An International Multicentre Study of Consecutively Diagnosed Patients with ALCL: Outcomes Following First-Line Therapy in Routine Clinical Practice

Introduction Anaplastic large-cell lymphoma (ALCL) is a rare subtype of T-cell non-Hodgkin lymphoma, characterized by uniformly strong CD30 expression and further delineated by expression of the Alk protein. Standard first-line (1L) therapy is CHOP-based chemotherapy, with or without consolidative autologous stem cell transplant (ASCT) (Schmitz, Blood, 2010). Despite intensive chemotherapy approaches, 40-65% of patients experience relapsed/refractory disease, for which brentuximab vedotin (BV) as monotherapy has established efficacy (Pro, Blood, 2017) Recent results from ECHELON-2 (E2), led to FDA approval of BV in combination with CHP (CHP+A) as first-line treatment for CD30+ PTCL, based on a 34% reduction in risk of death compared to CHOP, an effect only demonstrable in ALCL (70% of the E2 cohort) (Horwitz, Lancet, 2019). Given this renewed treatment landscape, we investigated outcomes of unselected patients with ALCL treated in routine clinical practice. Methods/Study Population Consecutively diagnosed patients with systemic ALCL from 6 UK and Australian centres (n=166) were studied (Dec 2004-Dec 2018). Patients ≥16 years with ALCL were included irrespective of Alk status. Treatment allocation was clinician choice and included best supportive care (BSC). Post-mortem diagnosis and 10 patients treated on E2 were excluded. Principal outcomes were PFS and OS following 1L treatment. Additional outcome measures included frequency of ASCT and use of BV for r/r ALCL. Data were retrospectively collected following GDPR guidelines and in accordance with the declaration of Helsinki. Results Median age at diagnosis was 57.5 years (range 16-93), 62% were male, 19% had ECOG ≥3 and 53 (35%) patients were ALK positive. Median lines of therapy was 1 (range 0-6). Baseline patient characteristics are shown in table 1. The most frequent 1L treatment regimen was CHOP in 104 pts (67%), 26 (18%) received intensified regimens (CHOEP, CHOP/IVE/MTX, CODOX-M, ALCL99), 4 received other regimens (2.6%) and 14 had best supportive care (9%). Treatment-related mortality was 5.6% (8/142). 12 (8%) patients underwent ASCT in first response, of whom 10 had received intensified induction regimens. Of 141 evaluable pts, ORR was 71% and CR rate was 52%. Median follow up of all patients was 40 months, 3-year PFS and OS for 1L of treatment were 46% and 58% respectively. For the CHOP-treated cohort (n=104), 3-year PFS and OS were 47% and 57%. Outcomes for ALK-negative patients treated with CHOP