SEC Form 4 · accession 0001104659-26-106340

Barinthus Biotherapeutics plc. · BRNS

Statement of changes in beneficial ownership, as filed. Original on EDGAR ↗

Reporting owner

Pierre A. Morgon

Director

Period of report

Sep 9, 2026

Accepted (ET)

Sep 9, 2026 · 4:19 pm EDT

Rule 10b5-1 plan

box not checked

Issuer CIK

0001828185

Table I — non-derivative securities

Security	Date	Code	Shares	Price	A/D	Owned after	D/I	Nature of ownership
Ordinary Shares^F1,F3	Sep 9, 2026	D	10,506	—	D	0	D

Table II — derivative securities

Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	D/I
Share Option (Right to Buy)^F4,F1	$0.0001	Sep 9, 2026	D	20,394	D	—	Jan 10, 2030	Ordinary Shares	20,394	D
Share Option (Right to Buy)^F4,F1	$17.00	Sep 9, 2026	D	34,328	D	—	May 1, 2031	Ordinary Shares	34,328	D
Share Option (Right to Buy)^F4,F1	$4.27	Sep 9, 2026	D	18,604	D	—	Jun 15, 2032	Ordinary Shares	18,604	D
Share Option (Right to Buy)^F4,F1	$2.27	Sep 9, 2026	D	19,197	D	—	May 11, 2033	Ordinary Shares	19,197	D
Share Option (Right to Buy)^F4,F1	$2.34	Sep 9, 2026	D	19,516	D	—	May 10, 2034	Ordinary Shares	19,516	D
Share Option (Right to Buy)^F4,F1	$1.00	Sep 9, 2026	D	20,174	D	—	Jun 10, 2035	Ordinary Shares	20,174	D

Explanation of responses

F1The Ordinary Shares may be represented by American Depositary Shares ("ADSs" and together with the Ordinary Shares, the "Shares"), each of which currently represents one Ordinary Share.
F2This Form 4 reports securities transacted in connection with the Agreement and Plan of Merger, dated September 29, 2025, as amended (the "Merger Agreement") by and among the Issuer, Beacon Topco, Inc. ("Topco"), a Delaware corporation and a direct wholly owned subsidiary of the Issuer, Cdog Merger Sub, Inc., a Delaware corporation and a direct wholly owned subsidiary of Topco, and Clywedog Therapeutics, Inc., a Delaware corporation. On September 9, 2026 (the "Effective Time"), in connection with the effectiveness of the scheme of arrangement under Part 26 of the United Kingdom Companies Act 2006 (the "Scheme") contemplated by the Merger Agreement, Topco acquired the entire issued share capital of the Issuer, resulting in the Issuer becoming a direct wholly owned subsidiary of Topco.
F3Pursuant to the Merger Agreement and in connection with the effectiveness of the Scheme, at the Effective Time, each Share of the Issuer was converted into the right to receive 0.111 shares of common stock, $0.0001 par value per share, of Topco (the "Topco Common Stock").
F4Pursuant to the Merger Agreement, at the Effective Time, each option to acquire Shares under the Issuer's equity plans that was outstanding as of immediately prior to the Effective Time ceased to represent a right to acquire Shares of the Issuer, and was converted into an option to acquire shares of Topco Common Stock and assumed by Topco on the same terms and conditions (including applicable vesting and exercisability conditions) as were applicable to such option immediately prior to the Effective Time.