Biogen (APLS counterparty) closes Apellis tender offer and merger with cash and CVR deal

Rhea-AI Filing Summary

Biogen Inc. filed an amended beneficial ownership report showing it now holds 0% of Apellis Pharmaceuticals’ common stock. The change follows Biogen’s acquisition of Apellis through a tender offer and merger.

Biogen’s subsidiary offered $41.00 in cash per share plus one non-transferable contingent value right per share, which can pay up to an additional $4.00 in cash if specified milestones are achieved. After the offer conditions were met, Biogen’s subsidiary accepted all validly tendered shares and was then merged into Apellis, leaving Apellis as a wholly owned Biogen subsidiary.

Insights

M&A and securities lawyer

Biogen’s tender offer and merger take Apellis private at a fixed cash-and-CVR price.

The filing confirms completion of Biogen’s acquisition of Apellis Pharmaceuticals. Biogen’s subsidiary launched a tender offer at $41.00 in cash per share plus a contractual contingent value right promising up to $4.00 upon specified milestones.

Once the minimum tender condition and other conditions were satisfied, the subsidiary accepted all validly tendered shares and immediately completed a merger under Delaware’s Section 251(h), eliminating the need for a separate shareholder vote. Apellis now operates as a wholly owned Biogen subsidiary, and the reporting person’s Schedule 13D position is fully exited.

Key Figures

Cash consideration per share: $41.00 per share Contingent value right: Up to $4.00 per share Beneficial ownership: 0.00 shares +2 more

5 metrics

Cash consideration per share $41.00 per share Tender offer price per Apellis common share

Contingent value right Up to $4.00 per share Maximum aggregate cash payable per CVR upon milestones

Beneficial ownership 0.00 shares Shares beneficially owned by Biogen after merger

Percent of class owned 0.0% Apellis common stock beneficially owned by Biogen

Event date May 14, 2026 Date tender offer accepted and merger completed

Key Terms

tender offer, contingent value right, Section 251(h), wholly owned subsidiary, +1 more

5 terms

tender offer financial

"Purchaser commenced a tender offer (the "Offer") to acquire any and all outstanding Shares"

A tender offer is a proposal made by a person or company to buy shares from existing shareholders at a set price, usually higher than the current market value, within a specific time frame. It matters to investors because it can lead to a change in ownership or control of a company, and shareholders must decide whether to sell their shares at the offered price.

contingent value right financial

"one contractual, non-transferable contingent value right per Share representing the right to receive contingent cash payments"

A contingent value right is a special security that gives its holder the right to receive one or more future payments only if specified events happen, such as a product reaching a sales target or getting regulatory approval. It matters to investors because it offers potential extra payout tied to uncertain outcomes—like a bet that a project will succeed—so it can add upside to a deal while also carrying extra risk and valuation uncertainty.

Section 251(h) regulatory

"without a vote of the stockholders of Apellis in accordance with Section 251(h) of the General Corporation Law of the State of Delaware"

Section 251(h) is a provision in Delaware corporate law that lets a company complete a merger without holding a separate shareholder vote if a prior, qualifying tender offer already secured the required number of shares on the same terms. For investors, it matters because it shortens the timetable and reduces the risk that a merger will be blocked by a follow-up vote—think of it as a shortcut that finalizes a deal once enough stockholders have already agreed.

wholly owned subsidiary financial

"with Apellis continuing as the surviving corporation of the merger and as a wholly owned subsidiary of Biogen"

A wholly owned subsidiary is a company whose entire ownership is held by another company (the parent), so the parent controls decisions, operations, and finances. Think of it as a fully controlled branch that runs as its own legal entity but whose results flow straight into the parent’s financial statements; investors watch these structures because they affect consolidated revenue, risk exposure, and how profits, liabilities, and cash flow are allocated across the corporate group.

Schedule 13D regulatory

"The filing of this Amendment represents the final amendment to the Prior and constitutes an exit filing for the Reporting Person."

A Schedule 13D is a legal document that investors file with regulators when they buy a large enough stake in a company to potentially influence its management or decisions. It provides details about the investor’s intention, ownership stake, and plans, helping other investors understand who is gaining control and what their motives might be.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)

Apellis Pharmaceuticals, Inc.

