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 November 2021

Commission File Number: 001-39173

I-MAB

Suite 802, West Tower, OmniVision, 88 Shangke Road, Pudong District

Shanghai, 201210

People’s Republic of China

(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 ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):  ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):  ☐

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.

Date: November 5, 2021

Exhibit Index

Exhibit 99.1

I-Mab to Present Clinical Data of Lemzoparlimab in Combination with Rituximab

in Non-Hodgkins’s Lymphoma at ASH 2021

SHANGHAI, China and GAITHERSBURG, MD. November 4, 2021 – I-Mab (the “Company”) (Nasdaq: IMAB), a clinical stage biopharmaceutical company committed to the discovery, development and commercialization of novel biologics, today announced that an abstract summarizing the most recent clinical data from an ongoing clinical trial of its differentiated CD47 antibody lemzoparlimab (also known as TJC4), will be presented at the 63^rd American Society of Hematology Annual Meeting (ASH 2021), taking place December 11 – 14, 2021.

The clinical data provide updates on the safety and efficacy of lemzoparlimab in combination with rituximab (Rituxan^®) in relapsed or refractory non-Hodgkin’s lymphoma (NHL). The trial (NCT03934814) is continuing to enroll more patients in the U.S., and has expanded to include clinical sites in China as an international multi-center clinical trial (IMCT). The study may potentially lead to the initiation of a registrational trial in 2022 in China .

The abstract is available online on the ASH 2021 website, and the presentation details are listed below.

I-Mab will also host an investor call on December 14, 2021, at 8:00 a.m. ET to discuss the data presented at the conference.

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About CD47 and Lemzoparlimab

CD47 is a cell surface protein over-expressed in a wide variety of cancers and can act to protect tumors by delivering a “don’t eat me” signal to otherwise tumor-engulfing macrophages. CD47 antibody blocks this signal and enables macrophages to attack tumor cells. However, development of CD47 antibody as a cancer therapy is hampered by its hematologic side effects, such as severe anemia, caused by natural binding of CD47 antibody to red blood cells. Scientists at I-Mab have discovered a novel CD47 antibody, lemzoparlimab, that is designed to target tumor cells while exerting a minimal untoward effect on red blood cells.

I-Mab continues to advance a combination study of lemzoparlimab with Keytruda^® for solid tumors in the U.S. and with Rituxan^® for lymphoma in the U.S. and China, in addition to an on-going clinical trial in patients with AML in China.

In September 2020, I-Mab and AbbVie entered into a global strategic collaboration to develop and commercialize lemzoparlimab. This includes the design and conduct of further clinical trials to evaluate lemzoparlimab in multiple cancers through global and China-specific trials. AbbVie has assumed sponsorship of the U.S. study as of April 2021.

About I-Mab

I-Mab (Nasdaq: IMAB) is an innovation-driven global biopharma company focused on the discovery, development and commercialization of novel and highly differentiated biologics for immuno-oncology and autoimmune diseases. The Company’s mission is to bring transformational medicines to patients around the world through innovation. I-Mab’s globally competitive pipeline of more than 15 clinical and preclinical-stage drug candidates is driven by its internal discovery and global partnerships for in-licensing, based on the Company’s Fast-to-Proof-of-Concept and Fast-to-Market development strategies. The Company is progressing from a clinical-stage biotech company into a fully integrated global biopharmaceutical company with cutting-edge R&D capabilities, a world-class GMP manufacturing facility, and commercial capability. I-Mab has established its global footprint in Shanghai (headquarters), Beijing, Hangzhou, Guangzhou, Lishui and Hong Kong in China, and Maryland and San Diego in the United States. For more information, please visit http://ir.i-mabbiopharma.com and follow I-Mab on LinkedIn, Twitter, and WeChat.

