Abstract INTRODUCTION The ECHELON-2 trial for newly diagnosed CD30+ peripheral T-cell lymphomas (PTCL) demonstrated superior overall survival with brentuximab vedotin plus chemotherapy (BV-CHP) compared to CHOP. However, total enrollment was restricted to only 30% of patients with non-anaplastic large cell lymphoma (ALCL) histologies and was not powered to analyze survival benefits in this cohort. Thus, the benefit of BV-CHP in non-ALCL patients remains less clear. Adding to this uncertainty, CHOP plus etoposide (CHOEP) remains a standard regimen for many non-ALCL PTCL histologies for patients 60 years of age. Which of these three regimens offers superior outcomes for patients with CD30+ non-ALCL PTCL remains to be determined, is a critical knowledge gap in this area, and could meaningfully inform the management of these patients. METHODS We conducted a retrospective analysis of chemotherapy-naïve CD30+ (≥1%) PTCL from 7 centers in the United States. Histologies were limited to PTCL-NOS and PTCL with a T follicular helper phenotype (PTCL-TFH). Frontline regimens were defined as BV-based (BV-CHP), etoposide-based (CHOEP/EPOCH), novel-CHOP (CHOP/CHOEP + novel drug on a clinical trial), or CHOP. CD30 was considered positive if any expression was reported, and when available, stratified as ≥10% or 10% of the total lymphocyte population. RESULTS The CD30+ PTCL cohort consisted of 194 patients with a median age of 68 years at diagnosis and a male (65%) predominance. Nodal PTCL-TFH (65%) was the most common histology. Most had stage III-IV disease (89%) with a high-intermediate to high-risk IPI score of 3-5 (54%). 18% had an ECOG of ≥2, 45% had ≥2 extranodal sites, and 43% had bone marrow involvement, although biopsies were not performed in all patients. CD30 expression in ≥10% of malignant T cells was observed in 55% of all quantitatively reported cases. Frontline therapy consisted of BV-based (36%), etoposide-based (30%), CHOP (27%), and novel-CHOP (7%). Baseline characteristics and CD30 expression were similar between treatment groups. The ORR was 72% (64% CR, 8% PR), with no differences observed by treatment or histology. On multivariate analysis (MVA), a high LDH was associated with lower CR (OR 2.84, p=0.003). For the patients who demonstrated a CR to frontline therapy, 61% underwent ASCT. With a median follow-up of 26.1 months (IQR 12.3-51.6), the median PFS and OS were 11.4 (9.8-14.2) and 47 (32-60.3) months, respectively. The 2-year PFS and OS were 34.9% (28.1-41.7) and 62% (54.5-68.6), respectively. PFS and OS were similar for PTCL-NOS compared to PTCL-TFH, and AITL fared similarly to non-AITL PTCL-TFH. By treatment, novel-CHOP demonstrated the most favorable PFS (median 41.9 months) and OS (median 68.1 months). Survival curves overlapped continuously with all other treatment regimens and was not statistically significant. For patients 60, PFS and OS were equivocal with BV-based (n=17) compared to etoposide-based (n=26) regimens. On MVA, stage III/IV disease conferred an inferior PFS (HR 2.00, p=0.018) as did an IPI score of 3-5 for OS (HR 2.15, p=0.001). Neither histology nor frontline treatment impacted PFS or OS. The chosen frontline treatment also had no survival impact in key subgroup analyses including patients 60 (n=56) or with CD30-expression ≥10% (n=43). For patients with CR to frontline therapy, ASCT demonstrated a significant PFS benefit (HR 0.59, p=0.028) but no statistically significant difference in OS benefit (HR 0.58, p=0.073). CONCLUSION These data provide valuable insight into the lesser-represented patient population from the pivotal ECHELON-2 trial. In this cohort of CD30+ (≥1%) non-ALCL PTCL, there was no clearly superior standard frontline regimen. The number of patients with quantitively reported CD30 expression was too small for definitive conclusions in the ≥10% CD30+ cohort and retrospective pathology review is ongoing. ASCT for patients in CR offered superior outcomes, supporting this strategy regardless of the frontline regimen, recognizing the limitations of non-randomized, retrospective analyses. Novel-CHOP regimens demonstrated encouraging survival, and clinical trials should maintain priority over standard regimens for patients with CD30+ (1-10%) PTCL-NOS and PTCL-TFH.
Han et al. (Mon,) studied this question.