Japanese industrial conglomerate Asahi Kasei Corp. has made an offer to acquire Swedish rare diseases specialist Calliditas Therapeutics AB for SEK11.8 billion (US$1.1 billion). The offer, at an 83% premium to the closing share price of SEK113.60 on Monday, May 27, is recommended by the three biggest shareholders and the board of Calliditas, which said the company would benefit from “being part of a larger platform.”