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Epsilogen announces successful completion of first ever clinical trial of an IgE antibody; phase I data for MOv18 IgE demonstrates potential of IgE therapy in cancer

July 31, 2023

Final results of phase I study of MOv18 IgE in ovarian cancer published in Nature Communications
MOv18 IgE found to be safe and well tolerated with evidence of anti-tumour activity observed

London, 25 July 2023 – Epsilogen, a global leader in the development of immunoglobulin E (IgE) antibodies to treat cancer, notes the publication today of the final phase I data from the first ever clinical trial of an IgE antibody therapeutic in Nature Communications ( MOv18 IgE is Epsilogen’s lead IgE antibody drug candidate and binds to anti-folate receptor (FRα), a well validated target for ovarian cancer. It was administered to 26 patients with high grade serous ovarian carcinoma whose cancer had become platinum-resistant.

Results from the study, entitled “A Cancer Research UK phase I study of MOv18 IgE, a first in class chimeric IgE antibody against folate receptor-alpha, in patients with advanced solid tumours” (, showed a manageable safety profile with transient urticaria being the most common adverse event. The urticaria always resolved within hours of dosing, either spontaneously or with the administration of systemic steroids and antihistamines.

Although the trial was not designed to demonstrate efficacy, tumour shrinkage and an associated fall in CA 125 tumour marker level was seen in one patient. Notably, the authors of the paper observed that the anti-tumour activity “occurred at doses very much lower than typically observed for IgG antibodies”, reflecting fundamental differences in Fc-receptor affinity and effector cell biology.

Professor James Spicer, Professor of Experimental Cancer Medicine at King’s College London, Consultant in Medical Oncology at Guy’s and St Thomas’ NHS Foundation Trust (GSTT) and the study’s lead investigator, said: “IgE is a completely new form of antibody therapy which has shown great promise in this phase I trial. Our findings show that the drug was well tolerated in patients and shrunk a cancerous tumour in a patient with ovarian cancer. The results pave the way to development of an entirely new class of anti-cancer drug for people with chemotherapy-resistant cancers. The immunology expertise in King’s College London laboratories allowed us to undertake this trial of a completely new form of antibody therapy.”

Dr Tim Wilson, Chief Executive Officer of Epsilogen, commented:The data published in Nature Communications, are encouraging and add further validation to support our belief that IgE antibodies have the potential to emerge as an entirely new treatment modality for patients with cancer. We have a robust clinical development plan in place to progress MOv18 IgE further into the clinic and the data generated will assist us in the development of our other IgE antibody drug candidates”.

Research Paper Available Here


About Epsilogen Ltd

Epsilogen is a global leader in the development of immunoglobulin E (IgE) antibodies to treat cancer. IgE’s natural function is to provide immunological defense against certain parasites. This functionality makes it an ideal treatment of solid tumours due to its strong potency, enhanced tumour access and long tissue half-life.

Epsilogen’s lead product candidate, MOv18 IgE, is the first therapeutic IgE antibody to enter the clinic and encouraging data from a completed phase I trial demonstrated MOv18 IgE to be safe and well tolerated with early signs of clinical activity. The company is also developing a proprietary IgEG antibody platform combining elements from both IgE and IgG antibodies into novel and proprietary antibody molecules with enhanced functionality.

Epsilogen began operations in 2017 as a spin out of King’s College London and has attracted venture capital financing from Epidarex Capital, Novartis Venture Fund, 3B Future Health, British Patient Capital, Alsa Ventures and Schroders Capital amongst others.

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For more information please contact:

Communications advisor to Epsilogen Ltd:
Simon Conway
Senior Managing Director
FTI Consulting
+44 (0)20 3727 1000