Alkermes raised its acquisition offer for Avadel to as much as $22.50 per share, valuing the deal at $2.37 billion, after Lundbeck submitted a competing bid of up to $23. The revised offer includes $21 in cash plus a $1.50 contingent value right. Avadel previously agreed to Alkermes $20 bid in October before Lundbeck challenge forced an increase.