CAMIDANLUMAB TESIRINE EFFICACY AND SAFETY IN AN OPEN‐LABEL, MULTICENTER, PHASE 2 STUDY OF PATIENTS (PTS) WITH RELAPSED OR REFRACTORY CLASSICAL HODGKIN LYMPHOMA (R/R CHL)

Introduction: Camidanlumab tesirine (Cami) is an antibody-drug conjugate comprising a human IgG1 anti-CD25 monoclonal antibody conjugated to pyrrolobenzodiazepine (PBD) dimer warhead. Cami has demonstrated encouraging antitumor activity and manageable toxicity in Ph 1 trial lymphomas, particularly R/R cHL. Here we present preliminary results of 2 study monotherapy pts with Methods: Pts cHL ≥3 prior therapy lines, including brentuximab vedotin (BV) PD-1 blockade (≥2 lines if ineligible for hematopoietic cell transplantation; HCT) were enrolled (NCT04052997). An interim analysis was conducted after meeting protocol-specified criterion pausing enrollment (Herrera et al. Blood 2020;136:Suppl.1:21–3). After safety efficacy review, the pause lifted. The primary objective evaluation by overall response rate (ORR; central review). Duration (DOR) progression-free survival (PFS) are secondary endpoints. Efficacy reported on ≥12 weeks since first dose. Safety endpoints include frequency severity TEAEs, assessed all treated pts. received 45 μg/kg IV Day each 3-week cycle cycles, then 30 subsequent cycles. Results: As Dec 4, 2020, 82 had enrolled. median 7 (range 3–19) therapy. mean (SD) 4 (3.0) Five 47 (10.6%) who discontinued treatment underwent HCT following administration. In 52 evaluable efficacy, ORR 82.7% (43/52 pts), 38.5% (20/52) attaining complete (Figure). Median DOR not reached at (range) follow-up 9.2 (2.0–14.3 [censored]) months. (95% CI) PFS (5.0–not reached) All-grade TEAEs ≥25% set fatigue (34, 41.5%), nausea maculopapular rash (each 23, 28.0%) pyrexia (21, 25.6%). Grade ≥5% hypophosphatemia (7, 8.5%) lymphopenia (5, 6.1%). leading dose delay/reduction or discontinuation occurred 8 (9.8%) 10 (12.2%) pts, respectively. Categories considered PBD-associated included skin reactions/nail disorders (48, 58.5%), liver function test abnormalities (23, edema/effusion (10, 12.2%). Guillain–Barré syndrome (GBS)/polyradiculopathy (4.9%) pts: GBS (Grade 2, resolved; improved); radiculopathy pt resolved); encephalitis polyneuropathy 3, ongoing). Best responses patients classical Hodgkin lymphoma (efficacy seta) Conclusions: high heavily pretreated failure BV blockade, DOR. Data continue mature. remains consistent findings. Pt completed Jan 29, 2021 updated total population (N = 117) will be presented. research funded by: ADC Therapeutics SA Keywords: lymphoma, Chemotherapy, Immunotherapy Conflicts interests pertinent abstract P. L. Zinzani Consultant advisory role: Verastem, MSD, Eusapharma, Sanofi, Therapeutics, Celltrion, Gilead, Janssen-Cilag, Bristol-Myers Squibb, Servier, Sandoz, TG Takdea, Roche, Kyowa Kirin C. Carlo-Stella Karyopharm Celgene/Bristol-Myers Incyte Honoraria: Merck Sharp & Dohme, Janssen Oncology, AstraZeneca, Celgene, Takeda, Incyte, Gilead Sciences Research funding: M. Hamadani Consultancy services R&D, Corporation, Celgene Pharmacyclics, Omeros, AbGenomics, Verastem TeneoBio; speaker's bureau Sanofi Genzyme, BeiGene AstraZeneca Takeda Pharmaceutical Company, Spectrum Pharmaceuticals Astellas Pharma A. F. Herrera Squibb; Genentech/Roche; Merck; Seattle Genetics; Squibb (Inst.); Genentech/Roche Immune Design Pharmacyclics Genetics (Inst.) Other remuneration: Travel/accommodation/expenses: S. Ansell Bristol Myers Genetics, Affimed, Regeneron, Trillium, AI J. Radford Novartis Kite Pharma; speaker Stock ownership: (spouse) Expert testimony K. Maddocks BMS, Karyopharm, Morphosys, BMS Kline Merck, Kite/Gilead, MorphoSys, Seagen iTeos Savage Novartis, Janssen, Kyowa, Servier Roche (Institutional) Beigene (Steering Committee) N. Bartlett Autolus, Forty Seven, Design, Pharma, Millennium, Pfizer, Roche/Genentech, Caimi support from Genentech; boards Genentech, Pharmaceuticals, Amgen; consultancy Therapeutics; Y. Negievich Employment leadership position: H. G. Cruz Wang America, Inc Wuerthner Collins Celleron, Beigene, Daiichi Sankyo, Amgen, Celleron SESSION 12: INDOLENT LYMPHOMAS