In the phase 3 ECHELON-2 trial, brentuximab vedotin, cyclophosphamide, doxorubicin, and prednisone (BV-CHP) significantly improved progression-free survival (PFS) and overall survival (OS) compared with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in patients with CD30+ peripheral T-cell lymphoma (PTCL), benefits that were maintained at 5 years. Interim positron emission tomography (PET) scan can be used to assess prognosis and risk stratify patients. The prognostic value of interim PET was assessed in this post hoc exploratory analysis from ECHELON-2 evaluating interim 18F-FDG PET scans after cycle 4 (PET4) and end-of-treatment-based response and correlated with PFS per investigator and OS. PET4 response was determined by Deauville score (scores of 1-3 were considered negative PET4-negative and 4-5 positive PET4-positive) by independent review. Overall, 452 patients were randomized 1:1 to the BV-CHP (n = 226) and CHOP (n = 226) arms. Of these, 32 in the BV-CHP arm and 41 in the CHOP arm were not evaluable for PET4. In both arms, PET4-negative status was associated with improved PFS (HR 95% CI BV-CHP 0.36 0.19-0.66, CHOP 0.26 0.17-0.41) and OS (HR 95% CI BV-CHP 0.38 0.18-0.78, CHOP 0.240.14-0.41) compared with PET4-positive status. In patients with systemic anaplastic large cell lymphoma, PET4-negative patients had improved PFS (HR 95% CI BV-CHP 0.28 0.14-0.60, CHOP 0.31 0.17-0.56) and OS (HR 95% CI BV-CHP 0.38 0.16-0.94, CHOP 0.25 0.12-0.55) compared with PET4-positive patients. In this exploratory analysis, PET4-negative status by Deauville score was associated with improved long-term PFS and OS in both the BV-CHP and CHOP arms.
Iyer et al. (Tue,) studied this question.