I-Mab Provides Business and Corporate Updates and Reports Financial Results for the Year Ended

I-Mab Provides Business and Corporate Updates and Reports

Financial Results for the Year Ended December 31, 2021

I-Mab to host conference calls and webcasts on March 29, 2022. A Mandarin session will be held at 7:00 a.m. ET,

and an English session will be held at 8:00 a.m. ET.

SHANGHAI and GAITHERSBURG, Md., March 29, 2022 /PRNewswire/ I-Mab (the Company ) (Nasdaq: IMAB), a clinical-stage biopharmaceutical company committed to the discovery, development, and commercialization of novel biologics, today announced financial results for the

12 months ended December 31, 2021, and provided key business updates.

During the reporting period, I-Mab has made significant progress in

key business areas. Firstly, on the R&D front, the Company has achieved almost all critical clinical milestones as set in early 2021. The pipeline is not only globally innovative and competitive but also advanced, including 10 clinical stage (7

assets in phase 2 and phase 3 clinical trials) and 10 pre-clinical assets. Importantly, the pipeline is expected to yield three near-term BLA filings and/or product launches between 2023 and 2025 in China,

including felzartamab, eftansomatropin alfa, and potentially lemzoparlimab. In addition, negotiations are underway to acquire another potential pre-BLA product to strengthen the focus of this near-term product

portfolio in hematologic malignancies, i.e. multiple myeloma, non-Hodgkin s lymphoma and AML/MDS.

Secondly, on the corporate development front, the Company has achieved the expected corporate milestones towards its goal to become an innovative

global biopharma. The Phase One GMP manufacturing facility in Hangzhou will become operational around June 2022 as planned, and the construction of the Phase Two large-scale GMP manufacturing facility is on track for completion by 2024. In addition,

the current commercialization capabilities can be rapidly expanded in concordance with the expected BLA submission and anticipated product launch schedule.

Thirdly, during the reporting period, the Company has accelerated its dual listing process and expanded its global R&D footprint with a newly

established R&D site in San Diego for translational medicine and formulation research and is now connected globally with eight sites in the U.S. and China. Plans are being made to establish an office site in Europe for business development and

global alliance management. In addition, I-Mab has further strengthened its senior management team with the new appointments of Mr. John Long as Chief Financial Officer and Mr. Jielun Zhu (the former

CFO) taking a new role as Chief Strategy Officer to focus on corporate strategy, strategic partnerships and large transactions and corporate ventures. Dr. Andrew Zhu, an internationally renowned oncologist, was appointed President and member of

the board of directors to lead the Company s R&D organization and pipeline development. Founder and Chairman Dr. Jingwu Zang resumed his role as acting Chief Executive Officer. Furthermore, I-Mab

has received multiple prestigious global honors for its achievement as a global leading immuno-oncology biotech company.

With tremendous passion

and commitment, I-Mab has successfully delivered outstanding R&D results and strengthened the Company s fundamentals in 2021, said Dr. Jingwu Zang.

I-Mab has become a truly global innovative biotech company with a rich and competitive pipeline. We are excited by the achievements and will continue creating the pipeline value through rigorous

execution. Looking ahead, 2022 will be another exciting year as we expect to achieve a series of critical clinical milestones.

will include initiation of one to two registrational trials for lemzoparlimab in China, five or more data readouts, the initiation of up to eight new phase 1 or phase 2 clinical trials in the U.S. and China, as well as up to five IND

submissions/approvals, further advancing of the pipeline to include 3 to 4 registrational trials, 11 phase 2 clinical trials and 3 phase 1 clinical trials by the end of 2022.

Dr. Zang continued, On the corporate development front, the Phase One manufacturing facility is

expected to be in operation around June 2022 to produce clinical trial material needed for our clinical trials in the U.S. and China and, more importantly, to prepare for felzartamab to be the first locally manufactured CD38 product for the China

market. Business development remains a key strategic area for the Company. We will increase our internal efforts and liaise with external resources to achieve the BD goals this year.

As the Company s pipeline advances rapidly, a near-term product portfolio has emerged to potentially include 3 to 4 BLA submissions or market

launches in China between 2023 and 2025. The commercialization outlook of this near-term product portfolio solidifies a critical step in I-Mab s journey to transition from a global biotech to a

specialized global biopharma. A large part of our current corporate focus is preparing to commercialize the near-term product portfolio under the leadership of Mr. Yifei Zhu. Our commercial partnership with Jumpcan on eftansomatropin alfa and

the on-going effort to potentially acquire one pre-BLA product to enrich our hematologic malignancy-focused product portfolio are examples of how we have taken steps to

transition rapidly into next stage of the Company s development and value realization. Dr. Zang concluded.

