Sironax Announces Option Exercise and Asset Purchase

Novartis exercises option to acquire Sironax’s brain delivery platform

Sironax to advance three clinical-stage programs and multiple early-stage candidates using purchase proceeds

Sironax to retain development rights to selected assets using platform

WALTHAM, Mass., Sept. 16, 2026 – Sironax, a global clinical-stage biotechnology company developing transformative therapies for neurodegenerative, inflammatory and immunologic, metabolic, and rare diseases, today announced that Novartis has exercised its exclusive option to acquire the full global rights to Sironax’s proprietary brain delivery platform following the option and asset purchase agreement announced in July 2025. Under the terms of the option exercise agreement, the company will receive $125 million following the closing of the transaction. Sironax will also retain rights to develop, manufacture, and commercialize selected assets using the platform.

Sironax’s next-generation brain delivery platform has the potential to transform the treatment of central nervous system diseases by overcoming the longstanding challenge of delivering therapeutics across the blood-brain barrier. The platform comprises proprietary brain delivery modules engineered to potentially enable the in vivo transport of diverse therapeutic modalities including monoclonal antibodies, peptides, proteins, gene therapies, and other large biologics to the brain, with the potential to expand treatment options for diseases such as Alzheimer’s, Parkinson’s, Huntington’s, amyotrophic lateral sclerosis (ALS), and other neurological disorders.

“The acquisition of our brain delivery platform by a global pharmaceutical leader marks a major milestone for Sironax and strongly validates our science, proprietary technology, and the expertise of our multidisciplinary R&D team,” said Dr. Shefali Agarwal, President and CEO of Sironax. “This achievement comes at a pivotal time as we advance our clinical-stage pipeline and accelerate the development of promising new therapies. The proceeds from this transaction strengthen our ability to execute our strategy and continue our mission of bringing transformative medicines to patients.”

Advancing Clinical- and Early-Stage Pipeline
Sironax currently has three programs in Phase 1b/2 with first- or potentially best-in-class molecules. The company is developing SIR2501, a first-in-class allosteric inhibitor of SARM1, to prevent neuroaxonal damage in diseases such as ALS and chemotherapy-induced peripheral neuropathy (for which it was granted Fast Track designation by the FDA). Sironax is also developing SIR4156, an allosteric and globally first-in-class NAMPT activator for metabolic dysfunction, and SIR9900, a highly selective, brain-penetrant allosteric RIPK1 inhibitor as a potential treatment for inflammatory and immunological diseases.

Forward-looking Statements
This press release contains forward-looking statements related to the Company’s pipeline, its clinical plans, and its use of the proceeds, all of which are subject to risks and uncertainties. Actual outcomes may differ based on technical, regulatory, and market factors.