Epsilogen Acquires TigaTx to Create Leading Pan-Isotype Cancer Antibody Company

U.K.-based Epsilogen has acquired Boston biotech TigaTx in a strategic move aimed at establishing "the world's leading pan-isotype cancer antibody company." The acquisition, announced on April 7, 2025, brings together two companies focused on developing innovative immunoglobulin antibodies for cancer treatment.

Merger Details and Strategic Vision

Epsilogen, which specializes in IgE antibodies, will integrate TigaTx's expertise in IgA therapies to expand its pipeline and technological capabilities. Tim Wilson, CEO of Epsilogen, emphasized the potential of this union, stating, "Combining the capabilities of Epsilogen with those of TigaTx gives us the ability to choose the most relevant isotype for a given cancer, whether a cold tumour environment we want to drive multiple immune effector cells into or leverage neutrophils."

The financial terms of the deal were not disclosed, but TigaTx will become a subsidiary of the London-based Epsilogen. This acquisition is expected to facilitate the development of hybrid antibodies that can activate multiple compartments of the immune system and possess improved pharmacokinetic and pharmacodynamic profiles.

Pipeline Expansion and Clinical Progress

The merger immediately bolsters Epsilogen's pipeline with the addition of TIGA-001, an anti-EGFR IgA antibody developed by TigaTx. Renamed EPS 401, this candidate is slated to enter clinical trials next year.

Epsilogen's lead candidate, MOv18 IgE, targeting the folate receptor alpha antigen, is already in clinical development. The company claims it is the world's first IgE antibody to enter human trials, despite the discovery of IgE antibodies in 1966. Early signs of clinical activity in a phase 1 trial have prompted Epsilogen to advance MOv18 IgE into a phase 1b trial for patients with platinum-resistant ovarian cancer.

Funding and Future Prospects

Both companies enter this merger with recent funding successes. Epsilogen completed a £12.5 million ($16 million) series B top-up in September, supported by investors including Novartis Venture Fund and British Patient Capital. This funding will help advance the phase 1b study of MOv18 IgE.

TigaTx secured $33.5 million in funding from the U.S. Department of Health and Human Services' Advanced Research Projects Agency for Health in December, along with a $2 million business grant from the National Cancer Institute.

The combined company now aims to leverage its expanded capabilities to develop more effective cancer therapies. Wilson highlighted the potential to "mix and match IgE, IgA and IgG functionality into a single antibody molecule," which could prove especially powerful given the importance of epitope selection in determining antibody clinical performance.