Leucid Bio and Syenex Announce Strategic Collaboration for In Vivo CAR-T Cell Engineering

• Enables in vivo delivery of LEU011 harnessing the VivoCell Platform^TM

LONDON and CHICAGO, Dec. 15, 2025 /PRNewswire/ -- Leucid Bio ("Leucid" or the "Company"), a privately-held biotechnology company developing innovative Chimeric Antigen Receptor T-cell (CAR-T) therapies using its proprietary lateral CAR platform, and Syenex, an open-science genetic medicines platform company, today announced a strategic collaboration to access Syenex's VivoCell Platform for the precise in vivo delivery of Leucid's CAR-T assets including LEU011 for the treatment of solid tumours.

In vivo CAR-T cell engineering, which generates CAR-T cells directly within the body, addresses many limitations of conventional CAR-T cell therapies. Enabling in vivo delivery removes the need for extensive and complex ex vivo cell processing and logistics, enhancing overall clinical outcomes.

The collaboration is focused on harnessing Syenex's VivoCell Platform to precisely deliver the LEU011 construct to T-cells in vivo when systemically administered. This represents a next-generation approach, fundamentally transforming the therapeutic profile of Leucid's lateral CAR platform, moving toward a simpler, potentially off-the-shelf administration route. By addressing the logistical hurdles of ex vivo cell administration – this collaboration is poised to unlock the full potential of the lateral CAR-T platform, including LEU011.

Under the non-exclusive agreement, Syenex will provide Leucid access to its VivoCell Platform and support the development of precision in vivo delivery vehicles tailored to Leucid's lateral CAR-T candidates. The aim of the collaboration is to accelerate the timeline of Leucid's in vivo programme, advancing from in vitro proof-of-concept to IND-enabling studies, while enabling Leucid to continue to clinically validate LEU011 in the ongoing Phase I/IIa AERIAL trial in patients with relapsed/refractory solid tumours.

Filippo Petti, Chief Executive Officer of Leucid Bio, said: "LEU011 has been well tolerated and demonstrated functional activity in our ongoing AERIAL trial for relapsed/refractory solid tumours. Gaining access to Syenex's innovative VivoCell Platform will enable precise in vivo delivery of our CAR-T assets and will be key to maximising the therapeutic impact and accelerate our reach. This partnership with Syenex is key to advancing this powerful therapeutic into a more scalable, patient-friendly format, bringing us closer to addressing one of the greatest challenges in oncology."

Jay Rosanelli, Co-Founder and Chief Executive Officer of Syenex, commented, "We are thrilled to partner with Leucid Bio to apply our precision delivery technology to their cutting-edge cell therapy. This collaboration advances our mission to Cure More and validates the power of our platform to enable the development of complex, next-generation CAR-T therapies, establishing the pathway toward an off-the-shelf product in a much more scalable and efficient in vivo format. By combining Leucid Bio's pan-cancer CAR-T with our targeted delivery system, we aim to significantly improve treatment options for patients battling solid tumours."

About Leucid Bio
Leucid Bio is a privately-held biotechnology company dedicated to the development of cell therapies for the treatment of solid tumours using the Company's proprietary lateral CAR platform. The Company's lead asset, LEU011, is a CAR-T cell therapy for the treatment of solid tumours. For more information, please visit the Leucid Bio website at www.leucid.com.

About LEU011
LEU011 is a lateral CAR-T cell therapy targeting NKG2D stress ligands, which are overexpressed on more than 80% of human tumour types and the cells within the surrounding tumour microenvironment. In addition to its novel architecture, LEU011 also co-expresses the chemokine receptor CXCR2 which is engineered to enhance cell trafficking and tumour infiltration, providing an extra mechanism to overcome significant limitations of CAR-T therapies currently in development for the treatment of relapsed / refractory solid tumours.

The Phase I/IIa AERIAL trial is a multi-centre, dose-escalation trial designed to evaluate the safety and clinical activity of LEU011 in patients with relapsed/refractory solid tumours, following a single intravenous dose of LEU011 after preconditioning chemotherapy. Additional information on the AERIAL trial can be found on ClinicalTrials.gov under the identifier NCT06193902.

About Syenex
Syenex is an open-science genetic medicines platform company that enables developers to program cells with precision and scale. Leveraging synthetic biology and a global network of contract development and manufacturing organizations (CDMOs), Syenex provides plug-and-play delivery platforms—spanning discovery through GMP manufacturing—so genetic medicine developers can rapidly advance ideas to clinical impact. Founded in 2022, Syenex has assembled a portfolio of cell-specific ex vivo and in vivo delivery platforms and over 50 partnerships with industry leaders across biopharma and academia. Learn more at www.syenex.com.