Ionis gets a double whammy

On Friday Ionis touted positive mid-stage results with fesomersen, a member of a new class of anticoagulants. The data, in end-stage renal disease patients on dialysis, were clearly not enough to convince Bayer, however: Ionis’s erstwhile partner handed back rights, leaving the smaller group searching for a new collaborator. Bayer is more exposed than most to the factor XIs, a much-hyped class that threatens to disappoint after recent mid-stage failures for Bayer’s asundexian and Bristol Myers Squibb/Johnson & Johnson’s milvexian; the developers have pressed on into phase 3 regardless. Given the cost of these trials, it would not be surprising if Bayer opts to fully focus on asundexian – which could be bad news for another asset the two groups are partnered on, osocimab, due to yield data soon. Meanwhile, Ionis also expanded the phase 3 Cardio-TTRansform trial of eplontersen, its Astrazeneca-partnered amyloidosis project, in the cardiomyopathy disease subtype for a second time. Ionis pointed to earlier diagnosis, which could lead to lower numbers of cardiac events, but investors read the move as increasing the risk of a negative readout. The trial, which will now enroll 1,400 patients, is still set to report in the first half of 2025. Ionis’s stock closed down 7% on Friday.