X0306 4 2017-03-15 0 0001422142 Aerpio Pharmaceuticals, Inc. NONE 0001609405 Khuong Chau Quang C/O AERPIO PHARMACEUTICALS, INC. 9987 CARVER ROAD, SUITE 420 CINCINNATI OH 25242 1 0 1 0 Common Stock 2017-03-15 4 P 0 762995 5.00 A 4416446 I See Footnotes These shares are held of record by OrbiMed Private Investments V, LP ("OPI V"). OrbiMed Capital GP V LLC ("GP V") is the sole general partner of OPI V, and OrbiMed Advisors LLC ("Advisors"), a registered adviser under the Investment Advisers Act of 1940, as amended, is the sole managing member of GP V. Samuel D. Isaly ("Isaly"), a natural person, is the managing member of, and holder of a controlling interest in, Advisors. By virtue of such relationships, GP V, Advisors and Isaly may be deemed to have voting and investment power with respect to the securities held by OPI V noted above and as a result may be deemed to have beneficial ownership over such securities. The Reporting Person is an employee of Advisors. Each of GP V, Advisors, Isaly and the Reporting Person disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its or his pecuniary interest therein, if any. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose. /s/Chau Khuong 2017-03-17