Exhibit 10.19

FIRST AMENDMENT TO BLACK TITAN CORPORATION

SENIOR UNSECURED CONVERTIBLE NOTE

This FIRST AMENDMENT TO THE BLACK TITAN CORPORATION SENIOR UNSECURED CONVERTIBLE NOTE (THIS “AMENDMENT”), as issued by Black Titan Corporation (the “Company”) is made and effective as of May 11, 2026 (“Effective Date”), by and among the Company, and the signatory hereto (the “Holder”).

RECITALS

WHEREAS, on January 16, 2026, the Company entered into a Securities Purchase Agreement (the “Purchase Agreement”), by and between the Company and the Holder, pursuant to which the Holder purchased a Senior Unsecured Convertible Note (the “Note”) from the Company upon the terms and conditions set forth in the Purchase Agreement and the Note;

WHEREAS, Section 18 of the Note provides that, except for Section 3(d), which may not be amended, modified or waived by the parties to the Note, the prior written consent of the Required Holder (as defined in the Purchase Agreement) is required for any amendment, modification or waiver of the Note;

WHEREAS, the Company and the Holder party hereto desire to amend the Note on the terms and subject to the conditions set forth herein.

NOW, THEREFORE, in consideration of the foregoing premises, and for other good and valuable consideration, the receipt and sufficient of which are hereby acknowledged, the parties to this Amendment, each intended to be legally bound, hereby agree as follows:

Definitions. Capitalized terms used but not defined in this Amendment shall have the respective meanings ascribed to such terms in the Note.

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Exhibit 10.18

FIRST AMENDMENT TO REGISTRATION RIGHTS AGREEMENT

This FIRST AMENDMENT TO THE REGISTRATION RIGHTS AGREEMENT (THIS “AMENDMENT”), is made and effective as of May 11, 2026, by and among Black Titan Corporation, a Cayman Islands exempted company (the “Company”), and the holder of registration rights under the Registration Rights Agreement (defined below) signatory hereto (the “Holder”).

RECITALS

WHEREAS, on January 16, 2026, the Company entered into a Securities Purchase Agreement (the “Purchase Agreement”), by and between the Company and the Holder, pursuant to which the Holder purchased a Senior Unsecured Convertible Note (the “Note”) from the Company upon the terms and conditions set forth in the Purchase Agreement and the Note;

WHEREAS, on January 16, 2026, the Company agreed to provide certain registration rights with respect to the Registrable Securities (as defined in the Registration Rights Agreement) to the Holder pursuant to that certain Registration Rights Agreement, dated as of January 16, 2026 (the “Registration Rights Agreement”);

WHEREAS, Section 10 of the Registration Rights Agreement provides that the provisions of the Registration Rights Agreement may be amended only with written consent of the Company and the Holder;

WHEREAS, the Company and the Holder party hereto desire to amend the Registration Rights Agreement on the terms and subject to the conditions set forth herein.

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Exhibit 10.17

FIRST AMENDMENT TO BLACK TITAN CORPORATION

SECURITIES PURCHASE AGREEMENT

This FIRST AMENDMENT TO THE BLACK TITAN CORPORATION SECURITIES PURCHASE AGREEMENT (THIS “AMENDMENT”), is made and effective as of May 11, 2026 (“Effective Date”), by and among Black Titan Corporation, a Cayman Islands exempted company (the “Company”), and the signatory hereto (the “Holder”).

RECITALS

WHEREAS, on January 16, 2026, the Company entered into a Securities Purchase Agreement (the “Purchase Agreement”), by and between the Company and the Holder, pursuant to which the Holder purchased a Senior Unsecured Convertible Note (the “Note”) from the Company upon the terms and conditions set forth in the Purchase Agreement and the Note;

WHEREAS, pursuant to Section 1(e) of the Purchase Agreement, the Holder may purchase at Additional Closings Additional Notes substantially in the form of Exhibit A to the Purchase Agreement;

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Exhibit 10.16

SETTLEMENT AND RELEASE AGREEMENT

This SETTLEMENT AND RELEASE AGREEMENT (“Agreement”), dated as of April 2, 2026, is entered into by and between Black Titan Corporation, as successor to Titan Pharmaceuticals, Inc. (the “Company”) and David Lazar (“Lazar,” together with the Company, the “Parties” and, each, a “Party”).

