ADC Therapeutics has reported positive results from the Phase II clinical trial of loncastuximab tesirine (ADCT-402) for treating relapsed or refractory diffuse large B-cell lymphoma (DLBCL).

Loncastuximab tesirine is an antibody drug conjugate (ADC) that includes a humanised monoclonal antibody. It is engineered to target the CD19-expressing cell, highly expressed in a range of B-cell hematological tumours including lymphoma.

The single-arm, multi-centre, open-label Phase II clinical trial aimed to test the efficacy, safety and pharmacokinetics of the candidate as a monotherapy in patients with relapsed or refractory DLBCL.

The study involved 145 patients administered with 30-minute intravenous infusions of loncastuximab tesirine once every three weeks.

The dose was fixed at 150μg/kg for the first two three-week cycles, followed by 75μg/kg in subsequent cycles until discontinuation.

Loncastuximab tesirine achieved an overall response rate (ORR) of 45.5%. In Phase I trials, the candidate demonstrated an ORR of 41.4% at the initial dose used in Phase II.

ADC Therapeutics senior vice-president and chief medical officer Jay Feingold said: “These data exceeded our primary endpoint target and reinforce the significant single-agent anti-tumour activity and manageable toxicity profile of loncastuximab tesirine in patients with relapsed or refractory DLBCL who have failed established therapies.

“Loncastuximab tesirine has demonstrated its potential to fill a critical unmet need for a new therapy and become a key part of the treatment paradigm for all heavily pretreated patients with DLBCL.

“We plan to present final data from the pivotal Phase II clinical trial at a future scientific meeting.”