ANTWERP, Belgium – December 9, 2025 – Spica Therapeutics (“Spica”), a biotechnology company pioneering precision macrophage-targeted therapies, today announced the nomination of ST101 as its first clinical development candidate. ST101 is a first-in-class monoclonal antibody designed to selectively deplete immunosuppressive CD163+ tumor-associated macrophages (TAMs). The company has initiated CMC activities to support upcoming IMPD enabling studies.
Based on a robust preclinical and translational data package, Spica intends to position ST101 in solid tumor indications where immune checkpoint inhibitors (CPIs) are the current standard-of-care in the first-line setting. Despite the success of CPIs, a significant proportion of patients remain unresponsive or develop resistance due to an immunosuppressive tumor micro-environment (TME). ST101 aims to bridge this gap by remodeling the TME from “cold” to “hot,” thereby sensitizing tumors to T-cell-mediated killing and enhancing the efficacy of immunotherapies like checkpoint inhibitor blockade.
“Nominating ST101 as our first clinical candidate is a transformative milestone for Spica, transitioning us from a discovery-stage company toward a clinical-stage organization,” said James Rush, Ph.D., Chief Executive Officer of Spica Therapeutics. “The limitations of current CPIs are well documented – too many patients simply do not respond. By targeting the upstream drivers of immunosuppression, ST101 has the potential to unlock the full value of first-line immunotherapies. With IMPD-enabling activities now underway, we are focused on bringing this potentially life-saving therapy to patients.”
The mechanism of action for ST101 leverages Spica’s proprietary understanding of functional macrophage fingerprinting. Unlike pan-macrophage depletion strategies that have safety liabilities and can compromise host immunity, ST101 specifically targets the subset of macrophages responsible for shielding the tumor from immune attack.
“We have generated compelling evidence that CD163+ macrophages are the ‘architects’ of the immunosuppressive barrier in many solid tumors,” said Dr. Anders Etzerodt, Chief Scientific Officer and Co-founder of Spica Therapeutics. “Our translational data clearly shows that ST101 effectively breaches this barrier, facilitating the activation of multiple immune cells, including tumor-specific T-cells, boosting tumor killing. By turning ‘cold’ tumors ‘hot,’ we are essentially priming the battlefield for CPIs and tumor-specific T-cell engagers to do their job more effectively. We believe this mechanism represents a potentially transformative next step in immuno-oncology combination strategies.”
About Spica Therapeutics
Spica Therapeutics is a biotechnology company dedicated to transforming the treatment of cancer, fibrosis and inflammatory diseases through precision targeting of macrophage biology. Founded on pioneering research from Aarhus University, the company utilizes a proprietary functional fingerprinting platform to identify and deplete specific pathogenic macrophage subsets while preserving beneficial immune cells. Headquartered in Antwerp, Belgium, Spica is backed by a syndicate of leading life science investors.
Contact:
Spica Therapeutics BV
Email: info@spicatx.com
Website: www.spicatx.com