X0306 4 2018-03-13 0 0001390478 SELLAS Life Sciences Group, Inc. SLS 0001724253 Stergiou Angelos M. C/O SELLAS LIFE SCIENCES GROUP, INC. 315 MADISON AVENUE, 4TH FLOOR NEW YORK NY 10017 1 1 0 0 President and CEO Stock Option (Right to Buy) 5.24 2018-03-13 4 A 0 95000 0.00 A 2028-03-12 Common Stock 95000 95000 D One-quarter (1/4) of the option shares will vest and became exercisable one year from the March 13, 2018 grant date, and the remainder will vest and become exercisable in equal monthly installments for thirty-six (36) months thereafter, provided that the Reporting Person remains in service with the Issuer through each such monthly vesting date. Angelos M. Stergiou, by /s/ Ron A. Metzger, Attorney-in-Fact 2018-03-15