FDA removes partial clinical hold on seclidemstat Phase 1/2 trial in Ewing sarcoma; Salarius plans to meet with FDA to discuss future development and potential registration pathways

SP-3164 targeted protein degrader preclinical data presented at AACR 2023 shows compelling anticancer activity; no adverse safety signals from two good laboratory practice (GLP) toxicology studies

SP-3164 IND submission on track for second quarter of 2023; clinical trial planned for second half of 2023

HOUSTON, May 11, 2023 (GLOBE NEWSWIRE) -- Salarius Pharmaceuticals, Inc. (Nasdaq: SLRX), a clinical-stage biopharmaceutical company using protein inhibition and protein degradation to develop cancer therapies for patients in need of new treatment options, today reported financial results for the three months ended March 31, 2023 and provided a business update.

Financial Highlights

• Cash and cash equivalents were $9.3 million as of March 31, 2023, compared with $12.1 million as of December 31, 2022.
• Net loss for the first quarter of 2023 was $5.3 million, or $2.23 per share, compared with net loss for the first quarter of 2022 of $6.1 million, or $3.30 per share. The decline reflects lower spending on seclidemstat in the 2023 quarter and one-time expenses of $2.0 million related to the purchase of the targeted protein degrader program in the 2022 quarter.

“Earlier this week we announced that the U.S. Food and Drug Administration (FDA) removed its partial clinical hold on our Phase 1/2 trial with seclidemstat in patients with Ewing sarcoma. We believe this is great news for patients as the interim data we reported last December are powerful, showing a 60% confirmed disease control rate and 7.4 months median time to tumor progression for Ewing sarcoma first-relapse patients, with no disease progression observed in either first- or second-relapse patients who achieved confirmed disease control. As I mentioned earlier this week, this decision puts us back on track to engage in dialogue with the FDA on various topics relating to further clinical development of seclidemstat, as well as possible registration pathways,” said David Arthur, president and chief executive officer.

“In addition, Salarius continued to execute on plan during the first quarter of 2023 and recent weeks as we advanced the development of SP-3164, our targeted protein degrader. We are preparing to submit an Investigational New Drug, or IND, application to the FDA later this quarter, with initiation of a Phase 1 clinical trial expected to begin in the second half of the year. To that end, we have completed two GLP toxicology studies with no unexpected safety findings, and we are working to complete the remaining activities prior to submitting the IND application.

“The SP-3164 preclinical data we have been sharing at prestigious medical and scientific conferences over the past few months, including compelling antitumor activity in animal models of diffuse large B cell lymphoma (DLBCL), follicular lymphoma and multiple myeloma, suggest that SP-3164 may be useful in treating non-Hodgkin lymphomas and other hematologic cancers, alone or in combination with standard-of-care chemotherapy,” he added.   “We look forward to sharing further details of our progress in the coming months.”

First Quarter Financial Results

Research and development expenses were $3.7 million for the first quarter of 2023, compared with $4.4 million for the first quarter of 2022. Spending associated with SP-3164 and seclidemstat for the first quarter of 2023 was $2.4 million and $1.3 million, respectively, compared with $2.2 million and $2.3 million, respectively, for the first quarter of 2022. General and administrative expenses were largely flat at $1.7 million for both periods.

Net cash used for operating activities during the first quarter of 2023 was $3.2 million, compared with $3.5 million during the same quarter in 2022, with an increase in overall spending offset by the receipt of $1.5 million during the 2023 quarter from the Cancer Prevention and Research Institute of Texas.

As of March 31, 2023, Salarius had cash, cash equivalents and restricted cash of $9.3 million, compared with $12.1 million as of December 31, 2022. Current cash and cash equivalents are expected to fund the company’s planned operations through the third quarter 2023.

Seclidemstat Highlights

• The FDA removed its partial clinical hold on Salarius’ Phase 1/2 trial evaluating seclidemstat in combination with topotecan and cyclophosphamide as a potential treatment for patients with Ewing sarcoma. Seclidemstat is the company’s novel oral, reversible, targeted LSD1 inhibitor.
  
