Perspective Therapeutics holder sells 113,914 shares

A ten percent owner of CATX, Lantheus Alpha Therapy, reported open-market sales totaling 113,914 shares over two days at weighted average prices just above $3 per share.

Rhea-AI Filing Summary

Perspective Therapeutics, Inc. (CATX) disclosed that Lantheus Alpha Therapy, LLC, a ten percent owner and subsidiary of Lantheus Holdings, Inc., reported selling a total of 113,914 shares of CATX common stock in open-market or private transactions on August 31 and September 1, 2026. The August 31 sale covered 78,145 shares at a weighted average price of $3.143 per share, with individual trades between $3.095 and $3.165. The September 1 sale covered 35,769 shares at a weighted average price of $3.1193, with trades between $3.08 and $3.165. The share amounts reflect Perspective Therapeutics’ 1-for-10 reverse stock split effective June 14, 2024, and the filing notes that Lantheus Holdings may be deemed to have indirect beneficial ownership of the shares held directly by Lantheus Alpha Therapy.

Insider Trade Summary

Net Seller: 113,914 shares

Net Sell 2 txns

Insider Lantheus Alpha Therapy, LLC

Role 10% Owner

Sold 113,914 shs ($357K)

Type	Security	Shares	Price	Value
Sale	Common Stock F1, F2, F4, F5	35,769	$3.1193	$112K
Sale	Common Stock F1, F2, F3, F5	78,145	$3.143	$246K

Holdings After Transaction: Common Stock — 11,563,425 shares (Direct)

Footnotes (5)

1. F1. Effective June 14, 2024, Perspective Therapeutics, Inc. ("CATX") effected a 1-for-10 reverse stock split of its common stock (the "Reverse Stock Split"). The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split.
2. F2. These sales were previously reported in Form 4s filed by Lantheus Holdings, Inc. on September 2, 2026 and September 3, 2026.
3. F3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.095 to $3.165, inclusive. The reporting person undertakes to provide to CATX, any security holder of CATX or the staff of the Securities and Exchange Commission ("SEC"), upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.
4. F4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.08 to $3.165, inclusive. The reporting person undertakes to provide to CATX, any security holder of CATX or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4.
5. F5. Represents securities directly held by Lantheus Alpha Therapy, LLC ("Lantheus"), a wholly owned indirect subsidiary of Lantheus Holdings, Inc. ("Lantheus Holdings"). Under SEC rules and regulations, Lantheus Holdings may be deemed to have indirect beneficial ownership of the shares held by Lantheus, which has direct beneficial ownership.

Key Figures

Shares sold August 31, 2026: 78,145 shares Weighted average price August 31, 2026: $3.143 per share Shares sold September 1, 2026: 35,769 shares +3 more

6 metrics

Shares sold August 31, 2026 78,145 shares Sale of CATX common stock by Lantheus Alpha Therapy on August 31, 2026

Weighted average price August 31, 2026 $3.143 per share CATX shares sold in multiple transactions between $3.095 and $3.165

Shares sold September 1, 2026 35,769 shares Sale of CATX common stock by Lantheus Alpha Therapy on September 1, 2026

Weighted average price September 1, 2026 $3.1193 per share CATX shares sold in multiple transactions between $3.08 and $3.165

Total shares sold in reported transactions 113,914 shares Net shares sold across both August 31 and September 1, 2026 transactions

Reverse stock split ratio 1-for-10 Reverse stock split of Perspective Therapeutics common stock effective June 14, 2024

Key Terms

weighted average price, 1-for-10 reverse stock split, indirect beneficial ownership, ten percent owner, +1 more

5 terms

weighted average price financial

"The price reported in Column 4 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.

