Salarius Pharmaceuticals Achieves Dosing Milestone in Ongoing Phase 1/2 Sarcoma Trial

Ewing sarcoma arm advances to second lead-in safety dosing cohort in Sarcoma trial evaluating seclidemstat in combination with chemotherapy agents in patients with relapsed/refractory Ewing sarcoma and as a single-agent therapy in FET-rearranged sarcomasHOUSTON, Dec. 29, 2021 (GLOBE NEWSWIRE) — Salarius Pharmaceuticals, Inc. (Nasdaq: SLRX), a clinical-stage biopharmaceutical company developing potential new medicines for patients with sarcomas, pediatric cancers, today announced an important dosing milestone in the Phase 1/2 Sarcoma clinical trial evaluating seclidemstat as a treatment for Ewing sarcoma and other FET-rearranged sarcomas. The trial’s Ewing sarcoma patient arm investigating seclidemstat in combination with chemotherapy agents topotecan and cyclophosphamide (TC) has advanced to the second lead-in safety cohort treating patients with seclidemstat at 900 mg BID in combination with topotecan and cyclophosphamide. Salarius continues to enroll patients with FET-rearranged sarcomas in a separate trial arm investigating single-agent seclidemstat administered at a 900 mg BID dose. Seclidemstat is a novel, oral, reversible inhibitor of the lysine-specific histone demethylase 1 enzyme (LSD1), an enzyme that has been shown to play a key role in the development and progression of certain cancers. “Advancing to the 900 mg safety lead-in cohort in the Ewing sarcoma trial arm marks the latest milestone in what has been a productive year for our clinical programs investigating seclidemstat,” stated David Arthur, CEO of Salarius Pharmaceuticals. “During the past several months, we have almost doubled the number of active trial sites participating in the Sarcoma clinical trial. Meanwhile, enrollment continues across all patient groups, and we continue to anticipate potential data readouts in 2022.” The Phase 1/2 Sarcoma trial is an open label study exploring the safety and efficacy of seclidemstat in three patient groups. Patients with Ewing sarcoma, a deadly pediatric bone cancer, are receiving seclidemstat in combination with topotecan and cyclophosphamide as a second- and third-line treatment. The other patient arms are investigating seclidemstat as a single-agent therapy in patients with myxoid liposarcoma and other FET-rearranged sarcomas. Patient recruitment for the Sarcoma trial is now occurring at 13 clinical trial sites across the U.S. These sites include Children’s Hospital of Los Angeles (Los Angeles, CA); Cleveland Clinic (Cleveland OH), Fox Chase Cancer Center (Philadelphia, PA), Dana-Farber Cancer Institute (Boston, MA); Johns Hopkins All Children’s Hospital (St. Petersburg, FL); MD Anderson Cancer Center (Houston, TX); Memorial Sloan Kettering Cancer Center (New York, NY); Moffitt Cancer Center (Tampa, FL); Nationwide Children’s Hospital (Columbus, OH); Oncology Consultants (Houston, TX); Sarcoma Oncology Center (Santa Monica, CA); Virginia Cancer Specialists (Fairfax, VA) and Washington University (St. Louis, MO). About Salarius Pharmaceuticals Salarius Pharmaceuticals, Inc. is a clinical-stage biopharmaceutical company developing cancer therapies for patients in need of new treatment options. Salarius’ lead candidate, seclidemstat, is being studied as a potential treatment for pediatric cancers, sarcomas, and other cancers with limited treatment options. Seclidemstat is currently in a Phase 1/2 clinical trial for relapsed/refractory Ewing sarcoma and select, additional sarcomas that share a similar biology to Ewing sarcoma, also referred to as Ewing-related or FET-rearranged sarcomas. Seclidemstat has received Fast Track Designation, Orphan Drug Designation, and Rare Pediatric Disease Designation for Ewing sarcoma from the U.S. Food and Drug Administration. Salarius is also exploring seclidemstat’s potential in several cancers with high unmet medical need, with a second Phase 1/2 clinical study initiated by MD Anderson Cancer Center in hematologic cancers. Salarius has received financial support from the National Pediatric Cancer Foundation to advance the Ewing sarcoma clinical program and was also a recipient of a Product Development Award from the Cancer Prevention and Research Institute of Texas (CPRIT). For more information, please visit salariuspharma.com or follow Salarius on Twitter and LinkedIn. Forward-Looking Statements   This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical facts, included in this press release are forward-looking statements. These forward-looking statements may be identified by terms such as “aim,” “anticipate,” “believe,” “can,” “continue,” “developing,” “estimate,” “expect,” “look forward to,” “opportunity,” “potential,” “progress,” “could prove,” “plan,” “position,” “potential,” “suggest,” “will,” and similar terms or expressions or the negative thereof. Examples of such statements include, but are not limited to, statements relating to the following: the value of seclidemstat as an alternative treatment for Ewing sarcoma, Ewing-related sarcomas and other cancers; the effectiveness of seclidemstat when compared to other LSD1 inhibitors; expanding the scope of the Company’s research and focus to high unmet need patient populations; the status and anticipated progress and milestones of the company’s current and future clinical trials, including timing of data readouts; initiating additional clinical programs in new indications; the number of clinical trial sites and the Company’s expectation or plans to add new sites; any outcomes or results from the Company’s current and future partnerships; and the use of seclidemstat in combination with chemotherapy agents. Salarius may not actually achieve the plans, carry out the intentions or meet the expectations or objectives disclosed in the forward-looking statements. You should not place undue reliance on these forward-looking statements. These statements are subject to risks and uncertainties which could cause actual results and performance to differ materially from those discussed in the forward-looking statements. These risks and uncertainties include, but are not limited to, the following: the sufficiency of the company’s capital resources; the ability of, and need for, the company to raise additional capital to meet the company’s business operational needs and to achieve its business objectives and strategy; the company’s ability to project future capital needs and cash utilization and timing and accuracy thereof; the ability of the company to access the remaining funding available under the CPRIT grant; future clinical trial results and impact of results on the company; that the results of studies and clinical trials may not be predictive of future clinical trial results; the sufficiency of Salarius’ intellectual property protection; risks related to the drug development and the regulatory approval process; the competitive landscape and other industry-related risks; market conditions and regulatory or contractual restrictions which may impact the ability of Salarius to raise additional capital; the possibility of unexpected expenses or other uses of Salarius’ cash resources; risks related to the COVID-19 outbreak; and other risks described in Salarius’ filings with the Securities and Exchange Commission, including those discussed in the company’s quarterly report on Form 10-Q for the quarter ended September 30, 2021 and in the company’s annual report on Form 10-K for the year ended December 31, 2020. The forward-looking statements contained in this press release speak only as of the date of this press release and are based on management’s assumptions and estimates as of such date. Salarius disclaims any intent or obligation to update these forward-looking statements to reflect events or circumstances that exist after the date on which they were made.  ContactTiberend Strategic Advisors, Inc. Maureen McEnroe, CFA (Investors)(212) 375-2664 [email protected] Johanna Bennett (Media)(212) 375-2686 [email protected]