Aktis Oncology medical chief sells 5,099, 7,401 shares

The sales were made under a Rule 10b5-1 trading plan adopted June 24, 2026.

Rhea-AI Filing Summary

Aktis Oncology, Inc. Chief Medical Officer Akos Czibere exercised options to acquire 12,500 common shares on September 23, 2026, at an exercise price of $4.9500 per share. He reported sales of 5,099 shares at a weighted average price of $20.1947 per share and 7,401 shares at a weighted average price of $21.0307 per share. The transactions were made pursuant to a Rule 10b5-1 trading plan adopted June 24, 2026. His reported direct option position following the exercise was 208,718 shares.

Insider Trade Summary 10b5-1

Exercise and Sale: 12,500 shares ($197K approx. pre-tax spread)

Exercise and Sale 4 txns

Insider Czibere Akos

Role Chief Medical Officer

Sold 12,500 shs ($259K)

Approx. gross sale proceeds $259K

Approx. exercise cost $62K

Approx. pre-tax spread $197K

Type	Security	Shares	Price	Value
Exercise	Stock Option (Right to Buy) F1, F4	12,500	$0.00	$0.00
Exercise	Common Stock F1	12,500	$4.95	$62K
Sale	Common Stock F1, F2	5,099	$20.1947	$103K
Sale	Common Stock F1, F3	7,401	$21.0307	$156K

Holdings After Transaction: Stock Option (Right to Buy) — 208,718 contracts (Direct); Common Stock — 0 shares (Direct)

Footnotes (4)

1. F1. The transactions reported herein were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 24, 2026.
2. F2. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $19.6700 to $20.6500, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.
3. F3. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.6700 to $21.5000, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.
4. F4. 25% of the original number of shares subject to the option vested on July 1, 2025, and 1/48th of the original number of shares subject to the option vested or shall vest in monthly installments thereafter, subject to the Reporting Person's continuous service through each vesting date, inclusive.

Key Figures

Options exercised: 12,500 shares Exercise price: $4.9500 per share Weighted average sale price: $20.1947 per share +3 more

6 metrics

Options exercised 12,500 shares September 23, 2026

Exercise price $4.9500 per share Options exercised September 23, 2026

Weighted average sale price $20.1947 per share 5,099 shares sold September 23, 2026

Weighted average sale price $21.0307 per share 7,401 shares sold September 23, 2026

Direct option position following exercise 208,718 shares Reported following the September 23, 2026 transaction

Trading plan adoption date June 24, 2026 Rule 10b5-1 trading plan

Key Terms

Rule 10b5-1 trading plan, weighted average price, vesting date

3 terms

Rule 10b5-1 trading plan regulatory

"pursuant to a Rule 10b5-1 trading plan"

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted average price financial

"The price reported is a weighted average price"

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

vesting date financial

"continuous service through each vesting date, inclusive"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many AKTS shares did Chief Medical Officer Akos Czibere sell, and at what prices?

Akos Czibere reported two sales on September 23, 2026: 5,099 shares at a weighted average of $20.1947 per share and 7,401 shares at a weighted average of $21.0307 per share. The respective reported price ranges were $19.6700 to $20.6500, inclusive, and $20.6700 to $21.5000, inclusive.

What were the AKTS option exercise terms for Akos Czibere?

He exercised options for 12,500 common shares at $4.9500 per share on September 23, 2026. His reported direct option position following the transaction was 208,718 shares.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 09/24/2026 - 04:06 PM Accepted by SEC EDGAR 09/24/2026 - 04:05 PM Learn about SEC filing dates

SEC 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

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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

X

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^*

Czibere Akos

(Last) (First) (Middle)

C/O AKTIS ONCOLOGY, INC.

17 DRYDOCK AVENUE, SUITE 17-401

(Street)

BOSTON MASSACHUSETTS 02210

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Aktis Oncology, Inc. [ AKTS ]

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/23/2026

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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/23/2026		M(1)		12,500	A	$4.95	12,500	D
Common Stock	09/23/2026		S(1)		5,099	D	$20.1947(2)	7,401	D
Common Stock	09/23/2026		S(1)		7,401	D	$21.0307(3)	0	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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$4.95	09/23/2026		M(1)			12,500	(4)	06/30/2034	Common Stock	12,500	$0	208,718	D

Explanation of Responses:

1. The transactions reported herein were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 24, 2026.

2. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $19.6700 to $20.6500, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.

3. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.6700 to $21.5000, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range.

4. 25% of the original number of shares subject to the option vested on July 1, 2025, and 1/48th of the original number of shares subject to the option vested or shall vest in monthly installments thereafter, subject to the Reporting Person's continuous service through each vesting date, inclusive.

	/s/ Kyle D. Kuvalanka, as Attorney-in-Fact	09/24/2026
	** 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)