Japan's Takeda Pharmaceutical said today it had received a key US regulatory approval for the $62 billion acquisition of London-listed Shire. 

Takeda has received unconditional clearance from the United States Federal Trade Commission for the Shire deal, the drugmaker said. 

The Shire deal would turn Takeda into one of the world's largest drugmakers. 

However, the remaining hurdles for the Tokyo-listed company include getting a regulatory nod from the European Union and China and approval from shareholders of both drugmakers. 

Chief executive Christophe Weber has been working to persuade investors about the deal, which has weighed heavily on Takeda's stock price.

Takeda said it expects the deal to close in the first half on 2019.