Novartis stands alongside Big Pharma peers that have similarly invested in technologies to penetrate the blood-brain barrier, including GSK, Roche and Eli Lilly.
Novartis is exercising its option to acquire Sironax’s proprietary drug delivery platform for $125 million, potentially opening up a path to bring the pharma’s drugs into the brain.
Novartis first linked up with Sironax in July 2025, when the pharma gained the exclusive option to acquire the biotech’s brain delivery technology for up to $175 million in upfront and near-term payments. Novartis has now exercised that option for $125 million, payable once the deal closes, according to a Sironax release on Thursday.
The biotech will retain the right to develop, produce and sell certain assets using the delivery technology. Sironax’s platform is designed to enable various therapeutic modalities to enter the brain, including antibodies, peptides and gene therapies.
The blood-brain barrier, a layer of tightly packed cells, protects the brain from damaging particles such as bacteria and viruses. While the barrier keeps harmful substances out, it also poses a challenge for drugmakers that want their products to cross into the brain to exert therapeutic effects. Several of the industry’s biggest players—including Roche, GSK and Eli Lilly—have made sizable investments in technologies to overcome this barrier over the years.
Outside of Sironax, Novartis in August 2025 also linked up with BioArctic, fronting $30 million to leverage the biotech’s BrainTransporter technology to cross the blood-brain barrier. This deal includes up to $772 million in milestones.
Novartis’ neuroscience portfolio is anchored by the multiple sclerosis therapy Kesimpta, which in the second quarter surged 32% to bring in $1.4 billion. The pharma is also advancing several investigational therapies in this space, including the antibody-oligonucleotide candidates del-brax for facioscapulohumeral muscular dystrophy and del-desiran for myotonic dystrophy type 1 (DM1). Both assets come from Avidity Biosciences, which Novartis acquired in October last year for $12 billion.
Last week, Novartis reported that del-desiran failed the Phase 3 HARBOR study in DM1, unable to significantly improve hand opening time—the trial’s primary endpoint. The pharma’s neuroscience pipeline took another hit with the discontinuation of the TREM2 stabilizer lifonebart, which the company had been testing for ALS. Lifonebart failed to meet the primary or secondary endpoints in the mid-stage ASTRALS trial in patients with early-stage disease.
