Mestag Therapeutics Announces $40 Million Financing and Appoints Chief Medical Officer and Chief Development Officer in Preparation to Enter the Clinic

-- Financing brings total funds committed to date to >$95 million

-- Proceeds support the STARLYS clinical trial evaluating targeted LTBR agonist MST-0312 in solid tumors, together with platform and pipeline activities in inflammatory diseases

-- Expands the leadership team with exceptional development executives to propel the clinical advancement of the pipeline

Cambridge, UK, March 17, 2026 – Mestag Therapeutics (“Mestag”), a biotech company harnessing fibroblast immunology to develop impactful treatments for patients with cancer and inflammatory diseases, today announced the closing of a $40 million financing supported by leading life science investors SV Health Investors, Johnson & Johnson, through its corporate venture capital organization, Johnson & Johnson Innovation – JJDC, Inc., Forbion, GV (Google Ventures) and Northpond Ventures. The company also announced the appointment of Lindsey Rolfe, BSc, MBChB, MRCP, FFPM, as Chief Medical Officer and Pascal Merchiers, PhD, as Chief Development Officer.

The financing will support the Phase 1 STARLYS clinical study, which is anticipated to start in cancer patients in mid-2026. MST-0312 is a novel FAP-targeted bispecific antibody directed to lymphotoxin-β receptor (LTBR) to induce the formation of tertiary lymphoid structures (TLS) and high endothelial venules (HEV) within solid tumors. An extensive body of clinical data correlates the presence of TLS and HEV in solid tumors with improved patient survival and enhanced response to therapy. MST-0312 is a first- and best-in-class program pioneering a new therapeutic approach to the treatment of cancer, including tumors that are typically resistant to immunotherapy.

“We are thrilled to welcome Lindsey and Pascal to the team at this exciting time as we progress our groundbreaking program MST-0312 into the STARLYS clinical trial,” said Susan Hill, PhD, Chief Executive Officer of Mestag Therapeutics. “We thank our exceptional investor syndicate for their unwavering support of our mission to develop impactful new antibody therapeutics for patients with cancer and inflammatory disease. Lindsey’s extensive experience leading global development, medical affairs and regulatory affairs across multiple programs, including regulatory approval, will be instrumental in shaping the advancement of our clinical programs. Additionally, we welcome Pascal, with his breadth and depth of expertise in cancer and inflammatory disease, to drive our development activities, including our innovative pipeline and platform uniquely focused on fibroblast immunology.”

Lindsey Rolfe, BSc, MBChB, MRCP, FFPM

Lindsey brings more than three decades of clinical experience to Mestag, serving most recently as the Chief Medical Officer of targeted radiotherapy company 3B Pharmaceuticals in Berlin where she established the clinical development function and oversaw early-stage clinical trials of the company’s molecules. From 2015 to 2023, she served as Chief Medical Officer at Clovis Oncology, where she led the team that obtained marketing approvals in the U.S. and Europe for Rubraca, a PARP inhibitor approved in ovarian and prostate cancer. Additionally, she was responsible for pre- and post-marketing medical activities and played a leading role in licensing activities, including the Phase 1 program FAP-2286 acquired by Novartis in 2023. Earlier in her career, Lindsey served in development roles at Celgene, Pharmion, Medimmune, UCB and Celltech. She obtained her medical degree from the University of Edinburgh, undertook post-graduate medical training in London, UK and has specialist registration in Pharmaceutical Medicine from the UK General Medical Council.

Pascal Merchiers, PhD

Pascal brings over 25 years of experience leading drug discovery and preclinical development programs. Most recently, he was the Chief Development Officer at Commit Biologics working on novel antibody-based BiCE bispecific molecules. As the Chief Scientific Officer of Aboleris, he led the advancement through CTA filing of a monoclonal antibody targeting CD45RC for the treatment of autoimmune diseases. Prior to Aboleris, Pascal served as the Chief Scientific Officer at Oncurious, responsible for R&D strategy focused on regulatory T cell (Treg) depletion and tertiary lymphoid structures in tumors. From 2015-2018, he established and led R&D focused on Treg biology at Tusk Therapeutics, which was acquired by Roche in 2018 for $759m. Earlier in his career, he advanced biologics and gene therapies across multiple therapeutic areas at Thrombogenics, Ablynx, Galapagos and Introgene, as well as target discovery at Galapagos. Pascal holds a PhD in Biomedical Sciences from Katholieke Universiteit Leuven and is named as an inventor in more than 20 patents.