NBP 6-K 2026 - Equibles

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER

THE SECURITIES EXCHANGE ACT OF 1934

For the month of July 2026

Commission File Number: 001-39173

NovaBridge Biosciences

2440 Research Boulevard, Suite 400

Rockville, MD 20850

United States

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒                Form 40-F ☐

Explanatory Note

NovaBridge Biosciences (the “Company”), a Cayman Islands exempted company with limited liability, will hold its Annual General Meeting of Shareholders (the “AGM”) on September 8, 2026 at 10:00 a.m. (Shanghai time) at NovaBridge Biosciences Shanghai office, 38F, AIA Tower, No. 866 Dongchangzhi Road, Shanghai, China.

Materials in connection with the AGM are available on the Company’s website at https://www.novabridge.com. The information contained in, or that can be accessed through, the Company’s website is not a part of this filing.

The following documents regarding the AGM, each of which are attached as an exhibit hereto, excluding Exhibit 99.1, shall be deemed to be incorporated by reference into the Company’s Registration Statements on Form F-3 (File No. 333-286954) and Form S-8 (File No. 333-239871, File No. 333-256603, File No. 333-265684, File No. 333-279842 and File No. 333-290195) (including any prospectuses forming a part of such registration statements) and to be a part thereof from the date on which this Form 6-K is furnished, to the extent not superseded by documents or reports subsequently filed or furnished.

EXHIBIT INDEX

Exhibit No.	Description

99.1	Press Release

99.2	Notice of Extraordinary General Meeting

99.3	Form of Proxy for Annual General Meeting

99.4	Form of Voting Instruction Card for Holders of American Depositary Shares

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

I-MAB

By	:	/s/ Kyler Lei
Name	:	Kyler Lei
Title	:	Chief Financial Officer

Date: July 24, 2026

EX-99.1

Exhibit 99.1

NovaBridge Biosciences to Hold Annual General Meeting on September 8, 2026

ROCKVILLE, MD, July 24, 2026 (GLOBE NEWSWIRE) – NovaBridge Biosciences (Nasdaq: NBP) (“NovaBridge” or the “Company”), a clinical-stage biopharmaceutical company advancing innovative medicines for areas of significant unmet need, today announced that it will hold its annual general meeting of shareholders (the “AGM”) at NovaBridge Biosciences Shanghai office, 38F, AIA Tower, No. 866 Dongchangzhi Road, Shanghai, China on September 8, 2026 at 10:00 a.m. (Shanghai time).

Holders of record of ordinary shares of a par value of US$0.0001 each of the Company at the close of business on July 27, 2026 (Shanghai time) are entitled to notice of, to attend and to vote at, the AGM or any adjournment(s) or postponement(s) thereof. Holders of the Company’s American depositary shares (“ADSs”) as of the close of business on July 27, 2026 (New York time) who wish to exercise their voting rights for the underlying ordinary shares must act through the depositary of the Company’s ADSs, Citibank, N.A.

The Notice of AGM, which sets forth the resolution to be submitted to shareholder approval at the AGM, and the form of proxy for the AGM are available on the Company’s website at https://www.novabridge.com.

The Company has filed its annual report on Form 20-F (as amended by Amendment No. 1 to the annual report on Form 20-F, the “Annual Report”), including its audited financial statements, for the fiscal year ended December 31, 2025, with the U.S. Securities and Exchange Commission (“SEC”). The Annual Report can be accessed on the Company’s website at https://www.novabridge.com, as well as on the SEC’s website at https://www.sec.gov.

About NovaBridge Biosciences

NovaBridge is a clinical-stage biopharmaceutical company advancing innovative medicines for areas of significant unmet need. The Company combines deep business development expertise with agile translational clinical development to identify, accelerate, and advance breakthrough assets, enabling transformative therapies to progress rapidly from discovery toward patients in need.

The Company’s differentiated pipeline is led by givastomig, a potential first-in-class Claudin 18.2-Targeted Immuno Amplifier (CTIA) — a Claudin 18.2 × 4-1BB bispecific antibody — and VIS-101, a purpose-designed, potential best-in-class dual VEGF-A × ANG-2 inhibitor.