WHEREAS, the Parties entered into a certain Settlement Agreement and General Mutual Release dated April 2 (without a year) (the “Prior Settlement Agreement”);

WHEREAS, a dispute has arisen between the Parties regarding Lazar’s entitlement to the Special Bonus referenced in Section 1.b of the Prior Settlement Agreement (the “Special Bonus”); and

WHEREAS, the Parties have agreed to resolve their dispute regarding the Special Bonus pursuant to the terms and conditions of this Agreement;

NOW, THEREFORE, in consideration of the mutual promises and obligations herein, and for other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the Parties agree as follows:

Incorporation of Whereas Clauses. Each of the above “Whereas” clauses is incorporated herein and made a part of this Agreement.

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Five American

Lane Greenwich, CT 06831

April 15, 2025 Valeri Liborski

Delivered via email

Dear Valeri,

On behalf of QXO, Inc. (the “Company”), I am happy to offer you the position of Chief Technology Officer. I know I speak for the rest of our team when I say how pleased we are to make you this offer.

In this role, you will report directly to Brad Jacobs, Chief Executive Officer, and you will be based out of Bellevue, Washington or its vicinity once office space becomes available, with regular travel expected to the Greenwich, Connecticut office and across locations and geographies in which the Company transacts or pursues business. The start of your employment with the Company (the “Start Date”) is expected to be April 21, 2025.

Your salary and compensation

We’d like to offer you the following compensation package:

•Base Salary: Your initial annual base salary will be $650,000, less all applicable withholdings and deductions, and pro-rated for any partial period worked.

•Annual Incentive: You will be eligible to participate in the Company’s annual incentive program. Your initial target annual incentive opportunity is 100% of your base salary.

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FORM OF 5.208% FIXED RATE/FLOATING RATE GLOBAL SECURITY

CUSIP No.: 404280 FQ7

ISIN: US404280FQ75

No.: [•]

THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE THEREOF. THIS GLOBAL SECURITY MAY NOT BE EXCHANGED IN WHOLE OR IN PART FOR A SECURITY REGISTERED, AND NO TRANSFER OF THIS SECURITY IN WHOLE OR IN PART MAY BE REGISTERED, IN THE NAME OF ANY PERSON OTHER THAN SUCH DEPOSITARY OR A NOMINEE THEREOF, EXCEPT IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE.

BY ITS ACQUISITION OF THE DEBT SECURITIES REPRESENTED BY THIS GLOBAL SECURITY, EACH HOLDER (WHICH, FOR THESE PURPOSES, INCLUDES EACH BENEFICIAL OWNER OF THE DEBT SECURITIES) ACKNOWLEDGES, ACCEPTS, CONSENTS AND AGREES, NOTWITHSTANDING ANY OTHER TERM OF THE DEBT SECURITIES, THE INDENTURE OR ANY OTHER AGREEMENTS, ARRANGEMENTS OR UNDERSTANDINGS BETWEEN THE ISSUER AND ANY HOLDER, TO BE BOUND BY (I) THE EFFECT OF THE EXERCISE OF ANY UK BAIL-IN POWER BY THE RELEVANT UK RESOLUTION AUTHORITY IN RELATION TO ANY DEBT SECURITIES THAT (WITHOUT LIMITATION) MAY INCLUDE AND RESULT IN ANY OF THE FOLLOWING, OR SOME COMBINATION THEREOF: (A) THE REDUCTION OF ALL, OR A PORTION, OF THE AMOUNTS DUE (AS DEFINED ON THE REVERSE OF THIS GLOBAL SECURITY); (B) THE CONVERSION OF ALL, OR A PORTION, OF THE AMOUNTS DUE INTO THE ISSUER’S OR ANOTHER PERSON’S ORDINARY SHARES, OTHER SECURITIES OR OTHER OBLIGATIONS (AND THE ISSUE TO, OR CONFERRAL ON, THE HOLDER OF SUCH ORDINARY SHARES, OTHER SECURITIES OR OTHER OBLIGATIONS),

