Biogen Inc. and Apellis Pharmaceuticals, Inc. have initiated a definitive merger agreement in which Biogen will purchase Apellis—developer of the FDA-approved SYFOVRE (pegcetacoplan injection).
Big news … let’s kick things off with a look at these players.
We’ll start with Biogen.
Headquartered in Cambridge, Massachusetts, the multinational biotechnology company is best known for its development of neurological and neurodegenerative disease therapies.
- Among its disease areas of focus: multiple sclerosis, Alzheimer’s disease, and Parkinson’s disease (to name a few). Check out its pipeline.
In the ophthalmic space: While not a primary focus, the company has participated in gene therapy and neuro-ophthalmology clinical programs for inherited retinal diseases (IRDs).
- See here for one such example.
And Apellis?
This global biopharmaceutical company is more heavily involved in the ophthalmic space, specializing in developing a new class of complement medicines—including SYFOVRE.
In case you need a little refresh: This FDA-approved (in 2023) therapeutic was cleared as the first treatment option for patients with geographic atrophy (GA) secondary to age-related macular degeneration (AMD).
- As for its latest news: Apellis released long-term (5-year) data on SYFOVRE in November 2025—and plans to submit a new application to the FDA for a pre-filled syringe (PFS) version of the therapeutic in H1 2026.
- See all company updates here.
Now to this anticipated deal.
Per the agreement, Biogen will acquire all outstanding shares of Apellis for $41 per share in cash (at closing).
- The total price tag: An estimated $5.6 billion.
Also noteworthy: Biogen expects “a significant proportion of Apellis employees to join the company.”
How is Biogen funding the deal?
Through a combination of cash and borrowings.
Biogen said it believes it can “fully de-lever by the end of 2027,” enabling the company to maintain “financial flexibility for future investments.”
See here for more on its anticipated revenue and growth potential.
And what’s in it for Apellis shareholders?
They’ll receive a nontransferable contingent value right (CVR) for each Apellis share held.
- Note: Referred to as “financial instruments” CVRs are typically issued in certain corporate deals to give additional future payments if specific conditions are met.
In this case: Holders will be entitled to two cash payments of $2 per share each—but only if SYFOVRE’s specified annual global net sales milestones are met.
Do we know those milestones?
Indeed we do. Each CVR equates to:
- A $2-per-share cash payment if SYFOVRE achieves $1.5 billion in annual global net sales in any calendar year between 2027 and 2030
- A right to receive an additional $2-per-share cash payment if SYFOVRE achieves $2 billion in annual global net sales in any of those aforementioned calendar years (2027 to 2030)
… what if those thresholds aren’t met?
If they aren’t met and, as such, no CVR payment is due for any of those years (2027 to 2030)—but SYFOVRE achieves $2 billion in annual global net sales in the 2031 calendar year—then Apellis stockholders will receive a cash payment of $4 per share.
Got it. Now circle back to Biogen — how does this benefit the company?
The addition of Apellis’s SYFOVRE—as well as EMPAVELI, an FDA-approved therapy for rare immune-mediated kidney diseases—is a major immediate revenue sales boost to Biogen’s rare disease portfolio.
Case in point: Apellis reported a combined 2025 net sales of $689 million for both therapies, with their continued revenue “expected to grow at a rate in the mid-to-high teens” though to at least 2028.
Go on …
Not necessarily on the ophthalmic front, but Biogen also plans to leverage Apellis’s “U.S. sales infrastructure and capabilities” in nephrology.
- Specifically: By advancing its commercial plans for felzartamab, an investigational candidate for kidney diseases currently in phase 3 studies.
See here for more details on the revenue impact for Biogen.
Anything else to be aware of with this deal?
Both companies’ Boards of Directors have approved the acquisition.
However, per usual, the deal is subject to customary closing conditions and receiving necessary regulatory approvals.
Lastly: When is it expected to be finalized?
Biogen is planning for a Q2 2026 closing.