Givastomig conditionally activates T cells via the 4-1BB signaling pathway in the tumor microenvironment where Claudin 18.2 is expressed, and is being developed to treat Claudin 18.2-positive gastric cancer and other gastrointestinal malignancies. It is being evaluated in a global, randomized Phase 2 study, following

positive topline results from a Phase 1b, multicenter, open-label study in first-line gastric cancer. NovaBridge is also collaborating with its partner, ABL Bio, on ragistomig, a bispecific antibody combining PD-L1 as a tumor engager with 4-1BB as a conditional T-cell activator, in solid tumors. In addition, NovaBridge holds worldwide rights outside of China to uliledlimab, an anti-CD73 antibody targeting adenosine-driven immunosuppression in cancer.

VIS-101 targets VEGF-A and ANG-2 to provide more rapid, robust, and durable treatment responses for patients with retinal vascular diseases, including wet age-related macular degeneration, diabetic macular edema, and retinal vein occlusion. It has completed a randomized, dose-ranging Phase 2a study in wet AMD and expects to initiate a dose-determining Phase 2b study in the second half of 2026. NovaBridge is the majority shareholder of Visara, Inc., which controls global rights to VIS-101 outside of Greater China and certain countries in Asia.

For more information, visit https://www.novabridge.com and follow NovaBridge on LinkedIn.

Forward-Looking Statements

This announcement contains forward-looking statements. These statements are made under the “safe harbor” provisions of the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified by terminology such as “will,” “expects,” “believes,” “designed to,” “anticipates,” “future,” “intends,” “plans,” “potential,” “estimates,” “confident,” “look forward” and similar terms or the negative thereof. NovaBridge may also make written or oral forward-looking statements in its periodic reports to the SEC, in its annual report to shareholders, in press releases and other written materials and in oral statements made by its officers, directors or employees to third parties. Statements that are not historical facts, including statements about the Company’s beliefs and expectations, are forward-looking statements. Forward-looking statements in this press release include, without limitation, statements regarding: the Company’s expectations regarding the AGM; the strategic and clinical development of the Company’s drug candidates, including givastomig, VIS-101, ragistomig, and uliledlimab; the potential for these product candidates to receive regulatory approval from the FDA or equivalent foreign regulatory agencies, and whether, if approved, these product candidates will be successfully distributed and marketed and the potential market opportunity for these product candidates; and anticipated clinical milestones and results, and related timing. Forward-looking statements involve inherent risks and uncertainties that may cause actual results to differ materially from those contained in these forward-looking statements, including but not limited to the following: the Company’s ability to demonstrate the safety and efficacy of its drug candidates; the clinical results for its drug candidates, which may or may not support further development or New Drug Application/Biologics License Application (NDA/BLA) approval or eligibility for or achievement of Accelerated Approval Pathway; the content and timing of decisions made by the relevant regulatory authorities, including the FDA, regarding regulatory approval of the Company’s drug candidates; the Company’s ability to achieve commercial success for its drug candidates, if approved; the Company’s ability to obtain and maintain protection of intellectual property for its technology and drugs; the Company’s reliance on third parties to conduct drug development, manufacturing and other services; the Company’s limited operating history and the Company’s ability to obtain additional funding for operations and to complete the development and commercialization of its drug candidates; the impact of macroeconomic conditions, including inflation, tariffs, volatile interest rates, regulatory uncertainty, potential government shutdowns, volatility in the capital markets, and regional and other global events, including ongoing armed conflicts in different regions of the world; and those risks more fully discussed in the “Risk Factors” section in the Company’s annual report on Form 20-F filed with the SEC on April 7, 2026 as well as the discussions of potential risks,

uncertainties, and other important factors in the Company’s subsequent filings with the SEC. All forward-looking statements are based on information currently available to the Company. The Company undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, except as may be required by law.

