Nivolumab in Relapsed/Refractory Classical Hodgkin Lymphoma - Extended Follow-up of 30 Patients Treated Within the CheckMate 205 Trial in a Single-Center

Controversies on the possible role of immune checkpoint inhibitors in pediatric cancers: balancing irAEs and efficacy

Pediatric cancers are not the equivalent of adult cancers occurring at a younger age and the prospect of immunotherapy in children has not been received with the same enthusiasm as in the adult setting. Although most pediatric malignancies are considered immunologically cold, we are learning more about PD-L1 expression, tumor mutational burden, and microsatellite instability in several pediatric cancers. The side effects of immunotherapy are an important consideration. Immune checkpoint inhibitors (ICIs) engender a unique constellation of inflammatory toxicities known as immune-related adverse events (irAEs). Three early-phase trials-KEYNOTE-051, iMATRIX, and ADVL1412-were the first to describe irAEs in pediatric patients and ICIs were well tolerated. There was concern about unknown late irAEs in pediatric patients, as they have much more time to develop than in adult or elderly patients. Academic clinicians, biopharmaceutical companies, and parents' advocates concluded that no benefit could be expected from further monotherapy trials employing other ICIs with the same mechanism of action until more scientific knowledge becomes available. On the other hand, ICIs could be useful in combination with other therapies to prevent the functional inactivation of several pathways in the hostile microenvironment. Future clinical studies on ICIs in children need to build on strong biological premises, taking into account the distinctive immunobiology of pediatric cancers vis-à-vis ICI-responsive adult cancers. We need to gain and share experiences of new therapies for managing pediatric patients with cancer, clarifying to what extent we can extrapolate the data obtained in adults.

[Checkpoint inhibitors in Hodgkin lymphoma]

BACKGROUND

Checkpoint blockade contributes to the immunosuppressive microenvironment in classical Hodgkin lymphoma (cHL) and in particular the interaction of Hodgkin cells and macrophages with T‑cells and natural killer cells via programmed cell death 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1).

OBJECTIVES

The aim of this article is the evaluation the role and potential of checkpoint blockade in cHL as compared with the results of standard chemo- and radiotherapy.

METHODS

We analyzed preclinical and clinical data from phase I and phase II studies with checkpoint blockade in cHL.

RESULTS AND DISCUSSION

In 60-70% of patients with chemotherapy-refractory cHL, PD‑1 blockade results in responses. Overall survival is excellent and a small number of patients achieve persistent response. Thus, the use of anti-PD‑1 monoclonal antibodies has become an important treatment approach in relapsed cHL in line with the label. The results of first-line therapy are still preliminary; initial phase II studies using nivolumab in combination with doxorubicin (=adriamycin), vinblastin and dacarbazin (AVD) in early unfavorable or advanced stages showed response rates of up to 90%. Thus, implementing immunomodulatory approaches using PD 1‑blockade have resulted in a significant reduction of chemotherapy. This might represent a paradigm shift in the therapy of cHL.