Karuna quintuples in value as schizophrenia combo clears Phase II bar

Karuna added about $1.8 billion in market cap Monday after a Phase II trial showed its combo therapy targeting muscarinic receptors led to significantly lower psychosis scores in patients with schizophrenia while avoiding the side effects that dogged a decades-old attempt to modulate the targets.

Shares of Karuna Therapeutics Inc. (NASDAQ:KRTX) rose $78.32 (443%) to $96 on Monday, giving the company a market cap of about $2.2 billion--more than five times its valuation of $413.9 million at Friday's close. Its previous peak share price had been $29, just days after its June 2019 IPO...