Final Analysis of the Ro-CHOP Phase III Study (Conducted by LYSA): Romidepsin Plus CHOP in Patients with Peripheral T-Cell Lymphoma

Background: Peripheral T-cell lymphoma (PTCL) is an aggressive form of non-Hodgkin lymphoma (NHL) that is typically associated with a poor prognosis. Romidepsin is a histone deacetylase inhibitor approved by the US Food and Drug Administration for patients with PTCL who have received at least 1 prior therapy (J Clin Oncol. 2012;30:631). Presented here is the final analysis of a phase III randomized study comparing romidepsin + cyclophosphamide, doxorubicin, vincristine, and prednisone (Ro-CHOP) with CHOP in patients with previously untreated PTCL.

Methods: Ro-CHOP (NCT01796002) is a randomized multicenter phase III study in adult patients with previously untreated PTCL (i.e. nodal or extranodal entities including primary cutaneous non epidermotropic TCL, with the exclusion of ALK-positive anaplastic large cell lymphomas and EBV-positive extranodal NK/T-cell lymphomas). Diagnostic biopsies were centrally reviewed (94%), and patients were randomized based on International Prognostic Index (IPI) score at baseline (< 2 vs ≥ 2), age (≤ 60 vs > 60 y), and histology type (nodal vs extranodal) to receive either Ro-CHOP or CHOP. Two-sided P-value from log-rank test stratified by all 3 stratification factors was used. All patients received CHOP in 3-week cycles for 6 cycles. Romidepsin, 12 mg/m², was administered intravenously on days 1 and 8 of each 3-week cycle for 6 cycles (Lancet Haematol. 2015;2:e160), with dose reductions to 10 and 8 mg/m² based on toxicity. The primary end point was progression-free survival (PFS) per Response Adjudication Committee assessment according to International Working Group 1999 criteria. Secondary end points included overall survival (OS), objective response rate (ORR), complete response (CR) + CR unconfirmed (CRu), and safety.

Results: As of the December 13, 2019 cutoff date, 421 patients were included in the intention-to-treat population (Ro-CHOP, n = 211; and CHOP, n =210). Median age was 65 y (range, 25-81); 76 patients (18%) had ECOG PS of 2-3; 267 (63%) had Ann Arbor stage IV disease; and 342 (81%) had IPI score ≥ 2. At a median follow-up of 27.5 mo, the study did not meet its primary end point because Ro-CHOP did not show a statistically significant PFS improvement vs CHOP alone. Median PFS for Ro-CHOP vs CHOP was 12.0 mo (95% CI, 9.0-25.8) vs 10.2 mo (95% CI, 7.4-13.2), with a hazard ratio of 0.81 (95% CI, 0.63-1.04; P = 0.096). Median OS for Ro-CHOP vs CHOP was 51.8 mo (95% CI, 35.7-72.6) vs 42.9 mo (95% CI, 29.9-not evaluable). ORR of Ro-CHOP vs CHOP was 63% vs 60% with CR + CRu rates of 41% vs 37%. In the safety population (Ro-CHOP, n = 210; CHOP, n = 208), any-grade treatment emergent adverse events (TEAEs) that occurred ≥ 40% in the Ro-CHOP or CHOP arms, respectively, included anemia (67% vs 38%), nausea (55% vs 31%), thrombocytopenia (52% vs 17%), neutropenia (51% vs 37%), and vomiting (40% vs 10%). Grade 3/4 TEAEs that occurred in ≥ 30% of patients in the Ro-CHOP or CHOP arm, respectively, included thrombocytopenia (50% vs 10%), neutropenia (49% vs 33%), anemia (47% vs 17%), and leukopenia (32% vs 20%). One grade 5 TEAE occurred in the Ro-CHOP arm (E. coli sepsis), and 2 occurred in the CHOP arm (colitis and acute cholecystitis). In the Ro-CHOP vs CHOP arms, TEAEs led to CHOP dose interruption in 75 (36%) vs 42 (20%) patients, reduction in 54 (26%) vs 31 (15%) patients, and discontinuation in 7 (3%) and 6 (3%) patients, respectively. In the Ro-CHOP arm, TEAEs led to romidepsin interruption, reduction, and discontinuation in 132 (63%), 77 (37%), and 17 (8%) patients, respectively.

Conclusions: The addition of romidepsin to CHOP did not improve PFS, the primary endpoint of the study, and response rates and OS appeared similar with the combination. The toxicity profile of Ro-CHOP was consistent with its phase Ib/II data, with no unexpected findings. The high rates of TEAEs with the addition of romidepsin hampered the ability to adequately administer 6 cycles of CHOP. Additional exploratory analyses to compare Ro-CHOP outcomes in specific patient subgroups are ongoing. The combination of CHOP plus romidepsin does not represent an advance in the standard of care for patients with previously untreated PTCL.