  
• Salarius presented data at the Keystone Symposia on Epigenetics suggesting that seclidemstat may have utility in treating small cell lung cancer (SCLC). In a 13 SCLC cell line panel, seclidemstat demonstrated significant anti-proliferative single-agent activity. In addition, seclidemstat demonstrated additive to synergistic activity in a subset of these cell lines when combined with current standard of care treatment options for second-line SCLC.
  
  
• The FDA has previously granted seclidemstat Fast Track Designation, Orphan Drug Designation and Rare Pediatric Disease Designation for Ewing sarcoma.
  

SP-3164 Targeted Protein Degrader Highlights

• Two abstracts were presented at the American Association for Cancer Research (AACR) Annual Meeting in April 2023:
  • One presentation demonstrated the robust protein degradation effects of SP-3164 and its anticancer activity in non-Hodgkin lymphoma (NHL) animal models. SP-3164’s compelling antitumor activity in animal models of follicular lymphoma, a type of NHL, as a single agent and in combination with venetoclax (Venclexta®) or tazemetostat (Tazverik®) was also demonstrated.
  • The other presentation demonstrated SP-3164's compelling anticancer activity in cell lines and animal models of multiple myeloma. In animal models, SP-3164 demonstrated superior single-agent activity compared with the approved agents lenalidomide (Revlimid®) and pomalidomide (Pomalyst®), and the combination of SP-3164 and bortezomib (Velcade®) was shown to be superior to the combination of pomalidomide and bortezomib.
    
    
• An oral presentation was delivered at the Inaugural Molecular Glue Drug Development Summit:
  
  • In a model of DLBCL, SP-3164 exhibited synergistic activity with the approved anti-CD20 drug rituximab, resulting in tumor regression in 50% of treated mice.
  • The SP-3164 and rituximab combination performed significantly better than the approved regimen of lenalidomide and rituximab.
    

Upcoming 2023 BIO International Convention and European Hematology Association 2023 Congress

Salarius will be participating in the 2023 BIO International Convention in Boston June 5-8, and the European Hematology Association 2023 Congress in Frankfurt, Germany June 8-11. Management plans to hold business development meetings with representatives of biotechnology and pharmaceutical companies to continue to expand awareness of both seclidemstat and SP-3164.

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.

Seclidemstat has received fast track, orphan drug and rare pediatric disease designations for Ewing sarcoma from the U.S. Food and Drug Administration and is currently in a Phase 1/2 clinical trial for relapsed/refractory Ewing sarcoma. 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. Salarius has received financial support from the National Pediatric Cancer Foundation to advance the Ewing program and was a recipient of a Product Development Award from the Cancer Prevention and Research Institute of Texas (CPRIT). SP-3164 is currently in IND-enabling studies and anticipated to enter the clinic in 2023. 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: the future of the company’s Phase 1/2 trial of seclidemstat as a treatment for Ewing sarcoma and FET-rearranged sarcomas, including our plans to engage in further dialogue with the FDA on various topics relating to further clinical development and possible registration pathways; the advantages of protein degraders including the value of SP-3164 as a cancer treatment; the timing of clinical trials for SP-3164 and expected therapeutic options for SP-3164 and related effects and projected efficacy;; the timing of Salarius’ IND submissions to the FDA and subsequent timing for initiating clinical trials; interim data related to Salarius’ clinical trials, including the timing of when such data is available and made public; Salarius’ growth strategy; 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; expanding the scope of Salarius’ research and focus to high unmet need patient populations; milestones of Salarius’ current and future clinical trials, including the timing of data readouts. 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: Salarius’ ability to continue as a going concern;; the sufficiency of Salarius’ capital resources; the ability of, and need for, Salarius to raise additional capital to meet Salarius’ business operational needs and to achieve its business objectives and strategy; 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; risks related to the drug development and the regulatory approval process; 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

(Tables to follow)

Source: Salarius Pharmaceuticals, Inc.