Poor Outcomes Among Patients Failing Dose-Adjusted EPOCH in Aggressive Lymphoma: A Collaborative, Retrospective Study

Introduction

Among patients with aggressive B-NHL who fail RCHOP, about half respond to standard salvage regimens and may proceed to curative-intent, transplant-based therapy.  However, whether pts failing more intensive regimens such as dose-adjusted, infusional EPOCH benefit from standard salvage regimens is unclear. We hypothesized that such patients comprise a higher-risk cohort, facing inferior response rates and outcomes using standard salvage regimens.   We undertook a collaborative study to assess response rates and survival among pts failing EPOCH for aggressive B-NHL, to inform patient management and design of clinical trials in this setting.

Methods

Pharmacy records and institutional databases were queried, identifying pts receiving EPOCH over the last 10 years at the University of Washington/SCCA and the Cleveland Clinic Foundation, for combined analysis. Under IRB approval, patient characteristics, histology, outcome with EPOCH, time to EPOCH failure, response to salvage, and overall survival were analyzed.  Diffuse large B cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma, B-cell-lymphoma unclassifiable, HIV-associated B cell lymphoma, and transformed B cell non-Hodgkin lymphoma were included.  Pts receiving <2 cycles EPOCH, or who had inadequate follow-up (<3 months), were excluded.  Failure of EPOCH was defined as failure to respond or progression during therapy, need for initiation of salvage therapy, or death during therapy of any cause.  Adverse events or treatment change due to toxicity were not included in the definition of failure.  JMP 11 was used to generate kaplan-meier survival estimates.

 Results

124 pts with aggressive B-NHL receiving EPOCH were identified.  54 had not relapsed, and among 70 remaining da-EPOCH failures, 37 met the above inclusion criteria.

 Median age was 55.  27% were female, and 23 received EPOCH as first-line therapy. All but 3 received rituximab with EPOCH.  Histologies were primarily DLBCL in 22/37 (60%) and BCL-U in 12/37 (32%) carrying a MYC translocation; most of these harbored additional translocations in BCL2 and/or BCL6 (10/12).  However, data regarding MYC rearrangement was not available for all pts. 2 had HIV-associated B-NHL and 3 had PMBCL.

With 18 months follow up, the median time to EPOCH failure was 5 months. Only 3 EPOCH failures occurred late (>12 months). 

Median OS from the date of EPOCH failure was 10 months (Figure 1).  Those receiving EPOCH as first-line therapy (23) had a median OS of 14 months from EPOCH failure, as opposed to 4 months for those receiving EPOCH as salvage therapy (log-rank p=.01). Salvage chemotherapy regimens after EPOCH were diverse, and generally ineffective; 6/28 (21%) regimens produced a response (Table 1).  Among patients failing EPOCH within a year, platinum-containing salvage (RICE/RDHAP) was effective in only 2/13 patients (15%).  9 patients did not receive any salvage, most of whom died or proceeded to palliative measures and/or hospice care.

Conclusions

A relatively low overall response rate (21%) was observed in this retrospective analysis of patients failing EPOCH.  Analogous to early RCHOP failure in the CORAL study, those failing EPOCH within a year may face inferior outcomes with platinum-based salvage therapy.  While combined from two institutions, our data represent a modest sample size and require confirmation. If verified, examination of mechanisms of resistance to EPOCH, and selecting EPOCH failures for clinical trials of novel targeted therapies and transplant-based approaches, may prove critical.

Table 1: Salvage Therapy for REPOCH failures
Regimen: response/total number treated	Notes
Response to any salvage: 6/28 (21%)	Some patients received more than 1 chemo salvage; responses were tabulated per regimen.
RICE: 4/12	2/3 alive post transplant (1 auto 1 allo; 1 declined transplant and survived; 1 died)
RDHAP: 1/6
Gemcitabine-based:  0/5
HyperCVAD  (Part A and/or B): 1/5	Survivor had CNS only relapse, received regimen B and transplant
9- received no systemic treatmen; most died or proceeded to palliative measures and/or hospice