DA-EPOCH-R appears more toxic than standard R-CHOP in DLBCL

The use of dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab (DA-EPOCH-R) as upfront treatment in patients with diffuse large B-cell lymphoma (DLBCL) showed greater toxicity and did not improve progression-free survival versus standard rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), according to results from a phase 3 trial.

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“Less favorable outcomes for patients with recurrent DLBCL prompted efforts to improve first-line approaches and biomarkers to identify high-risk patients,” wrote Nancy L. Bartlett, MD, of Washington University, St. Louis, and her colleagues wrote in the Journal of Clinical Oncology.

The Alliance/CALGB 50303 study included 491 patients with DLBCL who were randomized in a 1:1 fashion to receive DA-EPOCH-R or R-CHOP every 21 days for a total of six cycles. Dosing for the DA-EPOCH-R regimen was determined using absolute neutrophil and platelet counts.

The primary endpoint measured was progression-free survival (PFS); secondary endpoints included safety, overall survival (OS), and response rate.

After a median follow-up of 5.2 years, the researchers found no significant difference in PFS between the study arms (DA-EPOCH-R hazard ratio, 0.93; 95% confidence interval, 0.68-1.27; P = .65). Additionally, there was no significant difference in OS (HR, 1.09; 95% CI, 0.75-1.59; P = .64).

The overall response rate was 88.0% in the R-CHOP arm versus 86.7% in the DA-EPOCH-R arm (P = .67).

With respect to safety, grade 3 or 4 adverse events were more frequently seen in the DA-EPOCH-R group than in the R-CHOP group (P less than .001). These toxicities included febrile neutropenia, infections, neuropathy, and mucositis.

The researchers did see significantly improved PFS in the DA-EPOCH-R arm in post hoc subset analyses of patients with International Prognostic Index (IPI) 3-5, but the subset analysis “was unplanned and not powered” and the significance “must be tempered in light of multiple comparisons.”

“We now understand DLBCL is even more heterogeneous than appreciated when this trial was designed,” the researchers wrote. “Therefore, the National Clinical Trials Network is planning a precision medicine approach to identify molecular subsets of DLBCL and determine if specific chemotherapy platforms and/or targeted agents offer differential benefit.”

The study was supported by the National Cancer Institute. The authors reported financial relationships with Bristol-Myers Squibb, Celgene, Janssen, Jazz Pharmaceuticals, Morphosys, and other companies.

SOURCE: Bartlett NL et al. J Clin Oncol. 2019 Apr 2. doi: 10.1200/JCO.18.01994.