High-dose therapy and autologous stem cell transplant for transformed non-Hodgkin lymphoma in the rituximab era.

The impact of rituximab on the outcome of high-dose therapy and autologous stem cell transplant (HD-ASCT) for transformed non-Hodgkin lymphoma (NHL) has not been previously described. We analyzed 18 consecutive patients with indolent NHL who transformed to diffuse large B-cell lymphoma (DLBCL), received rituximab-containing therapy either before or after transformation and underwent subsequent HD-ASCT. With a median follow-up of 40 months, the 2-year progression-free survival (PFS) was 59% and the 2-year overall survival (OS) was 82%. Six patients did not receive rituximab pre-transformation. This group had a significantly better PFS at 2 years post-HD-ASCT compared to 12 patients who were exposed to rituximab pre-transformation (p = 0.03). HD-ASCT remains an effective therapeutic option for transformed NHL in the rituximab era. However, patients exposed to rituximab pre-transformation appear to have inferior HD-ASCT outcomes, and thus may benefit from novel conditioning and maintenance regimens in the setting of HD-ASCT.