The role of autologous stem-cell transplantation in classical Hodgkin lymphoma in the modern era.

Despite excellent cure rates with modern front-line regimens, up to 20% of patients with Hodgkin lymphoma will progress through front-line therapy or experience disease relapse. Worldwide, salvage chemotherapy followed by high-dose chemotherapy with autologous stem cell transplantation (HDT/ASCT) is considered the standard of care for these patients and can cure approximately 50% of relapsed or refractory (R/R) patients in the second line. Brentuximab vedotin (BV), an anti-CD30 antibody drug conjugate, and PD1 inhibitors like nivolumab and pembrolizumab, have high response rates in patients who recur after HDT/ASCT. When used prior to HDT/ASCT, BV and PD1 inhibitors appear to dramatically increase the effectiveness of salvage therapies with complete response rates often double those seen with historic chemotherapy-based regimens and durable progression free survival (PFS) post-HDT/ASCT. Emerging data in adults and from pediatric trials showing a durable PFS in a subset of relapsed patients raises the question of whether HDT/ASCT is essential for cure in R/R patients after PD1 based salvage. Future studies will help clarify if ASCT can omitted PD1 based salvage to avoid the potential toxicity of HDT/ASCT without compromising cure.