(Name of Issuer)

Common Stock, par value $0.0001 per share

(Title of Class of Securities)

03753U106

(CUSIP Number)

Wendell Taylor, Secretary
225 Binney Street,
Cambridge, MA, 02142
(617) 679-2000

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

05/14/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): 03753U106

1

Name of reporting person

Biogen Inc.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

0.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

0.0 %

14

Type of Reporting Person (See Instructions)

CO

Comment for Type of Reporting Person:

This Amendment No. 1 to Schedule 13D (this "Amendment") relates to the common stock, par value $0.0001 per share (the "Shares"), of Apellis Pharmaceuticals, Inc., a Delaware corporation ("Apellis") and amends and supplements the statement on Schedule 13D originally filed by Biogen Inc., a Delaware corporation ("Biogen"), on April 6, 2026 (the "Prior Schedule 13D"). The filing of this Amendment represents the final amendment to the Prior Schedule 13D and constitutes an exit filing for the Reporting Person. Except as otherwise specified in this Amendment, all items left blank remain unchanged in all material respects and any items that are reported are deemed to amend and restate the corresponding items in the Prior Schedule 13D. Unless otherwise indicated, all capitalized terms used herein but not defined herein shall have the same meanings ascribed to them in the Prior Schedule 13D.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $0.0001 per share
(b)	Name of Issuer: Apellis Pharmaceuticals, Inc.
(c)	Address of Issuer's Principal Executive Offices: 100 Fifth Avenue, Waltham, MASSACHUSETTS , 02451.
Item 4.	Purpose of Transaction
	Item 4 of the Prior Schedule 13D is hereby amended and supplemented by adding the following at the end thereof: As previously disclosed, on March 31, 2026, Biogen entered into an Agreement and Plan of Merger (the "Merger Agreement") with Apellis and Aspen Purchaser Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Biogen ("Purchaser"). Pursuant to the Merger Agreement, on April 14, 2026, Purchaser commenced a tender offer (the "Offer") to acquire any and all outstanding Shares, in exchange for (i) $41.00 per Share, net to the seller in cash, without interest and subject to reduction for any applicable tax withholding (the "Cash Amount"), plus (ii) one contractual, non-transferable contingent value right per Share (each, a "CVR") representing the right to receive contingent cash payments of up to an aggregate of $4.00 in cash, without interest and subject to reduction for any applicable tax withholding, upon the achievement of certain specified milestones, in each case upon the terms and subject to the conditions set forth in the Offer to Purchase, dated April 14, 2026 (as amended or supplemented from time to time, the "Offer to Purchase") and in the related Letter of Transmittal. As a result of the satisfaction of the Minimum Condition (as defined in the Offer) and each of the other conditions to the Offer, on May 14, 2026, Purchaser irrevocably accepted for payment all Shares that were validly tendered (and not validly withdrawn) pursuant to the Offer. Following the completion of the Offer, on May 14, 2026, pursuant to the terms of the Merger Agreement, Purchaser merged with and into Apellis, without a vote of the stockholders of Apellis in accordance with Section 251(h) of the General Corporation Law of the State of Delaware, with Apellis continuing as the surviving corporation of the merger and as a wholly owned subsidiary of Biogen (the "Merger").
Item 5.	Interest in Securities of the Issuer
(a)	Items 5(a), (b) and (e) of the Prior Schedule 13D are hereby amended and supplemented by adding the following at the end thereof: On May 14, 2026, the Merger was consummated and Purchaser was merged with and into Apellis, with Apellis surviving the Merger as a wholly owned subsidiary of Biogen. Upon the consummation of the Merger, the Tender and Support Agreement automatically terminated pursuant to its terms and is of no further force or effect.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Biogen Inc.

Signature:	/s/ Wendell Taylor
Name/Title:	Wendell Taylor / Secretary
Date:	05/14/2026

FAQ

What transaction between Biogen and Apellis Pharmaceuticals (APLS) does this amendment describe?

The amendment describes Biogen’s completed acquisition of Apellis. Biogen’s subsidiary conducted a tender offer for all Apellis common shares, then merged into Apellis so that Apellis became a wholly owned Biogen subsidiary under Delaware law.

What did Apellis Pharmaceuticals (APLS) shareholders receive in Biogen’s tender offer?

Shareholders received $41.00 in cash per Apellis share plus one contingent value right. Each CVR can pay up to an additional $4.00 in cash if certain specified milestones described in the offer documents are achieved after closing.

How did Biogen’s acquisition of Apellis Pharmaceuticals (APLS) become effective?

After the minimum tender condition and other conditions were satisfied, Biogen’s subsidiary accepted all validly tendered Apellis shares. It then merged with and into Apellis under Section 251(h), with Apellis surviving as a wholly owned Biogen subsidiary without a separate shareholder vote.

What does Biogen’s reported 0% ownership of Apellis Pharmaceuticals (APLS) common stock mean?

The filing shows Biogen now reports beneficial ownership of 0 shares and 0.0% of Apellis common stock. That reflects the completed merger, where Apellis became a wholly owned Biogen subsidiary rather than a separately held public company with reportable outside ownership.

What is the role of the contingent value right in the Apellis (APLS) acquisition terms?

Each Apellis share tendered received one non-transferable contingent value right. These CVRs entitle holders to potential additional cash payments of up to $4.00 per share if certain milestones specified in the transaction documents are achieved after completion of the merger.