What was published
Ractigen Therapeutics, a clinical-stage biopharmaceutical company based in Nantong, said a peer-reviewed study of its LiCO lipid-conjugated oligonucleotide platform has appeared in Molecular Therapy – Nucleic Acids. The company said the paper sets out the design, mechanism and preclinical translation of the platform, which joins an optimised lipid to a benzimidazole-based linker at the 5′ end of the passenger strand and is made as a single chemical entity by solid-phase synthesis. The article is open access.
Animal results
In mice, the company said a single systemic dose knocked down more than 90% of target mRNA in skeletal muscle, heart, aorta and adipose tissue, with at least half of that silencing still measurable at six months and activity seen out to nine months. Activity in the liver cleared quickly, leaving the lasting effect in tissues outside it. Work in Cd36-knockout models identified the fatty acid translocase CD36 as the main receptor carrying the compounds into muscle, heart and fat cells. In cynomolgus macaques, two intravenous doses of a LiCO-conjugated siRNA against myostatin produced roughly 90% knockdown of MSTN mRNA across skeletal muscles and 60–70% suppression of circulating myostatin protein through Day 98, with progressive muscle hypertrophy, the company said, and a clean clinical, haematological and biochemical safety profile.
Local delivery
The study also reported local administration with limited systemic exposure in three compartments: 90% target silencing in joint synovium after intra-articular dosing, 74% in the retina after intravitreal dosing, and 47% in bladder urothelium after intravesical dosing.
The clinical programmes
Ractigen said the platform underpins two programmes already in trials. RAG-18 is a systemically delivered saRNA designed to raise utrophin transcription to compensate for dystrophin loss in Duchenne muscular dystrophy regardless of mutation type; the company reported first-in-human data from it at the 2026 World Muscle Society Congress. RAG-01 is given into the bladder and is intended to switch on CDKN1A, the gene for p21, inside tumours; early complete responses and tolerability data from its Phase I trial in high-risk non-muscle invasive bladder cancer were presented at the European Association of Urology congress in 2025. Long-Cheng Li, the company's founder and chief executive and senior author of the paper, said the platform's uptake route unlocks muscle, heart and fat systemically while also reaching eye, joint and bladder locally, and that it is already being tested in patients by both routes.