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CERTAIN PERSONAL INFORMATION IN THIS EXHIBIT, MARKED BY [*], HAS BEEN REDACTED PURSUANT TO ITEM 601(A)(6) OF REGULATION S-K.

March 26, 2026

Eric Loumeau

[*]

Re: Terms of Separation

Dear Eric:

This letter confirms the agreement (“Agreement”) between you and AnaptysBio, Inc. (the “Company” or “Anaptys”) concerning the terms of your mutual separation and offers you the separation compensation below in exchange for a general release of claims and covenant not to sue. If you choose to enter into this Agreement, please sign below, on March 26, 2026.

Separation Date; Transition Services:

a.

Separation Date: Your last day of employment with the Company will be the date on which the Company completes the distribution to its stockholders of shares of common stock of First Tracks Biotherapeutics, Inc. (“TRAX”) (the “Separation Date”).

b.

Transition Services: Between the Announcement Date and the Separation Date (the “Transition Period”), you are expected to facilitate a smooth and effective transition of your duties, responsibilities, and institutional knowledge relating to your role as the Company’s Chief Legal Officer (the “Transition Services”), as coordinated by the Company’s CEO. Any specific Transition Services will be communicated to you by the Company’s CEO. Throughout the Transition Period, you will continue to receive your regular base salary and remain eligible to participate in all benefits customarily offered to the Company’s employees, including Company-sponsored health care coverage and stock option vesting, to the fullest extent permitted by the

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CERTAIN PERSONAL INFORMATION IN THIS EXHIBIT, MARKED BY [*], HAS BEEN REDACTED PURSUANT TO ITEM 601(A)(6) OF REGULATION S-K.

March 26, 2026

Dennis Mulroy

[*]

Re: Terms of Separation

Dear Dennis:

This letter confirms the agreement (“Agreement”) between you and AnaptysBio, Inc. (the “Company”) concerning the terms of your mutual separation and offers you the separation compensation below in exchange for a general release of claims and covenant not to sue. If you choose to enter into this Agreement, please sign below on March 26, 2026.

Separation Date; Transition Services:

a.

Separation Date: Your last day of employment with the Company will be the date on which the Company completes the distribution to its stockholders of shares of common stock of First Tracks Biotherapeutics, Inc. (“TRAX”) (the “Separation Date”).

b.

Transition Services: Between the Announcement Date and the Separation Date (the “Transition Period”), you are expected to facilitate a smooth and effective transition of your duties, responsibilities, and institutional knowledge relating to your role as the Company’s Chief Financial Officer (the “Transition Services”), as coordinated by the Company’s CEO. Any specific Transition Services will be communicated to you by the Company’s CEO. Throughout the Transition Period, you will continue to receive your regular base salary and remain eligible to participate in all benefits customarily offered to the Company’s employees, including Company-sponsored health care coverage and stock option vesting, to the fullest extent permitted by the applicable

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CERTAIN PERSONAL INFORMATION IN THIS EXHIBIT, MARKED BY [*], HAS BEEN REDACTED PURSUANT TO ITEM 601(A)(6) OF REGULATION S-K.

CONSULTING AGREEMENT

This Consulting Agreement (“Agreement”) is entered into as of April 20, 2026, (the “Effective Date”), between AnaptysBio, Inc., a Delaware corporation having its principal place of business in San Diego, California (“Company” or “Anaptys”), and Daniel Faga, an individual whose address is [*] (“Consultant”, and collectively with the Company, the “Parties”).

