Karim Mikhail resigned as CEO of Amarin Corporation earlier this week following the company’s feud with Sarissa Capital Management over a recent board refreshment process. 

In a filing with the Securities and Exchange Commission, Amarin said Mikhail informed the company Monday of his decision to resign as CEO and president, effective immediately. The company said Mikhail asserted he is entitled to severance pay as a result of his resignation but disagrees with this and intends to dispute the matter. 

Amarin said it is now in the process of identifying a permanent replacement for Mikhail.

The departure of Amarin’s top executive comes as the New Jersey-based pharma company dealt with Sarissa, its largest shareholder, in a public war of words.

The feud started in January when Amarin appointed Murray W. Stewart, D.M., F.R.C.P. to the company’s board of directors. Subsequently, Sarissa called for a special meeting of Sarissa shareholders to add seven shareholder representatives to the board and oust chairman Per Wold-Olsen.

Sarissa’s criticisms centered not only on the board refreshment process but also the fact that the company’s stock lost two-thirds of its value in 2022 and that the potential of Vascepa, a fish-oil derived heart drug created by Amarin, hasn’t been realized due to label expansion for cardiovascular risk reduction. 

Following the emergence of three generic competitors to Vascepa, Amarin laid off 40% of its workforce amid a $100 million cost-reduction plan last June.

Despite its protests about the proxy fight, Amarin had 21 days to call a special meeting in accordance with U.K. law, which was ultimately scheduled for February 28.

Following the vote, Sarissa issued a press release declaring “resounding victory” over Amarin.

“LET’S GET TO WORK AND FINALLY BEGIN RUNNING AMARIN FOR THE BENEFIT OF ALL SHAREHOLDERS!” the company added in its statement. 

The next day, Amarin released its Q4 2022 earnings report, highlighted by positive free cash flow following the stabilization of U.S. revenue. Within a week, the company announced the departure of all seven independent non-Sarissa board members, which Amarin said was done in the interest of avoiding “further proxy contests.”

Ten days later, Amarin released a statement noting that its new board members were “working with urgency” to address issues at the company. 

“With shareholders on the board, we believe Amarin’s best days are ahead,” the company stated.

By the end of the month, Mikhail was out the door.