Full B Cell Depletion Achieved in Blood, Spleen, and Lymph Nodes in Non-Human Primate Study
Data Supports the Nomination of OTX-201, a Novel In Vivo CAR-T Therapy, as Orbital’s First Product Candidate
Company Plans to Advance OTX-201 Toward Clinical Development for B Cell-Driven Autoimmune Diseases in 1H’26
CAMBRIDGE, Mass. – July 22, 2025 – Orbital Therapeutics, a biotechnology company pioneering a new generation of RNA medicines that reprogram the immune system in vivo to treat disease at its source, today announced encouraging preclinical results supporting the development of its lead RNA immunotherapy candidate, OTX-201, at the 5th Annual mRNA-Based Therapeutics Summit in Boston, held July 21–23, 2025. Specifically, in a non-human primate study, Orbital’s in vivo CAR-T approach achieved full B cell depletion in blood, spleen, and lymph nodes, which is required for an effective immune system reset in autoimmune disease. Based on preclinical findings to date, Orbital is advancing OTX-201 through IND-enabling studies 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 of Orbital. “By delivering precise molecular instructions directly to immune cells in vivo, our goal is to return the body to a healthier, pre-disease state. With the ability to fine-tune protein expression, durability, and targeted delivery, our platform enables the development of immune modulating therapies that fit seamlessly into standard care settings, without the burdens associated with conventional ex vivo CAR-T therapies. These initial data represent a pivotal milestone as we advance OTX-201, our first product candidate, toward clinical trials for patients with autoimmune disease who need better, more accessible treatment options.”
OTX-201 comprises an optimized circular RNA encoding a CD19-targeted CAR delivered via targeted lipid nanoparticles (LNPs) with in vivo administration. This in vivo approach, in which the patient’s own body serves as the manufacturer of CAR-T cells, has the potential to offer a reduced treatment burden and improved accessibility compared to ex vivo CAR-T therapies, which require patient cell collection and complex manufacturing processes followed by intensive conditioning regimens prior to infusion. Orbital is developing OTX-201 for B cell-driven autoimmune diseases, where the therapeutic goal is to deplete autoreactive B cells and reset the immune system. B cell-driven autoimmune diseases span more than 40 disease indications across multiple therapeutic areas, including rheumatology, neurology, and dermatology.
“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, with the power to reset dysregulated systems and deliver lasting change for patients,” said Gilles Besin, Ph.D., Chief Scientific Officer of Orbital. “These data, demonstrating full depletion of the autoreactive B cells that drive many autoimmune diseases, provide us strong conviction in the continued development of OTX-201 and our advancement toward the clinic in the first half of 2026.”
About Orbital Therapeutics
Orbital Therapeutics is advancing a new generation of RNA medicines designed to reprogram cells in vivo, treating diseases at their source. This approach offers patients a simpler, safer, and more accessible alternative to today’s complex treatments. Built from day one with a fully integrated platform spanning circular and linear RNA, targeted delivery, and AI-guided design, Orbital is working to develop durable, programmable therapies tailored to the distinct biology of each disease. The company’s lead program, OTX-201, targets autoimmune disease through B cell depletion to reset the immune system. Orbital’s platform is built for expansion into broader autoimmune indications, oncology, next-generation vaccines, and protein therapeutics. Led by a team with deep expertise in RNA science, clinical development, and commercialization, Orbital is united by a shared commitment to reach more patients, in more places, with fewer barriers. Learn more at www.orbitaltx.com.
Investor Contact
Alex Straus, THRUST
alex@thrustsc.com
Media Contact
Josie Butler, 1AB
josie@1abmedia.com
This links to an external website.