Grey Wolf Therapeutics Closes Oversubscribed $50 Million Series B Financing Expansion, Led by ICG Life Sciences, to Accelerate and Expand First-of-its-Kind Antigen Modulation Technology

Grey Wolf Therapeutics Closes Oversubscribed $50 Million Series B Financing Expansion, Led by ICG Life Sciences, to Accelerate and Expand First-of-its-Kind Antigen Modulation Technology.

Brings Total Series B Funds Raised to Nearly $100 Million.

Proceeds to Support Broadening Scope of Ongoing Clinical Trial of GRWD5769; First Clinical Data to be Reported at ASCO 2024. 

Company to Expand R&D Efforts to Develop Disease-Modifying Therapies for Autoimmune Disorders.

OXFORD, UK – May 23, 2024Grey Wolf Therapeutics (“Grey Wolf” or “the company”), a clinical-stage biotechnology company leveraging first-of-its-kind antigen modulation therapies to address the source of immune dysfunction in oncology and autoimmunity, today announced the closing of an oversubscribed $50 million Series B financing expansion, bringing the total amount of Series B funds raised to $99 million. The Series B expansion round was led by ICG’s Life Sciences team and included further investment from existing investors Pfizer Ventures, Andera Partners, Canaan, Earlybird Venture Capital, Oxford Science Enterprises and British Patient Capital. Proceeds from the round will be leveraged to broaden the scope of the company’s ongoing Phase 1/2 clinical trial of its lead immuno-oncology candidate, GRWD5769, in a range of solid tumour types. The funding also enables the company to expand research and development (R&D) for its versatile antigen modulation approach into treatments for autoimmune disease indications.

“The funds raised as part of this Series B expansion round allows us to enrich our ongoing clinical trial of GRWD5769 to include patients with a wider variety of tumour types and evaluate new combination treatment cohorts. In addition, the new capital enables us to more fully explore the breadth of potential therapeutic applications for our antigen modulation technology,” said Peter Joyce, Ph.D., chief executive officer of Grey Wolf Therapeutics. “There is a wealth of supportive recent clinical research and compelling human genetic associations pointing to the potential for antigen modulation driven by ERAP inhibition to open the door for disease-modifying therapies in the field of autoimmune disease. As such, we are expanding our R&D efforts and evaluating these broader therapeutic applications for our unique technology.”

Initial data on the ongoing adaptive Phase 1/2 trial of the lead asset GRWD5769, a first-in-class ERAP1 inhibitor will be presented at the upcoming 2024 American Society of Clinical Oncology (ASCO) annual meeting. A second ERAP1 inhibitor focussed on autoimmune disease is being advanced through IND-enabling studies with the goal of entering the clinic in 2025. 

Tracy Weightman, Associate Director, Life Sciences at ICG, added, “Grey Wolf is an exciting growth stage UK biotechnology company with a novel and differentiated approach that has the potential to transform the lives of millions of patients globally. This investment demonstrates our commitment to building leading biotechnology companies and enabling them to compete on a global stage. We are pleased to support Grey Wolf through the next stage of its growth journey, enabling the company to advance its clinical development strategy and expand into new therapeutic areas.”

In conjunction with the financing, Grey Wolf has announced that Ms. Weightman has been appointed to the company’s board of directors.

About ERAP Inhibition
Grey Wolf has developed and is advancing a unique therapeutic strategy that leverages the ability to effectively modulate the presentation of target antigens to the human immune system to upregulate or downregulate immune cell activity for specific therapeutic outcomes. This is achieved through the targeted inhibition of the endoplasmic reticulum aminopeptidases (ERAP1 or ERAP2), proteins that play a key role in the antigen presentation pathway. In cancer, inhibiting ERAP1 or ERAP2 drives the generation and presentation of novel and potent antigens to elicit targeted immune activity. Additionally, this mechanism works to block the production of disease-causing auto-antigens to prevent pathogenic immune responses that drive autoimmune diseases.

About Grey Wolf Therapeutics
Grey Wolf Therapeutics is a clinical-stage, UK- and Australian-based drug discovery and development biotechnology company spearheading a new therapeutic approach based on a first-of-its-kind antigen modulation platform. The company’s lead clinical development candidate, GRWD5769, is a potent and selective oral ERAP1 inhibitor that has shown the potential to elicit a powerful and differentiated immune response against tumours. A second ERAP1 inhibitor, GRWD0715, is advancing through preclinical development as a potential treatment for autoimmune disease. The company is also leveraging its leadership in neoantigen creation with an ERAP2 drug discovery program and by therapeutically targeting novel ERAP1 inhibitor generated cancer antigens with MHC Class I directed therapies, such as soluble T cell receptor (TCR) and TCR mimic bispecifics. 

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About ICG
ICG provides flexible capital solutions to help companies develop and grow. We are a leading global alternative asset manager with a 35-year history, managing $86.3bn of assets* and investing across the capital structure. We operate across four asset classes: Structured and Private Equity, Private Debt, Real Assets, and Credit.

ICG develops long-term relationships with its business partners to deliver value for shareholders, clients and employees, and uses its position of influence to benefit the environment and society. ICG is committed to being a net zero asset manager across our operations and relevant investments by 2040.

ICG is a member of the FTSE 100 and listed on the London Stock Exchange (ticker symbol: ICG). Further details are available at You can follow ICG on LinkedIn, X (Twitter) and Instagram.

*as at 31 December 2023

Grey Wolf Therapeutics        Vida Strategic Partners (on behalf of Grey Wolf)
Peter Joyce, CEO            Tim Brons (media)
+44 (0) 01235 644 970        415-675-7402  

Catherine Armstrong
Interim Head of Corporate Communications
+44 20 3545 1850