CAMBRIDGE, Mass. — Orbital Therapeutics presented new preclinical data at the 5th Annual mRNA-Based Therapeutics Summit in Boston, showing that its lead candidate, OTX-201, achieved full B cell depletion in blood, spleen, and lymph nodes in non-human primates—an essential step in resetting the immune system for treating autoimmune diseases.
The data mark a key milestone for the Cambridge-based biotech company, which is developing a new class of RNA-based immunotherapies designed to reprogram the immune system from within the body. Based on these findings, Orbital has officially nominated OTX-201 as its first product candidate and plans to begin clinical development in the first half of 2026.
“At Orbital, we’re pioneering a new generation of RNA immunotherapies that reprogram the immune system to restore health from within,” said Ron Philip, Chief Executive Officer. “These initial data represent a pivotal milestone as we advance OTX-201 toward clinical trials for patients with autoimmune disease who need better, more accessible treatment options.”
OTX-201 uses an optimized circular RNA encoding a CD19-targeted chimeric antigen receptor (CAR), delivered through targeted lipid nanoparticles (LNPs). This approach enables in vivo CAR-T therapy, meaning the patient’s body produces the therapeutic CAR-T cells internally—eliminating the need for the complex cell collection and manufacturing steps required by traditional ex vivo CAR-T treatments.
Orbital believes this approach could significantly reduce treatment burden while expanding access to CAR-T therapy, particularly for patients with B cell-driven autoimmune diseases. These diseases span more than 40 indications, including conditions in rheumatology, neurology, and dermatology, where depleting autoreactive B cells is a primary therapeutic objective.
Gilles Besin, Ph.D., Chief Scientific Officer of Orbital, emphasized the potential of the platform, stating, “The preclinical data supporting OTX-201 development validate the potential of our founding platform to produce RNA immunotherapies designed to match the unique biology of each disease. These data demonstrate full depletion of the autoreactive B cells that drive many autoimmune diseases, providing strong conviction in the continued development of OTX-201.”
Orbital is continuing IND-enabling studies in preparation for clinical trials. If successful, OTX-201 could offer a best-in-class profile for patients seeking more effective and accessible treatment for autoimmune conditions.
