Harpoon Therapeutics has commenced dosing of patients in a Phase I/IIa clinical trial being conducted to evaluate HPN536 for the treatment of solid tumours.
Based on the company’s Tri-specific T cell Activating Construct (TriTAC) platform, HPN536 is meant to target mesothelin expressed on cells of ovarian and pancreatic carcinoma, mesothelioma, non-small cell lung cancer, and breast cancer.
The TriTAC platform uses patient’s own immune cells to destroy tumours, and HPN536 is Harpoon’s second TriTAC-based candidate to enter the clinical phase.
During the multi-centre Phase I/IIa trial, HPN536’s safety, tolerability, pharmacokinetics and activity will be assessed in up to 80 patients with mesothelin-expressing cancers.
The Phase I dose escalation part of the trial is intended to establish a dose for further clinical studies. This portion will enrol around 20 ovarian cancer patients who will receive a once-weekly intravenous infusion of the drug candidate.
Primary outcome measures of the Phase I part are safety, tolerability, and determination of a dose for the Phase II portion.
The dose escalation phase will be followed by a further assessment of the safety and activity of HPN536 in around three other parallel cohorts of 20 patients each with ovarian, pancreatic and mesothelioma cancer.
Harpoon Therapeutics chief medical officer Natalie Sacks said: “The dose escalation portion of the trial will focus on patients with ovarian cancer, where mesothelin is overexpressed in a high percentage of patients.
“HPN536 is a targeted, off-the-shelf immunotherapy that has been optimised for delivery to solid tumours and designed to provide a novel way to engage a patient’s own immune cells to fight cancer for patients who have limited treatment options.”
The Phase I/IIa trial has been initiated at Sarah Cannon Research Institute and is expected to be completed in 2021.