X0306 4 2019-08-09 0 0001710340 Eton Pharmaceuticals, Inc. ETON 0001117167 CASAMENTO CHARLES J 21925 W FIELD PKWY #235 DEER PARK IL 60010 1 0 0 0 Common Stock 2019-08-09 4 P 0 3500 6.1057 A 71920 D The range of purchase prices paid is $6.10 to $6.11. Upon request by the SEC staff, the Issuer, or any security holder of the Issuer, full information will be provided regarding the number of shares purchased or sold at each separate price. /s/ W. Wilson Troutman, Attorney-in-fact 2019-08-12