NovaBridge Investor & Media Contacts

NovaBridge Biosciences +1-240-745-6330 [email protected]

Bill Begien, VP, Investor Relations [email protected]

Jessica Zhang, Director, Public Relations [email protected]

EX-99.2

Exhibit 99.2

NovaBridge Biosciences

(Incorporated in the Cayman Islands with limited liability)

(Nasdaq: NBP)

NOTICE OF ANNUAL GENERAL MEETING

To be held on September 8, 2026

(or any adjournment(s) or postponement(s) thereof)

NOTICE IS HEREBY GIVEN that an annual general meeting of shareholders (the “AGM”) of NovaBridge Biosciences (the “Company”) will be held at 10:00 a.m. (Shanghai time) on September 8, 2026 at NovaBridge Biosciences’ Shanghai office, 38F, AIA Tower, No. 866 Dongchangzhi Road, Shanghai, China for the purpose to consider and, if thought fit, pass the following resolution (the “Proposed Resolution”):

as an ordinary resolution, THAT Ms. Xin Liu be removed from her position as a director of the Company with immediate effect upon passing of this resolution, and each director of the Company be and is hereby authorized to take any and every action that might be necessary in relation to the foregoing resolution as such director, in his or her absolute discretion, thinks fit.

Consistent with the Company’s ongoing efforts to enhance its corporate governance framework and to optimize the size and composition of the board of directors (the “Board”) to improve operational efficiency and decision-making, the Board carefully considered the Proposed Resolution and has determined that its passing is in the best interests of the Company and its shareholders. The Board recommends that shareholders vote “FOR” the Proposed Resolution.

In addition, the meeting will transact any other business properly brought before the meeting.

SHARES RECORD DATE AND PROXY FORM

Holders of record of the Company’s ordinary shares of a par value of US$0.0001 each (the “Shares”) as of the close of business on July 27, 2026 (Shanghai time) (the “Share Record Date”) are entitled to attend and vote at the AGM and any adjournment(s) or postponement(s) thereof.

Holders of Shares as of the Share Record Date may either (1) attend the AGM in person to vote, or (2) appoint a proxy to exercise his or her rights at the AGM. You are urged to complete, sign, date and return the accompanying proxy form (for holders of Shares) as promptly as possible and before the prescribed deadline if you wish to exercise your voting rights. We must receive the proxy form by no later than 4:00 p.m. (Shanghai time) on September 6, 2026 by e-mail to [email protected] or by mail to the Company’s office at NovaBridge Biosciences Shanghai office, 38F, AIA Tower, No. 866 Dongchangzhi Road, Shanghai, China, to ensure your representation at the AGM.

ADS RECORD DATE AND ADS VOTING INSTRUCTIONS

Holders of record of the Company’s American depositary shares (the “ADSs”) as of the close of business on July 27, 2026 (Eastern Time) (the “ADS Record Date”) who wish to exercise their voting rights for

the underlying Shares must give voting instructions to Citibank, N.A., the depositary of the ADSs, as to how to vote the Shares represented by the ADSs.

You are urged to complete, sign, date and return your voting instructions to Citibank, N.A. (for holders of ADSs) as promptly as possible and before the prescribed deadline if you wish to exercise your voting rights. Citibank, N.A. must receive your voting instructions by no later than 10:00 a.m. (Eastern Time) on September 1, 2026 to enable the votes attaching to the Shares represented by your ADSs to be cast at the AGM. The voting instructions must be properly marked, signed and returned on time in order to be counted. If Citibank, N.A. does not receive voting instructions from a holder of ADSs by the time specified in the ADS voting instruction card, Citibank, N.A. will deem such holder of ADSs to have instructed it to give a proxy to a person designated by the Company.

ATTENDING THE AGM

Only holders of record of Shares as of the Share Record Date are entitled to attend and vote at the AGM.

All officers and agents of the Company reserve the right to refuse any person entry to the AGM venue, or to instruct any person to leave the AGM venue, where such officer or agent reasonably considers that such refusal or instruction is or may be required for the Company or any other person to be able to comply with applicable laws and regulations. The exercise of such right to refuse entry or instruct to leave shall not invalidate the proceedings at the AGM.

