Clinical Update including PR013 Phase II results

THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF EU REGULATION 596/2014

Realm Therapeutics Provides Clinical Update, including Results from a Phase 2 Study of PR013 in Allergic Conjunctivitis

MALVERN, PA, March 12 2018 - Realm Therapeutics plc (AIM: RLM), a clinical stage biopharmaceutical company focused on developing novel therapeutics in immune-mediated diseases, today provides an update on the Company's clinical programs.

The Company reports that its Phase 2 study of PR013, a topical ophthalmic solution for the treatment of Allergic Conjunctivitis, did not demonstrate efficacy. As a result, Realm has decided to discontinue further development of this program.

Enrollment for its Phase 2 Atopic Dermatitis study of PR022, a topical gel, is on track and the Company continues to expect to report top-line results in Q3 2018. Due to different immunologic pathways Atopic Dermatitis is not related to Allergic Conjunctivitis.

The Company's pre-clinical development program in Acne Vulgaris is also advancing well. Following preliminary discussions with the US Food and Drug Administration, the Company intends to file an Investigational New Drug (IND) application to study RLM023 in Acne Vulgaris in early Q4 2018.

"While the PR013 results are disappointing, we are extremely pleased with the progress we are making with our dermatology programs, as they continue to be our top priority," said Alex Martin, Chief Executive Officer of Realm. "Atopic Dermatitis and Acne Vulgaris have different immunologic pathologies and are otherwise unrelated to Allergic Conjunctivitis. We remain confident in our technology's potential to deliver immunomodulatory and anti-inflammatory benefits, and continue to believe that it has potential for application in multiple disease areas."

About Realm Therapeutics

Realm Therapeutics is a clinical-stage biopharmaceutical company focused on developing novel therapeutics that target the intersection between innate and adaptive immunity, to influence immune signaling and change the course of immune-mediated diseases in adults and children. Realm's lead drug development program utilizes the Company's proprietary immunomodulatory technology for the treatment of Atopic Dermatitis (PR022) and Realm is exploring its efficacy in Acne Vulgaris and other Dermatology indications, as well as other disease areas. For more information on Realm Therapeutics please visit www.realmtx.com.

Forward Looking Statements

Certain statements made in this announcement are forward-looking statements, including with respect to the Company's clinical trials and product candidate development plans. These forward-looking statements are not historical facts but rather are based on the Company's current expectations, estimates, and projections about its industry; its beliefs; and assumptions. Words such as 'anticipates,' 'expects,' 'intends,' 'plans,' 'believes,' 'seeks,' 'estimates,' and similar expressions are intended to identify forward-looking statements. These statements are not guarantees of future performance and are subject to known and unknown risks, uncertainties, and other factors, some of which are beyond the Company's control, are difficult to predict, and could cause actual results to differ materially from those expressed or forecasted in the forward-looking statements, including clinical developments and regulatory review of product candidates. The Company cautions shareholders and prospective shareholders not to place undue reliance on these forward-looking statements, which reflect the view of the Company only as of the date of this announcement. The forward-looking statements made in this announcement relate only to events as of the date on which the statements are made. The Company will not undertake any obligation to release publicly any revisions or updates to these forward-looking statements to reflect events, circumstances, or unanticipated events occurring after the date of this announcement except as required by law or by any appropriate regulatory authority.

Contact:

Realm Therapeutics plc


Alex Martin, Chief Executive Officer


Marella Thorell, Chief Financial Officer and Chief Operating Officer

Outside US: +44 (0) 20 3727 1000

US: +1 212 600 1902

Argot Partners

Stephanie Marks/Susan Kim

+1 212 600 1902

FTI Consulting


Simon Conway / Mo Noonan

+44 (0) 20 3727 1000

N+1 Singer (Nominated Adviser and Broker) Aubrey Powell / Jen Boorer

+44 (0) 20 7496 3000