Sironax will receive $125 million as Novartis exercises its option to acquire global rights to its brain delivery platform while Sironax retains three clinical programs.
Written By: Siddhi Bhadekar, M. Pharm (QA)
Reviewed By: Pharmacally Editorial Team
Sironax announced on September 16, 2026, that Novartis has exercised its exclusive option to acquire the full global rights to Sironax’s proprietary Brain Delivery Module (BDM) platform. The transaction originates from an option and asset purchase agreement executed in July 2025. Under the terms of the agreement, Sironax will receive $125 million following the closing of the transaction and will retain license rights to develop, manufacture, and commercialize selected pipeline assets using the platform technology.
Transaction Structure and Financial Terms
The transaction stems from the July 2025 agreement, under which Novartis obtained an evaluation period to assess Sironax’s BDM platform prior to deciding on a full acquisition. That original arrangement provided for up to $175 million in near-term and upfront payments.
By exercising its option, Novartis acquires worldwide rights to the BDM platform. Sironax will receive the $125 million payment upon transaction closing, which will be used directly to fund and advance its retained therapeutic development programs.
Novartis to Acquire Sironax’s Brain Delivery Platform
Sironax’s platform comprises proprietary brain delivery modules designed to enable the in vivo transport of diverse therapeutic modalities across the blood-brain barrier. These include monoclonal antibodies, peptides, proteins, gene therapies, and other large biologics.
The technology addresses a longstanding challenge in central nervous system drug development: efficiently delivering therapeutics into brain tissue. Sironax has identified potential applications across major neurological diseases, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis (ALS).
Sironax Retains Three Clinical-Stage Programs
Sironax confirmed it currently maintains three programs in Phase 1b/2 development, alongside multiple advancing early-stage candidates:
- SIR2501: A first-in-class allosteric inhibitor of SARM1 being evaluated for conditions including ALS and chemotherapy-induced peripheral neuropathy (CIPN).
- SIR4156: An allosteric NAMPT activator targeting metabolic dysfunction.
- SIR9900: A highly selective, brain-penetrant allosteric RIPK1 inhibitor under investigation for inflammatory and immunological diseases.
The transaction explicitly excludes these clinical programs from the asset transfer to Novartis. Sironax will continue advancing its retained pipeline using the proceeds from the platform transaction.
SIR2501 Holds FDA Fast Track Designation
SIR2501 is the most advanced program in Sironax’s pipeline from a regulatory standpoint. The U.S. FDA granted Fast Track designation to SIR2501 for the treatment of CIPN in May 2026.
According to clinical trial disclosures, SIR2501 is currently being evaluated in an open-label Phase 2 study in patients with solid tumors receiving paclitaxel chemotherapy. Registered under NCT07765446, the study assesses the drug’s safety, tolerability, and pharmacokinetics, as well as its potential to prevent CIPN onset.
Transaction Supports Sironax’s Pipeline
Sironax President and CEO Dr. Shefali Agarwal noted that the acquisition serves as strong validation of the company’s underlying science and proprietary engineering capabilities. Sironax plans to direct the transaction proceeds to accelerate its clinical-stage pipeline and expand its early-stage research activities.
While Novartis gains global rights to leverage the BDM platform across multiple therapeutic modalities for brain delivery, Sironax retains full operational and commercial autonomy over its therapeutic portfolio.
References
Sironax. “Sironax Announces Option Exercise and Asset Purchase, Sironax, September 16, 2026.
U.S. National Library of Medicine, ClinicalTrials.gov. “Study of SIR2501 in Solid Tumor Patients Receiving Paclitaxel.” Identifier NCT07765446
About the Writer
Siddhi Rajendra Bhadekar (Linkedin) is an M.Pharm professional with expertise in medical and scientific writing, literature review, publication writing, and evidence synthesis, supported by four peer-reviewed publications.
She brings working knowledge of ICH-GCP, MedDRA, pharmacovigilance, ADR/AE reporting, clinical data management, and regulatory documentation.
With experience across pharmaceutical R&D, Quality Control, and Quality Assurance, she combines scientific research skills with strong attention to accuracy and detail.
Her background in manuscript development, publication planning, and scientific communication enables her to translate complex healthcare information into clear, reliable content.