Ionis Pharmaceuticals Inc (NASDAQ:IONS) stock was down on Monday on safety concerns for its drug inotersen.
Ionis Pharmaceuticals Inc’s inotersen is a drug for treating familial amyloid polyneuropathy. Familial amyloid polyneuropathy, also called hereditary transthyretin amyloidosis with polyneuropathy, is a disease that causes TTR build up in major organs. This can affect organ function and lead to death.
Inotersen was being tested on patients with this genetic disease is a phase 3 study. The study met both of its primary endpoints for treating patents with hereditary transthyretin amyloidosis with polyneuropathy. This included benefits when compared to a placebo and an improvement in quality of life.
Despite the positive results from Ionis Pharmaceuticals Inc’s phase 3 study, there are also concerns over the side effects of inotersen. There were four cases of thrombocytopenia that happened during the study. One of these cases resulted in death and two suffered serious injury, but recovered. The final patient left the study after experiencing minor thrombocytopenia.
Another side effect that was seen during the study affected the patients’ kidneys. This was seen in four patients, all of which quit the study. Two had to due to reaching a stopping rule and the other two did after serious renal adverse events. There was also one case of a renal event in the placebo group.
The phase 3 study of inotersen included some 172 patients with hereditary transthyretin amyloidosis with polyneuropathy. The study was a double-blind, placebo-controlled, international one. Ionis Pharmaceuticals Inc has been working to prepare inotersen for FDA approval due to there being no approved drug for treatment of the disease.
IONS stock was down 11% as of Monday morning.