(Sharecast News) - Indivior's share price surged on Thursday after the pharma group announced plans for $100m share buyback following a strong first-half performance, with second-quarter revenues in line with recent guidance.

The company disappointed investors earlier this month with a profit warning due to slowing sales of its opioid addiction treatment Sublocade due to "adverse market dynamics", as well as plans to stop selling its Perseris drug - leading to a sharp sell-off in the stock.

The stock was up 16% at 961p by 0855 BST, but still remained down 24% over the past month.

"While 2024 has proved to be a more challenging year than we had anticipated, we remain highly confident in the underlying fundamentals of our business and strategy, and that we are on a clear path to create substantial shareholder value," said chief executive Mark Crossley.

"Reflecting our confidence, we are today announcing a new $100m share repurchase program which we intend to execute over an accelerated time frame."

Net revenues totalled $299m in the second quarter ended 30 June, up 8% on last year, helped by 24% growth in Sublocade sales.

However, the company swung to an operating loss of $132m compared with a profit of $61m previously.

Indivior said it continues to trade in line with recently updated guidance, expecting around 8% growth in net revenue this year along with 12% growth in adjusted operating profit.