Highlights and Upcoming Milestones

Lemzoparlimab: AML/MDS/NHL, end of phase 2 (EOP2) to start 1 or 2 registrational trials in 2022

Uliledlimab: Solid tumors, multiple ongoing phase 2 trials and new combo trials planned

Felzartamab: r/r MM, BLA ready for 3L, phase 3 for 2L, new IND for potentially 1L

Eftansomatropin alfa: PGHD, phase 3, patient recruitment completion in 2Q 2022

Efineptakin alfa: Solid tumors, two phase 2 ongoing

Enoblituzumab: Solid tumors, phase 2 and new combo trials planned

Lemzoparlimab (TJC4): a novel CD47 antibody being developed through a comprehensive clinical development plan for hematologic malignancies and solid

tumors in China. The Company s priority is to achieve the first registration of lemzoparlimab in its class in China. Additionally, I-Mab will continue to work closely with AbbVie to advance lemzoparlimab

as a potential best-in-class therapy globally. To achieve this goal, five clinical studies of lemzoparlimab are ongoing in parallel in both the U.S. and China, which

will potentially lead to one or two registrational clinical trials in China in 2022.

In terms of the safety profile of lemzoparlimab, the Company conducted a systemic data analysis and

safety review based on a larger patient population (over 180 patients) who were treated with lemzoparlimab. As of February 2022, 120 patients with hematologic malignancies and 60 patients with solid tumors have been treated with lemzoparlimab either

as a monotherapy or as combination therapies with pembrolizumab, rituximab, or AZA. Over 70 patients with MDS or AML were treated in combination therapy with AZA. The safety data from both the U.S. and China studies are consistent with our expected

safety profile without the need of a priming dose regimen. It is important to note that lemzoparlimab has shown encouraging efficacy signals in multiple clinical trials as described below. More efficacy data are expected to mature in 2022.

Uliledlimab (TJD5): a highly differentiated CD73 antibody being developed for

solid tumors. Phase 1 clinical trial conducted in the U.S. was under CRS finalization stage, and the clinical data was presented at ASCO 2021 as described below. The Company is advancing the asset in two phase 2 clinical trials in both the U.S. and

China in selected tumor types for clinical proof-of-concept. In parallel, the Company is in the process of exploring a potential global partnership deal.

Felzartamab (TJ202/MOR202): a differentiated CD38 antibody for the treatment of relapsing and refractory

multiple myeloma (MM) and potentially autoantibody-mediated autoimmune diseases such as systemic lupus erythematosus (SLE). I-Mab has the rights of development, manufacturing, and commercialization for

felzartamab in Greater China from MorphoSys.

Eftansomatropin alfa (TJ101): A differentiated long-acting growth hormone for pediatric growth hormone

deficiency (PGHD). Eftansomatropin alfa is the only rhGH in its proprietary fusion protein format (pure protein-based molecule) and is not chemically linked with PEG or other linkers. Its safety, tolerability, and efficacy have been well

demonstrated in a phase 2 clinical trial in the EU. I-Mab has the rights for development, manufacturing, and commercialization of eftansomatropin alfa in China from Genexine.

Efineptakin alfa (TJ107): The world s first and only

long-acting recombinant human interleukin-7 ( rhIL-7 ). This phase 2 clinical-stage asset is positioned as a monotherapy for the treatment of cancer patients

with lymphopenia because of its unique properties of increasing tumor-attacking T cell numbers and as a combination immunotherapy with a PD-1 or PD-L1 antibody because

of its potential synergism with PD-1/PDL-1 therapy. I-Mab has the rights for the development, manufacturing, and

commercialization of efineptakin alfa in Greater China from Genexine.

I-Mab is accelerating the clinical development of efineptakin alfa

by leveraging accumulative clinical data from multiple previous studies either as a monotherapy or in combination with checkpoint inhibitors in cancer patients, as conducted by I-Mab in China and Genexine and

NeoImmuneTech in South Korea and the U.S., respectively.

Enoblituzumab (TJ271): A humanized B7-H3 antibody as an immuno-oncology treatment agent. Enoblituzumab works through a unique dual mechanism, i.e. ADCC and immune activation. I-Mab has the rights for

development, manufacturing and commercialization of enoblituzumab in Greater China from MacroGenics.

(2) Other clinical assets

Plonmarlimab (TJM2): a monoclonal antibody targeting human granulocyte-macrophage colony-stimulating factor

(GM-CSF), a cytokine that plays a critical role in acute and chronic inflammation and cytokine release syndrome (CRS) associated with CAR-T and severe COVID-19.

