X0306 4 2017-04-10 0001228627 REXAHN PHARMACEUTICALS, INC. RNN 0001316420 Ahn Chang Ho C/O REXAHN PHARMACEUTICALS, INC. 15245 SHADY GROVE ROAD, SUITE 455 ROCKVILLE MD 20850 true Common Stock 2017-04-10 4 M 0 250000 0.31 A 6260000 D Common Stock 2017-04-10 4 S 0 250000 0.7015 D 6010000 D Common Stock 500000 I By spouse Stock Option (right to purchase) 0.31 2017-04-10 4 M 0 250000 0 D 2023-03-01 Common Stock 250000 0 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 17, 2016. The price of $0.7015 per share represents a weighted average. The shares were sold in multiple transactions at prices ranging from $0.70 to $0.709 per share, inclusive. The reporting person undertakes to provide upon request of the staff of the Securities and Exchange Commission, the issuer, or any security holder of the issuer, full information regarding the number of shares sold at each separate price within the range set forth herein. The reporting person disclaims beneficial ownership of these securities, and this report shall not be deemed an admission that the reporting person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose. The options vested and became exercisable based on the following schedule: 75,000 on March 1, 2014, 75,000 on March 1, 2015 and 100,000 on March 1, 2016. /s/ Tae Heum Jeong, as attorney-in-fact for Chang Ho Ahn 2017-04-12