Will post-transplantation cell therapies for pediatric patients become standard of care?

Although allogeneic hematopoietic stem cell transplantation (HSCT) is a curative approach for many pediatric patients with hematologic malignancies and some nonmalignant disorders, some critical obstacles remain to be overcome, including relapse, engraftment failure, graft-versus-host disease (GVHD), and infection. Harnessing the immune system to induce a graft-versus-tumor effect or rapidly restore antiviral immunity through the use of donor lymphocyte infusion (DLI) has been remarkably successful in some settings. Unfortunately, however, the responses to DLI can be variable, and GVHD is common. Thus, manipulations to minimize GVHD while restoring antiviral immunity and enhancing the graft-versus-tumor effect are needed to improve outcomes after allogeneic HSCT. Cellular therapies, defined as treatment modalities in which hematopoietic or nonhematopoietic cells are used as therapeutic agents, offer this promise for improving outcomes post-HSCT. This review presents an overview of the field for pediatric cell therapies in the transplant setting and discusses how we can broaden applicability beyond phase I.

The yield of monitoring for HSV and VZV viremia in pediatric hematopoietic stem cell transplant patients.

Reactivation of HSV and VZV is common following HSCT. Consensus guidelines do not support the use of routine screening for viremia following HSCT in adults, but no such clear guidelines exist in pediatrics. In our center, routine practice was to screen patients weekly for HSV and VZV viremia until engraftment in autologous transplant patients and up to day +100 in allogeneic transplant patients. We conducted a retrospective study of over 500 patients to establish whether this screening identified any patients with HSV or VZV viremia who would not have been identified by clinical signs or symptoms. Over a 4.5-yr period, routine screening identified three cases of HSV viremia and one case of VZV viremia. Two patients had persistent, unexplained fever and two patients had skin or mucosal lesions suggestive of HSV/VZV. We conclude that routine screening for HSV and VZV viremia in pediatric HSCT patients has a very low yield and that viremia can be reliably identified by targeted testing in patients with vesicular skin lesions, oral or genital ulceration, unexplained fever, neurological symptoms, or unexplained abnormal liver transaminases.

Severe lung injury and lung biopsy in children post-hematopoietic stem cell transplantation: The differences between allogeneic and autologous transplantation.

To review outcome of children post-allogeneic (allo) and autologous (auto) SCT with severe lung injury who had lung biopsy and to determine whether the diagnoses provided by lung biopsy had an impact on outcome. Retrospective study was carried out from January 2000 to June 2010. Nine hundred and eighteen children (0-18 yr) received SCT (allo 476, auto 442), and 59 biopsies were performed in 48 patients. Most common result of lung biopsy was non-infectious inflammation and recurrent disease in allo- and autorecipients, respectively. In a multivariate analysis, survival of allorecipients who had management change was inferior (p = 0.002; HR: 3.12). These patients were extremely sick, and management change was the last attempt to stabilize their respiratory status. There was a trend toward superior survival for children who had biopsy after 100 days following SCT (p = 0.09; HR: 0.55) and a trend toward inferior survival for those with proven infections within two wk of biopsy (p = 0.07; HR: 2.14). Only 31% of allorecipients and 25% of autorecipients survived. There were no biopsy-related complications. Lung biopsy itself appears to be well tolerated, although requiring a biopsy seems to carry a poor prognosis; this seems to be due to different causes, auto (relapse), allo (non-infectious inflammation).

Prospective PTCTC trial of myeloablative haplo-BMT with posttransplant cyclophosphamide for pediatric acute leukemias.

Promising results have been reported for adult patients with high-risk hematologic malignancies undergoing haploidentical bone marrow transplant (haploBMT) with posttransplant cyclophosphamide (PTCy). To our knowledge, we report results from the first multicenter trial for pediatric and young adult patients with high-risk acute leukemias and myelodysplastic syndrome (MDS) in the Pediatric Transplantation and Cellular Therapy Consortium. Nine centers performed transplants in 32 patients having acute leukemias or MDS, with myeloablative conditioning (MAC), haploBMT with PTCy, mycophenolate mofetil, and tacrolimus. The median patient age was 12 years. Diagnoses included AML (15), ALL (11), mixed-lineage leukemia (1), and MDS (5). Transplant-related mortality (TRM) at 180 days was 0%. The cumulative incidence (CuI) of grade 2 acute graft-versus-host disease (aGVHD) on day 100 was 13%. No patients developed grades 3-4 aGVHD. The CuI of moderate-to-severe chronic GVHD (cGVHD) at 1 year was 4%. Donor engraftment occurred in 27 patients (84%). Primary graft failures included 3 patients who received suboptimal bone marrow grafts; all successfully engrafted after second transplants. The CuI of relapse at 1 year was 32%, with more relapse among patients MRD positive pre-BMT vs MRD negative. Overall survival rates at 1 and 2 years were 77% and 73%, and event-free survival rate at 1 and 2 years were 68% and 64%. There was no TRM or severe aGVHD, low cGVHD, and favorable relapse and survival rates. This successful pilot trial has led to a phase 3 trial comparing MAC haploBMT vs HLA-matched unrelated donor BMT in the Children's Oncology Group. This trial was registered at www.clinicaltrials.gov as #NCT02120157.

