Mestag Therapeutics Appoints Philip Astley-Sparke and Victor Sandor, M.D.C.M., to its Board of Directors

-- Mr. Astley-Sparke brings more than two decades of biotech leadership, having scaled several highly innovative transatlantic companies, including Replimune, uniQure and BioVex

-- Dr. Sandor brings more than 20 years of oncology clinical development experience, including leading programs to regulatory approval at Array BioPharma, Incyte and AstraZeneca

-- Appointments strengthen the Board as Mestag evaluates MST-0312 in the Phase 1 STARLYS trial, currently enrolling patients with advanced solid tumors

CAMBRIDGE, United Kingdom, Oct. 20, 2026 (GLOBE NEWSWIRE) -- Mestag Therapeutics (“Mestag”), a clinical-stage biotech company harnessing fibroblast immunology for the benefit of patients with inflammatory disease and cancer, today announced the appointments of Philip Astley-Sparke and Victor Sandor, M.D.C.M., to its Board of Directors.

The appointments further build Mestag’s clinical, regulatory and strategic expertise as the Company advances the Phase I STARLYS trial evaluating MST-0312, its targeted lymphotoxin-beta (LTBR) agonist bispecific antibody. MST-0312 is designed to induce tertiary lymphoid structures (TLS) in tumors, a novel approach aimed at driving anti-tumor immune responses in patients with advanced solid tumors, both as monotherapy and in combination with other therapies.

“We are delighted to welcome Philip and Victor to the Mestag Board,” said Susan Hill, PhD, Chief Executive Officer of Mestag Therapeutics. “Both bring exceptional experience advancing innovative therapies from clinical development through to approval and commercialization. Their insights will be invaluable as we advance MST-0312 through the clinic and continue building a pipeline of first-in-class antibodies in cancer and inflammatory disease.”

Mr. Astley-Sparke is co-founder and Executive Chairman of Replimune Group, Inc., a developer of oncolytic immunotherapies. In August 2026, Replimune received accelerated approval from the US Food and Drug Administration (FDA) for Tudriqev™ (vusolimogene oderparepvec) in combination with nivolumab for adults with unresectable or metastatic melanoma that has progressed following anti–PD-1 therapy. He is also a Venture Partner at Forbion, Chairman of SynOx Therapeutics and a director of enGene. Previously, he served as President and Chief Executive Officer of BioVex Inc., prior to its acquisition by Amgen in 2011 for up to $1 billion, and later as President and Chair of uniQure. Mr. Astley-Sparke holds a BSc in Cellular and Molecular Pathology from the University of Bristol.

“Mestag is pursuing a differentiated approach to cancer immunotherapy by inducing tertiary lymphoid structures within tumors,” commented Mr. Astley-Sparke, newly appointed member of the Mestag Therapeutics Board of Directors. “I am pleased to join the Board and, on behalf of Forbion, support the team as it advances MST-0312 through clinical development and builds on the potential of its broader pipeline.”

Dr. Sandor has more than two decades of oncology drug development experience. He currently serves on the Boards of AbCellera Biologics, ADC Therapeutics, Kymera Therapeutics and Prelude Therapeutics, and previously served on the Board of Merus prior to its $8 billion acquisition by Genmab in 2025. Earlier in his career, Dr. Sandor served as Chief Medical Officer at Array BioPharma prior to its acquisition by Pfizer in 2019, where he played a key role in the approval of Braftovi® and Mektovi® for patients with BRAF-mutant cancers including melanoma and colorectal cancer. He also held senior leadership positions at Incyte Corporation, Biogen Idec and AstraZeneca. Dr. Sandor received his M.D.C.M. from McGill University and completed a Fellowship in Medical Oncology at the National Institutes of Health.

“The ability to induce tertiary lymphoid structures within tumors represents a compelling new frontier in the treatment of solid tumors,” remarked Dr. Sandor, newly appointed member of the Mestag Therapeutics Board of Directors. “Mestag's scientific approach is built on a strong biological rationale, and I look forward to working with the team as they translate those insights into meaningful new treatment options for cancer patients.”

For more information, please contact:
Optimum Strategic Communications
Zoe Bolt, Josh Evans, Henry Williams
+44 (0) 203 882 9621
Mestag@optimumcomms.com

About Mestag Therapeutics
Mestag is a clinical-stage biotech company harnessing new insights into fibroblast immunology to develop impactful antibody therapeutics for patients with cancer and inflammatory diseases.

Our pipeline includes MST-0312, a FAP-targeted LTBR agonist bispecific antibody that leverages a new understanding of tertiary lymphoid structures (TLS) and high endothelial venules (HEV) in solid tumors; the M402 program, designed to inhibit the activation of specific immune cell subsets in inflammatory disease; and earlier programs in discovery stage. Separately, we are also identifying novel targets for future therapies utilizing our specialist fibroblast-immune RAFT Platform including in collaboration with MSD (tradename of Merck & Co., Inc., Rahway, N.J., USA).

Our founding investigators comprise global experts in inflammatory disease, cancer, computational biology and fibroblast biology from the University of Oxford, Brigham & Women’s Hospital, Harvard Medical School and Cold Spring Harbor Laboratory. Mestag was founded by SV Health Investors and is supported by leading life science investors Johnson & Johnson, through its corporate venture capital organization, Johnson & Johnson Innovation – JJDC, Inc., Forbion, GV (Google Ventures) and Northpond Ventures.

For further information, please visit our website www.mestagtherapeutics.com.

About MST-0312
MST-0312 is a novel FAP-targeted bispecific agonist antibody directed to lymphotoxin-β receptor (LTBR), designed to induce the formation of tertiary lymphoid structures (TLS) and high endothelial venules (HEV) in solid tumors.

TLS are a hallmark of effective anti-tumor immunity consisting of aggregates of T, B and dendritic cells, associated with the recruitment, education, and activation of immune cells to drive anti-tumor immune responses. 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 currently being evaluated in a first in human trial, named the STARLYS trial, an adaptive, modular multi-part, multi-arm open-label study designed to evaluate the safety, tolerability, pharmacodynamics, pharmacokinetics and anti-tumor activity of MST-0312 alone and in combination with pembrolizumab (NCT07610941). MST-0312 is an unlicensed medical product.