Cytomegalovirus (CMV) disease and infection refractory to antiviral treatment after allogeneic stem cell transplantation (allo-SCT) is associated with a high mortality. Adoptive transfer of CMV-specific T cells could reconstitute viral immunity after SCT and could protect from CMV-related complications. However, logistics of producing virus-specific T-cell grafts limited the clinical application. We treated 18 patients after allo-SCT from human leukocyte antigen-mismatched/ haploidentical or human leukocyte antigen-matched unrelated donors with polyclonal CMV-specific T cells generated by ex vivo stimulation with pp65, followed by isolation of interferon-␥-producing cells. Patients with CMV disease or viremia refractory to antiviral chemotherapy or both were eligible for adoptive T-cell transfer and received a mean of 21 ؋ 10 3 /kg pp65-specific T cells. In 83% of cases CMV infection was cleared or viral burden was significantly reduced, even in cases of CMV encephalitis (n ‫؍‬ 2). Viral control was associated with in

PURPOSE Off-label use of vemurafenib (VMF) to treat BRAFV600E mutation–positive, refractory, childhood Langerhans cell histiocytosis (LCH) was evaluated. PATIENTS AND METHODS Fifty-four patients from 12 countries took VMF 20 mg/kg/d. They were classified according to risk organ involvement: liver, spleen, and/or blood cytopenia. The main evaluation criteria were adverse events (Common Terminology Criteria for Adverse Events [version 4.3]) and therapeutic responses according to Disease Activity Score. RESULTS LCH extent was distributed as follows: 44 with positive and 10 with negative risk organ involvement. Median age at diagnosis was 0.9 years (range, 0.1 to 6.5 years). Median age at VMF initiation was 1.8 years (range, 0.18 to 14 years), with a median follow-up of 22 months (range, 4.3 to 57 months), whereas median treatment duration was 13.9 months (for 855 patient-months). At 8 weeks, 38 complete responses and 16 partial responses had been achieved, with the median Disease Activity Score decreasing from 7 at diagnosis to 0 ( P < .001). Skin rash, the most frequent adverse event, affected 74% of patients. No secondary skin cancer was observed. Therapeutic plasma VMF concentrations (range, 10 to 20 mg/L) seemed to be safe and effective. VMF discontinuation for 30 patients led to 24 LCH reactivations. The blood BRAFV600E allele load, assessed as circulating cell-free DNA, decreased after starting VMF but remained positive (median, 3.6% at diagnosis, and 1.6% during VMF treatment; P < .001) and was associated with a higher risk of reactivation at VMF discontinuation. None of the various empirical therapies (hematopoietic stem-cell transplantation, cladribine and cytarabine, anti-MEK agent, vinblastine, etc) used for maintenance could eradicate the BRAFV600E clone. CONCLUSION VMF seemed safe and effective in children with refractory BRAFV600E-positive LCH. Additional studies are needed to find effective maintenance therapy approaches.

The transplantation of stem cells from a matched unrelated donor (MUD) or a haploidentical mismatched related donor (MMRD) is a widely used variant of curative treatment for patients with primary immunodeficiency (PID). Currently, different strategies are used to reduce the risk of post-transplant complications and enhance immune reconstitution. We report the preliminary results of MUD and MMRD transplantation with TCRαβ/CD19 depletion in patients with PID (trial registered at www.clinicaltrials.gov as NCT02327351). Thirty-seven PID patients (median age, 2.6 years; range, .2 to 17) were transplanted from MUDs (n = 27) or haploidentical MMRDs (n = 10) after TCRαβ(+)/CD19(+) graft depletion. The median numbers of CD34(+) and TCRαβ(+) cells in the graft were 11.7 × 10(6)/kg and 10.6 × 10(3)/kg, respectively. Acute graft-versus-host disease (GVHD) was observed in 8 patients (22%), without a statistically significant difference between MUDs and MMRDs; 7 of these patients had grade II acute GVHD and responded to first-line therapy, whereas 1 patient had grade IV acute GVHD with transformation to extensive chronic GVHD. Primary and secondary graft failure (nonengraftment or rejection) was observed in 10 patients (27%), 9 of whom were treated with 1 alkylating agent in the conditioning regimen. All these patients were successfully retransplanted with different rescue protocols. Preliminary data on immune reconstitution were very encouraging. Most patients had significant numbers of T lymphocytes detected on the first assessment (day +30) and more than 500 T cells/μL, on day +120. Based on our preliminary data, no significant difference was seen between MMRD and MUD hematopoietic stem cell transplantation (HSCT). With a median follow-up period of 15 months, the cumulative probabilities of overall patient survival and transplant-related mortality were 96.7% and 3.3%, respectively. Based on the results, the ability to control the main post-transplant complications and the immune reconstitution rates are the main factors leading to successful outcome in patients with PID after TCRαβ(+)-depleted HSCT.

We evaluated the depletion of TCR-alpha/beta cells from the graft of children with high-risk AML, who received transplantation from unrelated (n = 20) and haploidentical donors (n = 13). The preparative regimen included treosulfan, melphalan, fludarabine and anti-thymocyte globulin. Grafts were PBSC engineered by TCR-alpha/beta and CD19 depletion. The graft contained a median of 9 × 10 6 /kg of CD34+ and 20 × 10 3 /kg of αβ-T cells. Post-transplant immune suppression included tacrolimus till day +30 and Mtx in 21 patients, tacrolimus in 5, Mtx in 2 and no prophylaxis in 5 patients. Sixteen patients received native or TCR-alpha/beta-depleted donor lymphocytes at a median of 47 (40-204) days. Median follow-up is 1.76 years. Primary engraftment was achieved in 33 patients (100%). Cumulative incidence of acute GvHD (aGvHD) grade 2-3 was 39 (26-60)%, half of them had skin-only aGvHD. Cumulative incidence of chronic GvHD was 30(18-50)%. Transplant-related mortality is 10(4-26)%. Event-free survival (EFS) is 60 (43-76)% and overall survival (OS) is 67(50-84)% at 2 years. In a subgroup of patients, who received transplantation in CR, EFS is 66 (48-84)% and OS − 72(53-90)% at 2 years. Our data suggest that TCR-alpha/beta and CD19 depletion is a robust method of graft manipulation, which can be used to engineer grafts for children with AML

Alpha/beta T cell and CD19 depletion are used to improve the outcomes of hematopoietic stem cell transplantation (HSCT). We evaluated the burden of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) in pediatric patients after this HSCT type. A cohort of 182 patients with malignant (n = 114) or nonmalignant (n = 68) disorders was transplanted from either matched unrelated (n = 124) or haploidentical (n = 58) donors. The cumulative incidence of CMV and EBV viremia were 51% and 33%, respectively. Acute graft-versus-host disease (GVHD) grades II to IV, D-/R+ serology, and malignant HSCT indications were associated with increased risk of CMV viremia. CMV disease developed in 10 patients (6%). The occurrence of CMV viremia was not associated with inferior outcomes. Acute GVHD grade ≥ II was the only factor significantly associated with an increased risk of EBV viremia. Rituximab significantly decreased the rate of EBV reactivation in a subgroup that received a higher B cell dose in the graft. The rate of EBV-associated disease was .5%, and EBV viremia did not affect survival. TCR-α/β and CD19 depletion are associated with a significant rate of CMV viremia that does not affect survival. The hazard of EBV post-transplant lymphoproliferative disease (PTLD) is eliminated by the combination of CD19 depletion and rituximab.