Epsilogen has completed a Series B expansion financing round, raising £12.5m ($16.4m) to progress the development of its immunoglobulin E (IgE) antibodies for cancer treatment.

The investment was sourced entirely from existing backers British Patient Capital, the Novartis Venture Fund, Epidarex Capital, the 3B Future Health Fund and ALSA Ventures.

The latest funding takes the total raised in the Series B financing round to £43.25m.

The funds will primarily support the clinical proof of concept for MOv18 IgE, the company's leading asset, in a Phase Ib trial targeting platinum-resistant ovarian cancer.

MOv18 IgE, a therapeutic IgE antibody, is designed to target the folate receptor alpha (FRα) which is prevalent in various cancers.

The Phase Ib trial of MOv18 IgE will have dose escalation and expansion parts, enrolling patients with FRα-positive PROC who have undergone up to four previous treatments.

The trial follows a Phase I study where MOv18 IgE showed safety, tolerability and initial signs of clinical activity.

MOv18 IgE's unique mechanism of action is different from that of other clinical agents, due to its high-affinity binding to FcεR1 that promotes immunosurveillance and robust tumour cell destruction by myeloid cells.

IgE antibodies have the potential to alter the tumour immune microenvironment, making it more pro-inflammatory, which results in higher levels of activated T cells and macrophages within the tumour, enhancing its destruction.

Established in 2017, Epsilogen is a spin-out from King's College London, UK.

Its CEO Tim Wilson stated: “We are delighted to have received strong continued support from our existing investors, and we thank them.

“The promise of IgE to treat cancer is based upon its unique mechanism of action and MOv18 IgE is the first ever to be tested in man. Everything is ready for phase Ib initiation which will occur shortly and we look forward to reporting progress from the trial.”