APPN Appian Corporation

Item 1.01 Entry into a Material Definitive Agreement.

On April 17, 2018, Appian Corporation (the “Company”), as tenant, and Tamares 7950 Owner LLC, as landlord (“Landlord”), entered into a Deed of Lease (the “Lease”) for certain premises consisting of approximately 176,222 square feet of space in an office building located at 7950 Jones Branch Drive, Tysons, Virginia 22102 (the “Premises”), to serve as the Company’s new corporate headquarters.

The Company can take possession of the Premises for purposes of building tenant improvements as early as October

1, 2018 or as late as December 1, 2018. The initial term of the Lease will commence no later than May 1, 2019, when the Company takes occupancy following the completion of such tenant improvements to the Premises, and expires 150 months later, unless earlier terminated, with an option to extend the Lease term for two consecutive five-year periods. No annual rent is due for the first 15 months of the initial term of the Lease, after which time the monthly base rent will be $450,835, subject to a 3% annual increase. If the initial term of the Lease is extended for one or both of the optional five-year periods, the rent will be adjusted based on fair market rental value. Within 12 months of the commencement of the initial term of the Lease, an additional 28,805 square feet of adjacent office space will be added to the Premises (the “Must-Take Space”). No annual rent is due for a prorated period of time following the addition of the Must-Take Space to the Premises, after which time the monthly base rent for the Must-Take Space will be $73,693, subject to a 3% annual increase. The Company will receive parking permits in accordance with the size of the Premises and will pay a monthly fee of approximately $87 per parking permit beginning 73 months following the commencement of the initial term of the Lease, subject to a 2.5% annual increase beginning 85 months following the commencement of the initial term of the Lease. The Company also has agreed to pay a portion of taxes and operating expenses paid or accrued in connection with the ownership of the Premises. The Landlord has agreed to make certain tenant improvement payments to the Company for purposes of defraying the Company’s cost to build out the Premises, the Must-Take Space and any other space leased by the Company pursuant to the Lease.

Provided that certain conditions are met, the Company has a right of first refusal to lease any vacant space located in the same building as the Premises and has the express right to expand the Premises to include up to three additional adjacent floors of office space, containing approximately 91,673 square feet of space in aggregate, as further described in the Lease. The Lease includes customary provisions providing for late fees for unpaid rent, Landlord access to the Premises, insurance obligations and events of default.

The foregoing description of the terms of the Lease does not purport to be complete and is qualified in its entirety by reference to the full text of the Lease, a copy of which is attached hereto as Exhibit 10.1.