RAPT Therapeutics shares surge ~64% on $2.2 bln GSK buyout

Shares of RAPT Therapeutics RAPT.O were up ~64% in early trading on Tuesday, after Britain's GSK GSK.L said it would buy the biotech co for $2.2 bln

GSK will pay $58 per share in cash, a hefty premium to RAPT's last close

Deal includes an upfront investment of $1.9 bln

Acquisition gives GSK global rights to RAPT's experimental food allergy drug ozureprubart, excluding mainland China, Macau, Taiwan and Hong Kong

GSK shares fell about 1% to 1,800.5 pence

The buyout expands GSK's respiratory, immunology and inflammation pipeline, a key strategic focus

RAPT had a market value of about $972.65 mln before the announcement