After Amarin's clash with Sarissa, CEO Karim Mikhail hits the exit

In the wake of a fight over board control with activist investor group Sarissa Capital, Amarin's CEO Karim Mikhail has abruptly left the drugmaker. Friday, in a SEC filing, Amarin said Mikhail resigned from his post earlier this week. His departure is effective immediately.

The filing also revealed that Mikhail believes he is entitled to severance payments. The company disagrees and will fight Mikhail on the payments.

Mikhail joined the company in July 2020 as Amarin's commercial head in Europe. In August 2021, the drugmaker promoted him to president and CEO. The company is now looking for a new CEO.

Mikhail's departure comes at a tumultuous time for Amarin. For one, Amarin's lone drug Vascepa is contending with generics in the U.S., forcing the company to pivot its focus to Europe and other international markets.

Amarin lost a key patent on the drug back in 2020, prompting it to appeal its case all the way to the Supreme Court. That effort failed in 2021. Alongside the litigation, the company cut around 90% of its U.S. staff in recent years.

Meanwhile, Amarin has spent the last few months trading barbs with activist investor group Sarissa Capital. That fight recently resulted in the resignation of 7 board members, effectively giving Sarissa control of the company.

During the fight, Sarissa argued that the Vascepa launch in Europe was "behind schedule" and that the company's executive team "weakened the cash coffers." Eventually, Amarin shareholders sided with Sarissa in what the activist investor touted as a "huge landslide."

Before Amarin, Mikhail worked for more than two decades at Merck, leading many drug launches, according to Amarin's website.