Zai Lab Announces Pricing of Public Offering of American Depositary Shares

Zai Lab Announces Pricing of Public Offering

of American Depositary Shares

SHANGHAI, China, May 2, 2019 (GLOBE

NEWSWIRE) - Zai Lab Limited ("Zai Lab" or the "Company") (NASDAQ: ZLAB), a China and U.S.-based

innovative commercial stage biopharmaceutical company, today announced the pricing of its underwritten public offering of

7,843,138 American depositary shares ("ADSs"), each representing one ordinary share of the Company, at a price

of US$25.50 per ADS. The offering was upsized from the previously announced offering size of 5,000,000 ADSs.

The gross proceeds to Zai Lab from the

offering, before deducting underwriting discounts and commissions and other offering expenses, are expected to be

approximately US$200.0 million. In addition, Zai Lab has granted the underwriters a 30-day option to purchase up to an

additional 1,176,470 ADSs at the public offering price, less underwriting discounts and commissions. The offering is

expected to close on May 7, 2019, subject to customary closing conditions.

J.P. Morgan, Citigroup, Jefferies and SVB Leerink

are acting as joint book-running managers for the offering.

The ADS are offered pursuant to a shelf

registration statement on Form F-3ASR, which became automatically effective upon filing with the U.S. Securities and Exchange

Commission ("SEC") on March 29, 2019.

The offering is being made only by means of a

prospectus supplement and an accompanying prospectus included in Form-3ASR. The registration statement on Form F-3ASR and the

prospectus supplement are available at the SEC's website at: http://www.sec.gov. Copies

of the prospectus supplement and the accompanying prospectus may be obtained from: (i) J.P. Morgan Securities LLC, Attention:

Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, telephone: 1-866-803-9204 or email: prospectus-eq_fi@jpmchase.com,

(ii) Citigroup Global Markets Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717 or

telephone: 1-800-831-9146 (iii) Jefferies LLC, Attention: Equity Syndicate Prospectus Department, 520 Madison Avenue, 2nd

Floor, New York, NY 10022, by telephone at 1-877-821-7388, or by email at Prospectus_Department@jefferies.com or (iv) SVB

Leerink LLC, Attention: Syndicate Department, One Federal Street, 37th Floor, Boston, MA 02110, telephone: 1-800-808-7525 ex.

6132 or email: syndicate@svbleerink.com.

This press release does not constitute an offer

to sell or the solicitation of an offer to buy ADSs or any other securities, nor shall there be any sale of ADSs in any state or

jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities

laws of any such state or jurisdiction.

Zai Lab (NASDAQ:ZLAB) is a China and U.S.-based

innovative commercial stage biopharmaceutical company focused on bringing transformative medicines for cancer, infectious and autoimmune

diseases to patients in China and around the world. The Company's experienced team has secured partnerships with leading

global biopharma companies, generating a broad pipeline of innovative drug candidates targeting the fast-growing segments of China's

pharmaceutical market and addressing unmet medical needs. Zai Lab's vision is to become a fully integrated biopharmaceutical

company, discovering, developing, manufacturing and commercializing its partners' and its own products in order to impact

human health worldwide.

Zai Lab Forward-Looking StatementsThis press release includes certain disclosures which contain "forward-looking statements."

You can identify forward-looking statements because they contain words such as "anticipate" and "expected."Forward-looking

statements are based on Zai Lab's current expectations and assumptions. Because forward-looking statements relate to

the future, they are subject to inherent uncertainties, risks and changes in circumstances that may differ materially from

those contemplated by the forward-looking statements, which are neither statements of historical fact nor guarantees or assurances

of future performance. Important factors that could cause actual results to differ materially from those in the forward-looking

statements are set forth in Zai Lab's Annual Report on Form 20-F for the fiscal year ended December 31, 2018 and its

other filings with the U.S. Securities and Exchange Commission. Zai Lab 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

Media: Nancie Steinberg & Robert

Burns McClellan, on behalf of Zai

212-213-0006, ext. 318, nsteinberg@burnsmc.com

212-213-0006, ext. 364, rflamm@burnsmc.com

Investors: Jill Steier

Burns McClellan, on behalf of Zai Lab

212-213-0006, ext. 364, jsteier@burnsmc.com