ANNUAL REPORT

By Order of the Board of Directors,

NovaBridge Biosciences

By: /s/Fu Wei

Name: Fu Wei

Title: Chairman of the Board

Shanghai, July 24, 2026

EX-99.3

Exhibit 99.3

NovaBridge Biosciences

(Incorporated in the Cayman Islands with limited liability)

(Nasdaq: NBP)

Form of Proxy for Annual General Meeting

to be held on September 8, 2026

(or any adjournment(s) or postponement(s) thereof)

Introduction

This Form of Proxy is furnished in connection with the solicitation by the board of directors (the “Board”) of NovaBridge Biosciences, a Cayman Islands exempted company (the “Company”), of proxies from the holders of the issued ordinary shares of a par value of US$0.0001 each (the “Shares”) to be exercised at the Annual General Meeting of shareholders of the Company (the “Meeting”) to be held at NovaBridge Biosciences Shanghai office, 38F, AIA Tower, No. 866 Dongchangzhi Road, Shanghai, China on September 8, 2026 at 10:00 a.m. (Shanghai time), and at any adjournment(s) or postponement(s) thereof, for the purpose set forth in the accompanying Notice of Annual General Meeting (the “Meeting Notice”). Only the holders of record of the Shares on the Company’s register of members at the close of business on July 27, 2026 (Shanghai time) (the “Record Date”) are entitled to notice of, to attend and to vote at, the Meeting. Each Share is entitled to one vote on all matters. The quorum of the Meeting is one or more shareholders holding shares which carry in aggregate (or representing by proxy) not less than one-third of all votes attaching to all shares in issue and entitled to vote at such general meeting, present in person or by proxy or, if a corporation or other non-natural person, by its duly authorized representative.

The Shares represented by all properly executed proxies returned to the Company will be voted at the Meeting as indicated or, if no instruction is given, the proxy will vote the Shares in his/her discretion, unless a reference to the holder of the proxy having such discretion has been deleted and initialed on this Form of Proxy. Where the chairman of the Meeting acts as proxy and is entitled to exercise his/her discretion, he/she is likely to vote the Shares FOR the resolution. As to any other business that may properly come before the Meeting, all properly executed proxies will be voted by the persons named therein in accordance with their discretion. The Company does not presently know of any other business which may come before the Meeting. However, if any other matter properly comes before the Meeting, or any adjournment(s) or postponement(s) thereof, which may properly be acted upon, unless otherwise indicated the proxies solicited hereby will be voted on such matter in accordance with the discretion of the proxy holders named therein. Any person giving a proxy has the right to revoke it at any time before it is exercised by (i) submitting to the Company, at the address set forth below, a duly signed revocation or (ii) voting in person at the Meeting.

Holders of Shares may return this proxy by e-mail to [email protected] or by mail to the Company’s office at NovaBridge Biosciences Shanghai office, 38F, AIA Tower, No. 866 Dongchangzhi Road, Shanghai, China, so that it is received by the Company no later than 4:00 p.m. (Shanghai time) on September 6, 2026 to ensure your representation at the Meeting.

NovaBridge Biosciences

(Incorporated in the Cayman Islands with limited liability)

(Nasdaq: NBP)

Form of Proxy for Annual General Meeting

to be held on September 8, 2026

(or any adjournment(s) or postponement(s) thereof)

I/We ______________ of ______________________________________________________________________, being the registered holder of _________________________________________ ordinary shares (Note 1) of a par value of US$0.0001 each of NovaBridge Biosciences (the “Company”), hereby appoint the Chairman of the Annual General Meeting (Note 2) or _______ of ______________________ as my/our proxy to attend and act for me/us at the Annual General Meeting of the Company to be held at NovaBridge Biosciences Shanghai office, 38F, AIA Tower, No. 866 Dongchangzhi Road, Shanghai, China on September 8, 2026 at 10:00 a.m. (Shanghai time), and at any adjournment(s) or postponement(s) thereof, and in the event of a poll, to vote for me/us as indicated below, or if no such indication is given, as my/our proxy thinks fit. (Note 3)

RESOLUTIONS	FOR (Note 3)	AGAINST (Note 3)	ABSTAIN (Note 3)
AS AN ORDINARY RESOLUTION:<br><br>THAT Ms. Xin Liu be removed from her position as a director of the Company with immediate effect upon passing of this resolution, and each director of the Company be and is hereby authorized to take any and every action that might be necessary in relation to the foregoing resolution as such director, in his or her absolute discretion, thinks fit.

