HL-339 Camidanlumab Tesirine: Updated Efficacy and Safety in an Open-Label, Multicenter, Phase 2 Study of Patients With Relapsed or Refractory Classical Hodgkin Lymphoma (R/R cHL)

Context: Camidanlumab tesirine (Cami), an antibody–drug conjugate comprising a human IgG1 anti-CD25 monoclonal antibody conjugated to a pyrrolobenzodiazepine (PBD) dimer, displayed antitumor activity and manageable toxicity in a phase 1 trial in lymphoma, including R/R cHL (NCT02432235). Objective: Present updated efficacy and safety data from a phase 2 study of Cami monotherapy in R/R cHL (NCT04052997). Methods: Patients with R/R cHL and ≥3 prior systemic therapies including brentuximab vedotin and anti–PD-1 were enrolled. Primary endpoint: overall response rate (ORR). Patients received Cami 45 µg/kg on Day 1 of each 3-week cycle (2 cycles), then 30 µg/kg (subsequent cycles) for up to 1 year. Results: Enrollment is complete (N=117). Median age was 37 years, 62% of patients were male, and 95% had an ECOG score of 0–1. Fourteen patients (12.0%) withdrew to undergo transplant (12 [10.3%] received transplant and were censored). In the all-treated population (N=117), ORR was 70.1% (82/117; 95% CI: 60.9–78.2); 33.3% (39/117) had complete response (CR). At median (range) follow-up of 10.7 (1.2–25.2+) months, the median (95% CI) duration of response (DOR) was 13.7 months (7.4–14.7) for all responders, 14.5 (7.4–not reached, NR) months and 7.9 (3.8–NR) months for patients with CR or PR. Median (95% CI) progression-free survival (PFS) was 9.1 (5.1–15.0) months. All-grade treatment-emergent AEs (TEAEs) in ≥25% of 117 patients were fatigue (38.5%), maculopapular rash (MR, 32.5%), pyrexia (29.9%), nausea (27.4%), and rash (26.5%). Grade ≥3 TEAEs in ≥5% of patients were thrombocytopenia (9.4%), anemia (8.5%), hypophosphatemia (7.7%), neutropenia (7.7%), MR (6.8%), and lymphopenia (5.1%). TEAEs considered immune-related (IR) occurred in 32.5% of patients; Grade ≥3 IR AEs (TEAEs and non-TEAEs; 8.5%). Guillain–Barré syndrome (GBS)/polyradiculopathy occurred in 8 patients (6.8%). At data cutoff, 4 cases had recovered (grade 2, n=2; grade 4, n=2); 4 had not recovered (grade 4, n=1; grade 3, n=3). Conclusions: Cami demonstrated an ORR of 70.1% (CR: 33.3%) with an encouraging median DOR of 13.7 months and median PFS of 9.1 months. Safety is consistent with prior findings, including similar incidence rates of GBS/polyradiculopathy. Abstract accepted/presented at the EHA 2022 Congress; Funding: ADC Therapeutics SA; medical writing: CiTRUS Health Group.