Sec Form 4 Filing - Redmile Group, LLC @ ADC Therapeutics SA - 2025-06-11

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

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Redmile Group, LLC 2. Issuer Name and Ticker or Trading Symbol ADC Therapeutics SA [ ADCT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) ONE LETTERMAN DRIVE, BUILDING D, SUITE D3-300 3. Date of Earliest Transaction (MM/DD/YY) 06/11/2025 (Street) SAN FRANCISCO, CA94129 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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) Code V Amount (A) or (D) Price

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Pre-Funded Warrants ( 2 ) 06/11/2025 P( 1 ) 15,734,267 06/16/2025 ( 3 ) Common Share 15,734,267 $ 3.432 15,734,267 I See Footnotes ( 4 ) ( 5 ) Pre-Funded Warrants ( 2 ) 06/11/2025 P( 1 ) 12,465,234 06/16/2025 ( 3 ) Common Share 12,465,234 $ 3.432 12,465,234 D ( 5 ) ( 6 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Redmile Group, LLC ONE LETTERMAN DRIVE, BUILDING D SUITE D3-300 SAN FRANCISCO, CA94129 X Green Jeremy C/O REDMILE GROUP, LLC (NY OFFICE) 45 W. 27TH STREET, FLOOR 11 NEW YORK, NY10001 X RedCo II Master Fund, L.P. C/O REDMILE GROUP, LLC ONE LETTERMAN DRIVE, BUILDING D SUITE D3-300 SAN FRANCISCO, CA94129 X Signatures By: /s/ Jeremy Green, Managing Member of Redmile Group, LLC 06/13/2025 Signature of Reporting Person Date /s/ Jeremy Green, Managing Member of RedCo II (GP), LLC, the General Partner of RedCo II Master Fund, L.P. 06/13/2025 Signature of Reporting Person Date /s/ Jeremy Green 06/13/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On June 11, 2025, certain private investment vehicles managed by Redmile Group, LLC (collectively, the "Redmile Clients"), including RedCo II Master Fund, L.P. ("RedCo II"), entered into a securities purchase agreement (the "Purchase Agreement") in connection with a private placement by the Issuer to certain institutional investors. Pursuant to the terms of the Purchase Agreement, the Redmile Clients will acquire 15,734,267 pre-funded warrants to purchase Common Shares (the "Pre-Funded Warrants") as of the closing date on June 16, 2025. The purchase price per Pre-Funded Warrant, excluding the exercise price (see footnote 2 below), is $3.432. ( 2 )The exercise price of the Pre-Funded Warrants is CHF 0.08 per Pre-Funded Warrant Share. Based on the June 11, 2025 exchange rate of approximately US$1.219 to CHF 1.00, the exercise price of the Pre-Funded Warrants in US Dollars as of June 11, 2025 was approximately $0.098. ( 3 )The Pre-Funded Warrants are exercisable by the holder at any time on or after the closing date of the private placement until the tenth anniversary of such closing date, subject to a 9.99% beneficial ownership blocker. At any time during the last 90 days of the term of the Pre-Funded Warrants, the holder thereof may exchange a Pre-Funded Warrant with the Issuer for a new Pre-Funded Warrant to purchase the number of Pre-Funded Warrant Shares then remaining under such Pre-Funded Warrant, with a subsequent ten-year exercise period. ( 4 )These reported securities are directly owned by the Redmile Clients, including RedCo II. ( 5 )Redmile Group, LLC ("Redmile") may be deemed to beneficially own the reported securities as the investment manager of the Redmile Clients. The reported securities may also be deemed beneficially owned by Jeremy Green as the principal of Redmile. Redmile and Mr. Green disclaim beneficial ownership of the reported securities except to the extent of its and his respective pecuniary interest therein, if any. This report shall not be deemed an admission that Redmile or Mr. Green is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. ( 6 )These reported securities are directly owned by RedCo II and this transaction is a repetition of the same transaction disclosed in the row above to disclose this fund's direct ownership.

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