After disappointing sales of Kynamro® (mipomersen) prompted Ionis Pharmaceuticals to terminate its licensing agreement with Sanofi Genzyme in January 2016, the antisense developer has now sold global development and commercialisation rights to the orphan drug to start-up Kastle Therapeutics in a deal worth up to US$95 M. Kynamro is currently approved in the US for the treatment of homozygous familial hypercholesterolaemia, a rare genetic disease that leads to excessive levels of low-density lipoprotein cholesterol.