5 May 2026

Cytospire Therapeutics announces oversubscribed £61 million Series A financing

Cytospire Therapeutics, a UK based biotech developing differentiated multispecific immune cell engager antibodies designed to enhance and direct the activity of the body’s own immune system, today announces the closing of an oversubscribed £61 million ($83 million) Series A financing supported by a strong syndicate of new and existing biotech investors.

Cytospire will use the proceeds to advance its pipeline of first-in-class pan-gamma delta T cell engagers, including its lead programme, CYT X300, which is currently being advanced through IND-enabling preclinical studies and GMP manufacturing. A first-in-human clinical study is being planned to evaluate CYT X300 as a treatment for EGFR-positive solid tumours, such as colorectal, head and neck and non-small cell lung cancers.

The round was led by 4BIO Capital, with significant investment from new syndicate members Servier Ventures, British Business Bank, Sound Bioventures and Criteria Bioventures, as well as from existing investors Abingworth and LifeArc Ventures. Modi Ventures, Medical Incubator Japan and Pathway Bioventures also join the round as new investors.  It is the first investment from Servier Ventures, the newly established corporate venture fund of Servier, which aims to advance science and unlock tomorrow’s breakthrough therapies for the benefit of patients.

Natalie Mount, Chief Executive Officer of Cytospire Therapeutics, said:

We are excited to write the next chapter of Cytospire’s story with this fantastic group of specialist investors. Immune cell engagers are an important type of cancer immunotherapy, but we know that there are significant limitations from both an efficacy and safety perspective with conventional CD3 T cell engagers. We are building on the growing body of translational and clinical data showing gamma delta T cells are critical components of the anti-cancer immune response, with biology ideally suited to novel cell engagers. The significant fundraise that we are announcing today reflects the quality of our team and our science, and the huge potential of our pan-gamma delta T cell engagers.

Cytospire’s pan-gamma delta T cell engagers are uniquely engineered to target all gamma delta T cells rather than specific subtypes. Through this approach, Cytospire seeks to overcome patient heterogeneity and generate broader, more effective anti‑tumour immune responses through the activation of both tissue/tumour resident and blood resident effector cells.

Owen Smith, Partner at 4BIO Capital and Board Member at Cytospire, said:

Cancer immunotherapy has provided a step-change in treatment for many types of cancer over the past decade, but we need to do more. We are proud to have led the Series A alongside this strong investor syndicate.  It is exciting to see the company advance CYT X300 and its pioneering portfolio of cancer therapies into the clinic to improve outcomes for cancer patients.

Bali Muralidhar, Global Head of Life Sciences and Chief Investment Officer at Abingworth and Board Member at Cytospire, said:

As the founding investor in Cytospire, we are strong believers in the potential of gamma delta T cell-based therapies to change the treatment paradigm in multiple cancer indications. There is a need for novel strategies in the field of immune cell engagers, and we believe that Cytospire is well positioned at the forefront of this exciting space.

In connection with the financing, Cytospire’s Board of Directors has been strengthened by the appointments of Alexis Vandier (Global Head of Servier Ventures), Carmine Circelli (Investment Director, British Business Bank), and Anna Gran (Principal, Sound Bioventures).