Cara fails to convince, but pushes on anyway

A failed mid-stage trial is far from the desired springboard from which to launch a pivotal programme, but this is exactly what Cara Therapeutics asked investors to get behind today. The Kare study tested three doses of an oral formulation of the anti-itch project Korsuva in 401 atopic dermatitis patients; no cohort showed a significant improvement over placebo on the primary endpoint, and the key secondary also missed. Never fear, the subgroup is here; Cara managed to drag some “statistically significant” findings out of an apparently prespecified group of mild to moderates, which executives said had responded more strongly in other Korsuva studies. An added concern here is lack of a clear dose response, with the middle 0.5mg performing better than the highest 1.0mg on some measures. The sellside wondered whether running a dose-finding trial in mild to moderates might be wise before starting phase 3, but executives insisted that there was enough to go on. After previous mixed results it is little wonder that investors disagree: Cara shares plunged 42%, erasing $500m of market cap. Attention now turns to the IV formulation of Korsuva to treat itch in dialysis patients, an approval decision on which is due later this year.