HSCT with mismatched unrelated donors: Bone marrow versus peripheral blood stem cells sources in pediatric patients.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (HSCT) from an unrelated HLA-mismatched donor (MMUD) is one of the alternatives where an HLA-matched donor is not found. The aim of this study was to compare bone marrow (BM) versus peripheral blood stem cells (PBSC) as hematopoietic rescue following allogeneic unrelated mismatched stem cell transplantation (MMUD). METHODS: The patients were divided into two groups: 43 pediatric patients were treated with BM and 17 pediatric patients with PBSC. The study was registered at ClinicalTrials.gov NCT04598789. RESULTS: The 3-year Overall Survival (OS) was 74% versus 31% (p = .0011). Transplant related mortality (TRM) was 16% versus 33% (p = .025), and relapse incidence (RI) was 16% versus 35% (p = .005). The day-100 acute Graft-versus-host disease (GvHD) incidence grade II-IV and III-IV was 30% versus 28% (p = NS) and 17% versus 17% (p = NS). The 3-year chronic GvHD incidence was 22% versus 33% (p = NS). CONCLUSION: Despite all the limits of this retrospective study we were able to show how the combination of BM and ATG is able to prevent GvHDs and guarantee a high OS. Future studies addressing the issue of a post-transplant cellular therapy approach may potentially reduce relapses when GvHD is absent.

Post-Transplant Cyclophosphamide and Tacrolimus-Mycophenolate Mofetil Combination Governs GVHD and Immunosuppression Need, Reducing Late Toxicities in Allogeneic Peripheral Blood Hematopoietic Cell Transplantation from HLA-Matched Donors.

Combined direct antineoplastic activity and the long-lasting immunological effects of allogeneic hematopoietic cell transplant (HCT) can cure many hematological malignancies, but broad adoption requires non-relapse mortality (NRM) rates and graft-versus-host disease (GVHD) control. Recently, posttransplant cyclophosphamide (PTCy) given after a bone marrow transplant significantly reduced GVHD-incidence, while PTCy given with tacrolimus/mofetil mycophenolate (T/MMF) showed activity following allogeneic peripheral blood stem cell transplantation (alloPBSCT). Here, we report the experience of a larger cohort (85 consecutive patients) and expanded follow-up period (03/2011-12/2019) with high-risk hematological malignancies who received alloPBSCT from Human-Leukocyte-Antigens HLA-matched unrelated/related donors. GVHD-prophylaxis was PTCy 50 mg/kg (days+3 and +4) combined with T/MMF (day+5 forward). All patients stopped MMF on day+28 with day+110 = median tacrolimus discontinuation. Cumulative incidences were 12% for acute and 7% for chronic GVHD- and no GVHD-attributed deaths. For surviving patients, the 12, 24, and 36-month probabilities of being off immunosuppression were 92, 96, and 96%, respectively. After a 36-month median follow-up, NRM was 4%; median event-free survival (EFS) and overall survival (OS) had yet to occur. One- and two-year chronic GVHD-EFS results were 57% (95% CI, 46-68%) and 53% (95% CI, 45-61%), respectively, with limited late infections and long-term organ toxicities. Disease relapse caused the most treatment failures (38% at 2 years), but low transplant toxicity allowed many patients (14/37, 38%) to receive donor lymphocyte infusions as a post-relapse strategy. We confirmed that PTCy+T/MMF treatment effectively prevented acute and chronic GVHD and limited NRM to unprecedented low rates without loss of disease control efficacy in an expanded patient cohort. This trial is registered at U.S. National Library of Medicine as #NCT02300571.

Steroid-refractory acute graft-versus-host disease graded III-IV in pediatric patients. A mono-institutional experience with a long-term follow-up.

aGvHD remains a major obstacle to successful HSCT. We report our experience on steroid-refractory aGvHD III and IV from 1989 to 2017. Ninety patients with aGvHD III or IV were stratified according to the HSCT year: 1989-1998, 1999-2007, and 2008-2017 and to aGvHD extension (GvHD III vs IV) and finally the probability of OS, RI, and TRM was calculated accordingly. aGvHD III patients had a substantial improvement over time: day 100 OS raised from 64% (95% CI 39-89) in the first cohort to 100% in the latest (P = .022), and it was mainly due to a reduction of TRM (it was 28% [95% CI 12-65] in the first cohort to 0% in the latest (P = .01). The aGvHD IV patients did not present a significant improvement. Day 100 OS was 42% (95% CI 16-68) in the first group and 54% (95% CI 25-83) in the year 2008-2017 (P = NS), and the day-100 TRM was very similar (it was 57% [95% CI 36-90] in the first cohort and 45% [95% CI 23-89] in the latest (P = NS). We report significant improvements in OS and TRM in patients diagnosed with grade III aGvHD. Patients with the most severe aGvHD appear to have no or fewer benefits on long-term outcomes.

Outcome of Relapsed Pediatric Patients After Second Allogeneic Hematopoetic Stem Cell Transplantation: A Retrospective Study From a Single Institution.

Prognosis of relapsed leukemia patients after second allogeneic hematopoietic stem cell transplantation (HSCT2) is historically considered very poor. We report the outcome of 18 pediatric patients after failure of HSCT2. The 2-year overall survival was 26% (95% confidence interval [CI], 6-47). The lymphoid malignancies were associated with better survival (40% [95% CI, 12-68]) than myeloid malignancies (0%, P=0.002), together with time to relapse after the HSCT2 (≥5 mo: 44% [95% CI, 12-76] vs. 0% for patients who relapsed within 5 mo from HSCT2, P=0.005), other factors such as sex, donor type, conditioning regimen, and graft versus host disease prophylaxis did not have statistical significance. When the multivariate analysis was carried out, 2 independent protective factors were identified: the lymphoid malignancies and the graft versus host disease 0 to I after HSCT2. When we look at the treatments, patients receiving blinatumomab after relapse got benefit in terms of overall survival and, more importantly, with a long-term control of acute lymphoblastic leukemia.

