Cullinan Therapeutics, Inc. received an amended Schedule 13G from Biotechnology Value Fund–affiliated entities reporting a large, primarily passive stake in its common stock. As of the close of business on December 31, 2025, the BVF funds and a managed account beneficially owned an aggregate of 5,918,481 shares of Cullinan common stock, or about 9.99% of the outstanding shares, including shares issuable from Series A preferred stock.
The BVF group holds 555,935 shares of Series A convertible preferred stock, which is convertible into 5,559,350 common shares at a 10:1 ratio, but a 9.99% “Conversion Blocker” currently limits conversion to 167,798 underlying shares. The reporting persons certify that the securities were not acquired and are not held for the purpose of changing or influencing control of Cullinan, characterizing the position as a passive investment.
Positive
None.
Negative
None.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 6)
Cullinan Therapeutics, Inc.
(Name of Issuer)
Common Stock, par value $0.0001 per share
(Title of Class of Securities)
230031106
(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.
230031106
1
Names of Reporting Persons
BIOTECHNOLOGY VALUE FUND L P
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
3,302,376.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
3,302,376.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
3,302,376.00
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)
5.6 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP No.
230031106
1
Names of Reporting Persons
BVF I GP 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
3,302,376.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
3,302,376.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
3,302,376.00
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)
5.6 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP No.
230031106
1
Names of Reporting Persons
BIOTECHNOLOGY VALUE FUND II 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
2,271,662.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,271,662.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,271,662.00
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)
3.8 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP No.
230031106
1
Names of Reporting Persons
BVF II GP 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
2,271,662.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
2,271,662.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
2,271,662.00
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)
3.8 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP No.
230031106
1
Names of Reporting Persons
Biotechnology Value Trading Fund OS 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
224,641.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
224,641.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
224,641.00
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)
0.4 %
12
Type of Reporting Person (See Instructions)
PN
SCHEDULE 13G
CUSIP No.
230031106
1
Names of Reporting Persons
BVF Partners OS Ltd.
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
224,641.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
224,641.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
224,641.00
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)
0.4 %
12
Type of Reporting Person (See Instructions)
CO
SCHEDULE 13G
CUSIP No.
230031106
1
Names of Reporting Persons
BVF GP HOLDINGS 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
5,574,038.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,574,038.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,574,038.00
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)
9.4 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP No.
230031106
1
Names of Reporting Persons
BVF PARTNERS L P/IL
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
5,918,481.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,918,481.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,918,481.00
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)
9.99 %
12
Type of Reporting Person (See Instructions)
IA, PN
SCHEDULE 13G
CUSIP No.
230031106
1
Names of Reporting Persons
BVF INC/IL
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
5,918,481.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,918,481.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,918,481.00
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)
9.99 %
12
Type of Reporting Person (See Instructions)
CO
SCHEDULE 13G
CUSIP No.
230031106
1
Names of Reporting Persons
LAMPERT MARK N
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
5,918,481.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,918,481.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,918,481.00
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)
9.99 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Cullinan Therapeutics, Inc.
(b)
Address of issuer's principal executive offices:
ONE MAIN STREET, SUITE 1350, CAMBRIDGE, MA 02142
Item 2.
(a)
Name of person filing:
Biotechnology Value Fund, L.P. ("BVF")
BVF I GP LLC ("BVF GP")
Biotechnology Value Fund II, L.P. ("BVF2")
BVF II GP LLC ("BVF2 GP")
Biotechnology Value Trading Fund OS LP ("Trading Fund OS")
BVF Partners OS Ltd. ("Partners OS")
BVF GP Holdings LLC ("BVF GPH")
BVF Partners L.P. ("Partners")
BVF Inc.
Mark N. Lampert ("Mr. Lampert")
Each of the foregoing is referred to as a "Reporting Person" and collectively as the "Reporting Persons."
(b)
Address or principal business office or, if none, residence:
Biotechnology Value Fund, L.P.
44 Montgomery St., 40th Floor
San Francisco, California 94104
BVF I GP LLC
44 Montgomery St., 40th Floor
San Francisco, California 94104
Biotechnology Value Fund II, L.P.
