Commitments and Contingencies	12 Months Ended
Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings On December 13, 2021, Mark Colwell filed a putative securities class action lawsuit against the Company, David A. Giljohann and Brian C. Bock in the United States District Court for the Northern District of Illinois, captioned Colwell v. Exicure, Inc. et al., Case No. 1:21-cv-0663. On February 4, 2021, plaintiff filed an amended putative securities class action complaint. On March 20, 2023, the court entered an order appointing James Mathew as lead plaintiff and Bleichmar Fonti & Auld LLP as lead counsel in the action pursuant to the Private Securities Litigation Reform Act of 1995. On May 26, 2023, lead plaintiff filed a second amended complaint against the Company, Dr. Giljohann, Mr. Bock, and Grant Corbett. The second amended complaint alleges that Dr. Giljohann, Mr. Bock, and Dr. Corbett made materially false and/or misleading statements related to the Company’s clinical programs purportedly causing losses to investors who acquired Company securities between January 7, 2021 and December 10, 2021. The second amended complaint does not quantify any alleged damages but, in addition to attorneys’ fees and costs, lead plaintiff seeks to recover damages on behalf of himself and others who acquired the Company’s stock during the putative class period at allegedly inflated prices and purportedly suffered financial harm as a result. The parties filed a joint status report noting the mediation efforts taken by the parties. The report also proposes a litigation schedule going forward, which the Court adopted: plaintiff’s third amended complaint is due on or before June 28, 2024, and any motion to dismiss is due on or before August 27, 2024, with response due on or before October 8, 2024 and any reply due on or before November 5, 2024. Accordingly, the status hearing set for May 22, 2024 is reset to July 23, 2024. On March 1, 2022, Kapil Puri filed a shareholder derivative lawsuit on behalf of the Company in the United States District Court for the Northern District of Illinois, against Dr. Giljohann and Mr. Bock, Jeffrey L. Cleland, Elizabeth Garofalo, Bosun Hau, Bali Muralidhar, Andrew Sassine, Matthias Schroff, James Sulat and Timothy Walbert, captioned Puri v. Giljohann, et al., Case No. 1:22-cv-01083. On March 8, 2022, Yixin Sim filed a similar shareholder derivative lawsuit in the same court against the same individuals, captioned Sim v. Giljohann, et al., Case No. 1:22-cv-01217. On April 25, 2022, Stourbridge Investments LLC filed a similar shareholder derivative lawsuit against the same individuals in the United States District Court for the District of Delaware, captioned Stourbridge Investments LLC v. Exicure, Inc. et al., Case No. 1:22-cv-00526. Based on similar factual allegations presented in the Colwell complaint, described above, the Puri, Sim, and Stourbridge complaints (collectively, the “Derivative Complaints”) allege that the defendants caused the Company to issue false and/or misleading statements in the proxy statement for its 2021 Annual Meeting of Stockholders regarding risk oversight, code of conduct, clinical program and compensation matters, among other things, in violation of federal securities law, and committed breaches of fiduciary duties. The Derivative Complaints also assert that Dr. Giljohann and Mr. Bock are liable for contribution under the federal securities laws. The Puri and Stourbridge complaints further assert state law claims for unjust enrichment, and the Puri complaint additionally asserts state law claims for abuse of control, gross mismanagement and corporate waste. The plaintiffs do not quantify any alleged damages in the Derivative Complaints, but seek restitution for damages to the Company, attorneys’ fees, costs, and expenses, as well as an order directing that certain proposals for strengthening board oversight be put to a vote of the Company’s shareholders. On March 18, 2022, James McNabb, through counsel, sent a written demand to the Company (the “Demand Letter”) demanding that the Board of Directors investigate certain allegations and commence proceedings on the Company’s behalf against certain of the Company’s officers and directors for alleged breaches of fiduciary duties and corporate waste. All of the Derivative Cases have been stayed pending a decision on any motion to dismiss that may be filed in the Colwell case. In addition, the Stourbridge case has been administratively closed pending the decision on motion to dismiss that may be filed in the Colwell case. Further, pursuant to agreement, the Demand Letter is being held in abeyance and any related statute of limitations tolled pending such motion and decision. On October 3, 2023, a former employee filed a complaint against the Company and its executives related to the former employee’s separation from the Company. The parties will proceed with paper discovery and an in-person settlement conference is scheduled for June 26, 2024. Leases Refer to Note 7, Leases, for a discussion of the commitments associated with the Company’s lease agreements. Northwestern University License Agreements On December 12, 2011, (1) AuraSense, LLC, the Company’s former parent, assigned to the Company all of its worldwide rights and interests under AuraSense, LLC’s 2009 license agreement with Northwestern University (“NU”) in the field of the use of nanoparticles, nanotechnology, microtechnology or nanomaterial-based constructs as therapeutics or accompanying therapeutics as a means of delivery, but expressly excluding diagnostics (the “assigned field”); (2) in accordance with the terms and conditions of this assignment, the Company assumed all liabilities and obligations of AuraSense, LLC as set forth in its license agreement in the assigned field; and (3) in order to secure this assignment and the patent rights from NU, the Company agreed (i) to pay NU an annual license fee, which may be credited against any royalties due to NU in the same year, (ii) to reimburse NU for expenses associated with the prosecution and maintenance of the license patent rights, (iii) to pay NU royalties based on any net revenue generated by the Company’s sale or transfer of any licensed product, (iv) to pay NU, in the event the Company grants a sublicense under the licensed patent rights, the greater of a percentage of all sublicensee royalties or a percentage of any net revenue generated by a sublicensee’s sale or transfer of any licensed product, and (v) to pay NU a percentage of all other sublicense payments received by the Company. In August 2015, the Company entered into a restated license agreement with NU (the “Restated License Agreement”). In February 2016, the Company obtained exclusive license as to NU’s rights in certain SNA technology it jointly owns with NU (the “Co-owned Technology License”). The Company’s license to NU’s rights is limited to the assigned field, however the Company has no such limitation as to its own rights in this jointly owned technology. The Company’s rights and obligations in the Co-owned Technology License agreement is substantially the same as in the Restated License Agreement from August 2015 (collectively referred to as “the Northwestern University License Agreements”). As of December 31, 2023, the Company has paid to NU an aggregate of $11,567 in consideration of each of the obligations described above. On August 3, 2023, the company received a notice letter (the “Letter”) from counsel for NU alleging the Company breached the Northwestern University License Agreements. The Letter alleges that a lack of development required under the Northwestern University License Agreements is a breach. The Northwestern University License Agreements were subsequently terminated on September 10, 2023 and October 3, 2023, respectively.

