SAN DIEGO, CA, USA I September 12, 2023 I Replicate Bioscience, a clinical-stage company pioneering its novel self-replicating RNA (srRNA) technology to overcome the limitations of current mRNA modalities and expand use of RNA treatments to infectious disease, oncology, and autoimmune disease, today announced dosing of the first participant in a Phase 1 trial of its RBI-4000 vaccine for the prevention of rabies. The trial, which marks the first time a human has been dosed with Replicate’s next generation srRNA technology, will serve as a benchmark for utility in this indication and other complex infectious diseases and provide foundational insights to inform future clinical trials, most notably in oncology and autoimmune disease.

“Rabies represents an ideal opportunity to provide rapid clinical validation of our novel vaccine technology given the large exposure-naïve population and established correlates for protection as measured by the World Health Organization,” said Nathaniel Wang, Ph.D., founder and CEO of Replicate. “Dosing our first participant is a significant milestone for our company as we advance our next generation srRNA technology across several disease areas.”

“Replicate’s srRNA technology offers the potential for more robust and durable immune responses, and improved tolerability at lower doses than existing mRNA approaches,” said Zelanna Goldberg, M.D., CMO of Replicate. “In infectious disease specifically, our srRNA technology unlocks opportunities to effectively address more complex infectious disease indications and allows us to rapidly develop vaccine candidates to treat or prevent illness — a crucial capability for future pandemic readiness.”

About rabies, RBI-4000 and the Phase 1 trial: Rabies remains a public health threat in several geographical regions and is designated an NIAID Priority Pathogen. A next-generation rabies vaccine with improved immunogenicity and simpler manufacturing represents an opportunity to establish wider accessibility to rabies prevention worldwide. Replicate’s first vaccine product, RBI-4000, is an srRNA vaccine developed to stimulate virus-neutralizing immune responses to rabies for prophylactic use. The Phase 1 trial will evaluate the safety, tolerability, and immunogenicity of RBI-4000 in 84 participants in the U.S. In preclinical studies, intramuscular administration of RBI-4000 provided durable protection against the rabies virus, inducing antibody production and robust virus-specific T cells.

About Replicate Bioscience

Replicate Bioscience, an Apple Tree Partners portfolio company, is a clinical-stage company amplifying the power of RNA therapeutics by pioneering its novel self-replicating RNA (srRNA) technology to overcome the shortcomings of existing mRNA approaches, with potential improvements in bioactivity at lower doses, induction of more robust and durable immune responses, and improved tolerability. Replicate’s off-the-shelf srRNAs contain two components: virally derived genetic code to drive controlled and self-limiting amplification, and the RNA encoding therapeutic proteins. The company’s library of viral vectors, selected for driving robust and sustained protein expression and orders-of-magnitude improved performance over linear mRNA, allow for the development of treatments in applications including oncology, infectious disease, and autoimmunity. Differentiated by a team of srRNA experts, a customizable library of synthetic srRNA vectors, and end-to-end development capabilities, Replicate is uniquely positioned to finally expand the reach of RNA treatments toward widespread use in infectious disease, immuno-oncology, autoimmune disease, and more. Visit us at

SOURCE: Replicate Bioscience