Grey Wolf Therapeutics completes £2.5 million ($3.3 million) Series A2 financing to accelerate development of therapies targeting ERAP2

Grey Wolf targets ERAP antigen presentation pathways with the aim of ‘illuminating’ non-responsive tumors for attack and destruction by the immune system

Oxford, UK – 9th January 2020

Grey Wolf Therapeutics, a drug discovery biotechnology company focused on developing first-in-class therapies for immuno-oncology (IO), today announces it has completed a £2.5 million ($3.3 million) Series A2 financing round with existing leading international healthcare investors Andera Partners and Canaan.

The new funding – all from existing investors – will allow the company to accelerate development of therapies targeting endoplasmic reticulum aminopeptidase 2 (ERAP2), following many positive signals of its potential. Funds will also be used to continue to drive the lead endoplasmic reticulum aminopeptidase 1 (ERAP1) modulator program. For context, both of Grey Wolf’s novel ERAP approaches are aimed at directly altering tumor cells, illuminating them for attack and destruction by the immune system. The goal is to exploit this increased tumor visibility in monotherapy and to extend the therapeutic benefit of already approved immunotherapies to many more cancers. The company is developing small molecule modulators of ERAP1 and ERAP2, two key proteins in the antigen presentation pathway, to change the antigen repertoire of tumors and thereby increase the number and range of cancer-related antigens, including neoantigens, presented on tumor cells available to engage an immune response.

“We are delighted to have the continued support of Andera and Canaan.” said Peter Joyce, Chief Executive Officer and Co-Founder. “The financing reflects growing potential in both our ERAP1 and ERAP2 approaches. We continue to see momentum, both in our own work and in the broader scientific community. These funds will allow us to further capitalize on this opportunity and expand our leadership position in the discovery and development of both ERAP1 and ERAP2 modulators.”

Grey Wolf is expanding efforts around ERAP2 for two reasons. First, clinical data continues to demonstrate that tumors which are more visible to the immune system show improved responses to checkpoint inhibitors. One such example is the recent November 2019 paper published in Nature Medicine by the Chan group at MSKCC. The results are consistent across patients which either have a higher tumor mutational burden, heterozygosity of the Class I HLA locus or greater structural / sequence divergence at the Class I HLA locus. Second, the company has developed unique insight into the targeting of the ERAP enzymes through the lead program ERAP1 and validated the role for ERAP inhibition in modulating the cancer-related antigen repertoire. These in-house data provide compelling evidence that the therapies could have a real impact in the treatment of oncology.

“We have continued to generate data showing that modulation of both ERAP pathways drives change to the cancer-related antigen repertoire,” said Tom McCarthy, Executive Chairman and Co-Founder of Grey Wolf Therapeutics. “Data clearly demonstrates that modulation of ERAP2 drives an altogether different change to the antigen repertoire, when compared with ERAP1 modulation, due to ERAP2’s clearly differentiated peptide substrate specificities. With this investment and the prior knowledge base within Grey Wolf we will be able to accelerate the ERAP2 program quickly through optimization, building on our leading position in ERAP disease-related biology.”

The additional funds represent further confidence from investors. “Grey Wolf have already provided compelling insight into the potential of ERAP1 modulation,” said Raphaël Wisniewski, Partner at Andera Partners. “This timely investment further underlines our excitement in these approaches. Grey Wolf are fast becoming true experts in modulation of ERAP biology for treatment of cancer.” Brent Ahrens, General Partner at Canaan, added:Canaan continues to be excited by the potential of targeting the ERAP pathway and are impressed with the progress the team has made in such a short space of time since closing Series A. The additional A2 investment enables the Company to push forward ERAP2 whilst maintaining the momentum on the lead ERAP1 program.”

For more information about Grey Wolf Therapeutics please contact:

Grey Wolf Therapeutics
Peter Joyce, CEO
+44 (0) 01865 292 038

About Grey Wolf Therapeutics

Grey Wolf Therapeutics is an Oxford (UK)-based drug discovery biotechnology company focused on immuno-oncology. Rather than targeting the immune system, Grey Wolf’s approach is to directly alter the tumor cells, illuminating them for attack and destruction by the immune system. The Company is targeting ERAP proteases, key proteins in the antigen presentation pathway, to drive modulation of the cancer-related antigen repertoire on tumor cells, thus increasing tumor visibility and extending the reach of immunotherapy in oncology.

Grey Wolf was founded by experienced industry professionals Peter Joyce (CEO), formerly of Vertex Pharmaceuticals, and Tom McCarthy (Executive Chairman), former President and CEO of Spinifex Pharmaceuticals. It has raised a £12.5 million Series A from blue chip EU and US investors, Andera Partners and Canaan Partners and is working with leading academic and commercial drug discovery partners to deliver a clinical candidate against ERAP1 and ERAP2. Grey Wolf is headquartered in Oxford, UK. For more information, please visit

About Andera Partners

Andera Partners (previously Edmond de Rothschild Investment Partners) is a leading investor in minority investments into privately owned companies. The Management Company employs 57 people and has more than €2.3 billion under management. Its Life Sciences team of 12 professionals brings together deep experience both in the Life Science industry and in private equity and venture capital. The team has raised more than €800 million through its BioDiscovery franchise and is currently investing out of its €345 million BioDiscovery 5 fund. For more information, please visit

About Canaan

Canaan is an early stage venture capital firm that invests in entrepreneurs with visionary ideas. With $5 billion under management, a diversified fund and hundreds of exits to date, we partner with entrepreneurs building the next generation of consumer, fintech, frontier tech, biotech and digital health companies that will transform how we live, work and thrive. To learn more about our people and our portfolio, please visit