On December 13, 2021, Mark Colwell filed a putative securities class action lawsuit against the Company, David A. Giljohann and Brian C. Bock in the United States District Court for the Northern District of Illinois, captioned Colwell v. Exicure, Inc. et al., Case No. 1:21-cv-0663. On February 4, 2021, plaintiff filed an amended putative securities class action complaint. On March 20, 2023, the court entered an order appointing James Mathew as lead plaintiff and Bleichmar Fonti & Auld LLP as lead counsel in the action pursuant to the Private Securities Litigation Reform Act of 1995. On May 26, 2023, lead plaintiff filed a second amended complaint against the Company, Dr. Giljohann, Mr. Bock, and Grant Corbett. The second amended complaint alleges that Dr. Giljohann, Mr. Bock, and Dr. Corbett made materially false and/or misleading statements related to the Company’s clinical programs purportedly causing losses to investors who acquired Company securities between January 7, 2021 and December 10, 2021. The second amended complaint does not quantify any alleged damages but, in addition to attorneys’ fees and costs, lead plaintiff seeks to recover damages on behalf of himself and others who acquired the Company’s stock during the putative class period at allegedly inflated prices and purportedly suffered financial harm as a result. The parties filed a joint status report noting the mediation efforts taken by the parties. The report also proposes a litigation schedule going forward, which the Court adopted: plaintiff’s third amended complaint is due on or before June 28, 2024, and any motion to dismiss is due on or before August 27, 2024, with response due on or before October 8, 2024 and any reply due on or before November 5, 2024. Accordingly, the status hearing set for May 22, 2024 is reset to July 23, 2024.

