Despite a failed merger with Allergan, Pfizer Chief Executive Officer Ian Read still received support from investors. The merger collapsed after the U.S. Treasury Department blocked the merger by issuing a certain rule.

This failed takeover marked the second failed takeover attempt by CEO Ian Read. In 2014, the company failed to acquire AstraZeneca Plc, the British drugmaker in a $118 billion bid. At that time, British politicians strongly opposed the deal. This time the merger has to face similar enmity from politicans, particularly president Obama and his administration.

Since the negotiation for merger had started to take place, the U.S. president Barrack Obama criticized the deal. He said the merger and the relocation of Pfizer headquarter to Ireland is unpatriotic. In November last year, Pfizer Inc agreed to acquire Allergan in the $160 billion deal.

Last Monday, in order to block the deal, the United States Treasury Department issued a regulation that prohibit U.S. companies to reincorporate overseas after an acquisition of a foreign company. Many politicians and business people, including former Texas governor Rick Perry. Allergan CEO Brent Saunders said that the regulation specifically targeted the Allergan and Pfizer deal.

The regulation enforced Pfizer to walk away from the merger, but investors still gave credit to Pfizer CEO Ian Read. According to Reuters, portfolio manager at Columbus Circle Investor, Oliver Marti, said, "You work within the rules as best you can to win the game. Unfortunately, the Treasury has abused its authority and made up its own rules."

Another shareholder, director of research at Smead Capital Management, Tony Scherrer, who has been a longtime shareholders of Pfizer commented, "Read shouldn't be the fall guy."

Business Insider reported that the portfolio manager for the Hodges Funds in Dallas, Gary Bradshaw, also praised him, "Read gets an 'A' for effort. It was the right move for him to give Allergan a shot."

Pfizer has prepared an alternative solution to save the merger. Nevertheless, the company is aware that Washington will keep ruling against any merger attempt between the companies.

Pfizer will look for other options after they walk away from the deal. One of them is to spin off its large branded generics business. Another option is to acquire biotech companies or strengthen its patent-protected drugs business.

Regarding the regulation, CEO of the Committee of Economic Development, Steve Odland, told CNBC, "Most Americans and certainly businesses are very frustrated with the politicians here in Washington, targeting business leaders and calling them unpatriotic or un-American when they're simply following the rules and the laws placed."

Although the U.S. administration had prevented the merger with Allergan, Pfizer Chief Executive Officer Ian Read still garnered support from their investors. Pfizer will explore some options following the failed merger.