Salarius Completes FDA Type B Meeting for Seclidemstat Ewing Sarcoma Development Program

FDA briefing included new Ewing sarcoma clinical data from ongoing investigation where 60% of first-relapse patients achieved disease control and have not progressed after at least 14.5, 19.7 and 22.8 months

Future development activities were identified; Salarius intends to submit an amended Ewing sarcoma clinical trial protocol

HOUSTON, Nov. 07, 2023 (GLOBE NEWSWIRE) — Salarius Pharmaceuticals, Inc. (Nasdaq: SLRX) announces that it participated in a Type B End-of-Phase 2 (EOP2) meeting with the U.S. Food and Drug Administration (FDA) to receive guidance regarding the development program for seclidemstat to treat Ewing sarcoma. The Company has received the final meeting minutes and is amending the current clinical trial protocol to reflect guidance agreed to with FDA during the EOP2 meeting.

As previously reported on August 8, 2023, the Company retained Canaccord Genuity, LLC to lead a comprehensive review of strategic alternatives focusing on maximizing shareholder value including, but not limited to, an acquisition, merger, reverse merger, divestiture of assets, licensing or other strategic transactions involving the Company. Those activities are on-going and Salarius does not expect to disclose developments with respect to this process unless and until the evaluation of strategic alternatives has been completed or the Board of Directors has concluded that disclosure is appropriate or legally required. While these efforts are on-going, the Company continues to support the continuation of its protein inhibition and protein degradation programs as appropriate.

“Our objective in meeting with the FDA was to gain clarity on next steps and the potential approval pathway for seclidemstat, topotecan and cyclophosphamide combination therapy for the treatment of first-relapse Ewing sarcoma patients, a patient population in dire need of better therapeutic options,” said David Arthur, President and CEO of Salarius Pharmaceuticals. “We accomplished our objective and appreciate the FDA’s clear and thoughtful advice.”

Based on the advice received from the FDA and the new clinical data Salarius shared during the meeting process, Salarius is preparing an amendment to the Ewing sarcoma clinical trial protocol and plans to submit the amended protocol in the coming months. Salarius is currently evaluating strategic options to advance the clinical development of seclidemstat with a third party. The Company believes that the guidance provided by the FDA will support continued development by a potential partner or acquirer.

The Company-sponsored Ewing sarcoma clinical trial focuses on seclidemstat in combination with topotecan and cyclophosphamide (TC) chemotherapy as a treatment for relapsed and refractory Ewing sarcoma. As of June 2023, a total of 13 relapsed Ewing sarcoma patients, including five patients with first relapse and eight patients with second relapse, were enrolled at seclidemstat doses of 600 mg or 900 mg twice daily in combination with TC chemotherapy.

• The five first-relapse patients demonstrated a 40% objective response rate (ORR) and a 60% disease control rate (DCR) including a complete response, partial response and stable disease. Among the three patients achieving DCR, the median progression-free survival (mPFS) has not been reached with these patients still having disease control at 14.5, 19.7 and 22.8 months, and increasing, after starting seclidemstat + TC combination treatment.
• The eight second-relapse patients demonstrated a 12.5% ORR, a 25% DCR, and a mPFS of 1.6 months (range: 0.0 months to 10.7 months).
• The 13 first- and second-relapse patients, combined, demonstrated a median survival of 8.1 months (range: 2.0 months to 22.8 months). Five patients, or 38%, achieved confirmed disease control and progression has not been observed in any of these confirmed disease control patients while on study.

Seclidemstat is a novel oral reversible inhibitor of the LSD1 enzyme and has received fast track, orphan drug and rare pediatric disease designations for Ewing sarcoma from the FDA. In addition to the Ewing sarcoma clinical trial, Salarius is also exploring seclidemstat’s potential in several cancers with high unmet medical need, with an investigator-initiated Phase 1/2 clinical study in hematologic cancers at MD Anderson Cancer Center.

About Salarius Pharmaceuticals
Salarius Pharmaceuticals, Inc. is a clinical-stage biopharmaceutical company developing therapies for patients with cancer in need of new treatment options. Salarius’ product portfolio includes seclidemstat, Salarius’ lead candidate, which is being studied as a potential treatment for pediatric cancers, sarcomas and other cancers with limited treatment options, and SP-3164, an oral small molecule protein degrader being developed for the treatment of non-Hodgkin’s lymphoma. Salarius has received financial support from the National Pediatric Cancer Foundation to advance the Ewing sarcoma program and was 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 “will,” “believe,” “developing,” “expect,” “may,” “progress,” “potential,” “could,” “look forward,” “encouraging,” “might,” “should,” and similar terms or expressions or the negative thereof. Examples of such statements include, but are not limited to, statements relating to the following: Salarius’ expectations regarding the exploration of strategic alternatives, opportunities to extend Salarius’ resources, the future of the Company’s operations and product candidates; the future of the Company’s preclinical studies and clinical trials and development activities; the advantages of protein degraders including the value of SP-3164 as a cancer treatment; the value of seclidemstat as a treatment for Ewing sarcoma, Ewing-related sarcomas, and other cancers and its ability to improve the life of patients;. Salarius may not actually achieve the plans, carry out the intentions or meet the expectations or objectives disclosed in these 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 risk that exploration of strategic alternatives may not result in any definitive transaction or enhance stockholder value and may create a distraction or uncertainty that may adversely affect our operating results, business, or investor perceptions; expectations regarding future costs and expenses; our product candidates being in early stages of development; the uncertainty about the paths of our programs and our ability to evaluate and identify a path forward for those programs, particularly given the constraints we have as a small company with limited financial, personnel and other operating resources (including with respect to the allocation of our limited capital and the sufficiency of our capital in the near term for any path we do select); Salarius’ ability to continue as a going concern; the sufficiency of Salarius’ capital resources; availability of suitable third parties with which to conduct contemplated strategic transactions; whether the Company will be able to pursue a strategic transaction, or whether any transaction, if pursued, will be completed successfully and on attractive terms or at all; whether our cash resources will be sufficient to fund the Company’s foreseeable and unforeseeable operating expenses and capital requirements; changes in the Company’s operating plans that may impact its cash expenditures; the uncertainties inherent in research and development, future clinical data and analysis; the risks associated with reductions in workforce, including reduced morale and attrition of additional employees necessary for the strategic reprioritization; future clinical trial results and the impact of such results on Salarius; that the results of studies and clinical trials may not be predictive of future clinical trial results; the competitive landscape and other industry-related risks; and other risks described in Salarius’ filings with the Securities and Exchange Commission, including its Annual Report on Form 10-K for the fiscal year ended December 31, 2022, as revised or supplemented by its Quarterly Reports on Form 10-Q and other documents filed with the SEC. 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.

Contact:

LHA Investor Relations
Kim Sutton Golodetz
kgolodetz@lhai.com
212-838-3777