Precirix has dosed the first subjects in the Phase I/II clinical trial of its lead therapeutic asset, CAM-H2, to treat human epidermal growth factor receptor 2 (HER2)-positive metastatic cancer.

CAM-H2 includes a single-domain antibody that acts on HER2, covalently linked to iodine-131.

The company noted that single-domain antibodies are well fitted for targeted radiation delivery to tumours based on the size, specificity and pharmacokinetic properties.

The trial will assess the safety, tumour uptake, tumour retention as well as initial signs of antitumour activity of CAM-H2 in patients with HER2-positive metastatic breast and gastric/gastro-oesophageal cancer.

These subjects should have relapsed or are refractory to existing anti-HER2 treatments.

The continuous trial will have two segments.

Phase I dose-escalation trial will identify the recommended dose of the treatment for Phase II trial in 3+3 dose-ascending groups of subjects while Phase II will be a dose-expansion trial.

Precirix noted that the Phase I/II trial will also enrol brain metastases patients and have a total of nearly 70 subjects.

Precirix NV CEO Ruth Devenyns said: “We are very excited to have dosed the first patients in this clinical study, the result of years of thorough scientific research, collaboration, and operational excellence of our entire team and partners.

“We look forward to recruiting additional patients and generating efficacy data to confirm the strong results from our preclinical and first-in-human studies, with the goal of bringing new treatment options to cancer patients.”

HER2 is a validated treatment target and several agent, which act on HER2 are approved.

However, these therapies are not effective against metastatic disease and brain metastases have few therapy options.

No HER2 targeting radiopharmaceuticals are currently authorised for usage and CAM-H2 is the lead asset being developed which uses a single-domain antibody to offer targeted radiation to cancer.

This product also offers a novel mechanism of action in the existing HER2 therapy landscape to address key unmet medical needs, including brain metastases and reduced HER2 expression.

Precirix has a wide pipeline with one asset in a Phase I/II trial while two others are currently in the preclinical stage of development.