ALS is a severe, neurodegenerative disease which affects motor neurons leading to progressive muscle weakness, paralysis and ultimately death within a median time of two to four years from disease onset.

According to the firm, the ODD recognises the potential therapeutic role of aldesleukin in treating disease, and could provide a number of benefits for Clinigen should it obtain a marketing approval for this indication.

These benefits include seven years marketing exclusivity within the US upon launch, along with tax credits for clinical development costs and fee waivers.

Studies in ALS patients have shown that decreased levels of regulatory T-cells (Tregs) were associated with increased disease severity and predictive of disease progression and survival, suggesting that Tregs may be an attractive therapeutic target.

Aldesleukin has been shown to enhance Treg function in inflammatory and autoimmune conditions.

“The Orphan Drug Designation issued by the FDA recognises the potential of aldesleukin as a possible valuable new treatment for patients with ALS where there is a significant level of unmet need within the disease area,” said Shaun Chilton, group chief executive.

“Clinigen is also exploring the use of aldesleukin in several other therapeutic areas where its modulatory effects on Tregs may have a beneficial clinical effect.”