WHEREAS, the Company will complete a distribution to its stockholders of shares of common stock of First Tracks Biotherapeutics, Inc. (“TRAX”), a wholly owned subsidiary of the Company (the “Transaction”), which is anticipated to be completed on April 20, 2026;

WHEREAS, TRAX is a newly formed public company; and

WHEREAS, Consultant has agreed to provide consulting services to the Company following the Transaction, on the terms and conditions set forth in this Agreement;

NOW, THEREFORE, in consideration of the foregoing recitals and the mutual agreements contained herein, the receipt and sufficiency of which are hereby acknowledged, the Parties agree as follows with respect to the services to be rendered by the Consultant:

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CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [*], HAS BEEN OMITTED BECAUSE IT IS NOT MATERIAL AND WOULD LIKELY CAUSE CMPETITIVE HARM TO ANABTYSBIO, INC. IF PUBLICLY DISCLOSED.

Exhibit 10.1

AMENDMENT NO. 6 TO COLLABORATION AND EXCLUSIVE LICENSE AGREEMENT

This Amendment No. 6 to the Collaboration and Exclusive License Agreement (this “Amendment”) is dated as of April 10, 2026 and effective as of January 30, 2026 (the “Amendment Date”), is entered into by and between (a) AnaptysBio, Inc., a Delaware corporation, having a place of business at 10770 Wateridge Circle, Suite 210, San Diego, California 92121 (“AnaptysBio”), and (b) TESARO, Inc., a Delaware corporation, having a place of business at 1000 Winter Street, Suite 3300, Waltham, Massachusetts 02541 (“TESARO US”) and TESARO Development, Ltd., a Bermuda corporation, having its principal office at Clarendon House, 2 Church Street, Hamilton HM 11, Bermuda (together with TESARO US, “TESARO”). Collectively, AnaptysBio and TESARO are referred to as the “Parties” and, individually, as a “Party.” All capitalized terms used but not defined herein will have the meaning given to them in the Agreement (as defined below).

RECITALS

A.

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SIDE LETTER AGREEMENT

May 7, 2026

This Side Letter Agreement (this “Side Letter Agreement”), dated as of May 7, 2026, is by and between CID Holdco, Inc. (the “Company”) and White Lion Capital, LLC (“White Lion”). The Company and White Lion are collectively referred to herein as the “Parties”.

Reference is made to that certain Note Purchase Agreement (the “Note Purchase Agreement”), dated April 17, 2026, by and between the Parties. Capitalized terms used but not defined herein shall have the definitions ascribed to them by the Note Purchase Agreement.

In consideration of the mutual agreements contained herein, the Parties hereby agree as follows:

1. Amendments to Note Purchase Agreement. White Lion and the Company acknowledge and agree to the following terms and conditions in addition to those set forth in the Note Purchase Agreement:

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X4 Pharmaceuticals, Inc. SECOND AMENDED AND RESTATED 2017 EQUITY INCENTIVE PLAN

(AS AMENDED AND RESTATED MAY 11, 2026)

1.    Purpose

The purpose of this Second Amended and Restated 2017 Equity Incentive Plan (the “Plan”) of X4 Pharmaceuticals, Inc., a Delaware corporation (the “Company”), is to advance the interests of the Company’s stockholders by enhancing the Company’s ability to attract, retain and motivate persons who are expected to make important contributions to the Company and by providing such persons with equity ownership opportunities and performance-based incentives that are intended to better align the interests of such persons with those of the Company’s stockholders. Except where the context otherwise requires, the term “Company” shall include any of the Company’s present or future parent or subsidiary corporations as defined in Sections 424(e) or (t) of the Internal Revenue Code of 1986, as amended, and any regulations thereunder (the “Code”) and any other business venture (including, without limitation, joint venture or limited liability company) in which the Company has a controlling interest, as determined by the Board of Directors of the Company (the “Board”).

2.    Eligibility

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