Triple‑negative breast cancer (TNBC) is the most aggressive and least treatable form of breast cancer. It disproportionately affects younger women and often leads to rapid relapse and poor survival once metastatic. TNBC lacks actionable receptors, which means patients have very few treatment options and most are highly toxic. Pan Cancer T is developing PCT1:CO-STIM, an engineered TCR-T cell therapy designed to offer targeted, durable and tumour-specific immune responses for women facing this challenging disease. The therapy uses a patient’s own immune cells, modified to recognise ROPN1, a tumour-restricted antigen found in more than 90% of TNBC cases. It also incorporates our TCR:CO‑STIM engineering platform that provides intrinsic co‑stimulation only when the T cells encounter tumour cells. This helps the T cells remain active and resist suppression within the hostile tumour microenvironment, a major barrier in solid tumour immunotherapy. Preclinical studies show strong tumour regression, high specificity and encouraging safety results, highlighting the potential for a single-dose treatment that delivers long-lasting benefit.

Pan Cancer T is preparing this therapy for its first clinical trial in the Netherlands starting in early 2027, with a Clinical Trial Application planned for mid-2026. Bringing the study to Dutch clinical centres will give patients early access to an innovative cell therapy while also strengthening the Netherlands as a leader in advanced treatments for women’s health. PCT1:CO-STIM has the potential to reduce treatment burden, improve quality of life and transform outcomes for women with TNBC. The programme is led by an experienced team with deep expertise in T cell therapy research, clinical development, manufacturing and translational science, all committed to delivering a meaningful breakthrough for women facing this challenging cancer.