Promatix Biosciences Presents Positive Preclinical Data with First-in-Class PBS293 EGFR×EphA2 Cis-Bispecific ADC Demonstrating Enhanced Tumour Selectivity

  • Data presented at 16th World ADC London Summit with lead programme in colorectal cancer highlight the promise of Promatix’s proteomics-based platform to optimise cis-bispecific antibody-drug conjugate (ADC) discovery and design

  • Dual-antigen targeting strategy utilises hybrid avidity-gated binding to improve tumour cell selectivity, enhance efficacy and reduce toxicity in healthy tissues

  • Promatix lead ADC PBS293-MMAE was 50x more potent than cetuximab-MMAE in the KRAS mutant colorectal cell line HCT116 and showed superior tumour growth inhibition in xenograft studies using the same cell line 

 London and Cambridge, UK — 24 February 2026 — Promatix Biosciences Ltd (Promatix), an emerging UK-based biotechnology company developing innovative new classes of cancer therapies using cis-bispecific antibodies, today presented positive preclinical data at the 16th World ADC London Summit on its lead molecule, PBS293-MMAE, a first-in-class bispecific ADC for colorectal cancer. 

PBS293-MMAE was developed using Promatix’s proprietary proteomics-based discovery platform for ADC selection, which systematically analyses tumour and normal tissue surface proteins to identify novel anti-tumour antigen pairs. This approach delivers candidates engineered for cis-bispecific “AND-gate” targeting through hybrid avidity, whereby strong binding occurs when both target antigens are present on the same tumour cell, supporting improved efficacy and reduced toxicity compared to conventional ADC approaches. 

“The ADC field has made significant progress in payload, linker and conjugation chemistry, yet true tumour-selective targeting remains a major challenge,” said Dr. Michael Hunter, CEO and Co-Founder of Promatix. “Many of the most validated oncology targets, such as EGFR, are also expressed in healthy tissue, which can constrain the therapeutic window and limit efficacy. By utilising our unique capability to identify differentiated antigen pairings and engineering ADCs that depend on dual engagement, we aim to improve selectivity, enhancing both efficacy and safety across novel and validated targets. Our initial focus is in solid tumours where the prevailing standard of care remains inadequate for many patients. The data presented with our lead molecule, PBS293-MMAE, at the 16th World ADC London Summit provide early evidence that this strategy holds the promise of developing therapies with novel mechanisms that can provide meaningful new treatment options for patients.” 

PBS293-MMAE targets EGFR and EphA2, which are co-expressed in colorectal cancer cells. While EGFR is a clinically validated target in colorectal cancer, benefit from EGFR-targeted therapeutic antibodies such as cetuximab remains limited to a subset of patients, and its utility is restricted by toxicity related to widespread expression of EGFR in healthy tissues. 

Data presentation highlights 

Target co-expression: Proteomic analysis combined with FACS (fluorescence-activated cell sorting) analysis of patient-derived colon cancer xenograft tissue have demonstrated high levels of membrane co-localisation of EGFR and EphA2, supporting the biological rationale for dual-target engagement. 

Hybrid avidity: Hybrid avidity–dependent engagement, in which both antigens are required for binding, has been confirmed for PBS293 in a variety of studies, including cell binding, payload internalisation and cytotoxicity. 

Improved tumour suppression: In HCT116 colorectal cancer cells, PBS293-MMAE demonstrated low-nanomolar potency over 50-fold greater than cetuximab-MMAE. In a xenograft model, PBS293-MMAE achieved significantly higher dose-dependent tumour growth inhibition and sustained tumour suppression compared to cetuximab-MMAE. 

Reduced skin toxicity: PBS293-MMAE demonstrated substantially lower cytotoxicity in normal human keratinocytes (skin cells) compared with cetuximab-MMAE, further supporting its tumour-selectivity potential. 

Detailed results were presented at the 16th World ADC London Summit in a poster entitled: Hybrid Avidity–Gated EGFR/EphA2 Bispecific ADC Enables Tumour Selectivity and Keratinocyte Sparing. The poster can be accessed on the Promatix website here. 

