SELLAS Life Sciences Group (SLS) Proxy Filing summary

Executive summary

• Annual meeting scheduled for June 17, 2025, to be held virtually for shareholder participation.

• Shareholders are encouraged to review proxy materials and vote by June 16, 2025.

Voting matters and shareholder proposals

• Election of two Class III directors for a three-year term expiring at the 2028 annual meeting.

• Ratification of Moss Adams LLP as independent auditor for fiscal year ending December 31, 2025.

• Approval of amendment to the 2021 Employee Stock Purchase Plan to increase available shares by 800,000.

• Advisory approval of executive compensation and recommendation on frequency of future say-on-pay votes (one year recommended).

• Approval to allow postponement or adjournment of the meeting to solicit additional proxies or establish a quorum.

Board of directors and corporate governance

• Nominees for Class III director positions are Angelos M. Stergiou and John Varian.