CytomX Therapeutics, Inc.

The information set forth below is included for the purpose of providing disclosure under “Item 1.01 - Entry into a Material Definitive Agreement,” of Form 8-K.

On November 3, 2025, we entered into an Office/Laboratory Lease (the “Emery Lease” or the "Lease") with Emery Station West, LLC (the “Landlord”). The Emery Lease provides for an initial term of thirty-nine (39) calendar months, commencing on October 1, 2026 and expiring on December 31, 2029 (the “Term”), unless earlier terminated pursuant to its terms. In October 2026, the facility will begin serving as our relocated headquarters and primary office, research and laboratory space.

The Lease provides for an initial monthly base rent of approximately $151,232.00 (the “Base Rent”). The Base Rent under the Lease is abated for the first three (3) months of the Term and thereafter increases on a scheduled basis through the end of the Term. In addition to the Base Rent, we will also be responsible for our proportionate share of the building’s operating expenses, including taxes, insurance and maintenance costs, in accordance with the terms of the Lease. In connection with the Lease, we will deliver to the Landlord a letter of credit as a security deposit, subject to reduction as set forth in the Lease.

We also hold certain rights under the Lease, including a continuous right of first refusal to lease any space located on the fourth floor of the building.

The foregoing description of the Emery Lease does not purport to be complete and is qualified in its entirety by reference to the full text of the Emery Lease, a copy of which is filed as Exhibit 10.2 to this Quarterly Report on Form 10-Q and incorporated herein by reference.