TJ210/MOR210: A novel monoclonal antibody targeting C5aR1 to treat cancers through myeloid-derived suppressor cells and modulation of tumor

micro-environment in favor of enhanced anti-tumor immune response as a novel mechanism of action. The pre-clinical studies have provided ample scientific evidence for the role of TJ210 in the treatment of

cancers. Research is continuing, through in vitro and in vivo experimental systems, to identify and validate the most effective combo partner(s) for TJ210 to guide further clinical development of TJ210. I-Mab

has the rights for development, manufacturing and commercialization of TJ210 from MorphoSys and co-develops the asset globally with MorphoSys.

TJ-CD4B/ABL111: A novel Claudin 18.2 and 4-1BB bispecific antibody

capable of binding to tumor cells expressing Claudin 18.2, i.e., gastric cancer and pancreatic cancer cells, and stimulating intra-tumoral T cells by the 4-1BB arm designed to become active only upon tumor

engagement to avoid systemic toxicity. I-Mab recently received FDA Orphan Drug Designation status for TJ-CD4B for the treatment of gastric cancer, including cancer of

gastroesophageal junction.

TJ-L14B/ABL503: A differentiated PD-L1-based bispecific antibody with the PD-L1 arm as the

tumor-dependent T-cell activator and the 4-1BB arm as the conditional T cell activator upon local tumor engagement.

(3) Pre-clinical assets and programs

The Company has been working on generating additional bi-functional or

bi-specific antibody molecules with unique properties that rely on synergism of two given targets. The overarching goal behind these bi-specific molecules is to

stimulate the immune responses within the tumor environment to convert immunologically non-responsive cold tumors into responsive hot tumors. The company has made steady progress in the

past year culminating in successful candidate selection of two bispecific molecules.

TJ-L1IF is a next-generation

PD-L1/IFN- antibody-cytokine fusion protein, which is specifically designed for the treatment of solid tumors, especially for

PD1/PD-L1 resistant tumors, through addition of a strong immune adjuvant IFN- to convert cold tumor to hot tumor on top of a PD-L1 antibody

to achieve superior anti-tumor activity than PD-(L)1 antibody monotherapy. IFN- was the first cytokine approved for cancer treatment, but its use has been limited due to considerable systemic toxicity. TJ-L1IF is composed of a PD-L1 VHH nanobody linked with the Fc of human IgG with an engineered IFN- 2b fused at the C-terminus. It

is a prodrug in that the IFN- 2b moiety is masked by a PEG group through a protease-cleavable linker rendering the drug inactive in the systemic circulation, thus strongly reducing systemic toxicity. Once the drug reaches the tumor by PDL1

antibody targeting, the linker can be removed by tumor-associated proteases to achieve tumor-site specific activation. This unique property of TJ-L1IF has been confirmed in a series of in vitro and in vivo

studies, in which TJ-L1IF demonstrated plasma stability, good safety in cynomolgus monkeys, and superior activity against solid tumors in mouse models, particularly for the

PD1/PD-L1 resistant tumors, than that could be achieved by PD-L1 antibody or IFN- used either alone or in combination.

TJ-L1IF was developed using Affinity s TMEA technology, and is now under pre-clinical development.

TJ-C64B is the third bispecific molecule developed leveraging our conditional

4-1BB platform which has the advantage of systemic safety and minimizing liver toxicity. It is specifically designed to simultaneously target tumor-associated antigen Claudin 6 (CLDN6) and 4-1BB for CLDN6+ solid tumor treatment. CLDN6 is regarded as an attractive cancer target due to its tumor-specific expression pattern: it is aberrantly expressed in a variety of tumor types, especially those with

limited response to PD-1/PD-L1 immunotherapy, such as ovarian cancer, but is hardly detectable in normal adult tissues. We have now demonstrated that TJ-C64B activates T cells through 4-1BB stimulation only upon CLDN6 engagement, providing a more localized activation of the immune system with good efficacy and reduced

systemic toxicity. Owing to a competent Fc, TJ-C64B has an added advantage of specifically depleting CLDN6-expressing tumor cells and intratumor regulatory T cells which are typically 4-1BB high, which differentiates it from other 4-1BB bispecific antibodies under clinical development. Compelling immune activation and tumor inhibition have been observed

both in vitro and in vivo towards cancer cell lines with different CLDN6 expression levels. Importantly, no significant changes in liver enzymes following repeated administrations in mice and cynomolgus monkeys, suggesting little risks for liver