This study evaluated the effects of pretransplantation minimal residual disease (pre-MRD) on outcomes of patients with acute lymphoblastic leukemia (ALL) who underwent unmanipulated haploidentical stem cell transplantation (haplo-SCT). A retrospective study including 543 patients with ALL was performed. MRD was determined using multiparametric flow cytometry. Both in the entire cohort of patients and in subgroup cases with T-ALL or B-ALL, patients with positive pre-MRD had a higher incidence of relapse (CIR) than those with negative pre-MRD in MSDT settings (P < 0.01 for all). Landmark analysis at 6 months showed that MRD positivity was significantly and independently associated with inferior rates of relapse (HR, 1.908; P = 0.007), leukemia-free survival (LFS) (HR, 1.559; P = 0.038), and OS (HR, 1.545; P = 0.049). The levels of pre-MRD according to a logarithmic scale were also associated with leukemia relapse, LFS, and OS, except that cases with MRD <0.01% experienced comparable CIR and LFS to those with negative pre-MRD. A risk score for CIR was developed using the variables pre-MRD, disease status, and immunophenotype of ALL. The CIR was 14%, 26%, and 59% for subjects with scores of 0, 1, and 2-3, respectively (P < 0.001). Three-year LFS was 75%, 64%, and 42%, respectively (P < 0.001). Multivariate analysis confirmed the association of the risk score with CIR and LFS.The results indicate that positive pre-MRD, except for low level one (MRD < 0.01%), is associated with poor outcomes in patients with ALL who underwent unmanipulated haplo-SCT.

Steroid‐refractory (SR) acute graft‐versus‐host disease (aGVHD) is one of the leading causes of early mortality after allogeneic hematopoietic stem cell transplantation (allo‐HSCT). We investigated the efficacy, safety, prognostic factors, and optimal therapeutic protocol for SR‐aGVHD patients treated with basiliximab in a real‐world setting. Nine hundred and forty SR‐aGVHD patients were recruited from 36 hospitals in China, and 3683 doses of basiliximab were administered. Basiliximab was used as monotherapy (n = 642) or in combination with other second‐line treatments (n = 298). The cumulative incidence of overall response rate (ORR) at day 28 after basiliximab treatment was 79.4% (95% confidence interval [CI] 76.5%–82.3%). The probabilities of nonrelapse mortality and overall survival at 3 years after basiliximab treatment were 26.8% (95% CI 24.0%–29.6%) and 64.3% (95% CI 61.2%–67.4%), respectively. A 1:1 propensity score matching was performed to compare the efficacy and safety between the monotherapy and combined therapy groups. Combined therapy did not increase the ORR; conversely, it increased the infection rates compared with monotherapy. The multivariate analysis showed that combined therapy, grade III–IV aGVHD, and high‐risk refined Minnesota aGVHD risk score before basiliximab treatment were independently associated with the therapeutic response. Hence, we created a prognostic scoring system that could predict the risk of having a decreased likelihood of response after basiliximab treatment. Machine learning was used to develop a protocol that maximized the efficacy of basiliximab while maintaining acceptable levels of infection risk. Thus, real‐world data suggest that basiliximab is safe and effective for treating SR‐aGVHD.

Adoptive therapy with cytomegalovirus (CMV)‐specific cytotoxic T lymphocytes (CMV‐CTLs) has emerged as an effective method for CMV infection. However, the efficacy reportedly ranges from 50% to 90%, and factors affecting anti‐CMV efficacy have not been established. We investigated the safety and efficacy of adoptive therapy with CMV‐CTLs for CMV infection in 190 patients after haploidentical stem cell transplantation (haplo‐SCT), and importantly, we analyzed the main factors affecting antiviral efficacy. The CMV peak titer decreased from 19 (range, 1.0–503.0) × 103 copies/mL to 3.9 (range, 0–112) × 103 copies/mL after CMV‐CTL infusion. The cumulative complete response (CR) rates in the first, fourth, and sixth weeks after the first CMV‐CTL infusion were 37.9% (95% CI 35.0–40.8), 76.8% (95% CI 70.7–82.9), and 89.5% (95% CI 85.2–93.8), respectively. In multivariate analysis, persistent CMV infection prior to CMV‐CTL infusion (hazard ratio [HR] 2.29, 95% CI 1.29–4.06, p = .005) and basiliximab treatment within 2 weeks of CMV‐CTL infusion (HR 1.87, 95% CI 1.06–3.81, p = .031) were independent predictors of poor antiviral efficacy of CMV‐CTL therapy. Our data showed that adoptive therapy with CMV‐CTLs is a safe and effective treatment for CMV infection after haplo‐SCT. Persistent CMV infection and basiliximab treatment are correlated with poor anti‐CMV efficacy of CMV‐CTL therapy.

Purpose: Graft- versus-host disease (GVHD) is an important complication after human leukocyte antigen (HLA) haploidentical donor (HID) hematopoietic stem cell transplantation (HSCT), which may lead to poor prognosis. Our study intends to identify the efficacy and safety of mesenchymal stem cells (MSCs) for multidrug-resistant (MDR)-GVHD after HID HSCT. Methods: MDR-GVHD was referring to GVHD remaining no response to at least two types of therapy, and hUCB-MSCs were given at the dose of (1.0–2.0) × 106/kg once a week. Results: A total of 21 patients were enrolled in this retrospective study (acute GVHD (aGVHD): n = 14, chronic GVHD (cGVHD): n = 7). The median dose of MSCs was 1.2 × 106 cells/kg (range, 0.8–1.8 × 106) cells/kg, and the median numbers of infusion were 2 (range, 1–7) and 3 (range, 2–12) for MDR-aGVHD and MDR-cGVHD patients, respectively. In MDR-aGVHD patients, the overall response rate (ORR) was 57.1%, including 50.0% complete response (CR) and 7.1% partial response (PR), and the median time to response was 49.5 days (range, 16–118) days. The 2-year probability of overall survival after MSCs was 64.3%. Five patients (35.7%) developed infections after MSCs, and no obvious hematologic toxicities were observed. Five MDR-aGVHD patients died after MSCs treatments because of GVHD progression ( n = 1), severe infection (bacterial central nervous system infection: n = 1; fungal pneumonia: n = 2), and poor graft function ( n = 1). In MDR-cGVHD patients, three patients (42.9%) achieved PR after MSCs and the median time to response was 56 days (22–84) days. The ORRs for moderate and severe cGVHD were 50.0% and 33.3%, respectively. Four MDR-cGVHD patients died after MSCs treatments because of GVHD progression ( n = 2), severe fungal pneumonia ( n = 1), and relapse ( n = 1). Conclusion: MSCs treatment may be safe and effective for MDR-GVHD after HID HSCT.