I-Mab furnishes Exhibit 99.1: Phase I Givastomig clinical update

Rhea-AI Filing Summary

I-Mab furnished a Form 6-K announcing an investor presentation as Exhibit 99.1. The exhibit provides updated safety, efficacy, and biomarker analysis from a Phase I monotherapy study of Givastomig, a Claudin 18.2/4-1BB bispecific antibody, in Claudin 18.2 positive advanced gastroesophageal carcinoma.

The company states that Exhibit 99.1 is incorporated by reference into its Registration Statements on Form F-3 and Form S-8, making the presentation part of those filings from the furnishing date, to the extent not superseded. This is an informational update; no transaction terms or financial results are disclosed in the document provided.

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Biopharma filings analyst

Routine clinical update furnished; incorporated into existing shelves.

I-Mab submitted a Form 6-K that furnishes a clinical presentation (Exhibit 99.1) covering updated safety, efficacy, and biomarker observations from a Phase I monotherapy study of Givastomig in Claudin 18.2 positive advanced gastroesophageal carcinoma. The filing does not include numerical trial outcomes or financial results.

The company specifies the exhibit is incorporated by reference into its Form F-3 and Form S-8 registration statements, making the presentation part of those documents. This is an administrative step that aligns disclosures across filings; cash-flow effects are not described.

Any impact will depend on subsequent disclosures of clinical data or regulatory milestones. The current excerpt focuses on the existence and scope of the presentation rather than quantified results.

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 October 2025

Commission File Number: 001-39173

I-MAB

2440 Research Boulevard, Suite 400

Rockville, MD 20850

(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 ☐

DOCUMENTS INCORPORATED BY REFERENCE

Exhibit 99.1 set forth in this Form 6-K 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	Presentation - Updated Safety, Efficacy and Biomarker Analysis from the Phase I Monotherapy Study of Givastomig, a Novel Claudin 18.2/4-1BB Bispecific Antibody, in Claudin 18.2 Positive Advanced Gastroesophageal Carcinoma (GEC)

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/ Xi-Yong Fu
	Name	:	Xi-Yong (Sean) Fu
	Title	:	Chief Executive Officer

Date: October 23, 2025

FAQ

What did I-Mab (IMAB) file?

I-Mab furnished a Form 6-K containing Exhibit 99.1, an investor presentation with updated safety, efficacy, and biomarker analysis from a Phase I study of Givastomig.

What is Exhibit 99.1 about for IMAB?

Exhibit 99.1 is a presentation detailing updated safety, efficacy, and biomarker analysis from a Phase I monotherapy study of Givastomig in Claudin 18.2 positive advanced GEC.

How does this 6-K affect I-Mab’s registrations?

The company states Exhibit 99.1 is incorporated by reference into its Form F-3 and Form S-8 registration statements, becoming part of those filings.

Does the I-Mab 6-K include financial results or transactions?

No. The excerpt describes a furnished presentation and its incorporation by reference; it does not include financial results or transaction terms.

What is Givastomig in the IMAB filing?

Givastomig is described as a Claudin 18.2/4-1BB bispecific antibody evaluated as monotherapy in Claudin 18.2 positive advanced gastroesophageal carcinoma.

Who signed the I-Mab 6-K?

The report was signed on behalf of I-Mab by Xi-Yong (Sean) Fu, Chief Executive Officer.