The influence of patient reported outcomes on the discussion of psychosocial issues in children with cancer.

BACKGROUND: This study investigates the effect of using patient reported outcomes (PROs) about health-related quality of life (HRQOL) in clinical practice on the type and amount of psychosocial topics discussed during a paediatric oncology consultation. PROCEDURE: Children (N = 193) with cancer participated in a sequential cohort intervention study, with a control (no PRO was used) and intervention group (a PRO was used). For each child three consecutive consultations with the paediatric oncologist were audio recorded in order to assess the discussed psychosocial topics. One third of the audio recordings were qualitatively analysed. RESULTS: The type of the discussed psychosocial topics in the control and intervention group did not differ from each other. However, the discussion of psychosocial topics increased in the intervention group compared to the control group. In both groups, topics within the social domain occurred most frequently and topics regarding the emotional domain had the lowest incidence. CONCLUSIONS: PROs do not change the psychosocial content of communication. Paediatric oncologists already address psychosocial issues during the consultation, regardless of the use of a PRO. However, with a PRO available they address these issues more systematically and more often.

Association between busulfan exposure and outcome in children receiving intravenous busulfan before hematologic stem cell transplantation.

Busulfan, combined with therapeutic drug monitoring-guided dosing, is associated with higher event-free survival (EFS) rates due to fewer graft failures/relapses and lower toxicity. The optimal target area under the curve (AUC) and dosing schedule of intravenous busulfan in children undergoing hematopoietic stem cell transplantation (HSCT) remain unclear, however. We conducted a retrospective analysis of the association between busulfan exposure and clinical outcome in 102 children age 0.2 to 21 years who received busulfan 1 or 4 times daily before undergoing HSCT (46 malignant and 56 nonmalignant indications). EFS and overall survival after a median of 2 years of follow-up were 68% and 72%, respectively. EFS was optimal when the exposure of busulfan (AUC) was 78 mg x h/L (95% confidence interval=74 to 82 mg x h/L). Acute graft-versus-host disease (aGVHD) grade II-IV occurred more frequently with greater busulfan exposure. The addition of melphalan was an independent risk factor; melphalan use combined with high busulfan exposure (AUC >74 mg x h/L) was associated with high incidences of aGVHD (58%), veno-occlusive disease (66%), and mucositis grade III-IV (26%). Dosing frequency (1 or 4 times daily) was not related to any outcome. In conclusion, dose targeting of busulfan to a narrow therapeutic range was found to increase EFS in children. Adding melphalan to optimal busulfan exposure is associated with a high incidence of toxicity.

Optic nerve relapse in a child with common acute lymphoblastic leukemia, treated with systemic anti-CD-20 (rituximab).

We describe a two- year old boy who was diagnosed with pre-B acute lymphoblastic leukemia (ALL). He developed a central nervous system (CNS) relapse with optic nerve involvement. Initially he was treated according to the ALL relapse protocol, including CNS radiotherapy. Despite an initial complete reponse, relapse occurred within six weeks of treatment. The leukemic blast cells were CD-20 positive and he was treated with systemic anti CD-20 therapy (rituximab) with no CNS recurrence over a six-month period. He died due to a CD-20 negative bone marrow relapse. This case illustrates a potential role for rituximab in pediatric CD-20 positive malignancies.

Need for a cooperative study: Pulmonary Langerhans cell histiocytosis and its management in adults.

BACKGROUND: Pulmonary involvement with Langerhans cell histiocytosis (LCH, formerly known as histiocytosis-X) presents as an interstitial process in children and adults either with or without symptoms. In contrast to other manifestations of LCH, most patients with pulmonary disease are adults. PROCEDURES: We reviewed the literature on pulmonary LCH to determine what were the clinical presentations, prognostic variables, and treatment options for this disease. RESULTS: Although there are spontaneous remissions, a large number of patients have progressive pulmonary deficiency and experience significant morbidity if not mortality from the disease. The efficacy of steroid versus chemotherapy in halting the process remains controversial, even if smoking is taken into consideration. CONCLUSIONS: A multicenter study of therapy for pulmonary LCH is the obvious answer to this dilemma. We propose that interested centers organize via the Histiocyte Society to plan and execute such a trial.