Third Amendment to Lease, dated January 26, 2024, by and between the Company and AG-LC 465 North Halstead Owner, L.P

THIS THIRD AMENDMENT TO LEASE (“Third Amendment”) is made and entered into as of the 26th day of January, 2024, by and between AG-LC 465 NORTH HALSTEAD OWNER, L.P., a Delaware limited partnership (“Landlord”) and XENCOR, INC., a Delaware corporation (“Tenant”).

1.Landlord and Tenant entered into that certain Lease dated as of April 30, 2021 (the “Original Lease”), as modified by (i) that certain First Amendment to Lease dated as of July 13, 2021 by and between Landlord and Tenant (“First Amendment”), and (ii) that certain Second Amendment to Lease dated as of August 2, 2022 by and between Landlord and Tenant (“Second Amendment”), whereby Landlord leased to Tenant and Tenant leased from Landlord certain space located in that certain building located and addressed at 465 North Halstead Street, Pasadena, California (the “Building”). The Original Lease, as modified by the First Amendment and the Second Amendment, may be referred to herein as the “Lease.”

2.By this Third Amendment, Landlord and Tenant desire to memorialize Landlord’s and Tenant’s agreement regarding the upgrade of the Building’s HVAC system and to otherwise modify the Lease as provided herein.

3.Unless otherwise defined herein, capitalized terms as used herein shall have the same meanings as given thereto in the Lease.

NOW, THEREFORE, in consideration of the foregoing recitals and the mutual covenants contained herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto hereby agree as follows:

1.HVAC Work. Landlord shall engage a California licensed, reputable HVAC contractor (the “Contractor”) to perform upgrades to the base building HVAC system of the Building (the “HVAC Work”). Such HVAC Work is more particularly described in the HVAC scope of work attached hereto as Exhibit A (the “HVAC Scope of Work”). Landlord shall cause the HVAC Work to be performed in a good and workmanlike manner in compliance with applicable Law. All of the costs and expenses pertaining to the HVAC Work is referred to herein as the “HVAC Work Costs.” A schedule of the estimated HVAC Work Costs is set forth on Exhibit B. As used herein, “Tenant’s Contribution” shall mean an amount equal to seventy-five percent (75%) of the actual HVAC Work Costs. Tenant’s Contribution shall be paid as follows: (i) twenty-five percent (25%) of Tenant’s Contribution (in the estimated amount of Three Hundred Fifty-Eight Thousand Two Hundred Eighteen Dollars ($358,218.00)) shall be paid by Tenant to Landlord concurrently with Tenant’s execution and delivery of this Third Amendment to Landlord, and (ii) the remaining balance of Tenant’s Contribution (in the

estimated amount of Seven Hundred Sixteen Thousand Four Hundred Thirty-Seven Dollars ($716,437.00)) shall be paid from the Phase 2 Tenant Improvement Allowance (as defined in the Tenant Work Letter), with Landlord deducting from the Phase 2 Tenant Improvement Allowance Tenant’s remaining balance of Tenant’s Contribution. In furtherance of the foregoing, Tenant hereby authorizes Landlord, during the course of the HVAC Work, to disburse from the Phase 2 Tenant Improvement Allowance the HVAC Work Costs owed by Tenant (beyond the initial twenty-five percent (25%) contribution paid for by Tenant toward the HVAC Work Costs). Landlord shall pay for the remaining twenty-five percent (25%) of the HVAC Work Costs (in an estimated amount equal to Three Hundred Fifty-Eight Thousand Two Hundred Eighteen Dollars ($358,218.00), at Landlord’s sole cost and expense. The estimated costs set forth above are set forth in Exhibit B. Upon completion of the HVAC Work and once the final costs of the HVAC Work are determined, Landlord shall reconcile the total HVAC Work Costs to confirm that each party has paid its share of the HVAC Work Costs.

2.Other Costs. As provided in Exhibit B, Landlord shall, at Landlord’s sole cost and expense, be responsible for the POD C Compressor Upgrade (estimated cost to be One Hundred Five Thousand Ninety-Nine Dollars ($105,099.00) in the aggregate, provided that if the actual cost of the POD C Compressor Upgrade exceeds such estimated cost, any such excess cost shall be borne solely by Landlord).

3.Temporary HVAC Costs. Landlord and Tenant acknowledge and agree that Landlord, prior to the date hereof, provided temporary HVAC service to the Premises. Concurrently with Tenant’s execution and delivery of this Third Amendment to Landlord, Tenant shall pay to Landlord an amount equal to One Hundred Thirty-Six Thousand Nine Hundred Sixteen Dollars ($136,916), which amount represents fifty percent (50%) of such temporary HVAC costs incurred by Landlord.

4.Authority. Each party represents and warrants that it has full right and authority to enter into this Third Amendment and to perform all of its obligations hereunder and that all persons signing this Third Amendment on its behalf are authorized to do so.

5.Brokers. Each party represents and warrants to the other that no broker, agent or finder negotiated or was instrumental in negotiating or consummating this Third Amendment. Each party further agrees to defend, indemnify and hold harmless the other party from and against any claim for commission or finder’s fee by any person or entity who claim or allege that they were retained or engaged by the indemnifying party or at the request of such party in connection with this Third Amendment.

6.Signatures. The parties hereto consent and agree that this Third Amendment may be signed and/or transmitted by facsimile, e-mail of a .pdf document or using electronic signature technology (e.g., via DocuSign or similar electronic signature technology), and that such signed electronic record shall be valid and as effective to bind the party so signing as a paper copy bearing such party’s handwritten signature. The parties further consent and agree that (1) to the extent a party signs this Third Amendment using electronic signature technology, by clicking “SIGN”, such party is signing this Third Amendment electronically, and (2) the electronic

signatures appearing on this Third Amendment shall be treated, for purposes of validity, enforceability and admissibility, the same as handwritten signatures.

7.Defaults. Tenant hereby represents and warrants to Landlord that, as of the date of this Third Amendment, Tenant is in full compliance with all terms, covenants and conditions of the Lease and that there are no breaches or defaults under the Lease by Landlord or Tenant, and that Tenant knows of no events or circumstances which, given the passage of time, would constitute a default under the Lease by either Landlord or Tenant. Landlord hereby represents and warrants to Tenant that, as of the date of this Third Amendment, Landlord is in full compliance with all terms, covenants and conditions of the Lease and that there are no breaches or defaults under the Lease by Landlord or Tenant, and that Landlord knows of no events or circumstances which, given the passage of time, would constitute a default under the Lease by either Landlord or Tenant.