Karo Bio drops eprotirome and split up plans

There was a double-dose of bad news for Sweden’s Karo Bio (STO: KARO), which this week said it would discontinue the development program for its late-stage cholesterol lowerer eprotirome after an animal study has demonstrated unwanted effects following long-term exposure.

Moreover, the company said, the previously-announced planned spin-off of the preclinical part of operations will not proceed (The Pharma Letter October 26, 2011). Although the firm’s shares were suspended ahead of the announcement, they plunged more than 68% to 0.38 Swedish kronor on the news by close of trading on Tuesday.

The animal study is a toxicology study in which damage to cartilage was seen in dogs that were given eprotirome for up to 12 months. The cartilage damage was apparent only after 12 months exposure and occurred in all animals treated with high doses but was also seen in the lower dose groups. The control animals displayed no damage. These unexpected findings mean that it cannot be excluded that also humans may suffer from similar cartilage damage, the company noted. Chronic treatment with eprotirome must therefore be considered as too risky in relation to the lipid-lowering effect that the current study intends to demonstrate.