Aro Biotherapeutics Presents ABX1200 Myositis Data at ACR 2026, Plans Clinical Studies in 2027

Aro Biotherapeutics presented preclinical data on November 10, 2026 showing that ABX1200, its CD71-Centyrin CD40-siRNA conjugate, reduced CD40 expression in models of inflammatory myositis, and said it plans to begin clinical studies in 2027. The findings were given in an oral presentation at ACR Convergence 2026 in Orlando, Florida, according to GlobeNewswire.

Aro Biotherapeutics' ABX1200 Myositis Findings

Aro Biotherapeutics is a clinical-stage Philadelphia biotechnology company developing tissue-targeted siRNA medicines on its Centyrin protein platform. The myositis work was done with the Karolinska Institute, whose Professor of Rheumatology Dr. Ingrid Lundberg said: "Because myositis is a muscle disease, patients stand to benefit from the development of muscle-targeted therapies like ABX1200, and this collaboration has taken steps to advance this approach."

Patient muscle samples were analyzed by RNA sequencing and immunohistochemistry. RNA sequencing showed elevated CD40 expression in muscle from inclusion body myositis patients and predominant CD40L expression in CD4+ central memory T cells in blood and in T cells infiltrating myositis muscle. Immunohistochemistry showed CD40 co-expression with muscle-infiltrating macrophages, and CD40 expression correlated with high serum creatine kinase levels and disease activity scores.

ABX1200 reduced CD40 mRNA in vitro in macrophages and myotubes. In a preclinical model of muscle inflammation, it reduced the upregulation of CD40 and of chemokines that are upregulated in idiopathic inflammatory myopathies. CEO Purnanand Sarma said: "We are planning to begin clinical studies in 2027." ABX1200 is investigational and has not been evaluated for safety or efficacy by any regulatory authority.

Aro Biotherapeutics' Funding and Pipeline Record

According to akta.pro company records, Aro Biotherapeutics has raised total funding of $166.5 million across four rounds, most recently a $41.5 million Series B in November 2023 led by Cowen Healthcare Investments. The same records list a $88 million Series A closed in January 2021 and a $13 million start-up investment raised in December 2018.

The records also show positive Phase 1b topline results reported in March 2026 for ABX1100 in late-onset Pompe disease, with approximately 62% sustained GYS1 mRNA knockdown in muscle and a mean FVC improvement of approximately 2.5% at 5 months, with no serious adverse events.

siRNA Peers Advance Their Own Programs

Silexion Therapeutics received Israeli Ministry of Health approval to start a Phase 2/3 trial of SIL204 in locally advanced pancreatic cancer, Business & Financial reported on October 30, 2026. OliX Pharmaceuticals resubmitted a New Zealand trial application for OLX301A after it was rejected over administrative issues, Naver reported on October 28, 2026. Ting Therapeutics received China IND approval for TT004 and began a Phase Ib trial in head and neck cancer, PRLog reported on October 28, 2026.

Aro Biotherapeutics' 2027 Clinical Plan

Aro Biotherapeutics said it plans to begin clinical studies of ABX1200 in 2027. The company's announcement is posted on its website.