About PBS293-MMAE 

PBS293-MMAE is a full IgG1 cis-bispecific antibody–drug conjugate (ADC) targeting EGFR and EphA2 in development for advanced colorectal cancer (CRC). The programme has the potential to address a major unmet need in metastatic CRC. While monoclonal antibodies targeting EGFR, such as cetuximab, are effective in only about 15% of patients1, PBS293-MMAE is designed to address a broader patient population, independent of RAS/BRAF mutation status and including right-sided colorectal tumours, for which current treatments are ineffective. 

About Promatix Biosciences Ltd 

Promatix is a UK-based oncology drug discovery and development company developing next-generation bispecific antibody–drug conjugates (ADCs) through rational, data-driven cis-target pairing. 

The company’s approach centres on identifying optimal combinations of cancer surface markers for cis-bispecific “AND-gate” targeting, in which strong binding, payload delivery and uptake occur only when two distinct antigens are present on the same tumour cell. This dual-antigen engagement is designed to enhance tumour selectivity. By exploiting hybrid avidity, Promatix aims to reduce on-target off-tumour toxicity and expand the range of targets that can be addressed with ADCs. 

At the core of the platform is TxPro, a comprehensive tumour surface proteomics database covering membrane proteins across multiple cancer types. TxPro is supported by proprietary computational analytics (CipherPro) to systematically mine tumour-selective antigen pairs, affinity-engineering capabilities (AviPro) to optimise bispecific engagement, and BiPro, a modular functional validation framework for rapid evaluation and lead selection. 

Promatix is developing a pipeline of novel bispecific ADCs in colorectal cancer and additional solid tumour indications. 

For more information, visit www.pro-matix.com and follow us on LinkedIn. 

CONTACT INFORMATION: 

Promatix Biosciences Ltd
info@promatix.com 

MEDIA CONTACT: 

MC Services AG
Julia Bittner
+49 211 529 252 28

In the US:
Laurie Doyle
+1 339 832 0752
promatix@mc-services.eu 

Dr. Graeme Martin

Executive Chairman

Graeme is a Pharmaceutical industry veteran and life-science venture capitalist with over three decades of innovative therapeutic R&D experience with Wellcome, GlaxoWellcome, Roche and Takeda that produced 4 IND submissions. He was the preclinical lead for the development of Zomig for migraine acute treatment. He also has two decades of life-science investment experience, having built and led the corporate venture unit of Takeda Pharmaceutical Company.  He currently serves strategic advisory and Board roles with private stage biotechnology companies and life science venture capital funds (ALSA Ventures; Harrington Discovery Institute) in the UK and USA, and was Chair of DJS Antibodies, acquired by AbbVie in 2022.

Bruce Goldsmith

Advisor, Operating Partner, ALSA Ventures

Bruce has a strong background in Pharma and Biotech leadership over the past 25 years. He held progressively senior roles at Pharma and Biotech companies, including Johnson & Johnson, Allos Therapeutics and Lycera Corp. Following this experience, he joined Deerfield Healthcare as a Venture Partner and led a new company creation as CEO. He then joined Passage Bio as CEO leading an IPO and advancing four programs through IND. Throughout his career Bruce has led business development deals, strategy and operations. Bruce holds a PhD in Biology and an MBA.

Richard Onyett

Business Development Director

Richard Onyett, Business Development Director has worked with Promatix since Autumn 2025 to lead outreach with regard to commercial partnerships and licensing of technology and/or product assets. Prior to joining Promatix he was V.P. Business Development at ADC Therapeutics from 2012 until late 2024. Prior to that he served as Head of Business Development for Spirogen Ltd 2011 to 2012 and Oxagen Limited from 2006 to 2011. Richard led the business development programme at KuDOS Limited which resulted in the sale of the company to AstraZeneca (2001-2006). Prior to this Richard served as Head of Business and Corporate at several biotech companies and for two major pharma companies in marketing and business development roles.

