PHASE I/II STUDY OF BRENTUXIMAB VEDOTIN IN REFRACTORY/RELAPSED HODGKIN LYMPHOMA PATIENTS TREATED BY CHEMOTHERAPY (ICE) IN SECOND LINE BEFORE AUTOLOGOUS TRANSPLANTATION

SOHO State of the Art Updates and Next Questions: Hodgkin Lymphoma

Until recently, advances in classic Hodgkin lymphoma (HL) treatment primarily consisted of minor modifications of highly effective decades-old chemotherapy and radiation approaches. In early-stage disease, excellent outcomes have been reported with fewer cycles of chemotherapy, lower doses, smaller radiation fields and in some circumstances, radiation elimination. In advanced-stage disease, maintaining the dose intensity of standard chemotherapy regimens has resulted in modest improvements in outcomes. During the past decade, the use of early interim positron emission tomography (PET) scans to escalate or de-escalate treatment has been the subject of intense investigation with the goal of maximizing efficacy and minimizing toxicity. Important updates from recent PET-directed trials include; elimination of bleomycin in patients with advanced-stage HL and negative interim PET findings, the benefit of therapy escalation in patients with unfavorable early-stage HL and positive interim PET findings, and the minimal benefit of consolidative radiotherapy in patients with unfavorable early-stage HL and negative interim PET findings. A more nuanced approach to consolidative radiotherapy is required for patients with favorable early-stage disease based on age, disease sites, secondary cancer risk, and cardiovascular disease. Brentuximab vedotin and nivolumab/pembrolizumab have provided promising new options with surprisingly high response rates and modest toxicity for patients with relapsed HL whose disease does not respond to standard treatments. Incorporating these agents into earlier therapy is an area of active investigation for all stages of HL. Although the overall prognosis for HL patients has seen incremental improvement, efforts to optimize treatment with more effective and less toxic approaches continue.

Emerging role of novel therapies in Hodgkin lymphoma: proceed with caution

Based on very high response rates in the relapsed and refractory setting, brentuximab vedotin and the programmed cell death protein 1 (PD-1) inhibitors, nivolumab and pembrolizumab, have quickly been incorporated into clinical trials for first- and second-line therapy of Hodgkin lymphoma. Preliminary data show that brentuximab vedotin alone is not adequate therapy for newly diagnosed Hodgkin lymphoma in older patients, but modestly decreases the risk of relapse when combined with adriamycin, vinblastine, and dacarbazine in patients with previously untreated advanced-stage disease. In second-line therapy, combining brentuximab vedotin with conventional chemotherapy or with PD-1 inhibitors as pretransplant salvage is associated with high overall and complete response rates, although further follow up is needed to assess whether posttransplant outcomes are improved. Although these new drugs are well tolerated when given as single agents, unexpected toxicities have been encountered with combination regimens, specifically severe pulmonary toxicity with the bleomycin and brentuximab vedotin combination and frequent infusion-related reactions. There is concern with the use of PD-1 inhibitors as first-line therapy due to the theoretical potential for more frequent or severe immune-mediated toxicities in patients who have not received prior chemotherapy. Aside from these concerns, these new agents have the potential to improve outcomes for patients even further, bringing us closer to eradicating recurrent Hodgkin lymphoma.