Notification of change in holding of shareholder

24 April 2017

Motif Bio plc

("Motif Bio" or the "Company")

Notification of change in holding of significant shareholder

Motif Bio plc (AIM: MTFB), the clinical stage biopharmaceutical company specialising in developing novel antibiotics, announces that it was informed on 21 April 2017 by Sabby Healthcare Master Fund Ltd ("Sabby") that as at 10 April 2017, Sabby's interest in shares in the Company to which voting rights are attached, being ordinary shares of 1 pence each in the capital of the Company ("Ordinary Shares"), had fallen from an interest in 17,191,980 Ordinary Shares (held by way of American Depositary Shares ("ADSs")), representing 9.52% of the Company's issue share capital, to an interest in 5,887,050 Ordinary Shares (held by way of 157,698 ADSs and 2,733,090 Ordinary Shares), representing 3% of the Company's issued share capital.

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Notes to Editors:

Motif Bio is a clinical-stage biopharmaceutical company, engaged in the research and development of novel antibiotics designed to be effective against serious and life-threatening infections in hospitalised patients caused by multi-drug resistant bacteria. Our lead product candidate, iclaprim, is being developed for the treatment of acute bacterial skin and skin structure infections (ABSSSI) and hospital acquired bacterial pneumonia (HABP), including ventilator associated bacterial pneumonia (VABP), which is often caused by MRSA (methicillin resistant Staphylococcus aureus). We are currently enrolling and dosing patients in two global Phase 3 clinical trials (Revive 1 and Revive 2) with an intravenous formulation of iclaprim, for the treatment of ABSSSI. Data readout for REVIVE-1 is expected in the second quarter of 2017 and REVIVE-2 is on track for data readout in the second half of 2017.