Fig. 1: Patterns of 2 L treatment and prior 1 L treatment by era of 2 L treatment.

A–C Patterns of treatment in Era 1–3. D Summary of treatment groups by era of 2 L treatment. Abbreviations: 1 L first-line, 2 L second line, ASCT autologous stem cell transplant, BEAM carmustine, etoposide, cytarabine, and melphalan, BR, bendamustine plus rituximab, BTKi Bruton tyrosine kinase inhibitor, CHOP cyclophosphamide, doxorubicin, vincristine, and prednisone, HiDAC high dose cytarabine, R: rituximab. Treatment groups: HiDAC-based: R-Hyper-CVAD/R-MA, R-maxi-CHOP/R-HiDAC (Nordic regimen) or R-CHOP/R-DHAP; R-CHOP/R-CHOP-like: R-CHOP, R-CVP, R-EPOCH, R-CHOP + methotrexate, R-CHOP + ibritumomab; Other systemic therapy: rituximab/cladribine with and without temsirolimus, fludarabine/rituximab, cladribine/fludarabine or fludarabine/rituximab/cyclophosphamide/mitoxantrone, VcR-CVAD; Targeted therapy: lenalidomide with or without rituximab, bortezomib, ibritumomab, sorafenib, venetoclax, everolimus, temsirolimus, single agent rituximab; BTKi: ibrutinib, acalabrutinib, or zanubrutinib; Non-systemic therapy: surgical resection (including splenectomy) or radiation therapy.