Acquisition | MERSANA THERAPEUTICS INC | 6th January 2026

Initially announced on November 13, 2025 DAY ONE BIOPHARMACEUTICALS I made a cash offer for MERSANA THERAPEUTICS INC of USD 25 and one CVR for each share held. per MERSANA THERAPEUTICS INC share held. Pending the completion of customary closing conditions, the Acquisition is expected to be completed on January 6, 2026. Trading in shares of MERSANA THERAPEUTICS INC is expected to be halted effective January 6, 2026. Due to the presence of a CVR in the offer, Solactive will remove MERSANA THERAPEUTICS INC at its last close price effective January 6, 2026 (open).

The treatment below will be applied to the following indices:

• MERSANA THERAPEUTICS INC will be removed from the Index.
• The weight of MERSANA THERAPEUTICS INC (MRSN.OQ) based on its last close price will be distributed pro rata to remaining Index constituents.
• Effective Date (open): 06/01/2026

Solactive US Extended Broad Market Index (GTR)