44 Montgomery St., 40th Floor
San Francisco, California 94104
BVF II GP LLC
44 Montgomery St., 40th Floor
San Francisco, California 94104
Biotechnology Value Trading Fund OS LP
PO Box 309 Ugland House
Grand Cayman, KY1-1104
Cayman Islands
BVF Partners OS Ltd.
PO Box 309 Ugland House
Grand Cayman, KY1-1104
Cayman Islands
BVF GP Holdings LLC
44 Montgomery St., 40th Floor
San Francisco, California 94104
BVF Partners L.P.
44 Montgomery St., 40th Floor
San Francisco, California 94104
BVF Inc.
44 Montgomery St., 40th Floor
San Francisco, California 94104
Mark N. Lampert
44 Montgomery St., 40th Floor
San Francisco, California 94104
(c)
Citizenship:
Biotechnology Value Fund, L.P.
Delaware
BVF I GP LLC
Delaware
Biotechnology Value Fund II, L.P.
Delaware
BVF II GP LLC
Delaware
Biotechnology Value Trading Fund OS LP
Cayman Islands
BVF Partners OS Ltd.
Cayman Islands
BVF GP Holdings LLC
Delaware
BVF Partners L.P.
Delaware
BVF Inc.
Delaware
Mark N. Lampert
United States
(d)
Title of class of securities:
Common Stock, par value $0.0001 per share
(e)
CUSIP No.:
230031106
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:
As of the close of business on December 31, 2025, the Reporting Persons and a certain Partners managed account (the "Partners Managed Account") held an aggregate of 555,935 shares of Series A convertible preferred stock (the "Series A Preferred Stock"), convertible into an aggregate of 5,559,350 shares of the Issuer's Common Stock, par value $0.0001 per share (the "Shares"). Each share of Series A Preferred Stock is convertible into 10 Shares at the option of the holder at any time, subject to certain limitations, including that the holder will be prohibited from converting its Series A Preferred Stock into Shares if, as a result of such conversion, the holder, together with its affiliates, would beneficially own a number of Shares above 9.99% of the total Common Stock then issued and outstanding immediately following the conversion of such shares of Series A Preferred Stock (the "Conversion Blocker"). As of the close of business on December 31, 2025, the Conversion Blocker limits the conversion of the Series A Preferred Stock held by the Reporting Persons and the Partners Managed Account to 167,798 out of the 5,559,350 Shares underlying the Series A Preferred Stock held by them.
As of the close of business on December 31, 2025, (i) BVF beneficially owned 3,302,376 Shares, including 167,798 Shares underlying certain Series A Preferred Stock held by it and excluding 2,830,702 Shares underlying certain Series A Preferred Stock held by it, (ii) BVF2 beneficially owned 2,271,662 Shares, excluding 2,207,150 Shares underlying the Series A Preferred Stock held by it, and (iii) Trading Fund OS beneficially owned 224,641 Shares, excluding 300,000 Shares underlying the Series A Preferred Stock held by it.
BVF GP, as the general partner of BVF, may be deemed to beneficially own the 3,302,376 Shares beneficially owned by BVF.
BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 2,271,662 Shares beneficially owned by BVF2.
Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own the 224,641 Shares beneficially owned by Trading Fund OS.
BVF GPH, as the sole member of each of BVF GP and BVF2 GP, may be deemed to beneficially own the 5,574,038 Shares beneficially owned in the aggregate by BVF and BVF2.
Partners, as the investment manager of BVF, BVF2 and Trading Fund OS, and the sole member of Partners OS, may be deemed to beneficially own the 5,918,481 Shares beneficially owned in the aggregate by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, including 119,802 Shares held in the Partners Managed Account, which excludes 53,700 Shares underlying the Series A Preferred Stock held in the Partners Managed Account.
BVF Inc., as the general partner of Partners, may be deemed to beneficially own the 5,918,481 Shares beneficially owned by Partners.
Mr. Lampert, as a director and officer of BVF Inc., may be deemed to beneficially own the 5,918,481 Shares beneficially owned by BVF Inc.
