Exhibit 16.1
Our Ref AS/HD 08551822
U.S. Securities and Exchange Commission
Office of the Chief Accountant
100 F Street, NE
Washington, DC 20549
Grant Thornton UK LLP
101 Cambridge Science Park
Milton Road
Cambridge CB4 OFY
T +44 (0)1223 225600
F +44 (0)1223 225619
www.grant-thornton.co.uk
31 August 2017
Dear Sir
NightstaRx Limited
Company number08551822
We have read the section titled ‘Dismissal of Independent Auditors’ included under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations” within the Registration Statement on Form F-1 of Nightstar Therapeutics Limited to be filed with the U.S. Securities and Exchange Commission on or about August 31, 2017, and agree with the statements concerning our Firm contained therein.
Yours faithfully
/s/ Grant Thornton UK LLP
For Grant Thornton UK LLP