUSIONS: Sequential monitoring of WT1 could predict relapse in pediatric AML after allo-HSCT. WT1-directed immunotherapy may have the potential to prevent relapse and improve survival.