Aslan retools CSL deal, taking control of would-be Dupixent rival

A multiple ascending dose study of Aslan Pharmaceuticals' atopic dermatitis candidate ASLAN004 in patients is planned for the second half of 2019. (Pixabay/rawpixel)

Aslan Pharmaceuticals has secured the global rights to atopic dermatitis candidate ASLAN004 from CSL. The revision of the original deal ties Aslan to milestones including a $30 million payment when ASLAN004 enters phase 3.

Singapore's Aslan first secured a stake in anti-IL-13Rα1 antibody ASLAN004 in 2014. That deal tasked Aslan with taking the drug up to clinical proof of concept in an Asian-centered development program, and then partnering up for phase 3 development and commercialization. CSL would receive 40% to 50% of the proceeds of the outlicensing agreement and any other revenues related to ASLAN004.

Now, Aslan has claimed full global rights to ASLAN004 for itself. The new deal commits Aslan to the aforementioned phase 3 payout, up to $95 million in regulatory milestones and as much as $655 million in fees tied to the commercial success of ASLAN004. CSL will receive sub-10% royalties, too.

The restructuring of the deal puts Aslan in control of the program and positions it to share a smaller slice of the revenues derived from ASLAN004. 

ASLAN004, then known as CSL334, was seen as a potential treatment for asthma when Aslan struck the original deal in 2014. But the focus of ASLAN004 development has shifted to atopic dermatitis, mirroring the path taken by tralokinumab, another IL-13 drug. While tralokinumab failed in asthma at AstraZeneca, Leo Pharma is working to write a second act for the antibody in atopic dermatitis.

Leo, which is testing tralokinumab in multiple phase 3 clinical trials, is one of a number of rivals for the atopic dermatitis market. Regeneron and Sanofi showed the therapeutic impact of inhibiting the signaling of both IL-4 and IL-13 through the development of Dupixent.

The data got Dupixent to market and are driving blockbuster sales but have failed to deter rivals for the atopic dermatitis market. Leo is joined in the race by Demira, which posted competitive-looking phase 2b data on ex-Roche drug lebrikizumab earlier this year, and others.

Aslan is still some way from showing ASLAN004 is a threat to these companies. In March, Aslan finished the first part of a single ascending dose study in healthy volunteers. A multiple ascending dose study in patients is planned for the second half of 2019.