I-Mab Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and other federal securities laws, including statements regarding data from the lemzoparlimab clinical studies, the potential implications of clinical data for patients, and I-Mab’s advancement of, and anticipated clinical development, regulatory milestones, and commercialization of lemzoparlimab. Actual results may differ materially from those indicated in the forward-looking statements as a result of various important factors, including but not limited to I-Mab’s ability to demonstrate the safety and efficacy of its drug candidates; the clinical results for its drug candidates, which may not support further development or NDA/BLA approval; the content and timing of decisions made by the relevant regulatory authorities regarding regulatory approval of I-Mab’s drug candidates; I-Mab’s ability to achieve commercial success for its drug candidates, if approved; I-Mab’s ability to obtain and maintain protection of intellectual property for its technology and drugs; I-Mab’s reliance on third parties to conduct drug development, manufacturing and other services; I-Mab’s limited operating history and I-Mab’s ability to obtain additional funding for operations and to complete the development and commercialization of its drug candidates; and the impact of the COVID-19 pandemic on the Company’s clinical development, commercial and other operations, as well as those risks more fully discussed in the “Risk Factors” section in I-Mab’s most recent annual report on Form 20-F, as well as discussions of potential risks, uncertainties, and other important factors in I-Mab’s subsequent filings with the U.S. Securities and Exchange Commission. All forward-looking statements are based on information currently available to I-Mab, and I-Mab 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.

I-Mab Contacts

Investor Inquiries

Exhibit 99.2

Lemzoparlimab, a Differentiated Anti-CD47 Antibody in Combination with Rituximab in Relapsed and Refractory Non-Hodgkin’s Lymphoma: Initial Clinical Results

Program: Oral and Poster Abstracts

Session: 623. Mantle Cell, Follicular, and Other Indolent B Cell Lymphomas: Clinical and

Epidemiological: Poster III

Hematology Disease Topics & Pathways:

Clinical Trials, Clinical Research

Monday, December 13, 2021, 6:00 PM-8:00 PM

Amitkumar Mehta, MD¹, Wael Harb, MD², Claire Xu, MD, PhD³, Yuan Meng, MD^4*, Linda Lee, PharmD^3*, Vivian Yuan, PhD^3*, Zhengyi Wang, PhD^4*, Pengfei Song, PhD^3*, Joan Huaqiong Shen, MD, PhD^4* and Ajay K Gopal, MD⁵

Introduction

Lemzoparlimab (also known as TJ011133 or TJC4) is a differentiated CD47 IgG4 antibody targeting a distinct CD47 epitope to enable a unique red blood cell sparing property, while retaining strong anti-tumor activity as demonstrated previously in patients with solid tumors. Lemzoparlimab does not induce significant hematologic toxicity without the need of priming dosing commonly required for other CD47 antibodies. Lemzoparlimab exhibits an enhanced treatment effect when combined with rituximab in lymphoma animal models.

Methods

This ongoing Phase 1b study (NCT03934814) enrolled relapsed and refractory (R/R) patients with CD20 positive Non-Hodgkin’s Lymphoma (NHL) who had at least two prior lines of therapy in a 3+3 dose escalation design followed by a dose expansion. Lemzoparlimab was administered intravenously at doses of 20 or 30 mg/kg weekly with rituximab (375 mg/m2 QW for 5 doses followed by once monthly for 3 doses). Safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and anti-tumor activity based on Lugano criteria were assessed. Preliminary data as of 2 July 2021 are reported here with the updated data set to be presented at the 2021 ASH meeting.

