Form 8-K

8-K — ArriVent BioPharma, Inc.

Accession: 0001104659-26-118550

Filed: 2026-10-26

Period: 2026-10-25

CIK: 0001868279

SIC: 2834 (PHARMACEUTICAL PREPARATIONS)

Item: Regulation FD Disclosure

Item: Other Events

Item: Financial Statements and Exhibits

Documents

8-K — tm2628237d1_8k.htm (Primary)

EX-99.1 — EXHIBIT 99.1 (tm2628237d1_ex99-1.htm)

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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):

October 25, 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 7.01

Regulation FD Disclosure.

On October 25, 2026, ArriVent BioPharma, Inc. issued a press

release announcing initial Phase 1 data for cadherin-17 (CDH17)-targeted antibody-drug conjugate ARR-217 (MRG007), in patients with gastrointestinal

cancers at the European Society for Medical Oncology Congress 2026. A copy of the press release is filed as Exhibit 99.1 hereto and

is hereby incorporated by reference into this Item 7.01.

The information in this Item 7.01 is being furnished and shall not

be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange

Act”), or otherwise subject to the liabilities of that Section, nor shall it be deemed incorporated by reference into any registration

statement or other filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by

specific reference in such filing.

Item 8.01

Other Events.

The information set forth in the press release referred to in Item

7.01 above, other than the second paragraph thereof, is incorporated by reference into this Item 8.01 of this Current Report on Form 8-K.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.

Description

99.1

Press Release dated October 25, 2026.

104

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

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: October 26, 2026

EX-99.1 — EXHIBIT 99.1

EX-99.1

Filename: tm2628237d1_ex99-1.htm · Sequence: 2

Exhibit 99.1

ArriVent Announces Initial Phase 1 Data for

CDH17-targeted ADC ARR-217 in Patients with Gastrointestinal Cancers at ESMO Congress 2026

· 44.8%

ORR at 6mg/kg dose in late-line CRC patients

· ARR-217 was generally well-tolerated

· ArriVent to host virtual webinar on Monday,

October 26, 2026, at 8 am ET to discuss the data from the ARR-217 program

NEWTOWN SQUARE, PA, October 25, 2026 (GLOBE

NEWSWIRE) -- ArriVent BioPharma, Inc. (Company or ArriVent) (Nasdaq: AVBP), a clinical-stage company dedicated to accelerating the

global development of innovative biopharmaceutical therapeutics, today announced initial encouraging Phase 1 results for ARR-217, (MRG007),

a cadherin-17 (CDH17)-targeting antibody-drug conjugate (ADC) developed in partnership with Lepu Biopharma Co., Ltd., in patients

with gastrointestinal malignancies. The findings were presented as part of an oral presentation at the 2026 European Society for Medical

Oncology (ESMO) Congress 2026.

"These initial results reinforce our confidence

in ARR-217 and in CDH17 as a potential therapeutic target for patients with gastrointestinal cancers who face limited treatment options

following prior lines of therapy," said Bing Yao, Ph.D., Chief Executive Officer of ArriVent. "We believe the responses observed

in this heavily pretreated patient population, together with a manageable safety profile, provided a strong foundation for advancing ARR-217

into a Phase 1b dose optimization study. As the first ADC from our pipeline to enter clinical development, ARR-217 represents an important

milestone for our ADC pipeline, and we look forward to dose optimization data expected in 2027."

The ongoing multicenter, open-label Phase 1 study

(NCT07066657) conducted in the US and China is evaluating the safety, tolerability, efficacy, and pharmacokinetics of ARR-217 in patients

with unresectable, locally advanced, or metastatic solid tumors, with an initial clinical development focus in colorectal, pancreatic,

and other gastrointestinal (GI) cancers. As of the August 5, 2026 data cutoff, 123 patients with heavily pretreated GI malignancies

were treated across 6 dose levels ranging from 2 mg/kg to 8 mg/kg, including 113 patients with Colorectal Cancer (CRC).

