I-Mab Announces Financial Results for the Full Year Ended

I-Mab Announces Financial Results for the Full Year Ended December 31, 2019, and Provides

Successfully completed initial public offering raising approximately $114.5 million in gross proceeds

Continued execution across broad pipeline portfolio; multiple clinical data readouts expected in 2020

Company to host conference call and webcast, March 31 at 8:00 a.m. EDT

SHANGHAI, China and ROCKVILLE, MD., March 31, 2020 (GLOBE NEWSWIRE) I-Mab (the

Company ) (Nasdaq: IMAB), a clinical stage biopharmaceutical company committed to the discovery, development and commercialization of novel or highly differentiated biologics to treat diseases with significant unmet medical needs,

particularly cancers and autoimmune disorders, today announced financial results for the full year ended December 31, 2019 and provided an overview of recent highlights and upcoming milestones.

2019 was a highly-productive year for I-Mab, which culminated in the successful completion of our initial public

offering in the beginning of 2020, said Dr. Jingwu Zang, founder, Honorary Chairman and Director of I-Mab. This achievement signals a critical turning point for our company as we transition

from I-Mab 1.0 to I-Mab 2.0. As we look at the remainder of 2020, despite the difficulties associated with COVID-19, we expect to

deliver a series of key development milestones, including both clinical and partnership milestones in the U.S. and China. We have made significant progress on key value drivers of our pipeline advancing TJC4 and TJD5 from our global portfolio, as

well as TJ202 and TJ101 from our China portfolio, along with other clinical and pre-clinical programs. In particular, we believe TJC4 holds great promise as a differentiated CD47 antibody offering potential

safety advantages. We are in a strong financial position to deliver on our key milestones. The goal of I-Mab 2.0 is to move toward becoming a leading, fully integrated, global biopharmaceutical company. 2020

will be an important year for this goal.

Dr. Joan Huaqiong Shen, Chief Executive Officer and Director of

I-Mab commented, At I-Mab, we remain fully committed to science and innovation to deliver a global impact on human health. To that end, and in light of the current

COVID-19 pandemic, we have recently announced our planned development in the U.S. of TJM2, our proprietary GM-CSF antibody, to treat cytokine release syndrome (CRS)

associated with severe and critical illness caused by COVID-19 infection. In addition, we plan to expand trials on COVID-19 in other

hardest-hit countries. We remain on track to delivering multiple clinical data readouts in 2020. These include initial data from TJC4, our differentiated CD47 antibody, as well as from TJD5, our differentiated

CD73 antibody. In parallel with our clinical progress in the U.S., we continue to leverage our clinical development capabilities and expertise domestically to diligently execute on our

Fast-to-Market China strategy. Specifically, TJ202, our in-licensed CD38 antibody, continues to advance in two parallel

registrational studies in China for treatment of multiple myeloma. Additionally, TJ101, our licensed long-acting growth hormone for pediatric growth hormone deficiency is on track for IND submission followed by the planned initiation of a Phase 3

registrational trial in China by the end of 2020 or early 2021. We also look forward to releasing Phase 2 clinical data from TJ301 in patients with ulcerative colitis by the end of 2020.

Recent Highlights and Upcoming Milestones

Internally Discovered Global Pipeline

Fast to Market China Portfolio

I-Mab continues to assess potential impact of COVID-19 on its business.

Currently, I-Mab expects the COVID-19 worldwide health crisis to have immaterial impact on its business as its operations in China are in conjunction with hospitals

located in regions that were relatively less affected by COVID-19. However, as research hospitals and government agencies focus clinical resources on the pandemic, I-Mab

believes there could be some delays in regulatory interactions and inspections, and patient recruitment and participation, particularly in the first quarter of 2020. Similarly, the worsening situation of

COVID-19 in the U.S. may cause some delays in the on-going clinical trials in the U.S. On the other hand, I-Mab clinical trials

in both the U.S. and China involve many clinical sites and hospitals located in many different regions. While the full scope and duration of the crisis is far from clear at this time, I-Mab is actively and

diligently working to minimize delays and disruptions to its clinical trials. At the present time, the COVID-19 situation has improved in China, and I-Mab will continue

to execute on its regulatory and clinical development goals in China and the U.S.

Full Year 2019 Financial Results

As of December 31, 2019, the Company

had cash, cash equivalents, restricted cash and short-term investments of RMB1.2 billion (US$176.0 million), compared with RMB1.7 billion as of December 31, 2018. In addition, I-Mab successfully

completed its initial public offering (IPO) of American depositary shares in January 2020, resulting in gross proceeds of approximately $114.5 million, including the partial exercise of the underwriter s over-allotment option.

Total net revenues for the full year of

2019, which were generated from licensing and collaboration, were RMB30.0 million (US$4.3 million), compared with RMB53.8 million for the full year of 2018. Net revenues for the period were contributed by upfront and milestone payments

Research & Development Expenses

Research and development expenses for the full year of 2019 were RMB840.4 million (US$120.7 million), compared with RMB426.0 million for the full

year of 2018. The increase was primarily due to increases in CRO service fees to advance the Company s pipelines, additional patent right fees including an upfront payment of US$15.0 million to MacroGenics, and higher employee salary and

benefits expenses due to increased research and development headcount.