Lorna Collings

CFO

Lorna has more than twenty years of experience in private equity and venture capital with roles at EQT, Hermes GPE, Citco, Coller Capital, Ariadne Capital, Actis and BancBoston Capital. She holds a BA in Applied Psychology and is registered with the Chartered Institute of Management Accountants (ACMA).

Dr. Robert Balfour

Non-Executive Director

Robert has a successful background in venture capital and Big Pharma, with companies such as GSK and Eli Lilly. He is a passionate start-up entrepeneur with experience in university technology transfer. Robert holds a BSc in Physiology and a PhD in Neurophysiology.

Alek Safarian

Non-Executive Director

Alek has a diverse background in drug development spanning more than thirty years. Trained as a pharmacist, he worked in regulatory affairs and clinical research roles for European and US-based multinational pharmaceutical companies in Australia, with responsibility across the Asia-Pacific. He subsequently founded Novotech, a Sydney-based contract research organisation working with hundreds of clinical stage biotech companies over a twenty-one year period. Alek holds a BPharm and an MBA from the University of Sydney.

Dr. Daniel Holdbrook

Principal Data Scientist

Daniel currently leads efforts in applying data analytics, proteomics, and computational modelling to target identification and drug discovery. He has 16 years of experience in these areas and has worked at prestigious research institutions in the UK and Singapore. Additionally, he has extensive experience in developing ‘omics’ solutions within biotech start-up companies. Daniel holds a BSc in Biochemistry, an MSc in Bioinformatics, and a PhD in Computational Biochemistry.

Dr. Katherine Vousden

Vice President, Research

Katherine is a proven leader in biologics discovery, with 25 years experience across biotech, biopharm and service organisations where she has built an extensive portfolio of candidate biologics in multiple disease areas. She has had significant strategic, project and group leadership roles at MedImmune/ AstraZeneca, Charles River and most recently held the position of site lead for AbCellera’s UK-based laboratory. Katherine holds a PhD in Genetics from the University of Leicester.

Dr. Shan Vinall

Project Manager

Shan has over 20 years biotech experience in drug discovery and development. She has previously held project management positions at Atopix and Oxagen where she gained extensive experience in the management of outsourced preclinical and clinical development studies, documentation, project planning and budgeting. Shan holds a BSc in Biochemistry and a PhD in Intracellular signalling.

Dr. Roy Pettipher

CSO

Roy is a co-founder of Promatix with over 30 years of industry experience in anti-inflammatory and oncology drug discovery and development. He is the founder and CSO at Orca Pharmaceuticals, a program licensed to AstraZeneca and has previously served as the research director at Atopix, which was sold to Chiesi in in 2016. He has also held senior R&D executive positions in biotech (Oxagen & AdoRx)and Pharma(Pfizer & Wellcome). Roy holds a PhD in Pharmacology from the University of London.

Dr. Mark Edwards

CTO

Mark is a co-founder of Promatix and has a 40-year background in applying protein engineering to drug discovery and development. He previously held positions at Searle, PA Technology, British Biotech and was the founding Director at Oxagen. Prior to joining Promatix, he was as a consultant working with start-ups on a wide range of products ranging from antibody therapies to antibiotic resistance and vaccines. He holds a BA in Biochemistry and DPhil in bacterial gene expression from Oxford.

Dr. Mick Hunter

CEO

Mick is a co-founder of Promatix and has over 40 years biotech experience spanning concept to clinic for multiple IND candidates across a range of therapeutic indications including management of process development and GMP biologics production. He has held senior R&D executive positions at GD Searle, Atopix, Oxagen, British Biotech. He was the CSO of Atopix, sold to Chiesi in 2016, and founder and CEO of Orca Pharmaceuticals, whose ROR gamma program was licensed to AstraZeneca and to Brickell Biotech. More recently Mick was Entrepreneur in Residence at Evotec. He holds a PhD in Molecular Biology and Genetics from the University of Nottingham.