Dated ______________, 2026 Signature(s) (Note 4) ____________________________

______________

Notes:

Please insert the number of ordinary shares registered in your name(s) to which this proxy relates. If no number is inserted, this form of proxy will be deemed to relate to all the ordinary shares in the Company registered in your name(s).
If any proxy other than the Chairman is preferred, strike out the words “THE CHAIRMAN OF THE ANNUAL GENERAL MEETING” and insert the name and address of the proxy desired in the space provided. A member may appoint one or more proxies to attend and vote in his/her stead. ANY ALTERATION MADE TO THIS FORM OF PROXY MUST BE INITIALED BY THE PERSON(S) WHO SIGN(S) IT.
IMPORTANT: IF YOU WISH TO VOTE FOR THE RESOLUTION, TICK THE APPROPRIATE BOX MARKED “FOR.” IF YOU WISH TO VOTE AGAINST THE RESOLUTION, TICK THE APPROPRIATE BOX MARKED “AGAINST.” IF YOU WISH TO ABSTAIN FROM VOTING ON THE RESOLUTION, TICK THE BOX MARKED “ABSTAIN.” Failure to complete any or all the boxes will entitle your proxy to cast his or her votes at his or her discretion. A proxy need not be a member of the Company, but must attend the Meeting in person. A member may only have one form of proxy valid at any one time. Completion and deposit of a form of proxy does not prevent a member from attending the Meeting in person but if a member attends the Meeting and votes, this proxy will be revoked.
This form of proxy must be signed by you or your attorney duly authorized in writing or, in the case of a corporation, must be either executed under its seal or under the hand of an officer or attorney or other person duly authorized to sign the same.

EX-99.4

Exhibit 99.4

Annual General Meeting of Shareholders

The Voting Instructions must be signed, completed and received at the indicated address prior to 10:00 A.M. (Eastern Time) on September 1, 2026 for action to be taken.

2026 VOTING INSTRUCTIONS		AMERICAN DEPOSITARY SHARES
NovaBridge Biosciences (the “Company”)
---	---	---

CUSIP No.:		44975P103.
ADS Record Date:		July 27, 2026 (New York time).
Meeting Specifics:		Annual General Meeting to be held at 10:00 a.m. (Shanghai time) on September 8, 2026 at NovaBridge Biosciences Shanghai office, 38F, AIA Tower, No. 866 Dongchangzhi Road, Shanghai, China (the “Meeting”).
Meeting Agenda:		Please refer to the Company’s Notice of Meeting enclosed herewith. The Company's Notice of Meeting and other relevant documents are posted on the investor section of the Company's website https://www.novabridge.com.
Depositary:		Citibank, N.A.
Deposit Agreement:		Deposit Agreement, dated as of January 22, 2020.
Deposited Securities:		Ordinary shares, nominal value US$0.0001 per share, of the Company (the "Shares").
Custodian:		Citibank, N.A. - Hong Kong.

You as the undersigned holder, as of the ADS Record Date, of the American Depositary Share(s) issued under the Deposit Agreement (“ADSs”) and identified above, acknowledge receipt of a copy of the Depositary’s Notice of General Meeting and hereby authorize and direct the Depositary to cause to be voted at the Meeting (and any adjournment or postponement thereof) the Deposited Securities represented by your ADSs in the manner indicated on the reverse side hereof. All capitalized terms not defined herein shall have the meaning given to such term in the Deposit Agreement. The information with respect to the Meeting and the ADS Voting Instructions contained herein and in any related materials may change after the date hereof as a result of a change in circumstances (e.g., an adjournment or cancellation of the Meeting, a change in location and/or manner of holding the Meeting). The Company intends to announce any changes and updates only on its website https://www.novabridge.com. We encourage you to check the referenced Company website for any updates to the information with respect to the Meeting and the ADS Voting Instructions as it is not expected that any additional information will be distributed to you via mail or email.