Comparison of two different conditioning regimens before autologous transplantation for children with high-risk neuroblastoma.

BACKGROUND: Although high-dose chemotherapy (HDC) represents the standard of treatment for high-risk neuroblastoma (NBL), the most effective conditioning regimen still remains to be identified. PATIENTS AND METHODS: Forty-one high-risk NBL entered into local protocol based on induction chemotherapy, surgery and HDC with either etoposide/thiotepa/cyclophophamide (ETC) or i.v. busulfan and L-PAM (Bu/L-PAM). RESULTS: Thirty-seven patients underwent HDC; 29 with ETC and 8 with Bu/L-PAM. No toxic deaths were recorded. The 5-year progression-free survival (PFS) of patients given ETC was 21% (95% confidence interval CI (9-36%), while PFS for patients given Bu/L-PAM was 88% (95% CI=39-98%) (p<0.05). In multivariate analysis, treatment with the ETC regimen predicted progression/recurrence with a hazard ratio (HR) of 16.8 (p<0.05), as well as MYCN amplification which had an HR of 4.4 (p<0.05). CONCLUSION: Although the number of studied cases is limited, our data suggest that in high-risk NBL the combination of Bu/L-PAM is superior to the ETC regimen.

Expression of multidrug resistance-associated proteins in paediatric soft tissue sarcomas before and after chemotherapy.

Expression of multidrug resistance (MDR) proteins is thought to significantly contribute to the different biological/clinical behaviour of soft tissue sarcomas (STS) of various histological types and clinicopathological stages, as they are responsible for active efflux of cytotoxic drugs from tumour cells. We investigated the expression of 3 MDR proteins, i.e., permeability glycoprotein 1 (P-gp), multidrug resistance-associated protein 1 (MRP1) and multidrug resistance 3 (MDR3), in 43 STS specimens from newly-diagnosed paediatric patients, 31 with rhabdomyosarcoma (RMS) and 12 with non-RMS STS. To assess the influence of chemotherapy on STS drug resistance, the number of MDR-associated protein-positive cells was determined in 15 patients on both primary lesions before chemotherapy and on residual tumour after chemotherapy. At least one of the MDR-associated proteins tested was detected in 84% of primary untreated STS specimens. In these specimens, MRP1 was detected in a high percentage (70%) of the cases, followed by MDR3 in 58% and P-gp in 44%. Many specimens showed co-expression of two different MDR proteins. Interestingly, MDR3 was significantly associated with the presence of PAX3/PAX7-FKHR transcripts in RMS (p<0.05). Moreover, expression of MRP1 and MDR3 was significantly more frequent in group III and IV tumours as compared with those of groups I and II (p<0.01). After chemotherapy MRP1, MDR3 and, to a lesser extent, P-gp expression was found to be increased in most of the samples. The frequent expression of these MDR-associated proteins in primary tumour cells before chemotherapy and the increase of their levels after chemotherapy, suggest that these proteins play a pivotal role in conferring drug resistance and in producing therapy-induced differentiation on STS.

Continuing response to subsequent treatment lines with tyrosine kinase inhibitors in an adolescent with metastatic renal cell carcinoma.

A 14-year-old girl with metastatic renal cell carcinoma was treated with nephrectomy, interferon, and several lines of the targeted agents sorafenib, bevacizumab, sunitinib, and everolimus, either alone or in combination. Treatment was well tolerated, but the patient developed hypothyroidism and significant hypertension with bevacizumab and sunitinib. She responded to all agents and was given radiation treatment twice at the time of symptomatic disease progression; she died 33 months from diagnosis.

Pancreatitis as an unusual presentation of rhabdomyosarcoma.

The most common etiologies of acute pancreatitis in children are trauma, multi-system disease, drugs, infections, idiopathic and congenital anomalies of the pancreaticobiliary system. Acute pancreatitis is rarely associated with underlying childhood malignancies. We report a 12-year-old male with acute pancreatitis as the presenting symptom of an alveolar metastatic rhabdomyosarcoma.

Extracorporeal photopheresis for steroid resistant graft versus host disease in pediatric patients: a pilot single institution report.

This study was aimed at ascertaining whether extracorporeal photopheresis (ECP) is an effective treatment for pediatric patients with steroid resistant graft versus host disease (GvHD). Fifteen patients with acute GvHD (aGvHD) and 10 patients with chronic GvHD (cGvHD) were enrolled in the study. At the start of the ECP protocol, aGvHD was staged as II (n=7), III (n=4), and IV (n=4). The response rate was 100% for aGvHD II, 75% for aGvHD III, and finally 0% for aGvHD IV (P=0.02). In multivariate analysis, the strongest predictor for ECP response was the aGvHD severity: aGvHD II 100%, aGvHD III-IV 30% [relative risk (RR) 5.071, confidence interval (CI) 95% 2.2-5.5, P=0.0016], this translates in a higher risk of transplant-related mortality for ECP nonresponders (RR 5.26, CI 95% 3.4-6.2, P=0.02). cGvHD was diagnosed as limited n=3, and extensive n=7; the response rate was 100% and 28% for limited or extensive cGvHD, respectively (P=0.03). For cGvHD the strongest predictor for ECP response was the absence of visceral organ involvement (RR 5.17, CI 95% 2-4.9, P=0.001), and the highest risk of transplant-related mortality was among patients not responding to ECP (RR 12.4, CI 95%, P=0.02). Our results suggest that ECP can rescue good-risk GvHD-patients, whereas for advanced, poor-risk GvHD patients, new therapies are required.