Precision against cancer.

Despite considerable progress in cancer treatment, unwanted side effects remain a significant challenge. Many anticancer therapies interact with molecules beyond their intended target, reducing treatment precision and contributing to adverse events that can affect both patients and long-term outcomes.

Improving target specificity remains one of the key opportunities in oncology. More precise therapies have the potential to maintain strong anti-cancer activity while reducing unwanted effects and expanding treatment options.

At Selecta Biotech, we are addressing this challenge through ESiNAR-X®, our proprietary oligonucleotide platform. By improving the precision of RNA-targeted therapeutics, we aim to develop safer and more effective treatments for patients with cancer.

Indication

Chronic Myeloid Leukemia

Chronic myeloid leukemia (CML) is a blood cancer driven by a well-defined genetic abnormality that causes the uncontrolled growth of white blood cells. Advances in understanding the biology of CML led to the development of tyrosine kinase inhibitors (TKIs), transforming the disease from a life-threatening diagnosis into a manageable condition for many patients.

Despite this success, important challenges remain. Around 20 to 30% of patients develop resistance to treatment or do not respond adequately to available therapies during the course of their disease. These patients continue to need new treatment options with different mechanisms of action.

Molecular rationale
Causality
BCR-ABL1 oncoprotein
Driver of leukemogenesis
Molecular target
BCR-ABL1 RNA
Encoding the BCR-ABL1 oncoprotein
Therapeutic lead · ASP210

A new approach to an established target

Previous oligonucleotide approaches have demonstrated the potential of RNA-targeted therapies while revealing important challenges. ASP210 was designed to address these limitations through the ESiNAR-X® platform.

Key challenge
Earlier oligonucleotide approaches
ASP210
Target specificity
Can interact with homologous off-target RNAs.
Recognizes only the intended target RNA without interacting with native off-targets.
Cellular uptake
Limited uptake often requires high doses to achieve a therapeutic effect.
Demonstrates spontaneous cellular uptake, with more than 500 million molecules delivered per cell.
Safety
Toxicity may arise from chemistry and off-target interactions.
Showed excellent tolerability across preclinical studies, with healthy cell viability above 98%, no signs of toxicity at extreme concentrations, and no treatment-related histopathological changes.
Target suppression
Often achieves only partial reduction of target RNA.
Reduced BCR-ABL1 RNA levels by 99% in mice within 10 days.
Therapeutic selectivity
Non-selective activity can contribute to treatment-related side effects.
Demonstrated selective activity against leukemic cells, eliminating detectable leukemic cells from the bone marrow within 10 days while reducing total leukemic cell burden by an average of 50%.
Reduction of BCR-ABL1 RNA levels in 10 days
500M+
Molecules delivered per cell, spontaneously
Healthy cell viability — no toxicity
Detectable leukemic cells in bone marrow after 10 days
More programs

Explore the full pipeline.