Key Highlights for ARR-217 Phase 1 Study Include:

· Strong Anti-tumor Activity with ARR-217 at

Multiple Dose Levels

o At 6 mg/kg Q3W dose, 44.8% (13/29) objective response rate (ORR) observed in pre-treated CRC patients,

including 7 confirmed partial responses, 4 partial responses pending confirmation, and 2 unconfirmed partial responses

o At 6 mg/kg Q3W dose, 93.1% (27/29) disease control rate (DCR) observed

o At doses 4 mg/kg Q3W and higher, 34.2% (25/73) ORR observed in CRC patients, including 15 confirmed partial

responses, 5 partial responses pending confirmation and 5 unconfirmed partial responses

o At doses 4 mg/kg Q3W and higher, 91.8% DCR observed

o Majority of the responding patients remained on study treatment as of the August 5, 2026 data cutoff

· Generally, Well Tolerated Safety Profile

o The most common treatment-related adverse events were Grade 1/2

o Across all doses, 30.1% (37/123) patients experienced Grade 3 or higher treatment-related adverse events,

including neutropenia (12.2%) and diarrhea (8.9%)

o At 6.0 mg/kg Q3W dose, Grade 3 or higher TRAE was 20.4% (10/49) including 2.0% diarrhea (1/49)

o No grade 5 TRAE or ILD observed

Dose Optimization and Next Steps

ARR-217 has advanced into Phase 1b dose optimization

at doses of 5 and 6 mg/kg Q3W with further dose optimization data expected in 2027.

About ARR-217

ARR-217 (also known as MRG007) is a potentially

best-in-class cadherin-17 (CDH17)-targeted antibody-drug conjugate (ADC), utilizing a glycan-linked, exatecan-based payload. CDH17 is

a membranous cell adhesion molecule frequently overexpressed in colorectal cancer and several other gastrointestinal cancers, with limited

expression in normal intestinal tissue and pancreatic duct, making it an attractive target for ADC therapy. ArriVent obtained exclusive

rights to develop and commercialize ARR-217 worldwide outside of Greater China under a collaboration agreement with Lepu Biopharma Co., Ltd.

ARR-217 is the lead clinical candidate from ArriVent's growing ADC portfolio.

About ArriVent

ArriVent is a clinical-stage biopharmaceutical

company dedicated to the identification, development, and commercialization of differentiated medicines to address the unmet medical needs

of patients with cancers. ArriVent seeks to utilize its team’s deep drug development experience to maximize the potential of its

lead development candidate, firmonertinib, and advance a pipeline of novel therapeutics, such as next-generation antibody drug conjugates,

through approval and commercialization.

Forward-Looking Statements

This press release includes certain disclosures

that contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 about

us and our industry that involve substantial risks and uncertainties. All statements other than statements of historical facts contained

in this press release, including statements regarding, business strategy and plans; the activity safety and tolerability of ARR-217; the

expected timing and future results of the ongoing clinical study of ARR-217, and objectives of management for future operations, are forward-looking

statements. In some cases, you can identify forward-looking statements because they contain words such as “anticipate,” “believe,”

“contemplate,” “continue,” “could,” “estimate,” “expect,” “intend,”

“may,” “plan,” “potential,” “predict,” “project,” “should,” “target,”

“will,” or “would” or the negative of these words or other similar terms or expressions. Forward-looking statements

are based on ArriVent’s current expectations and are subject to inherent uncertainties, risks and assumptions that are difficult

to predict. Factors that could cause actual results to differ include, but are not limited to, risks and uncertainties that are described

more fully in the section titled “Risk Factors” in our annual report on Form 10-K for the fiscal year ended December 31,

2025, filed with the Securities and Exchange Commission on March 5, 2026 and our other filings with the Securities and Exchange Commission.

Forward-looking statements contained in this press release are made as of this date, and ArriVent undertakes no duty to update such information

except as required under applicable law.

Contact:

Joyce Allaire

LifeSci Advisors, LLC

jallaire@lifesciadvisors.com

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