Results

Eight heavily pre-treated patients with R/R NHL who had progressed on prior CD20 targeted therapies were enrolled to the dose cohorts of 20 mg/kg (n=6) and 30 mg/kg (n=2) of lemzoparlimab in combination with rituximab. The diagnoses included diffuse large B-cell lymphoma (DLBCL) [n=2], mantle cell lymphoma (MCL) [n=1], and follicular lymphoma (FL) [n=5]. Patients had a median age of 63 years (range: 43-83) and a median of 4 prior therapies (range: 2-10). Safety and tolerability: The most common treatment-related adverse events (TRAEs) were infusion-related reactions (n=4), pruritus (n=3), fatigue (n=3), rash (n=2), constipation (n=2), and dyspnea (n=2). All TRAEs were Grade 1 or 2, with one exception who reported Grade 3 TRAEs including pleural effusion, tachycardia, cough, pruritis, fatigue, rash and dyspnea, at 20 mg/kg dose level. Mild hematologic AEs were observed as one isolated episode of anemia and thrombocytopenia, respectively, and no treatment was required. PK and PD: Co-administration of rituximab did not affect the PK or immunogenicity of lemzoparlimab. On average, 80% and 90% CD47 receptor occupancy was detected in biopsied lymph nodes from the patients dosed at 20 and 30 mg/kg, respectively, indicating significant tumor target engagement. Anti-tumor activity: Among 7 efficacy-evaluable patients, 3 complete responses (CR) [1 transformed FL-DLBCL + 2 FL] and 1 partial response (PR) of FL were observed (ORR=57%), together with 3 stable disease (SD duration between 3-6 months). The overall DCR was 100%. Tumor shrinkage was observed in all evaluable patients. One patient was not efficacy evaluable due to clinical disease progression after withdrawal from the study at the first cycle. The median time to an initial response to the treatment was 2 months and all responders remained in clinical response at time of data cutoff. During continued treatment, two patients developed improved responses. One patient with transformed FL-DLBCL improved from PR at 2^nd month to CR at 8^th month and another patient with FL improved from SD at 2^nd month to PR at 4^th month.

Conclusion

Consistent with the previously reported monotherapy results, lemzoparlimab given at 20 – 30 mg/kg with rituximab is safe and well tolerated in patients with R/R NHL without the need for a priming dose. A high level of intra-tumoral target engagement was reached at both dose levels. The combination therapy exhibited evidence of clinical activity in heavily pre-treated R/R NHL patients who had progressed on prior CD20 targeted therapies. The results provide the basis for RP2D and impetus for accelerated clinical development for NHL.

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Disclosures: Mehta: Seattle Genetics; Incyte; TG Therapeutics: Consultancy; Seattle Genetics; Incyte; TG Therapeutics: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Affirmed; Kite/Gilead; Roche-Genetech; Celgene/BMS; Oncotartis; Innate Pharmaceuticals; Seattle Genetics; Incyte; Takeda; Fortyseven Inc/Gilead; TG Therapeutics; Merck; Juno Pharmaceuticals/Bristol Myers Squibb: Research Funding. Xu: I-Mab Biopharma: Current Employment. Meng: I-Mab Biopharma: Current Employment. Lee: I-Mab Biopharma: Current Employment. Yuan: I-Mab Biopharma: Current Employment. Wang: I-Mab Biopharma: Current Employment. Song: I-Mab Biopharma: Current Employment. Shen: I-Mab Biopharma: Current Employment. Gopal: Merck: Consultancy, Honoraria, Research

Funding; Beigene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research

Funding; Astra-Zeneca: Research

Funding; MorphoSys: Honoraria; Gilead: Consultancy, Honoraria, Research

Funding; Acrotech: Consultancy, Honoraria; Kite: Consultancy, Honoraria; Epizyme: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Takeda: Research

Funding; Genetech: Consultancy, Honoraria, Research

Funding; Karyopharm: Consultancy, Honoraria; Bristol Meyers Squibb: Research

Funding; Agios: Research Funding; I-Mab bio: Consultancy, Honoraria, Research

Funding; Incyte: Honoraria; Nurix Inc: Consultancy, Honoraria; ADC

Therapeutics: Consultancy, Honoraria; IGM Biosciences: Research

Funding; SeaGen: Consultancy, Honoraria, Research Funding; Teva: Research

Funding; Cellectar: Consultancy, Honoraria.

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