The foregoing should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of any Shares owned by another Reporting Person. BVF GP disclaims beneficial ownership of the Shares beneficially owned by BVF. BVF2 GP disclaims beneficial ownership of the Shares beneficially owned by BVF2. Partners OS disclaims beneficial ownership of the Shares beneficially owned by Trading Fund OS. BVF GPH disclaims beneficial ownership of the Shares beneficially owned by BVF and BVF2. Each of Partners, BVF Inc. and Mr. Lampert disclaims beneficial ownership of the Shares beneficially owned by BVF, BVF2 and Trading Fund OS and held in the Partners Managed Account, and the filing of this statement shall not be construed as an admission that any such person or entity is the beneficial owner of any such securities.
(b)
Percent of class:
The following percentages are based upon a denominator that is the sum of (i) 59,076,259 Shares outstanding as of October 31, 2025, which is the total number of Shares outstanding as disclosed in the Issuer's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on November 6, 2025, and (ii) 167,798 Shares underlying certain Series A Preferred Stock held by the Reporting Persons and the Partners Managed Account, as applicable.
As of the close of business on December 31, 2025, (i) BVF beneficially owned approximately 5.6% of the outstanding Shares, (ii) BVF2 beneficially owned approximately 3.8% of the outstanding Shares, (iii) Trading Fund OS beneficially owned less than 1% of the outstanding Shares, (iv) BVF GP may be deemed to beneficially own approximately 5.6% of the outstanding Shares, (v) BVF2 GP may be deemed to beneficially own approximately 3.8% of the outstanding Shares, (vi) Partners OS may be deemed to beneficially own less than 1% of the outstanding Shares, (vii) BVF GPH may be deemed to beneficially own approximately 9.4% of the outstanding Shares and (viii) each of Partners, BVF Inc. and Mr. Lampert may be deemed to beneficially own approximately 9.99% of the outstanding Shares (less than 1% of the outstanding Shares are held in the Partners Managed Account).
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
See Cover Pages Items 5-9.
(ii) Shared power to vote or to direct the vote:
See Cover Pages Items 5-9.
(iii) Sole power to dispose or to direct the disposition of:
See Cover Pages Items 5-9.
(iv) Shared power to dispose or to direct the disposition of:
See Cover Pages Items 5-9.
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.
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.
BVF GP, BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by BVF. BVF GPH, Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by BVF2. Partners, BVF Inc. and Mr. Lampert share voting and dispositive power over the Shares beneficially owned by Trading Fund OS and held in the Partners Managed Account.
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.
If a group has filed this schedule pursuant to §240.13d-1(b)(1)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to §240.13d-1(c) or §240.13d-1(d), attach an exhibit stating the identity of each member of the group.
See Exhibit 99.1 to the Schedule 13G filed by the Reporting Persons with the Securities and Exchange Commission on November 8, 2021.
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 the BVF group report in Cullinan Therapeutics (CGEM)?
The BVF group reports beneficial ownership of about 9.99% of Cullinan’s common stock, or 5,918,481 shares
How many Cullinan Therapeutics (CGEM) shares does BVF hold through preferred stock?
BVF-affiliated entities and an advised account hold 555,935 shares of Series A convertible preferred stock. These are convertible into 5,559,350 common shares at a 10-for-1 ratio, subject to a 9.99% beneficial ownership limitation on conversions.
What is the 9.99% Conversion Blocker described for Cullinan Therapeutics (CGEM)?
The filing explains that each Series A preferred share converts into 10 common shares, but a 9.99% “Conversion Blocker” prevents BVF and its affiliates from converting if it would push their ownership above 9.99% of Cullinan’s outstanding common stock.
How many underlying Cullinan Therapeutics (CGEM) shares can BVF currently count from its preferred stock?
As of December 31, 2025, the Conversion Blocker limits BVF and the managed account to 167,798 common shares counted from their Series A preferred stock, out of a total 5,559,350 underlying shares that would be issuable without that cap.
Which BVF entities are reporting ownership in Cullinan Therapeutics (CGEM)?
Reporting persons include Biotechnology Value Fund, L.P., Biotechnology Value Fund II, L.P., Biotechnology Value Trading Fund OS LP, several affiliated general partners and managers, and Mark N. Lampert, who may be deemed to share beneficial ownership through control relationships.
Is BVF’s position in Cullinan Therapeutics (CGEM) described as passive or activist?
The filing states the securities were not acquired and are not held to change or influence control of Cullinan. The reporting persons certify the holdings are not in connection with any control-related transaction, aligning this disclosure with a passive investment stance.
