Apellis Pharmaceuticals Acquisition Under Investigation

Ademi LLP probing whether Apellis shareholders are getting a fair deal in Biogen buyout

Apr. 7, 2026 at 12:06pm

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A high-end, photorealistic studio still-life photograph featuring a stack of pharmaceutical pill bottles, a syringe, and a tablet computer on a clean, monochromatic background, conceptually representing the financial and corporate strategy implications of the Apellis-Biogen acquisition.A shareholder lawsuit could impact the final terms of Biogen's proposed acquisition of Apellis Pharmaceuticals.Today in Milwaukee

Ademi LLP, a law firm specializing in shareholder litigation, has launched an investigation into the proposed acquisition of Apellis Pharmaceuticals by Biogen. The investigation will examine whether Apellis' board of directors is fulfilling its fiduciary duties to all shareholders in the transaction, which includes a $41 per share cash payment plus contingent value rights tied to the performance of Apellis' drug SYFOVRE.

Why it matters

Apellis shareholders could be entitled to additional compensation if the acquisition terms are deemed unfair or if the board is found to have breached its duties. The investigation will scrutinize the deal's structure, including the limitations on competing bids, to ensure Apellis shareholders are getting the best possible outcome.

The details

Under the proposed deal, Apellis shareholders will receive $41 per share in cash plus contingent value rights. The CVRs would provide an additional $2 per share if SYFOVRE achieves $1.5 billion in annual global net sales between 2027 and 2030, and another $2 per share if it reaches $2 billion in annual sales during the same period. If the sales thresholds are not met but SYFOVRE hits $2 billion in sales in 2031, shareholders would receive $4 per share.

  • The acquisition was announced on April 7, 2026.

The players

Apellis Pharmaceuticals Inc.

A clinical-stage biopharmaceutical company focused on the development of novel therapeutic compounds to treat serious diseases.

Biogen

A multinational biotechnology company that develops and markets therapies for the treatment of neurological and neurodegenerative diseases.

Ademi LLP

A law firm specializing in shareholder litigation involving buyouts, mergers, and individual shareholder rights.

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What they’re saying

“We are investigating the conduct of the Apellis board of directors, and whether they are fulfilling their fiduciary duties to all shareholders.”

— Ademi LLP, Law Firm

What’s next

Ademi LLP is encouraging Apellis shareholders to contact the firm to learn more about the investigation and how to potentially join the legal action.

The takeaway

This investigation highlights the importance of ensuring that public company shareholders receive fair treatment and maximum value in merger and acquisition transactions. The outcome could impact the final terms of the Apellis-Biogen deal.