Recent progress: hematopoietic cell transplant for diffuse large B-cell lymphoma

Ofatumumab, Etoposide, and Cytarabine Intensive Mobilization Regimen in Patients with High-risk Relapsed/Refractory Diffuse Large B-Cell Lymphoma Undergoing Autologous Stem Cell Transplantation

BACKGROUND

More than one-half of high-risk patients with relapsed/refractory (rr) diffuse large B-cell lymphoma (DLBCL) relapse after autologous hematopoietic cell transplantation (auto-HCT). In this phase II study, we investigate the long-term outcomes of high-risk patients with rrDLBCL receiving intensive consolidation therapy (ICT) with OVA (ofatumumab, etoposide, and high-dose cytarabine) prior to auto-HCT.

PATIENTS AND METHODS

The primary endpoints were the ability of OVA to mobilize peripheral stem cells and the 2-year progression-free survival (PFS) rate following OVA. Secondary endpoints included safety, 2-year overall survival (OS), impact of cell of origin (COO), and the prognostic utility of next-generation sequencing minimal residual disease (MRD) testing. We simultaneously retrospectively assessed the outcomes of DLBCL patients who underwent ICT with a similar regimen at our institution.

RESULTS

Twenty-seven patients received salvage chemotherapy, with a response rate of 25% in patients with germinal center B-cell (GCB)-DLBCL versus 92% in patients with non-GCB-DLBCL (P = .003). Nineteen responding patients underwent ICT with OVA (100% successful stem cell mobilization). The 2-year PFS and OS rate was 47% and 59%, respectively, with no difference based on COO. Similar findings were observed when the study and retrospective cohorts were combined. Neutropenia was the most common toxicity (47%). MRD-negative patients at the completion of salvage had a median OS of not reached versus 3.5 months in MRD-positive patients (P = .02).

CONCLUSIONS

OVA followed by auto-HCT is effective and safe for high-risk rrDLBCL. Patients with GCB-DLBCL had a lower response to salvage chemotherapy, but no difference in outcomes based on COO was seen after auto-HCT. MRD testing in the relapsed setting was predictive of long-term survival.

Minimal residual disease in non-Hodgkin lymphoma - current applications and future directions

Non-Hodgkin Lymphomas (NHLs) are a heterogeneous group of tumours with distinct treatment paradigms, but in all cases the goal of treatment is to maximize quality and duration of remission while minimizing therapy-related toxicity. Identification of persistent disease or relapse is most often the trigger to intensify or re-initiate anti-neoplastic therapy, respectively. In the current era of NHL treatment, this determination is mostly based on imaging and clinical evaluations, tools with imperfect sensitivity and specificity. The availability of minimal residual disease (MRD) monitoring could transform treatment paradigms by allowing intensification of treatment in at-risk patients or early intervention for impending relapse. Novel methods based on polymerase chain reaction and next-generation sequencing are now being studied in NHL with promising results. This review outlines the current status of the field in the use of MRD techniques for diffuse large B-cell lymphoma, mantle cell lymphoma and follicular lymphoma. Specifically, we address their demonstrated and potential clinical utility in risk stratification, monitoring of remission status, and guiding interim and post-treatment escalation. Future applications of these techniques could identify novel markers of MRD, improve initial treatment selection, guide treatment escalation or de-escalation, and allow for real-time monitoring of patterns of clonal evolution, which together could redefine NHL treatment paradigms.

Orbital MALT Lymphoma after Autologous Stem Cell Transplantation for Follicular Lymphoma as Relapse of Diffuse Large B-Cell Lymphoma

We report a patient who developed orbital MALT lymphoma after autologous peripheral blood stem cell transplantation for follicular lymphoma as relapse of diffuse large B-cell lymphoma. A 54-year-old woman with systemic lymphadenopathy was diagnosed with diffuse large B-cell lymphoma by left supraclavicular lymph node biopsy, and underwent 6 courses of R-CHOP chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone, leading to complete response. Five years later in the follow-up, an abdominal mass with abnormal uptake was found by whole-body 2-[¹⁸F]fluoro-2-deoxy-D-glucose positron emission tomography, and computed tomography-guided biopsy demonstrated follicular lymphoma. She underwent 4 courses of R-IDEA chemotherapy with rituximab, ifosfamide, dexamethasone, etoposide, and cytarabine, resulting in partial response, and then, underwent autologous peripheral blood stem cell transplantation with myeloablative conditioning with R-MCEC chemotherapy (rituximab, ranimustine, cyclophosphamide, etoposide, and carboplatin). She was well for the following 3 years with no treatment until the development of a right orbital mass. The excisional biopsy this time revealed MALT lymphoma. She underwent 3 courses with rituximab monotherapy and local orbital radiation at the total dose of 30 Gy. She had no relapse for the following three years. Relapse as MALT lymphoma after hematopoietic stem cell transplantation for relapsed and refractory lymphoma may not be a poor prognostic sign.