Commitment and Contingencies Sponsored Research Agreement Commitments In April 2017, the Company entered into a sponsored research agreement with a university pursuant to which the Company and the university are conducting a research program related to understanding the mechanisms of failed long-term adaptive immunity in WHIM patients. Under the terms of the agreement, the Company agreed to provide funding for the research program of up to $499 thousand over a three years period. The agreement will remain in effect for three years, unless earlier terminated. The Company may terminate the agreement at any time upon at least 60 days prior written notice. For the years ended December 31, 2019, 2018, and 2017, the Company incurred $166 thousand, $166 thousand and $111 thousand, respectively, of research and development expenses related to its payment obligations to the university under the agreement. As of December 31, 2019, the Company had non-cancelable purchase commitments under this agreement totaling $55 thousand committed in 2020. In May 2019, the Company amended its agreement with a clinical research organization (CRO) pursuant to which the Company and the CRO are conducting a global Phase 3 clinical trial of mavorixafor for the treatment of WHIM syndrome. The Company may terminate the agreement by providing 30 days notice and if such termination occurred, the Company would incur early termination fees of up to $0.6 million based on a percentage of committed resources of the CRO as of the termination. Indemnification Agreements In the ordinary course of business, the Company may provide indemnification of varying scope and terms to vendors, lessors, business partners and other parties with respect to certain matters including, but not limited to, losses arising out of breach of such agreements or from intellectual property infringement claims made by third parties. In addition, the Company has entered into indemnification agreements with members of its board of directors and its executive officers that will require the Company to, among other things, indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is, in many cases, unlimited. To date, the Company has not incurred any material costs as a result of such indemnification obligations. The Company is not currently aware of any indemnification claims and has not accrued any liabilities related to such obligations in its consolidated financial statements as of December 31, 2019 or December 31, 2018. License Agreements In February 2017, Arsanis entered into an option and license agreement with Adimab to obtain rights to certain RSV antibodies, which are being used in the ASN500 program. The Company exercised this option for an up-front payment of $250 thousand. In July 2019, as further described in Note 16, the Company transferred the intellectual property related to the ASN500 program through an exclusive, worldwide license with a third party. The Company remains obligated to make payments to Adimab based on future clinical and regulatory milestones of up to approximately $25.0 million, as well as royalty payments on a product-by-product and country-by-country basis of a mid-single-digit percentage based on net sales of products based on certain RSV antibodies during the applicable term for such product in that country. The third party is required to fund any future payments that may become due to Adimab. Legal Proceedings The Company is not a party to any litigation and does not have contingency reserves established for any litigation liabilities. At each reporting date, the Company evaluates whether or not a potential loss amount or a potential range of loss is probable and reasonably estimable under the provisions of the authoritative guidance that addresses accounting for contingencies. The Company expenses as incurred the costs related to such legal proceedings.