Potential for new immune-oncology therapy using an antibody drug conjugate that targets regulatory T cells
ADC Therapeutics, an oncology drug discovery and development company that specializes in the development of proprietary antibody drug conjugates (ADCs), today announced that the first patient has been dosed in its Phase Ib clinical trial evaluating the safety, tolerability, pharmacokinetics and anti-tumor activity of ADCT-301 (camidanlumab tesirine) in patients with selected solid tumors that are locally advanced or metastatic.
ADCT-301 is already being evaluated in relapsed and refractory Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). At the 2018 American Society of Hematology (ASH) Annual Meeting, ADC Therapeutics presented interim data on 113 patients dosed in its Phase Ia/Ib clinical trial in lymphoma. In HL patients with a median of five prior lines of therapy and no other approved therapy options, the overall response rate was 86.5 percent, including a 43 percent complete response rate, at the dose being considered for a pivotal Phase II clinical trial that the Company anticipates initiating in 2019.
Jay Feingold, MD, PhD, Chief Medical Officer and Senior Vice President of Clinical Development at ADC Therapeutics, said, "We continue to be very encouraged by the anti-tumor activity of ADCT-301 in Hodgkin lymphoma and non-Hodgkin lymphoma. In addition, based on the immune-oncology potential ADCT-301 has demonstrated in preclinical studies, we are excited to be starting this clinical trial for ADCT-301 in solid tumors to see if we can make an impact and improve patient outcomes in multiple difficult-to-treat solid tumor cancers."
ADCT-301 in Solid Tumors
At the Society for Immunotherapy of Cancer's (SITC) 33rd Annual Meeting, ADC Therapeutics presented preclinical data showing that an engineered version of ADCT-301 demonstrated highly potent anti-tumor activity, both as a monotherapy and in combination with a checkpoint inhibitor, in multiple solid tumor models with infiltrating CD25-positive regulatory T cells (Tregs).
Patrick van Berkel, PhD, Senior Vice President of Research and Development at ADC Therapeutics, said, "ADCT-301 targets CD25, which is expressed on Tregs that infiltrate the local tumor environment. In preclinical models, a single dose of the CD25-targeted ADC induced strong and durable anti-tumor activity against established CD25-negative solid tumors with infiltrating Tregs both as a monotherapy and in combination with a checkpoint inhibitor. Moreover, re-challenged mice did not develop new tumors indicating the CD25-targeted ADC was able to induce tumor-specific protective immunity."
The Phase Ib trial of ADCT-301 in patients with advanced solid tumors has both dose escalation and cohort expansion parts. The dose escalation part is designed to establish a safe and tolerated dose and dosing schedule of ADCT-301 in these patients. The identified dose and dosing schedule will be studied in the dose expansion part. Approximately 50 patients will be enrolled in the trial.
For more information about this Phase Ib clinical trial in solid tumors, please visit www.clinicaltrials.gov (identifier NCT03621982).
ADCT-301 (camidanlumab tesirine) is an antibody drug conjugate (ADC) composed of a monoclonal antibody that binds to CD25 (HuMax(R)-TAC, licensed from Genmab A/S), conjugated to a pyrrolobenzodiazepine (PBD) dimer toxin. Once bound to a CD25-expresing cell, ADCT-301 is internalized into the cell where enzymes release the PBD-based warhead. The intra-tumor release of its PBD warhead may cause bystander killing of neighboring tumor cells. In addition, the PBD warhead will trigger immunogenic cell death, which in turn will strengthen the immune response against tumor cells. In addition to the Phase Ib clinical trial in solid tumors, ADCT-301 is being evaluated in ongoing Phase Ia/Ib clinical trials in patients with relapsed or refractory Hodgkin lymphoma and non-Hodgkin lymphoma (NCT02432235).