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, 2022

and SHANGHAI, China, March 31, 2023 - I-Mab (the "Company") (Nasdaq: IMAB), a clinical-stage biopharmaceutical

company committed to the discovery, development, and commercialization of novel biologics, today announced its financial results for the

12 months ended December 31, 2022, and provided key business updates.

In 2022, the Company

faced a series of risks, including macroeconomic and geopolitical headwinds, which prompted the Company to re-position its overall business

in response to these challenges, while focusing on re-prioritizing the pipeline development to deliver on key clinical milestones. These

measures resulted in a streamlined workforce and laser-focused R&D activity on five key clinical assets, significantly reducing the

cash burn rate in 2022 and beyond. Today, the risks imposed by the Holding Foreign Companies Accountable Act (the "HFCAA")

and the COVID-19 pandemic are largely mitigated. Collectively, the Company is now in a strong position to continue to deliver the expected

key catalysts and value through pipeline progress and global partnerships with a more prudent expenditure strategy to support its key

business operations for the next three years.

More specifically, the

Company made significant progress in its pipeline development by focusing on five key clinical assets: eftansomatropin alfa, felzartamab,

lemzoparlimab, uliledlimab, and givastomig. The major achievements in 2022 included (1) positive Phase 2 data readout for lemzoparlimab

and regulatory approval to initiate a Phase 3 clinical trial in China; (2) positive Phase 2 data readout for uliledlimab -

a very encouraging clinical dataset for CD73 and PD-1 combination therapy in advanced non-small cell lung cancer (NSCLC) to date, which

is enabled by CD73 expression as a predictive biomarker. The clinical development plan is being finalized to initiate a biomarker-guided

pivotal trial in 2H 2023 in advanced NSCLC. In addition, the Company expects that the recent Phase 2 data could contribute to the ongoing

discussions for a potential global partnership; (3) encouraging Phase 1 data for givastomig (TJ-CD4B), which will potentially enable

the initiation of a Phase 2 trial in 2H 2023, and a potential global partnership, and (4) significant progress on eftansomatropin

alfa and felzartamab, leading to Phase 3 data readout expected in 2H 2023 and potential BLA submission in China by the end of 2023 or

early 2024 for eftansomatropin alfa, and at a later time for felzartamab.

facing unprecedented challenges, we strived to achieve two overarching business goals. One is the re-positioning of our core business

and the optimization of our organization and resources to reduce our cash burn rate and extend our cash runway. The other is the achievement

of thirteen key milestones, including positive data readouts for lemzoparlimab, uliledlimab, and givastomig and significant progress made

for two pre-BLA assets, felzartamab and eftansomatropin alfa, towards BLA submission," said Dr. Andrew Zhu, Acting CEO of I-Mab.

we are now in a strong position to deliver on our innovative pipeline and corporate milestones, as well as to make expected progress in

global partnerships and commercial partnerships given that business development remains a key strategic priority of the Company. We will

stay laser-focused on creating value for our shareholders while extending the cash runway to support key business operations in the coming

years," Dr. Zhu concluded.

Updated Pipeline Development

Highlights and Upcoming Milestones

The five prioritized

clinical assets include the Company's three Phase 3 assets (eftansomatropin alfa, felzartamab, and lemzoparlimab), one End-of-Phase

2 (EOP2) asset (uliledlimab), and one Phase 1 asset (givastomig). As the studies progress, the Company expects to have two potential near-term

BLA submissions in China (potentially by the end of 2023 or early 2024 for eftansomatropin alfa and at a later time for felzartamab),

two key assets entering into Phase 3 or pivotal trials in China (lemzoparlimab for myelodysplastic syndromes (MDS) in Phase 3 and uliledlimab

for NSCLC in a pivotal clinical trial) and one asset entering into Phase 2 (givastomig) in 2023.

alfa (Phase 3 data readout expected in 2H 2023 followed by BLA submission):

pediatric growth hormone deficiency (PGHD): This Phase 3 registrational trial (TALLER) of eftansomatropin alfa as a weekly treatment

for PGHD is ongoing in China. On May 31, 2022, the Company announced the completion of patient enrollment in the TALLER study for

the treatment of PGHD. TALLER is a multi-center, randomized, open-label, active-controlled Phase 3 clinical study (NCT04633057) of 168

patients in China. The study aims to evaluate the efficacy, safety, and pharmacokinetics (PK) of eftansomatropin alfa in PGHD, as compared

to Norditropin , a daily rhGH marketed in China. The study is on track, and the final dataset is anticipated in the second half of

2023, which is expected to be followed by a BLA submission by the end of 2023 or early 2024.

plan for eftansomatropin alfa: In November 2021, the Company announced a strategic commercial partnership with Jumpcan, a leading

domestic pharmaceutical company specializing in pediatric medicines, to accelerate the commercialization of eftansomatropin alfa. I-Mab

will be the marketing authorization holder (MAH) of the product and supply the product at an agreed cost rate to Jumpcan. Jumpcan will

be responsible for commercializing the product and developing new indications in collaboration with I-Mab in mainland China. Jumpcan has

made an upfront payment of RMB224 million (US$32.5 million) to I-Mab. Moreover, upon the achievement of certain development, registration,

and sales milestones, I-Mab will be eligible to receive milestone payments in aggregate of up to RMB 1.792 billion (US$259.8 million).

