ZYNLONTA (Loncastuximab Tesirine) and RITUXAN (rituximab) - (LOTIS-5)

June 3, 2026: ADC Therapeutics SA (NYSE: ADCT) reported topline Phase 3 results from the LOTIS-5 confirmatory trial (NCT04384484) evaluating ZYNLONTA (loncastuximab tesirine-lpyl) plus rituximab vs standard R-GemOx (rituximab gemcitabine-oxaliplatin) in patients with relapsed/refractory diffuse large B-cell lymphoma (r/r DLBCL) after ≥1 prior systemic therapy. The study met the primary endpoint of PFS per independent review (HR 0.73; p=0.008; median PFS 6.1 vs 4.7 months). Overall survival showed no detrimental effect vs control (HR 0.96). Secondary efficacy measures favored ZYNLONTA+rituximab: ORR 58.1% vs 45.2%, CR 39.5% vs 26.7%, median DOR 9.2 vs 7.7 months, median DoCR 16.8 vs 12.3 months; 48.5% vs 16.7% of CR patients remained in CR at 24 months.

Safety: overall TEAE rates were similar (98.5% vs 97.5%), but SAEs were higher in the test arm (49.0% vs 34.5%), as were Grade 5 TEAEs (13.2% vs 4.6%) and withdrawals (25.5% vs 9.1%); most Grade 5 events in the test arm occurred in patients ≥75 years.

Regulatory catalyst: the company plans a pre-sBLA meeting with FDA in August 2026 and a planned sBLA submission in Q4 2026 to support continued approval/clinical benefit verification.