Perspective Therapeutics, Inc. received a Schedule 13G from Commodore Capital entities and principals reporting passive ownership of 11,939,753 shares of common stock. This represents 9.9 % of the company’s common shares as of early February 2026.
The position includes 6,336,782 common shares plus 5,602,971 shares issuable upon exercise of a pre-funded warrant that is capped by a 9.99 % beneficial ownership limitation. An additional 995,075 warrant shares are excluded because of this cap. The filers certify the stake is not held to change or influence control of the company.
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Insights
Commodore Capital reports a sizable but passive 9.9 % stake in Perspective Therapeutics.
Commodore Capital LP, its master fund, and managing partners Michael Kramarz and Robert Egen Atkinson report beneficial ownership of 11,939,753 Perspective Therapeutics common shares, including pre-funded warrant shares subject to a 9.99% Beneficial Ownership Limitation.
The ownership percentage is calculated using 113,914,078 shares outstanding as of February 3, 2026, plus 5,602,971 warrant shares. The filing uses Schedule 13G, and the filers certify the position is not intended to change or influence control, indicating a passive institutional stake rather than an activist one.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
Perspective Therapeutics, Inc.
(Name of Issuer)
Common Stock, $0.001 par value
(Title of Class of Securities)
46489V302
(CUSIP Number)
02/02/2026
(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.
46489V302
1
Names of Reporting Persons
Commodore Capital LP
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
11,939,753.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
11,939,753.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
11,939,753.00
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)
9.9 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP No.
46489V302
1
Names of Reporting Persons
Commodore Capital Master LP
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
CAYMAN ISLANDS
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
11,939,753.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
11,939,753.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
11,939,753.00
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)
9.9 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP No.
46489V302
1
Names of Reporting Persons
Robert Egen Atkinson
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
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
11,939,753.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
11,939,753.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
11,939,753.00
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)
9.9 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
CUSIP No.
46489V302
1
Names of Reporting Persons
Michael Kramarz
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
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
11,939,753.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
11,939,753.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
11,939,753.00
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)
9.9 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Perspective Therapeutics, Inc.
(b)
Address of issuer's principal executive offices:
2401 Elliott Avenue, Suite 320, Seattle, WASHINGTON, 98121.
Item 2.
(a)
Name of person filing:
Commodore Capital LP
Commodore Capital Master LP
Robert Egen Atkinson
Michael Kramarz
Each a "Filer."
(b)
Address or principal business office or, if none, residence:
The address for Commodore Capital LP, Robert Egen Atkinson, and Michael Kramarz is 444 Madison Avenue, Floor 35, New York, NY 10022.
The address for Commodore Capital Master LP is c/o Maples Corporate Services Limited, Ugland House, South Church Street, PO Box 309, Grand Cayman KY1-1104, Cayman Islands.
(c)
Citizenship:
See Item 4 of the cover page for each Filer.
(d)
Title of class of securities:
Common Stock, $0.001 par value
(e)
CUSIP No.:
46489V302
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:
See Item 9 of the cover page for each Filer.
This report on Schedule 13G is being filed by Commodore Capital LP (the "Firm"), Commodore Capital Master LP ("Commodore Master"), Michael Kramarz, and Robert Egen Atkinson. The Firm is the investment manager to Commodore Master. As of February 2, 2026, the Firm may be deemed to beneficially own an aggregate of 11,939,753 shares Common Stock, $0.001 par value per share (the "Common Stock"), consisting of (i) 6,336,782 shares of the Common Stock and (ii) 5,602,971 shares of Common Stock each Filer has the right to acquire through the exercise of a pre-funded warrant ("Pre-Funded Warrant") of Perspective Therapeutics, Inc. (the "Issuer"), which is subject to a beneficial ownership limitation of 9.99% (the "Beneficial Ownership Limitation"). The foregoing excludes 995,075 shares of Common Stock underlying the Pre-Funded Warrant, which is subject to the Beneficial Ownership Limitation. The Firm, as the investment manager to Commodore Master, may be deemed to beneficially own these securities. Michael Kramarz and Robert Egen Atkinson are the managing partners of the Firm and exercise investment discretion with respect to these securities. Ownership percentages are based on 113,914,078 shares of Common Stock reported as issued and outstanding on February 3, 2026, in the Issuer's Rule 424(b)(5) Prospectus Supplement filed with the Securities and Exchange Commission on February 3, 2026, plus 5,602,971 shares of Common Stock which the Filers may acquire upon the exercise of the Pre-Funded Warrant, subject to the Beneficial Ownership Limitation.
(b)
Percent of class:
See Item 11 of the cover page for each Filer.
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
See Item 5 of the cover page for each Filer.
(ii) Shared power to vote or to direct the vote:
See Item 6 of the cover page for each Filer.
(iii) Sole power to dispose or to direct the disposition of:
See Item 7 of the cover page for each Filer.
(iv) Shared power to dispose or to direct the disposition of:
See Item 8 of the cover page for each Filer.
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
Not Applicable
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 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.
What stake does Commodore Capital report in Perspective Therapeutics (CATX)?
Commodore Capital and related filers report beneficial ownership of 11,939,753 shares of Perspective Therapeutics common stock, representing 9.9 % of the class. This total combines existing shares and warrant shares calculated under a specified beneficial ownership limitation.
How is Commodore Capital’s 9.9% ownership in CATX structured?
The reported 11,939,753-share position includes 6,336,782 common shares and 5,602,971 shares that can be acquired by exercising a pre-funded warrant. The warrant is constrained by a 9.99 % beneficial ownership limitation, which also excludes 995,075 additional underlying shares.
Who are the reporting persons on the CATX Schedule 13G filing?
The Schedule 13G lists Commodore Capital LP, Commodore Capital Master LP, and individuals Robert Egen Atkinson and Michael Kramarz as filers. Commodore Capital LP acts as investment manager to the master fund, and Atkinson and Kramarz are managing partners exercising investment discretion.
Is Commodore Capital’s CATX stake reported as passive or activist?
The position is reported on Schedule 13G, and the filers certify the securities were not acquired and are not held for the purpose of changing or influencing control of Perspective Therapeutics. This indicates a passive institutional ownership stance rather than an activist campaign.
How was the 9.9% ownership in Perspective Therapeutics calculated?
The ownership percentage is based on 113,914,078 common shares reported outstanding as of February 3, 2026, plus 5,602,971 shares that the filers may acquire upon warrant exercise, all subject to the 9.99 % beneficial ownership limitation described in the filing.
What is the beneficial ownership limitation mentioned in the CATX filing?
The pre-funded warrant held by the filers is subject to a 9.99 % beneficial ownership limitation. This cap prevents the filers from exercising the warrant to the extent ownership would exceed 9.99 %, leaving 995,075 underlying shares uncounted in the reported stake.
