ADC Therapeutics has dosed the first subject in the Phase Ib clinical trial of ADCT-601 (mipasetamab uzoptirine) in selected advanced solid tumour patients.

The open-label, dose-escalation and dose-expansion trial is analysing the safety and tolerability of ADCT-601 as monotherapy and along with gemcitabine in these patients. 

Nearly 18 subjects with sarcoma will be enrolled in the trial’s first arm.

Sarcoma is a tumour resistant to presently available cancer therapies in which AXL is overexpressed. 

Acting on AXL, ADCT-601 comprises a humanised monoclonal antibody that attaches to human AXL. 

It is conjugated using GlycoConnect technology to a linker with a pyrrolobenzodiazepine (PBD)-dimer toxin. 

AXL is a cancer antigen seen in solid tumours such as sarcoma and is linked to chemotherapy resistance.

On attaching to an AXL-expressing cell, ADCT-601 is internalised into the cell, where enzymes release the PBD-based warhead. 

In a Phase Ia trial, ADCT-601 was found to have a manageable tolerability profile as a single agent.

The therapy showed lasting anti-tumour activity in preclinical human cancer models through AXL-facilitated delivery of a PBD dimer warhead.

ADC Therapeutics chief medical officer Joseph Camardo said: “We look forward to the continued evaluation of ADCT-601, our AXL-targeting ADC, in advanced solid tumours after having established a manageable tolerability profile in our Phase Ia dose-escalation trial. 

“In addition, the combination of ADCT-601 with gemcitabine is demonstrated to be synergistic in preclinical models of solid tumours.”

In June this year, the company dosed the first patient in the Phase Ib LOTIS-7 trial of Zynlonta (loncastuximab tesirine-lpyl) plus other anti-cancer agents for relapsed or refractory B-cell non-Hodgkin lymphoma.