OneChain Immunotherapeutics Unveils Promising OC-1d Data at ISCT 2025

OneChain Immunotherapeutics has unveiled promising preclinical data about their innovative CAR-T-cell product, OC-1d, designed to combat T-cell malignancies. Specifically engineered to target the antigens CD1a and CCR9, OC-1d shows promise in treating relapsed or refractory T-cell Acute Lymphoblastic Leukaemia (r/rT-ALL) and T-cell Lymphoblastic Lymphoma (r/rT-LL). These antigens are prominently expressed on cancerous cells while being absent from healthy cells, thus minimizing potential adverse effects.

Unlike conventional CAR-T-cell therapies, which frequently lead to leukopenia—a significant reduction in white blood cells—OC-1d is crafted to avoid this complication. This makes it a noteworthy development in the medical field for patients grappling with r/rT-ALL and r/rT-LL, both of which currently offer limited treatment options and have a dire prognosis. The introduction of OC-1d is a breakthrough, providing a new therapeutic avenue for patients who face a significant unmet medical need.

The research behind OC-1d was conducted in collaboration with the Josep Carreras Leukaemia Research Institute. The findings are being presented at the International Society for Cell & Gene Therapy 2025 Annual Meeting. This presentation, titled “Pre-clinical optimization of a dual-target CAR T therapy for relapsed/refractory T-cell acute lymphoblastic leukaemia and lymphoblastic lymphoma (T-ALL/LL),” has received the prestigious Top Scoring Start-Up Abstract Award in the Therapeutics category. Moreover, these results will be published in a special issue of Cytotherapy, emphasizing the significance of this advancement.

One of the standout features of OC-1d is its ability to specifically target CD1a and CCR9, setting it apart from existing CAR-T-cell therapies that target broader pan-T-cell antigens like CD5 or CD7. Such traditional approaches often result in leukopenia and necessitate a haematopoietic stem cell transplant (HSCT). By preserving healthy T-cells, OC-1d offers a potential treatment for patients who are not candidates for HSCT, expanding the pool of patients who might benefit from this therapy.

Another critical advantage of the dual-targeting mechanism in OC-1d is its ability to tackle immune escape. This phenomenon occurs when tumor cells downregulate a single target to evade destruction. By targeting two antigens, OC-1d reduces the likelihood of immune escape, enhancing the treatment’s efficacy. Furthermore, since CD1a and CCR9 are not found on healthy T-cells, OC-1d reduces the risk of fratricide, a complication where the treatment inadvertently attacks the body’s T-cells, a common issue with other T-cell targeting therapies.

T-ALL and T-LL represent areas with dire unmet medical needs. For patients with relapsed or refractory T-ALL, the survival rates drop from below 70% at diagnosis to merely 20% after five years and an alarming 6% after ten years. OC-1d offers a new, potentially life-saving treatment option for these patients, promising to improve survival rates and quality of life. This innovative therapy signifies hope and a critical step forward in addressing these aggressive forms of cancer.