Form 8-K

8-K — ArriVent BioPharma, Inc.

Accession: 0001104659-26-058706

Filed: 2026-05-11

Period: 2026-05-11

CIK: 0001868279

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Other Events

Item: Financial Statements and Exhibits

Documents

8-K — tm2614177d1_8k.htm (Primary)

EX-5.1 — EXHIBIT 5.1 (tm2614177d1_ex5-1.htm)

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2026-05-11

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):

May 11, 2026

ARRIVENT BIOPHARMA, INC.

(Exact name of registrant as specified in its

charter)

Delaware

001-41929

86-3336099

(State

or other jurisdiction

of incorporation)

(Commission

File Number)

(IRS

Employer

Identification No.)

18 Campus Boulevard, Suite 100

Newtown Square, PA

19073

(Address

of principal executive offices)

(zip

code)

Registrant’s telephone number, including

area code: (628) 277-4836

N/A

(Former name or former

address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended

to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities

Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange

Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under

the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under

the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title

of each class

Trading

Symbol(s)

Name of each exchange

on which registered

Common Stock,

$0.0001 par value per share

AVBP

The

Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth

company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange

Act of 1934 (17 CFR §240.12b-2).

Emerging Growth Company x

an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying

with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Item 8.01 Other Events.

On May 11, 2026, ArriVent BioPharma, Inc. (the “Company”)

filed with the Securities and Exchange Commission (the “SEC”) a prospectus supplement (the “Prospectus Supplement”),

dated May 11, 2026, with respect to the Company’s existing “at the market offering” program (the “ATM Program”).

Pursuant to the Prospectus Supplement, the Company may offer and sell shares of its common stock having an aggregate offering price of

up to $250,000,000, from time to time, through Jefferies LLC as sales agent, pursuant to the Open Market Sale AgreementSM,

dated as of February 3, 2025, by and between the Company and Jefferies LLC (the “Sales Agreement”). The Prospectus Supplement

was filed pursuant to the automatic shelf registration statement on Form S-3ASR (File No. 333-284661) previously filed with

the SEC on February 3, 2025, which became effective upon the filing thereof.

A copy of the Sales Agreement is filed as Exhibit 1.1 to this

Current Report on Form 8-K and is incorporated herein by reference.

In connection with the filing of the Prospectus Supplement, the Company

is filing as Exhibit 5.1 hereto the opinion of its counsel, Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Number

Description

1.1

Open Market Sale AgreementSM, dated February 3, 2025, by and between ArriVent BioPharma, Inc. and Jefferies LLC (incorporated by reference to Exhibit 1.2 to the Registration Statement on Form S-3ASR (File No. 333-284661) filed with the Securities and Exchange Commission on February 3, 2025).

5.1*

Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.

23.1*

Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. (included in Exhibit 5.1).

104*

Cover Page Interactive Data File (embedded within the Inline XBRL document).

Filed herewith.

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.

ARRIVENT BIOPHARMA, INC.

By:

/s/ Winston Kung

Winston Kung

Chief Financial Officer and Treasurer

Date: May 11, 2026

EX-5.1 — EXHIBIT 5.1

EX-5.1

Filename: tm2614177d1_ex5-1.htm · Sequence: 2

Exhibit 5.1

One Financial Center

Boston, MA

617-542-6000

www.mintz.com

May 11,

2026

ArriVent BioPharma, Inc.

18 Campus Boulevard, Suite 100

Newtown Square, PA 19073

Ladies and Gentlemen:

have acted as counsel to ArriVent BioPharma, Inc., a Delaware corporation (the “Company”), with respect

to certain matters in connection with the Automatic Shelf Registration Statement on Form S-3ASR (File No. 333-284661) (the

“Registration Statement”), filed with the Securities and Exchange Commission (the “Commission”)

under the Securities Act of 1933, as amended (the “Act”), the related prospectus dated February 3, 2025

included within the Registration Statement (the “Base Prospectus”) and the prospectus supplement dated May 11,

2026, relating to the issue and sale of up to $250,000,000 of shares of the Company’s common stock, par value $0.0001 per share

(the “Shares”), each filed with the Commission pursuant to Rule 424(b) promulgated under the Act

(together with the Base Prospectus, the “Prospectus”). The Shares are to be sold by the Company in accordance

with that certain Sales Agreement, dated February 3, 2025, between the Company and Jefferies LLC (the “Sales Agreement”),

as described in the Prospectus.

connection with this opinion, we have examined the Company’s Amended and Restated Certificate of Incorporation and Amended and

Restated Bylaws, both as currently in effect, such other records of the corporate proceedings of the Company, and certificates of the

Company’s officers as we have deemed relevant, as well as the Registration Statement and the exhibits thereto and the Prospectus.

our examination, we have assumed the genuineness of all signatures, the legal capacity of natural persons, the authenticity of all documents

submitted to us as originals, the conformity to original documents of all documents submitted to us as certified, photostatic or facsimile

copies and the authenticity of the originals of such copies.

Based

upon the foregoing, and subject to the limitations set forth below, we are of the opinion that the Shares, when issued by the Company

out of the Company’s duly authorized common stock and issued and delivered by the Company against payment therefor as contemplated

by the Sales Agreement, on terms approved by the Board of Directors of the Company, or a duly authorized committee thereof, will be duly

and validly issued, fully paid and nonassessable.

Our

opinion is limited to the General Corporation Law of the State of Delaware, and we express no opinion with respect to the laws of any

other jurisdiction. No opinion is expressed herein with respect to the qualification of the Shares under the securities or blue sky laws

of any state or any foreign jurisdiction.

have relied as to certain matters on information obtained from public officials, officers of the Company, and other sources believed

by us to be responsible.

Please

note that we are opining only as to the matters expressly set forth herein, and no opinion should be inferred as to any other matters.

This opinion is based upon currently existing statutes, rules, regulations and judicial decisions, and we disclaim any obligation to

advise you of any change in any of these sources of law or subsequent legal or factual developments which might affect any matters or

opinions set forth herein.

Boston Los

Angeles MIAMI New York San Diego San Francisco toronto Washington

Mintz,

Levin, Cohn, Ferris, Glovsky and Popeo, P.C.

MINTZ

May 11, 2026

Page 2

We hereby consent to the filing

of this opinion as an exhibit to a Current Report on Form 8-K in accordance with the requirements of Item 601(b)(5) of

Regulation S-K under the Act and to the use of this firm’s name therein and in the Prospectus under the caption “Legal

Matters.” In giving such consent, we do not hereby admit that we are in the category of persons whose consent is required under

Section 7 of the Act or the rules and regulations of the Commission.

Very truly yours,

/s/ Mintz, Levin, Cohn, Ferris, Glovsky

and Popeo, P.C.

Mintz, Levin, Cohn, Ferris, Glovsky

and Popeo, P.C.

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