RIGImmune Announces Acquisition of Antiviral Company Subintro


RIGImmune Inc. recently announced the acquisition of Subintro, a biotechnology company specializing in the development and delivery of antiviral therapeutics for respiratory diseases caused by RNA viruses, including influenza, RSV, rhinovirus, and SARS-CoV-2. Founded by prominent Yale University professors and experts in respiratory drug discovery Akiko Iwasaki, PhD, and Anna Marie Pyle, PhD, RIGImmune has been developing stemloop RNA therapeutics (SLRs) that selectively activate the innate immune sensor RIG-I (Retinoic acid Inducible Gene I). The newly combined company will further advance novel compounds that both activate the natural immune activation and demonstrate antiviral activity. F-Prime Capital has invested in the new company as part of the Subintro acquisition.

“Joining with the experienced Subintro team will allow us to further advance our development of new treatments, prophylactics, and vaccine adjuvants for respiratory diseases caused by RNA viruses,” said Susan Sobolov, PhD, President of RIGImmune Inc. “By combining our stem-loop RNA therapeutics or “SLRs” with the Subintro antivirals and novel topical delivery systems, we aim to achieve optimal management of viral respiratory diseases.”

Building on the foundational work of the company’s co-founders, RIGImmune has developed a specialized understanding of RIG-I, a cytosolic sensor protein and host surveillance pathway that is essential to the innate immune response to RNA viruses and tumor DNA. The RIGImmune stem-loop therapeutic compounds have been designed to selectively target RIG-I with optimized drug properties and a favorable tolerability profile. The lead SLR development candidate, RIG-101, has demonstrated pre-clinical efficacy and tolerability proof of principle in multiple viral respiratory disease and oncology models. RIGImmune is currently conducting IND-enabling activities for RIG-101 for the potential treatment of influenza and adjuvancy with the conventional and selected mRNA influenza vaccines in development.

With the strategic Subintro acquisition, RIGImmune will target intranasal delivery to amplify the mucosal innate immune and antiviral responses. Published research reveals that intranasal delivery may be more effective for treating respiratory viruses with improved delivery to the lungs as compared to the oral route of administration or intramuscular injection.

“At Subintro, we have been investigating a range of new approaches to maximize the cellular activity and safety of diverse antiviral agents when delivered to respiratory epithelium. Topical delivery of macromolecules is a complex challenge, but we are confident that our approach will enable the successful delivery of RIGImmune’s stem-loop RNA therapeutics,” said Dr. Garth Rapeport, co-founder and Chief Executive Officer of Subintro and entrepreneur-in-residence at F-Prime Capital, who will be joining the RIGImmune leadership team. Subintro will become a wholly owned subsidiary of RIGImmune and Nihal Sinha, Ph.D. from F-Prime Capital will join the board of RIGImmune.

RIGImmune is a platform biopharmaceutical company developing a novel investigational class of RNA immunotherapies termed “SLRs” for the potential pan-viral treatment and prophylaxis of viral respiratory diseases and selected cancers. The RIGImmune development candidates act to specifically modulate RIG-I, a host surveillance pathway that triggers the innate immune system to enhance an intrinsic response to RNA viruses, including influenza, RSV, rhinovirus, and SARS-CoV-2, and tumor DNA. The lead development candidate at RIGImmune is RIG-101.

The company was co-founded by the prominent Yale University professors, Anna Marie Pyle, PhD, and Akiko Iwasaki, PhD, who currently serve as scientific advisors to the company. Dr. Pyle co-discovered the RIG-I receptor family and conducted many of the first structural and biochemical investigations on the cytosolic protein, RIG-I. Dr. Pyle is also a specialist in RNA structure and design. She designed the stem-loop RNA therapeutics (SLR) for selective targeting of RIG-I using crystal structure data of RIG-I complexed with RNA and developed them as antitumor and anticancer compounds in collaboration with Dr. Iwasaki, whose expertise in mucosal immunity has been highly sought during the COVID-19 pandemic.

RIGImmune is a UConn Technology Incubation Program (TIP) company located in Farmington, CT, was founded by Yale scientists, and has an experienced management team of successful biotech entrepreneurs and world-renowned scientists. For more information, visit www.RIGImmune.com.