Biopharmaceutical firm Apexigen has begun enrolling patients in a Phase I/II clinical trial of APX005M in combination with pembrolizumab (Keytruda) to treat metastatic melanoma.
APX005M is a humanised monoclonal antibody being developed to utilise the immune system's antigen-presenting cells (APC) to trigger an anti-tumour response in the tumour microenvironment.
Pembrolizumab is an immune checkpoint PD-1 inhibitor with an ability to generate T-cells from immunosuppression, which is complemented by APX005M's APC activation.
The Phase I/II trial is designed to assess the safety, tolerability and efficacy of locally administered APX005M in combination with systemically given pembrolizumab.
Apexigen chief medical officer Ovid Trifan said: "APX005M has demonstrated robust immune system activation and an excellent safety profile and we are eager to explore the therapeutic benefit of combining our antibody with pembrolizumab for patients living with melanoma.
"We expect that APX005M's anti-tumour immune response through antigen-presenting cells will become a cornerstone of many new therapeutic I-O combinations that can help treat cancer patients in the coming years."
The dose escalation part of the Phase I/II trial will determine the maximum tolerated dose of the combination, while the dose-expansion part will measure the overall response rate as the primary endpoint using immune-related response criteria (irRC).
The trial's secondary endpoint includes the immune-related best overall response.
A previous clinical trial showed the efficient immune activation and favourable safety profile of APX005M.
The pre-clinical data indicated synergistic anti-tumour efficacy for a CD40 agonistic antibody that is combined with an immune checkpoint inhibitor such as an anti-PD-1, anti-PD-L1 and / or anti-CTLA4 antibody.