Mereo BioPharma Regains Compliance with Nasdaq Minimum Bid Price Requirement London and Mountain View, CA

Mereo BioPharma Regains Compliance with Nasdaq Minimum Bid Price Requirement

London and Mountain View, CA, July 05, 2022 Mereo BioPharma Group plc (NASDAQ: MREO), ( Mereo or the Company ), a

clinical-stage biopharmaceutical company focused on rare diseases and oncology, today announced that it has received a written notification (the Notification Letter ) from the Listing Qualifications Department of the Nasdaq Stock Market,

LLC ( Nasdaq ) informing the Company that it has regained compliance with the minimum bid price requirement set forth in Nasdaq Listing Rule 5450(a)(1) (the Minimum Bid Price Requirement ) and the matter is closed.

As announced on May 26, 2022, the Company was notified by Nasdaq that it was not in compliance with the Minimum Bid Price Requirement, as the closing bid

price of the Company s American Depositary Shares (the ADSs ) had been below US$1.00 for 30 consecutive business days. To regain compliance with the Minimum Bid Price Requirement, Mereo was required to maintain a minimum closing bid

price of $1.00 or more for at least 10 consecutive business days.

The Notification Letter confirmed that the Company evidenced a closing bid price of the

Company s ADSs on Nasdaq at or greater than the $1.00 per ADS minimum requirement for the last 10 consecutive business days from June 17, 2022 to July 1, 2022 and that the Company has regained compliance with Minimum Bid Price

About Mereo BioPharma

is a biopharmaceutical company focused on the development of innovative therapeutics for rare diseases and in oncology and plans to commercialize selected rare disease programs. The Company has developed a portfolio of six clinical stage product

candidates. The Company has two rare disease product candidates, setrusumab for the treatment of osteogenesis imperfecta (OI) and alvelestat for the treatment of severe Alpha-1 antitrypsin deficiency (AATD)

and Bronchiolitis Obliterans Syndrome (BOS). The Company s partner, Ultragenyx Pharmaceutical, Inc., has initiated a pivotal Phase 2/3 pediatric study in young adults (5-25 years old) for setrusumab in OI

and expects to initiate a study in pediatric patients (2-5 years old) in the second half of 2022. The partnership with Ultragenyx includes potential milestone payments of up to $254 million and royalties

to Mereo on Ultragenyx territories. Mereo has retained EU and UK commercial rights and will pay Ultragenyx royalties on those territories. Alvelestat has received U.S. Orphan Drug Designation for the treatment of AATD and positive top-line data were recently reported from a Phase 2 proof-of-concept study in North America, Europe and the UK. Mereo s lead

oncology product candidate, etigilimab (anti-TIGIT), is currently in an open label Phase 1b/2 basket study evaluating anti-TIGIT in combination with an anti-PD-1 in a

range of tumor types. The Company s second oncology product, navicixizumab, for the treatment of late line ovarian cancer, has completed a Phase 1 study and has been partnered with OncXerna Therapeutics, Inc. The global licensing agreement with

OncXerna includes payments of up to $300 million in milestones and royalties. OncXerna has stated that they intend to initiate a Phase 3 trial of navicixizumab in late line ovarian cancer patients.

Forward-Looking Statements

This press release contains forward-looking statements. All statements other than statements of historical fact contained in this press release are

forward-looking statements within the meaning of Section 27A of the United States Securities Act of 1933, as amended (the Securities Act ), and Section 21E of the United States Securities Exchange Act of 1934, as amended (the

Exchange Act ). Forward-looking statements usually relate to future events and anticipated revenues, earnings, cash flows or other aspects of our operations or operating results. Forward-looking statements are often identified by the

words believe, expect, anticipate, plan, intend, foresee, should, would, could, may, estimate, outlook

and similar expressions, including the negative thereof. The absence of these words, however, does not mean that the statements are not forward-looking. These forward-looking statements are based on the Company s current expectations, beliefs

and assumptions concerning future developments and business conditions and their potential effect on the Company. While management believes that these forward-looking statements are reasonable as and when made, there can be no assurance that future

developments affecting the Company will be those that it anticipates.

All of the Company s forward-looking statements involve known and unknown

risks and uncertainties some of which are significant or beyond its control and assumptions that could cause actual results to differ materially from the Company s historical experience and its present expectations or projections. You should

carefully consider the foregoing factors and the other risks and uncertainties that affect the Company s business, including those described in the Risk Factors section of its latest Annual Report on Form 20-F, reports on Form 6-K and other documents furnished or filed from time to time by the Company with the Securities and Exchange Commission. The Company wishes to caution

you not to place undue reliance on any forward-looking statements, which speak only as of the date hereof. The Company undertakes no obligation to publicly update or revise any of our forward-looking statements after the date they are made, whether

as a result of new information, future events or otherwise, except to the extent required by law.