The groups behind the letter alleged that Novo Nordisk’s plant purchases could hinder not only the Danish drugmaker’s chief commercial rival, Eli Lilly, but also companies like Viking Therapeutics, Pfizer, Roche and AstraZeneca, who are working on their own metabolic offerings.

Catalent, a leading contract drug manufacturer, issued an open letter Monday to reassure customers that a proposed $16.5 billion deal will not raise competitive concerns.

Catalent CEO Alessandro Maselli said on Monday he will remain at the helm of the U.S.-based contract drugmaker after it is acquired by Novo Holdings, the controlling shareholder of weight-loss drug manufacturer Novo Nordisk.

Novo Holdings is encountering more resistance as it aims to close its $16.5 billion acquisition of pharma manufacturing giant Catalent by the end of the year. | A dozen consumer groups and trade unions penned a letter to Lina Khan,

U.S. consumer groups and two large labor unions urged the U.S. Federal Trade Commission on Thursday to block Novo Holdings, the controlling shareholder of Novo Nordisk , from acquiring contract drug manufacturer Catalent ,