1-for-10 reverse stock split financial

"effected a 1-for-10 reverse stock split of its common stock"

indirect beneficial ownership regulatory

"Lantheus Holdings may be deemed to have indirect beneficial ownership"

ten percent owner regulatory

"reporting person is indicated as a ten percent owner of CATX"

open market or private transaction financial

"Sale in open market or private transaction"

FAQ

What insider transactions in CATX stock did Lantheus Alpha Therapy report on this Form 4?

Lantheus Alpha Therapy reported two open-market or private sales of CATX common stock, totaling 113,914 shares, executed on August 31, 2026 and September 1, 2026.

How many CATX shares were sold on each date in this Form 4?

On August 31, 2026, Lantheus Alpha Therapy sold 78,145 CATX shares. On September 1, 2026, it sold an additional 35,769 shares, for a combined total of 113,914 shares sold.

What prices did Lantheus Alpha Therapy receive for the CATX shares sold?

The August 31 sale had a weighted average price of $3.143 per share, with trades from $3.095–$3.165. The September 1 sale had a weighted average price of $3.1193, with trades from $3.08–$3.165.

How does the CATX reverse stock split affect the share amounts in this Form 4?

Perspective Therapeutics effected a 1-for-10 reverse stock split of its common stock on June 14, 2024. The Form 4 states that the reported share amounts are adjusted to reflect this reverse split.

Who is considered to own the CATX shares involved in these transactions?

The shares are directly held by Lantheus Alpha Therapy, LLC. The filing states that Lantheus Holdings, Inc., its parent, may be deemed to have indirect beneficial ownership of those shares under SEC rules.

Were the CATX insider sales made under a Rule 10b5-1 trading plan?

The filing’s Rule 10b5-1 checkbox is not marked as affirming a trading plan, and the footnotes do not state that the transactions were made pursuant to a Rule 10b5-1 plan.

Why does this CATX Form 4 reference earlier filings by Lantheus Holdings, Inc.?

A footnote explains that these same sales were previously reported on Forms 4 filed by Lantheus Holdings, Inc. on September 2 and 3, 2026, indicating a change in which affiliated entity is reporting the transactions.

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

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 09/04/2026 - 04:59 PM Accepted by SEC EDGAR 09/04/2026 - 04:58 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).

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^*

Lantheus Alpha Therapy, LLC

(Last) (First) (Middle)

C/O LANTHEUS HOLDINGS, INC.

201 BURLINGTON ROAD, SOUTH BUILDING

(Street)

BEDFORD MASSACHUSETTS 01730

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Perspective Therapeutics, Inc. [ CATX ]

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
08/31/2026

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	08/31/2026		S		78,145(1)(2)	D	$3.143(3)	11,599,194(1)(2)	D(5)
Common Stock	09/01/2026		S		35,769(1)(2)	D	$3.1193(4)	11,563,425(1)(2)	D(5)

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

Explanation of Responses:

1. Effective June 14, 2024, Perspective Therapeutics, Inc. ("CATX") effected a 1-for-10 reverse stock split of its common stock (the "Reverse Stock Split"). The amount of securities reported on this Form 4 has been adjusted to reflect the Reverse Stock Split.

2. These sales were previously reported in Form 4s filed by Lantheus Holdings, Inc. on September 2, 2026 and September 3, 2026.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.095 to $3.165, inclusive. The reporting person undertakes to provide to CATX, any security holder of CATX or the staff of the Securities and Exchange Commission ("SEC"), upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (2) to this Form 4.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $3.08 to $3.165, inclusive. The reporting person undertakes to provide to CATX, any security holder of CATX or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (3) to this Form 4.

5. Represents securities directly held by Lantheus Alpha Therapy, LLC ("Lantheus"), a wholly owned indirect subsidiary of Lantheus Holdings, Inc. ("Lantheus Holdings"). Under SEC rules and regulations, Lantheus Holdings may be deemed to have indirect beneficial ownership of the shares held by Lantheus, which has direct beneficial ownership.

	/s/ Eric M. Green, Assistant Corporate Secretary	09/04/2026
	** 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)