Exicure Reports Activity of AST-008 in Patients with Merkel Cell Carcinoma and Will Enroll Patients in Phase 2 Study

– Phase 1b/2 dose escalation trial of AST-008 shows tolerability of Exicure drug candidate

– Preliminary data show signs of activity in patients with Merkel cell carcinoma

– Exicure to proceed to Phase 2 study in Merkel cell carcinoma

CHICAGO & CAMBRIDGE, Mass.–(BUSINESS WIRE)–#DigitalDrugDesign–Exicure, Inc. (NASDAQ:XCUR), the pioneer in gene regulatory and immunotherapeutic drugs utilizing spherical nucleic acid (SNA™) technology, today announced an update from its Phase 1b/2 trial with AST-008 in patients with solid tumors. AST-008 is an investigational SNA consisting of toll-like receptor 9 (TLR9) agonists designed for immuno-oncology application, and is being evaluated in combination with pembrolizumab in patients with solid tumors.

“We’re very pleased with the preliminary data generated so far in our ongoing Phase 1b/2 trial and we look forward to enrolling patients in the Phase 2 portion of the trial,” said Dr. David Giljohann, CEO of Exicure. “Based on these results, we are considering adding additional cohorts to the trial in other cancers where AST-008 may have benefit,” concluded Dr. Giljohann.

The primary objective of the dose escalation portion of the study is to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of AST-008 alone and in combination with pembrolizumab, and to produce a recommended Phase 2 dose. Fourteen patients have been enrolled and dosed with AST-008. No treatment-related serious adverse events or dose-limiting toxicities have been observed. The fifth and final dose escalation cohort is now open and enrolling.

The study has enrolled five melanoma patients, four Merkel cell carcinoma (MCC) patients, two cutaneous squamous cell carcinoma patients, two head and neck squamous cell carcinoma patients, and one mucosal melanoma patient. Prior to enrolling, most patients had progressive disease on anti-PD-(L)1 antibodies.

Available data show:

• AST-008 administration, alone or in combination with pembrolizumab, produced cytokine and chemokine expression and immune cell activation in patient blood indicative of desired immune activation.
• Of the 4 MCC patients, one patient, which had previously progressed on anti-PD-1 antibody therapy, has confirmed stable disease with decreased target lesion diameters for a period in excess of twelve weeks, while a second MCC patient experienced a target lesion complete response and a confirmed overall partial response longer than 24 weeks.
• Nine patients had progressive disease, two patients have not yet been evaluated and one is not evaluable.

“The initial results are highly encouraging and warrant expansion of the trial, and I’m looking forward to participating,” stated Dr. Steven O’Day, Executive Director of the John Wayne Cancer Institute and Cancer Clinic, and a principal investigator on the study.

Detailed results are expected to be presented at major upcoming oncology meetings. Based on these early results, showing positive biomarker data and initial tumor responses, Exicure anticipates enrolling MCC patients, which have previously failed anti PD-1/PD-L1 therapy, in its Phase 2 study during the first quarter of 2020.

About Exicure, Inc.

Exicure, Inc. is a clinical-stage biotechnology company developing therapeutics for immuno-oncology, inflammatory diseases and genetic disorders based on our proprietary Spherical Nucleic Acid, or SNA technology. Exicure believes that its proprietary SNA architecture has distinct chemical and biological properties that may provide advantages over other nucleic acid therapeutics and may have therapeutic potential to target diseases not typically addressed with other nucleic acid therapeutics. Exicure’s lead program is in a Phase 1b/2 trial in patients with advanced solid tumors. Exicure is based outside of Chicago, IL and in Cambridge, MA.

For more information, visit Exicure’s website at www.exicuretx.com.

Exicure Forward-Looking Statements

This press release contains forward-looking statements (including within the meaning of Section 21E of the United States Securities Exchange Act of 1934, as amended, and Section 27A of the United States Securities Act of 1933, as amended) concerning the Company, the Company’s technology, potential therapies (including AST-008 and its potential clinical results), potential studies, and other matters. Forward-looking statements generally include statements that are predictive in nature and depend upon or refer to future events or conditions, and include words such as “may,” “will,” “should,” “would,” “expect,” “plan,” “believe,” “intend,” “look forward,” and other similar expressions among others. Statements that are not historical facts are forward-looking statements. Forward-looking statements are based on current beliefs and assumptions that are subject to risks and uncertainties and are not guarantees of future performance. Actual results could differ materially from those contained in any forward-looking statement as a result of various factors, including, without limitation: unexpected costs, charges or expenses that reduce cash runway; that Exicure’s pre-clinical or clinical programs do not advance or result in approved products on a timely or cost effective basis or at all; the cost, timing and results of clinical trials; that many drug candidates that have completed Phase 1 trials do not become approved drugs on a timely or cost effective basis or at all; the ability to enroll patients in clinical trials; possible safety and efficacy concerns; regulatory developments; and the ability of Exicure to protect its intellectual property rights. Risks facing the Company and its programs are set forth in the Company’s filings with the SEC. Except as required by applicable law, the Company undertakes no obligation to revise or update any forward-looking statement or to make any other forward-looking statements, whether as a result of new information, future events or otherwise.

Contacts

MacDougall

Karen Sharma

781-235-3060

[email protected]