Rituximab Increases Response to ESHAP in Relapsed, Refractory, and Transformed Aggressive B-Cell Lymphoma.

Background: Patients with relapsed or refractory aggressive B-cell lymphoma, or transformed indolent lymphoma can achieve long-term survival with high dose therapy and autologous stem cell transplant (HDT/ASCT), provided their disease is sensitive to salvage chemotherapy. Unfortunately, approximately 50% of patients are insensitive to standard salvage regimens.

Objectives: This trial investigated whether adding Rituximab to ESHAP (etoposide, solumedrol, cytosine arabinoside, cisplatin) induction improved chemosensitivity. The primary outcome was overall response rate (CR + CRu + PR) to R-ESHAP. Secondary outcomes were toxicity, ability to undergo ASCT, progression free survival (PFS) and overall survival (OS).

Methods: The protocol was approved by the local ethics review board and all patients provided informed consent. Eligible patients received ESHAP every 28 days with GCSF support until < 15% bone marrow involvement was achieved (2–4 cycles). Rituximab was given weekly x 8 weeks concurrent with the first 2 cycles of ESHAP. GCSF mobilized stems cells were collected on day 10–11 of cycle 1 or 2.

Results: The trial was stopped early after the complete response (CR) rate at a planned interim analysis exceeded 40% (a pre-specified criteria for stopping the trial). Final results of 26 patients are presented. Median age was 55.5 years (range 42–64). Twelve patients had relapsed aggressive lymphoma, 2 had refractory disease and 12 had transformed indolent lymphoma. Twenty-two of 26 patients were stage III/IV. The overall response rate to R-ESHAP was 92% (95% CI 82% to 100%). Twelve patients (46%; 95% CI 27% to 65%) had a CR or unconfirmed CR. Grade 3–4 thrombocytopenia, neutropenia, and anemia occurred in 57%, 40%, and 15% of R-ESHAP cycles respectively. Grade 3–4 infections complicated 7% of cycles. Median follow-up was 17 months (range 2.9 to 43.2) from enrollment. Twenty-three of 26 patients (88%) were transplanted. Notable post-transplant toxicity included 5 cases of herpes zoster, 2 cases of bacterial pneumonia, 1 case of pulmonary aspergillosis, and 1 fatal case of pneumocystis carnii pneumonia (PCP). Three patients did not proceed to HDT/ASCT; 2 were refractory to R-ESHAP and 1 died of a myocardial infarction after induction chemotherapy but prior to ASCT. Fifteen of 23 patients who received ASCT remain in remission, 6 have relapsed. Seven patients have died, 4 of progressive disease, 1 of myocardial infarction, 1 of PCP, and 1 of accelerated Parkinson’s Disease. Median PFS and median OS have not yet been reached.

Conclusions: In this single-arm, phase II study of relapsed or refractory aggressive B-cell lymphoma and transformed indolent B-cell lymphoma, R-ESHAP induction therapy resulted in a very high ORR (92%) and enabled a large percentage of patients (88%) to proceed to HDT/ASCT. Toxicity of the R-ESHAP regimen was acceptable, and its efficacy compared favorably with other salvage regimens reported in the literature, including R-ICE.