In addition, I-Mab and Jumpcan will share profits generated from the commercialization of the product in mainland China on a 50/50

basis, pursuant to which I-Mab will be entitled to receive tiered low double-digit royalties on net sales. This partnership deal represents

one of the largest in China's biopharma market to date.

Jumpcan and I-Mab have

been working together to prepare for the future product launch of eftansomatropin alfa in China.

Felzartamab (Phase 3 ongoing):

Third-line multiple myeloma (MM): The pivotal

trial has been completed, and the topline data met the preset primary and secondary endpoints. The clinical data confirmed the clinical

advantages of felzartamab in terms of lower infusion-related reaction rate and shorter infusion time, which has made it feasible and practical

for its use in an outpatient clinic setting.

China phase 3 trial as a second-line treatment

for MM: Patient enrollment for a randomized, open-label, parallel-controlled Phase 3 registrational trial of felzartamab in combination

with lenalidomide and dexamethasone as a second-line treatment for MM was completed in September 2021. The study is on track.

BLA submission, local manufacturing and commercialization:

The Company is focusing on a local manufacturing plan to support felzartamab's BLA submission in positioning felzartamab as the

first locally manufactured CD38 antibody for the Chinese market, which could lead to increased affordability and commercial competitiveness.

In parallel, the Company is exploring a potential commercial partnership for felzartamab, with the goal of enabling the Company to quickly

gain and scale up market share for felzartamab without investing significant resources in its own commercialization capabilities.

Lemzoparlimab (Phase 3, potential first-in-class

Lemzoparlimab in combination

with azacitidine (AZA) for MDS: In September 2022, the Company announced encouraging data from its Phase 2 trial (NCT04202003)

of Lemzoparlimab in combination with AZA in patients with newly diagnosed higher-risk myelodysplastic syndrome (HR-MDS), presented

in a selected oral presentation at the 2022 European Society for Medical Oncology (ESMO). Topline data of 53 patients enrolled as of March 31,

2022, showed that for patients who began treatments six months or longer prior to the analysis, the overall response rate (ORR) and

complete response rate (CRR) were 86.7% and 40.0%, respectively. It should be noted that this study enrolled more patients

with worse baseline conditions than the comparable clinical trials conducted in western countries due to the underlying disease that is

heavily influenced by clinical practice in China. In this group, 74% of patients had grade 3 anemia, and 51% of patients had grade

3 thrombocytopenia at baseline. The overall results showed that lemzoparlimab combined with AZA was well-tolerated, and the

safety profile was comparable with that of AZA monotherapy. Updated results from the most recent data analysis of 62 patients on

the study have demonstrated consistent clinical efficacy including ORR and CRR with no new safety signals identified. The Company plans

to present the updated data at a major scientific meeting in 2H 2023.

Phase 3 clinical trial

of lemzoparlimab in combination with AZA as a 1L treatment for HR-MDS: In September 2022, the Company obtained approval from

the Center for Drug Evaluation (CDE) to initiate a Phase 3 registrational trial evaluating lemzoparlimab in combination with AZA as a

first-line treatment for patients with newly diagnosed HR-MDS. This is the first approved Phase 3 trial for anti-CD47 therapies in China.

With this, the Company aims to develop lemzoparlimab as a potential first-in-class product in China.

Other ongoing clinical trials: the Company

continues to evaluate lemzoparlimab in combination with rituximab for non-Hodgkin's lymphoma and lemzoparlimab in combination with

PD-1 therapy for selected advanced solid tumors.

Update on AbbVie partnership: In

August 2022, I-Mab and AbbVie entered into an amendment to the original license and collaboration agreement dated September 3,

2020 (as amended, the "Agreement"). The parties are collaborating on the global development of anti-CD47 antibody therapy

under the Agreement. According to the Agreement, the Company will be eligible to receive certain milestone payments and tiered royalties

upon the accomplishments of the conditions set forth therein (Form 6-K filed on August 16, 20221). The Company has

the exclusive right to develop and commercialize all licensed products under the Agreement in Greater China. AbbVie discontinued the

global Phase 1b study of lemzoparlimab combination therapy with AZA and venetoclax in patients with MDS and acute myeloid leukemia (AML),

and a Phase 1b study of lemzoparlimab in patients with relapsed/refractory multiple myeloma. This discontinuation was not related to