Voting instructions may be given only in respect of a number of ADSs representing an integral number of Deposited Securities. Upon the timely receipt from a Holder of ADSs as of the ADS Record Date of voting instructions in the manner specified by the Depositary, the Depositary shall endeavor, insofar as practicable and permitted under applicable law, the provisions of the Deposit Agreement, the Articles of Association of the Company and the provisions of the Deposited Securities, to vote, or cause the Custodian to vote, the Deposited Securities (in person or by proxy) represented by such Holder’s ADSs as follows: (a) in the event voting takes place at a shareholders’ meeting by a show of hands, the Depositary will instruct the Custodian to vote all Deposited Securities in accordance with the voting instructions timely received from a majority of Holders of ADSs who provided voting instructions, and (b) in the event voting takes place at a shareholders’ meeting by poll, the Depositary will instruct the Custodian to vote the Deposited Securities in accordance with the voting instructions timely received from the Holders of ADSs. If voting is by poll and the Depositary does not receive voting instructions from a Holder as of the ADS Record Date on or before the date established by the Depositary for such purposes, such Holder shall be deemed, and the Depositary shall (unless otherwise specified in the Notice of Meeting) deem such Holder, to have instructed the Depositary to give a discretionary proxy to a person designated by the Company to vote the Deposited Securities; provided, however, that no such discretionary proxy shall be given by the Depositary with respect to any matter to be voted upon as to which the Company informs the Depositary that (a) the Company does not wish such proxy to be given, (b) substantial opposition exists, or (c) the rights of holders of Deposited Securities may be adversely affected.

Deposited Securities represented by ADSs for which no timely voting instructions are received by the Depositary from the Holder shall not be voted (except (a) in the case voting is by show of hands, in which case the Depositary will instruct the Custodian to vote all Deposited Securities in accordance with the voting instructions received from a majority of Holders of ADSs who provided timely voting instructions, and (b) as otherwise contemplated in the Deposit Agreement). Neither the Depositary nor the Custodian shall under any circumstances exercise any discretion as to voting and neither the Depositary nor the Custodian shall vote, attempt to exercise the right to vote, or in any way make use of, for purposes of establishing a quorum or otherwise, the Deposited Securities represented by ADSs, except pursuant to and in accordance with the voting instructions timely received from Holders or as otherwise contemplated in the Deposit Agreement. If the Depositary timely receives voting instructions from a Holder which fail to specify the manner in which the Depositary is to vote the Deposited Securities represented by such Holder’s ADSs, the Depositary will deem such Holder (unless otherwise specified in the Notice of Meeting) to have instructed the Depositary to vote in favor of the items set forth in such voting instructions.

Please indicate on the reverse side hereof how the Deposited Securities are to be voted.

The Voting Instructions must be marked, signed and returned on time in order to be counted.

By signing on the reverse side hereof, the undersigned represents to the Depositary and the Company that the undersigned is duly authorized to give the voting instructions contained therein.

Agenda

Ordinary resolution

THAT Ms. Xin Liu be removed from her position as a director of the Company with immediate effect upon passing of this resolution, and each director of the Company be and is hereby authorized to take any and every action that might be necessary in relation to the foregoing resolution as such director, in his or her absolute discretion, thinks fit.

The Depositary has been informed that the Company's Board of Directors recommend a "For" vote for the foregoing resolution.

A		Issues	NovaBridge Biosciences
Ordinary resolution
---	---	---	---	---	---	---
		For		Against		Abstain

Resolution 1		☐		☐		☐

B		Authorized Signatures - Sign Here - This section must be completed for your instructions to be executed.

If these Voting Instructions are signed and timely returned to the Depositary but no specific direction as to voting is marked above as to an issue, the undersigned shall be deemed to have directed the Depositary to give voting instructions “FOR” the unmarked issue.

If these Voting Instructions are signed and timely returned to the Depositary but multiple specific directions as to voting are marked above as to an issue, the undersigned shall be deemed to have directed the Depositary to give an “ABSTAIN” Voting Instruction for such issue.

Please be sure to sign and date this Voting Instructions Card.

Please sign your name to the Voting Instructions exactly as printed. When signing in a fiduciary or representative capacity, give full title as such. Where more than one owner, each MUST sign. Voting Instructions executed by a corporation should be in full name by a duly authorized officer with full title as such.

Signature 1 - Please keep signature within the line		Signature 2 - Please keep signature within the line		Date (mm/dd/yyyy)