SEC FORM 4

SEC FORM 4SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

O'Brien Stephanie Monaghan

(Last)

(First)

(Middle)

C/O APELLIS PHARMACEUTICALS, INC.

100 FIFTH AVENUE, 3RD FLOOR

(Street)

WALTHAM

MASSACHUSETTS

02451

(City)

(State)

(Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Apellis Pharmaceuticals, Inc. [ APLS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
	Officer (give title below)	Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/14/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	05/14/2026		U⁽¹⁾⁽²⁾⁽³⁾		25,666	D	⁽¹⁾⁽²⁾⁽³⁾	0	D
Common Stock	05/14/2026		U⁽¹⁾⁽²⁾⁽³⁾		5,750	D	⁽¹⁾⁽²⁾⁽³⁾	0	I	By Spouse
Common Stock	05/14/2026		D		3,062	D	⁽⁴⁾⁽⁵⁾	0⁽⁴⁾⁽⁵⁾	D
Common Stock	05/14/2026		D		5,744	D	⁽⁴⁾⁽⁵⁾	0⁽⁴⁾⁽⁵⁾	D
Common Stock	05/14/2026		D		7,961	D	⁽⁴⁾⁽⁵⁾	0⁽⁴⁾⁽⁵⁾	D
Common Stock	05/14/2026		D		3,877	D	⁽⁴⁾⁽⁵⁾	0⁽⁴⁾⁽⁵⁾	D
Common Stock	05/14/2026		D		3,544	D	⁽⁴⁾⁽⁵⁾	0⁽⁴⁾⁽⁵⁾	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
Stock Option (right to buy)	$13.19	05/14/2026		D			17,580	⁽⁶⁾	⁽⁶⁾	Common Stock	17,580	⁽⁶⁾	0	D
Stock Option (right to buy)	$14	05/14/2026		D			121,894	⁽⁶⁾	⁽⁶⁾	Common Stock	121,894	⁽⁶⁾	0	D
Stock Option (right to buy)	$25.12	05/14/2026		D			14,684	⁽⁶⁾	⁽⁶⁾	Common Stock	14,684	⁽⁶⁾	0	D
Stock Option (right to buy)	$30.62	05/14/2026		D			27,600	⁽⁶⁾	⁽⁶⁾	Common Stock	27,600	⁽⁶⁾	0	D
Stock Option (right to buy)	$31.91	05/14/2026		D			11,199	⁽⁶⁾	⁽⁶⁾	Common Stock	11,199	⁽⁶⁾	0	D
Stock Option (right to buy)	$47.28	05/14/2026		D			8,554	⁽⁷⁾	⁽⁷⁾	Common Stock	8,554	⁽⁷⁾	0	D
Stock Option (right to buy)	$51.71	05/14/2026		D			7,441	⁽⁷⁾	⁽⁷⁾	Common Stock	7,441	⁽⁷⁾	0	D
Stock Option (right to buy)	$57.2	05/14/2026		D			27,600	⁽⁷⁾	⁽⁷⁾	Common Stock	27,600	⁽⁷⁾	0	D
Stock Option (right to buy)	$59.86	05/14/2026		D			5,748	⁽⁷⁾	⁽⁷⁾	Common Stock	5,748	⁽⁷⁾	0	D

Explanation of Responses:

1. Pursuant to the terms of that certain Agreement and Plan of Merger (the "Merger Agreement"), by and among Apellis Pharmaceuticals, Inc. (the "Issuer"), Biogen Inc. ("Parent") and Parent's direct wholly-owned subsidiary, Aspen Purchaser Sub, Inc. ("Purchaser"), dated as of March 31, 2026, the shares of common stock, par value $0.0001 per share, of the Issuer (the "Common Stock") that were tendered to Purchaser prior to the expiration time of the tender offer were exchanged for: (i) $41.00 per share of Common Stock, 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 of Common Stock (each, a "CVR"),

2. (continued from footnote 1) which entitles the holder to receive potential 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 accordance with the terms and conditions of a contingent value rights agreement (the "CVR Agreement" and the Cash Amount plus one CVR, together, the "Offer Price"). After completion of the tender offer, pursuant to the terms of the Merger Agreement, Purchaser merged with and into the Issuer (the "Merger"), effective as of the filing and acceptance of the certificate of merger relating thereto on May 14, 2026 (the "Effective Time"), with the Issuer continuing as the surviving corporation (the "Surviving Corporation") and a wholly owned subsidiary of Parent. In the Merger, each share of Common Stock issued and outstanding immediately prior to the Effective Time, subject to certain exceptions,

3. (continued from footnote 2) was automatically converted into the right to receive the Offer Price from Purchaser, without interest and subject to reduction for any applicable withholding taxes.

4. Pursuant to the terms of the Merger Agreement, effective as of immediately prior to the Effective Time, each Converted RSU Award that was subject solely to a time-based vesting schedule (including, for the avoidance of doubt, any Converted RSU Award for which the performance period of any applicable performance metric had already ended) was automatically cancelled and converted into the contingent right to receive (i) an amount of cash, without interest and less applicable tax withholding, equal to the product of (x) the total number of shares of Common Stock underlying such Converted RSU Award multiplied by (y) the Cash Amount and (ii) one CVR for each share of Common Stock underlying such Converted RSU Award.

5. (continued from footnote 4) Subject to the holder's continued service through the vesting dates applicable to the Converted RSU Award under its terms as in effect immediately prior to the Effective Time, all payments in respect of such Converted RSU Award pursuant to the Merger Agreement will vest and become payable at the same time as the underlying Converted RSU Award would have vested and become settled pursuant to its terms and shall otherwise remain subject to the same terms and conditions (including any "double-trigger" vesting provisions applicable to the Converted RSU Award immediately prior to the Effective Time, as extended as provided by the Merger Agreement) as were applicable to the underlying RSU immediately prior to the Effective Time and the terms of the CVR Agreement.

6. Pursuant to the terms of the Merger Agreement, effective as of immediately prior to the Effective Time, each outstanding and unexercised option to purchase shares of Common Stock that was vested pursuant to its existing terms or that vested as a result of the transactions contemplated by the Merger Agreement (each, a "Cash-Out Option") and had an exercise price per share that was less than $41.00 (the Cash Amount) was automatically cancelled and converted into the right to receive (i) an amount of cash, without interest and less applicable tax withholding, equal to the product of (x) the total number of shares of Common Stock underlying such option, multiplied by (y) the excess of the Cash Amount over the exercise price per share of such option and (ii) one CVR for each share of Common Stock underlying such option.

7. Pursuant to the terms of the Merger Agreement, effective as of immediately prior to the Effective Time, each vested or unvested option with an exercise price per share that was equal to or greater than $45.00 (the Aggregate Amount) was cancelled without consideration and will have no further force or effect.

	/s/ David Watson, attorney-in-fact for Stephanie Monaghan O'Brien	05/14/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

Director O'Brien Stephanie Monaghan returned 24,188 shares to the company, closing all direct ownership in the company (SEC Form 4) (for tax liability)