ASCO24: Grey Wolf gains $50M after ERAP1 inhibitor shows early immune response

Grey Wolf Therapeutics recently augmented its Series B funding round with an additional $50 million, elevating the total amount raised to $99 million. This substantial financial boost is set to expand the clinical strategy of their ERAP1 inhibitors to encompass more solid tumour types and autoimmune diseases.

The additional funding was primarily driven by promising early clinical data for Grey Wolf's lead candidate, GRWD5769. This first-in-class candidate has demonstrated compelling results in terms of safety, tolerability, and mechanism of action, which have bolstered investor confidence. ERAP1 inhibition aims to incite the production and presentation of new cancer antigens on tumor cell surfaces, thereby eliciting a T-cell response against the cancer cells.

Preliminary data from a Phase I/II trial, which was previewed ahead of its presentation at the American Society of Clinical Oncology (ASCO) annual meeting, indicated that GRWD5769 was well-tolerated and exhibited a dose-dependent engagement of its target, ERAP1, in 12 patients with advanced, refractory solid tumors. According to Grey Wolf, the findings align with the anticipated mechanistic effects of ERAP1 inhibition observed in preclinical models. Notably, this marks the first instance of demonstrating that the human immunopeptidome (ImPD) can be altered pharmacologically in cancer patients, potentially enabling T-cells to identify new targets on tumors. The ongoing study is also evaluating GRWD5769 in combination with immune checkpoint inhibitors.

The compound's favorable tolerability profile, along with genetic data from patients suffering from ankylosing spondylitis, has encouraged Grey Wolf to explore ERAP1 inhibition in the context of autoimmune diseases as well. The company believes that targeting ERAP1 could potentially "hide" disease-causing antigens from the immune system, thus preventing the activation of disease processes.

The recent funding will also support the development of a second ERAP1 inhibitor, GRWD0715, which is projected to enter clinical trials by 2025.

The Series B extension round was spearheaded by the Life Sciences team at ICG, with participation from existing investors including Pfizer Ventures, Andera Partners, Canaan, Earlybird Venture Capital, Oxford Science Enterprises, and British Patient Capital. This collaborative financial backing is set to propel Grey Wolf Therapeutics towards broadening their innovative approach in both oncology and autoimmune disease treatment.