CALGARY, AB – May 8, 2018 – XORTX Therapeutics Inc. (“XORTX” or the “Company”) (CSE:XRX), a biopharmaceutical company focused on developing innovative therapies to treat progressive kidney
disease, is pleased to announce the appointment of Bruce Rowlands, a director of XORTX as Chairman of the Board of Directors.

Bruce Rowlands has extensive experience in the life sciences industry in Canada through his long association with Lorus Therapeutics, a leading Canadian biotechnology company, where he acted as a
consultant, banker and senior executive during its early drug development years. Lorus Therapeutics, now Aptose Biosciences Inc., is dual-listed on the TSX and NASDAQ exchanges. Bruce’s involvement in
the Canadian life sciences industry coupled with his investment banking experience as Vice President and Director of Dominick & Dominick Securities Canada and his corporate governance knowledge gained
through a decade of leading a TSX Venture listed company will be valuable in leading the Board of Directors of XORTX.

Dr. Allen Davidoff, XORTX’s founder and CEO stated, “Bruce Rowlands has been an excellent director and supporter of XORTX for several years and expanding his role with XORTX is a natural transition. This
expanded role will permit him to bring his broad capital markets and extensive pharmaceutical industry talents to the benefit of the XORTX. I look forward to working with Bruce to grow the Company and
increase the focus on future value creation.”

About XORTX Therapeutics Inc.
XORTX Therapeutics Inc. is a biopharmaceutical company focused on developing innovative therapies to treat progressive kidney disease. XORTX has lead programs to develop treatments for progressive
kidney disease due to diabetes, diabetic nephropathy and polycystic kidney disease. Secondary programs focus on developing therapies for health consequences that accompany pre-diabetes, diabetes
and cardiovascular disease. Additional information on XORTX Therapeutics is available at www.XORTX.com.

For further information, please contact: Erik Matthews, Corporate Communications & Investor Relations
+1-747-203-5240 or erik@xortx.com /  ray@xortx.com

The CSE has neither approved nor disapproved the contents of this news release. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information
contained herein.