Administrative Expenses

Administrative expenses for the full year of 2019 were RMB654.6 million (US$94.0 million), compared with RMB66.4 million for the full year of 2018.

The increase was primarily due to additional share-based compensation expenses of RMB514.7 million (US$73.9 million) to the senior management, additional salary and benefits expenses resulting from increased headcount, and increased

professional fees primarily in relation to the preparation of I-Mab s IPO and to support the expansion of I-Mab s business operations.

Net loss for the full year of 2019 was

RMB1,452.0 million (US$208.6 million), compared with RMB402.8 million for the full year of 2018. Net loss per share attributable to ordinary shareholders for 2019 was RMB201.2 (US$28.9), compared with RMB61.7 for 2018.

Non-GAAP adjusted net loss, which excludes share-based compensation expenses, for the full year of 2019 was

RMB936.7 million (US$134.6 million), compared with RMB399.3 million for the full year of 2018. Non-GAAP adjusted net loss per share attributable to ordinary shareholders for 2019 was RMB131.4

(US$18.9), compared with RMB61.2 for 2018.

Conference Call and Webcast Information

The Company s management will host a conference call and webcast today, March 31, 2020 at 8:00 AM U.S. Eastern Daylight Time (8:00 PM Beijing/Hong

Dial-in details for the live earnings conference call are as follows:

A telephone replay will be available two hours after the call until April 14, 2020 by dialing:

Additionally, a live and archived audio webcast of the conference call will be available on the Company s investor

relations website at http://ir.i-mabbiopharma.com/.

I-Mab (Nasdaq: IMAB) is a dynamic, global biotech company exclusively focused on developing biologics of novel

or highly differentiated in the therapeutic areas of immuno-oncology and autoimmune diseases. Company s mission is to bring transformational medicines to patients through innovation. I-Mab s

innovative pipeline of more than 10 clinical and pre-clinical stage drug candidates is driven by the Company s Fast-to-PoC (Proof-of-Concept) and Fast-to-Market development strategies through internal R&D and global partnerships. The Company is on

track to become a fully integrated end-to-end global biopharmaceutical company with cutting-edge discovery platforms, proven preclinical and clinical development

expertise, and world-class GMP manufacturing capabilities. I-Mab has offices in China and the United States. For more information, please visit

http://ir.i-mabbiopharma.com/.

Use of Non-GAAP Financial Measures

To supplement its consolidated financial statements which are presented in accordance with U.S. GAAP, the Company uses adjusted net loss as a non-GAAP financial measure. Adjusted net loss represents net loss before share-based compensation. The Company s management believes that adjusted net loss facilitates better understanding of operating results

and provide management with a better capability to plan and forecast future periods. For more information on the non-GAAP financial measures, please see the table captioned Reconciliation of GAAP and Non-GAAP Results set forth at the end of this press release.

information is not prepared in accordance with GAAP and may be different from non-GAAP methods of accounting and reporting used by other companies. The presentation of this additional information should not be

considered a substitute for GAAP results. A limitation of using adjusted net loss is that adjusted net loss excludes share-based compensation expense that has been and may continue to be incurred in the future.

Exchange Rate Information

This announcement contains

translations of certain RMB amounts into U.S. dollars at a specified rate solely for the convenience of the reader. Unless otherwise noted, all translations from Renminbi to U.S. dollars are made at a rate of RMB6.9618 to US$1.00, the rate in

effect as of December 31, 2019 published by the Federal Reserve Board.

Safe Harbor Statement

This press release contains statements that may constitute forward-looking statements pursuant to the safe harbor provisions of the

U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified by terminology such as will, expects, anticipates, aims, future,

intends, plans, believes, estimates, likely to and similar statements. Statements that are not historical facts, including statements about

I-Mab s beliefs, plans and expectations, are forward-looking statements. Forward-looking statements involve inherent risks and uncertainties. Further information regarding these and other risks is

included in I-Mab s filings with the SEC. All information provided in this press release is as of the date of this press release, and I-Mab does not undertake any

obligation to update any forward-looking statement, except as required under applicable law.

For more information, please contact:

E-mail: jielun.zhu@i-mabbiopharma.com

Office line: +86 21 6057 8000

Burns McClellan, Inc. (Americas and Europe)

E-mail: sklass@burnsmc.com

Office line: +1 212 213 0006

The Piacente Group, Inc. (Asia)

Office line: + 86 21 6039 8363

Media Inquiries (Americas and Europe):

Ryo Imai / Robert Flamm, Ph.D.

E-mail: rimai@burnsmc.com / rflamm@burnsmc.com

Office line: +1 212 213 0006

Consolidated Balance Sheets

(All amounts in thousands, except for share and per share data, unless otherwise noted)

Consolidated Balance Sheets (Continued)