OrbiMed details 4.7% ADC Therapeutics (ADCT) ownership position

Rhea-AI Filing Summary

ADC Therapeutics received an amended Schedule 13G showing updated ownership by OrbiMed investment entities as of 12/31/2025. OrbiMed Advisors LLC reports beneficial ownership of 2,592,057 common shares, representing 2.1% of the class, with shared voting and dispositive power over these shares.

OrbiMed Capital LLC reports beneficial ownership of 3,230,797 common shares, representing 2.6% of the class, with sole voting and dispositive power. Together, the reporting persons hold an aggregate 4.7% of ADC Therapeutics’ common shares on behalf of other persons entitled to dividends or sale proceeds. They certify the shares are held in the ordinary course of business and not for the purpose of changing or influencing control of the company.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

ADC Therapeutics SA

(Name of Issuer)

Common Shares, par value CHF 0.08 per share

(Title of Class of Securities)

H0036K147

(CUSIP Number)

12/31/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. H0036K147

1

Names of Reporting Persons

ORBIMED ADVISORS LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 2,592,057.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 2,592,057.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,592,057.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

2.1 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

CUSIP No. H0036K147

1

Names of Reporting Persons

ORBIMED CAPITAL LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 3,230,797.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 3,230,797.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,230,797.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

2.6 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: ADC Therapeutics SA
(b)	Address of issuer's principal executive offices: Biopole Route de la Corniche 3B, 1066 Epalinges, Switzerland
Item 2.
(a)	Name of person filing: OrbiMed Advisors LLC OrbiMed Capital LLC
(b)	Address or principal business office or, if none, residence: 601 Lexington Avenue, 54th Floor New York, NY 10022
(c)	Citizenship: Please refer to Item 4 on each cover sheet for each filing person.
(d)	Title of class of securities: Common Shares, par value CHF 0.08 per share
(e)	CUSIP No.: H0036K147
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: OrbiMed Advisors LLC: 2,592,057 OrbiMed Capital LLC: 3,230,797
(b)	Percent of class: OrbiMed Advisors LLC: 2.1% OrbiMed Capital LLC: 2.6%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: OrbiMed Advisors LLC: 0 OrbiMed Capital LLC: 3,230,797
	(ii) Shared power to vote or to direct the vote: OrbiMed Advisors LLC: 2,592,057 OrbiMed Capital LLC: 0
	(iii) Sole power to dispose or to direct the disposition of: OrbiMed Advisors LLC: 0 OrbiMed Capital LLC: 3,230,797
	(iv) Shared power to dispose or to direct the disposition of: OrbiMed Advisors LLC: 2,592,057 OrbiMed Capital LLC: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. The Reporting Persons hold 4.7% of the Common Shares in the aggregate on behalf of other persons who have the right to receive or the power to direct the receipt of dividends from, or proceeds from the sale of, such securities. OrbiMed Advisors LLC and OrbiMed Capital LLC exercise investment and voting power over the Common Shares through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the Common Shares reported herein.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

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.

ORBIMED ADVISORS LLC

Signature:	/s/ Carl L. Gordon
Name/Title:	Carl L. Gordon/Member
Date:	02/17/2026

ORBIMED CAPITAL LLC

Signature:	/s/ Carl L. Gordon
Name/Title:	Carl L. Gordon/Member
Date:	02/17/2026

FAQ

What ownership stake in ADCT does OrbiMed report in this Schedule 13G/A?

OrbiMed investment entities report beneficial ownership of an aggregate 4.7% of ADC Therapeutics’ common shares. This includes 2,592,057 shares (2.1%) by OrbiMed Advisors LLC and 3,230,797 shares (2.6%) by OrbiMed Capital LLC, all held on behalf of other persons.

How many ADCT shares does OrbiMed Advisors LLC beneficially own?

OrbiMed Advisors LLC beneficially owns 2,592,057 ADC Therapeutics common shares, representing 2.1% of the outstanding class. It has shared voting and shared dispositive power over these shares, with no sole voting or dispositive authority reported in the filing.

How many ADCT shares does OrbiMed Capital LLC beneficially own?

OrbiMed Capital LLC beneficially owns 3,230,797 ADC Therapeutics common shares, representing 2.6% of the class. It reports sole voting and sole dispositive power over all of these shares, with no shared voting or dispositive power indicated.

Do OrbiMed entities control more than 5% of ADCT’s shares individually or in aggregate?

Individually, OrbiMed Advisors LLC holds 2.1% and OrbiMed Capital LLC holds 2.6% of ADCT, each under 5%. In aggregate, they hold 4.7% of the common shares on behalf of other persons, still remaining below the 5% threshold.

Are OrbiMed’s ADCT holdings intended to influence control of the company?

The filing states the ADC Therapeutics securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control. It also notes they are not held in connection with any control-related transaction, except certain nomination activities.

Who ultimately benefits from OrbiMed’s reported ADCT shareholdings?

The OrbiMed entities hold 4.7% of ADC Therapeutics’ common shares on behalf of other persons who have rights to dividends or sale proceeds. A management committee at OrbiMed exercises investment and voting power, and its members disclaim beneficial ownership of the reported shares.

What is the event date for OrbiMed’s reported ADCT ownership in this filing?

The Schedule 13G/A specifies 12/31/2025 as the date of the event requiring the filing. This date anchors when the reported ownership levels—2.1% for OrbiMed Advisors LLC, 2.6% for OrbiMed Capital LLC, and 4.7% in aggregate—were measured for ADC Therapeutics.