On March 1, 2022, Kapil Puri filed a shareholder derivative lawsuit on behalf of the Company in the United States District Court for the Northern District of Illinois, against Dr. Giljohann and Mr. Bock, Jeffrey L. Cleland, Elizabeth Garofalo, Bosun Hau, Bali Muralidhar, Andrew Sassine, Matthias Schroff, James Sulat and Timothy Walbert, captioned Puri v. Giljohann, et al., Case No. 1:22-cv-01083. On March 8, 2022, Yixin Sim filed a similar shareholder derivative lawsuit in the same court against the same individuals, captioned Sim v. Giljohann, et al., Case No. 1:22-cv-01217. On April 25, 2022, Stourbridge Investments LLC filed a similar shareholder derivative lawsuit against the same individuals in the United States District Court for the District of Delaware, captioned Stourbridge Investments LLC v. Exicure, Inc. et al., Case No. 1:22-cv-00526. Based on similar factual allegations presented in the Colwell complaint, described above, the Puri, Sim, and Stourbridge complaints (collectively, the

“Derivative Complaints”) allege that the defendants caused the Company to issue false and/or misleading statements in the proxy statement for its 2021 Annual Meeting of Stockholders regarding risk oversight, code of conduct, clinical program and compensation matters, among other things, in violation of federal securities law, and committed breaches of fiduciary duties. The Derivative Complaints also assert that Dr. Giljohann and Mr. Bock are liable for contribution under the federal securities laws. The Puri and Stourbridge complaints further assert state law claims for unjust enrichment, and the Puri complaint additionally asserts state law claims for abuse of control, gross mismanagement and corporate waste. The plaintiffs do not quantify any alleged damages in the Derivative Complaints, but seek restitution for damages to the Company, attorneys’ fees, costs, and expenses, as well as an order directing that certain proposals for strengthening board oversight be put to a vote of the Company’s shareholders.

On March 18, 2022, James McNabb, through counsel, sent a written demand to the Company (the “Demand Letter”) demanding that the Board of Directors investigate certain allegations and commence proceedings on the Company’s behalf against certain of the Company’s officers and directors for alleged breaches of fiduciary duties and corporate waste. All of the Derivative Cases have been stayed pending a decision on any motion to dismiss that may be filed in the Colwell case. In addition, the Stourbridge case has been administratively closed pending the decision on motion to dismiss that may be filed in the Colwell case. Further, pursuant to agreement, the Demand Letter is being held in abeyance and any related statute of limitations tolled pending such motion and decision.

On December 12, 2011, (1) AuraSense, LLC, the Company’s former parent, assigned to the Company all of its worldwide rights and interests under AuraSense, LLC’s 2009 license agreement with Northwestern University (“NU”) in the field of the use of nanoparticles, nanotechnology, microtechnology or nanomaterial-based constructs as therapeutics or accompanying therapeutics as a means of delivery, but expressly excluding diagnostics (the “assigned field”); (2) in accordance with the terms and conditions of this assignment, the Company assumed all liabilities and obligations of AuraSense, LLC as set forth in its license agreement in the assigned field; and (3) in order to secure this assignment and the patent rights from NU, the Company agreed (i) to pay NU an annual license fee, which may be credited against any royalties due to NU in the same year, (ii) to reimburse NU for expenses associated with the prosecution and maintenance of the license patent rights, (iii) to pay NU royalties based on any net revenue generated by the Company’s sale or transfer of any licensed product, (iv) to pay NU, in the event the Company grants a sublicense under the licensed patent rights, the greater of a percentage of all sublicensee royalties or a percentage of any net revenue generated by a sublicensee’s sale or transfer of any licensed product, and (v) to pay NU a percentage of all other sublicense payments received by the Company. In August 2015, the Company entered into a restated license agreement with NU (the “Restated License Agreement”). In February 2016, the Company obtained exclusive license as to NU’s rights in certain SNA technology it jointly owns with NU (the “Co-owned Technology License”). The Company’s license to NU’s rights is limited to the assigned field, however the Company has no such limitation as to its own rights in this jointly owned technology. The Company’s rights and obligations in the Co-owned Technology License agreement is substantially the same as in the Restated License Agreement from August 2015 (collectively referred to as “the Northwestern University License Agreements”). As of December 31, 2023, the Company has paid to NU an aggregate of $11,567 in consideration of each of the obligations described above.