Biotechnology company Ionis Pharmaceuticals Inc (Nasdaq:IONS) said on Thursday that it has entered into a licensing agreement granting Recordati exclusive rights to develop and commercialise zilganersen for Alexander disease (AxD) in all countries outside the United States.

Ionis will retain sole commercial responsibility for zilganersen in the US market and continue leading the drug's global development, while Recordati will oversee regulatory filings, commercialisation, and country-specific access pathways outside the US.

Zilganersen is currently under US FDA review with a Prescription Drug User Fee Act action date of 22 September, and could become the first and only disease-modifying treatment for AxD if approved.

The company recently reported positive pivotal study results, with zilganersen 50 mg achieving statistically significant and clinically meaningful stabilisation of gait speed at Week 61 compared with control in patients aged five years and older. Secondary and exploratory assessments also favoured zilganersen, and the treatment demonstrated a favourable safety and tolerability profile, with serious treatment-emergent adverse events occurring less frequently than in the control group.

Under the agreement, Ionis will receive a USD30m upfront payment and is eligible for additional milestone-based payments and tiered royalties of up to the mid-20% range on annual net sales.