A PHASE 1/2 STUDY OF BRENTUXIMAB VEDOTIN IN PEDIATRIC PATIENTS WITH RELAPSED/REFRACTORY (R/R) SYSTEMIC ANAPLASTIC LARGE-CELL LYMPHOMA (SALCL) OR R/R HODGKIN LYMPHOMA (HL)

Nouvelles perspectives dans l’immunothérapie des cancers pédiatriques

NEW PERSPECTIVES IN IMMUNOTHERAPIES FOR PEDIATRIC MALIGNANCIES

New therapeutic paradigms are needed to improve the survival of children and adolescents with high-risk malignancies, and to reduce the sequelae associated with treatment. Immunotherapies, targeting tumor cells and/or the immune system to enhance existing anti-tumor immunity or induce novel anti-tumor immune responses, are becoming increasingly successful in adult oncology. Based on the results obtained with anti-ganglioside2 antibodies in neuroblastoma, rituximab in mature B malignancies, immune checkpoint inhibitors in lymphoma and especially in Hodgkin lymphoma, blinatumomab and CAR-T CD19 cells for B-cell acute lymphoblastic leukemia, immunotherapy has demonstrated irrefutable benefits in pediatric patients. However, these results are currently limited to a minority of patients and histologies. Current and ongoing trials tend to focus on a single type of immunotherapy, but it is likely that combinations of immunotherapies with different mechanisms of action or combination with other classes of anti-cancer treatments will be additives or even synergistic. The development of this new class of drugs in the treatment of pediatric cancers has multiple challenges: to better evaluate the response to treatment, to define the optimal doses and schedules, to manage immuno-mediated toxicities, to identify its specific sequelae, and, finally, to better understand the strategies of immune evasion of pediatric cancers in order to develop efficient immunotherapies.

Pulmonary toxicity in paediatric patients with relapsed or refractory Hodgkin lymphoma receiving brentuximab vedotin

Brentuximab vedotin (Bv) is becoming increasingly important in the treatment of Hodgkin lymphoma (HL), with improved outcomes and an overall favourable toxicity profile. However, Bv is associated with severe pulmonary toxicity when combined with bleomycin, suggesting that additive toxicity may be an important consideration. Furthermore, little has been published on tolerability in paediatric patients. We retrospectively evaluated the occurrence of pulmonary toxicity of Bv in 19 paediatric and young adult patients with relapsed or refractory HL. Patient characteristics, baseline health status, treatment regimens including cumulative doses of Bv, bleomycin, gemcitabine, radiation and carmustine, and the occurrence of pulmonary toxicity were collected. Seven (36·8%) of the 19 patients were treated with Bv. The odds of pulmonary toxicity were 4·0-fold higher (95% confidence interval 0·55-29·18) in patients exposed to Bv compared to unexposed patients in univariate analysis (P = 0·17). Similar results were found in multivariable analysis. Pulmonary toxicity occurred frequently in our cohort and was more common in patients who received Bv than in patients who did not receive Bv, although this was not statistically significant. Because patients with HL are exposed to a myriad of therapies with potential for pulmonary toxicity, continuing to evaluate the risk associated with Bv is critical.

Pharmacotherapeutic Management of Pediatric Lymphoma

Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) comprise approximately 15% of all childhood malignancies. Cure rates for both lymphoma entities have evolved tremendously during the last couple of decades, raising the 5-year survival rates to almost 100% for HL and to 85% for NHL. The mainstay therapy for both malignancies is still chemotherapy-with different regimens recommended for different types of disease. In HL, combined modality treatment, i.e., chemotherapy followed by radiotherapy, has long been the standard regimen. In order to reduce long-term side effects, such as second malignancies, most major pediatric HL consortia have studied response-based radiotherapy reduction strategies over the last 3 decades. For recurrent disease, high-dose chemotherapy followed by an autologous or an allogeneic hematopoietic stem-cell transplant is an option. No targeted agents have yet gained regulatory approval for use in pediatric patients with lymphoma. For adult lymphoma patients, the CD20 antibody rituximab and the CD30 antibody-drug conjugate brentuximab vedotin are targeted agents used regularly in first- and second-line treatment regimens. More recently, immune checkpoint inhibitors, phosphatidyl-inositol-3-kinase inhibitors, and Bruton's tyrosine kinase inhibitors appear to be very promising new treatment options in adult lymphoma. Here, we discuss the current experience with these types of agents in pediatric lymphoma patients.