Autologous Stem Cell Transplant in Fit Patients With Late Relapsed Diffuse Large B-Cell Lymphoma That Responded to Salvage Chemotherapy.

The standard of care (SOC) for fit patients with relapsed diffuse large B-cell lymphoma (DLBCL) ≥12 months after completing frontline therapy is salvage chemotherapy (ST) followed by autologous stem cell transplant (ASCT). However, this strategy may not be optimal for patients with certain clinical characteristics. We retrospectively studied 151 patients with DLBCL that relapsed ≥12 months after R-CHOP or R-CHOP-like frontline therapy who underwent ST and ASCT at Mayo Clinic between July 2000 and December 2017 or the University of Iowa between April 2003 and April 2020. Clinical characteristics, treatment information, and outcome data were abstracted. Progression-free survival (PFS) and overall survival (OS) from the time of ASCT were analyzed using the Kaplan-Meier method. The median time from frontline therapy completion to 1st relapse was 26.9 months. The median line of ST was 1 (range 1-3), and 17 (11%) patients required >1 line of ST. Best response before ASCT was partial response (PR) in 60 (40%) and complete response (CR) in 91 (60%) patients. The median age at ASCT was 64 yr (range 19-78), and 36 (24%) patients were of ≥70 yr. The median follow-up after ASCT was 87.3 months. The median PFS and OS were 54.5 and 88.9 months, respectively. There was no significant difference in PFS and OS based on the age at ASCT (including patients aged ≥70-78 yr), sex, transplant era, time to relapse, LDH, extranodal site involvement, and central nervous system/nerve involvement at relapse. However, patients with advanced-stage relapse had inferior PFS than those with early-stage relapse (median 45.3 versus 124.7 months, P = .045). Patients who required > 1 line of ST, compared to those requiring 1 line, had significantly inferior PFS (median 6.1 versus 61.4 months, P < .0001) and OS (17.8 versus 111.7 months, P = .0004). There was no statistically significant difference in survival in patients who achieved PR versus CR, though numerically inferior in the former, with median PFS of 38.9 versus 59.3 months (P = .23) and median OS of 78.3 versus 111.7 months (P = .62). Patients achieving CR after 1 line of ST had excellent post-ASCT outcomes, with median PFS of 63.7 months. In conclusion, survival after ASCT was unfavorable in patients with late relapsed DLBCL (≥12 months) who required more than 1 line of ST to achieve PR or CR, and such patients should be treated with alternative therapies. Conversely, survival was favorable in patients who required only 1 line of ST, supporting the current clinical practice of ASCT consolidation in these patients. Moreover, outcomes were favorable in patients aged ≥70 to 78 yr at ASCT, similar to younger patients, highlighting the safety and feasibility of this approach in such patients.