DHX9

Enables ATX-559 Phase 1 study in solid tumor patients with a focus on BRCA1/2-deficient breast cancer and solid tumors with microsatellite instability (MSI-H) and/or deficient mismatch repair (dMMR); first patient dosed anticipated in Q4 2024 Second program targeting KIF18A on track to enter clinical trials in early 2025, underscoring rapid advancement of novel therapies Clinical Advisory Board (CAB) of global oncology drug development experts formed to support the advancement of Accent's clinical pipeline LEXINGTON, Mass., Oct. 24, 2024 /PRNewswire/ -- Accent Therapeutics, a biopharmaceutical company pioneering novel small molecule targeted cancer therapeutics, today announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application for ATX-559, a first-in-class DHX9 inhibitor. In addition, Accent has established a Clinical Advisory Board (CAB) to help guide the Company's progress in the clinic. The ATX-559 Phase 1/2 trial (NCT06625515) is expected to begin dosing patients with a focus on BRCA1- or BRCA2-deficient breast cancer and patients with MSI-H and/or dMMR solid tumors (including certain patients with colorectal, endometrial, gastric, and other cancers) in the fourth quarter of 2024. The clinical study will evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of ATX-559. For more information on the trial, visit the study page on ClinicalTrials.gov. "The FDA's IND clearance is a pivotal moment for Accent Therapeutics, propelling our lead program into the clinical arena. This milestone not only validates our scientifically rigorous approach to identifying innovative targets, but also brings us one step closer to helping cancer patients with significant unmet need," said Jason Sager, M.D., Chief Medical Officer of Accent Therapeutics. "ATX-559 has shown remarkable promise in preclinical studies, and we're excited to now evaluate its potential to meaningfully improve outcomes for patients facing these challenging malignancies." As Accent prepares to initiate its first clinical trial, the company has also established a Clinical Advisory Board to guide the advancement of its clinical pipeline. The Clinical Advisory Board consists of renowned clinician-scientists and leaders whose strategic insights and clinical expertise will support the Company's efforts to advance its mission of creating life-changing therapeutics for patients living with cancer. The newly formed Clinical Advisory Board includes: Lillian L. Siu, M.D., FRCPC, medical oncologist, Director of the Phase I Program at Princess Margaret Cancer Centre, Professor of Medicine at the University of Toronto, and President-Elect of the American Association for Cancer Research (AACR) Josep Tabernero, M.D., Ph.D., Professor of Medicine, Head of the Medical Oncology Department at the Vall d'Hebron Barcelona Hospital Campus, and Director of the Vall d'Hebron Institute of Oncology (VHIO) Sam Blackman, M.D., Ph.D., co-founder and Head of Research and Development of Day One Biopharmaceuticals "We are honored to have such distinguished experts join our Clinical Advisory Board as we advance our programs into the clinic," said Shakti Narayan, Ph.D., J.D., Chief Executive Officer of Accent Therapeutics. "Their experience will be invaluable as we work to bring transformative therapies to patients." Accent is also on track to advance its second program, targeting KIF18A in chromosomally instable tumors, into the clinic with a Phase 1 trial anticipated to begin in early 2025. This marks an exciting phase of growth for the company as it continues to build on its foundational platform technology to develop innovative cancer therapies. About ATX-559 ATX-559 is a first-in-class DHX9 inhibitor with the potential to address high unmet need indications not adequately served by existing therapies, such as BRCA-deficient tumors (including breast, ovarian, and others), MSI-H and/or dMMR cancers (including colorectal, endometrial, gastric, and others) and additional undisclosed cancer types representing large patient populations. DHX9 is a DNA/RNA helicase that has been reported to play important roles in replication, transcription, translation, RNA splicing, RNA processing, and maintenance of genomic stability. Inhibition of DHX9 exploits key tumor vulnerabilities, resulting in cancer-specific cell death, and thus this enzyme represents a compelling novel oncology target. Accent retains full worldwide rights to ATX-559 and the DHX9 program. About KIF18A Accent's second lead program is a potential best-in-class inhibitor for KIF18A which may address a large patient population across several cancer indications, including ovarian and triple negative breast cancer (TNBC). KIF18A is a mitotic kinesin motor protein critical for cell division in select tumors with chromosomal instability. A subset of tumor cells with an abnormal number of chromosomes (aneuploid) are reliant on KIF18A and show rapid cell killing in vitro and in vivo upon KIF18A inhibitor treatment, while cells with normal numbers of chromosomes (euploid) are unaffected. About Accent Therapeutics Accent Therapeutics is pioneering a new class of small molecule precision cancer therapies targeting critical intracellular dependencies that span multiple types of cancer. Building upon industry-leading expertise in RNA-modifying proteins (RMPs) and the systematic mapping of both the RMP space and adjacent high-value areas for drug discovery, the company is building a flexible model that allows for a diversity of approaches to developing potentially transformative biomarker-driven cancer medicines. Accent's therapies are designed for both novel and known, but suboptimally addressed, high-impact oncology targets with the potential to benefit large patient populations with significant unmet need. For more information on Accent's mission to translate extraordinary science into life-changing therapeutics for patients living with cancer, visit or follow us on LinkedIn. SOURCE Accent Therapeutics, Inc. 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SAN DIEGO, Sept. 12, 2024 (GLOBE NEWSWIRE) -- Oncternal Therapeutics, Inc. (Nasdaq: ONCT) (the “Company”) today announced its decision to discontinue its clinical trials evaluating ONCT-534, its dual action androgen receptor inhibitor for the treatment of patients with metastatic castration resistant cancer, and ONCT-808, its ROR1-targeting autologous CAR T program for the treatment of patients with aggressive B-cell lymphoma, and to explore strategic alternatives. In the current study, interim Phase 1 results of ONCT-534 did not show clinically meaningful improvements of disease, including prostate-specific antigen (PSA) levels, in the 20 patients treated in eight dosing cohorts with various doses and schedules of administration of ONCT-534. ONCT-534 was generally well tolerated, with dose limiting toxicity observed in 2 of 3 patients at the highest dose tested, 1200 mg given orally once per day. The results with ONCT-808 at an interim Phase 1 analysis showed anti-tumor activity at every dose tested, including a complete metabolic response lasting eight months and long-term persistence of the CAR-T cells, with expected treatment emergent adverse events for a CAR-T therapy, and one death due to complications of shock at the highest dose tested. Based on the available clinical data and capital requirements for continued development, the Company has decided to terminate these studies. The Company will focus on exploring strategic alternatives with the goal of maximizing value for its stockholders, which may include asset sales, licensing or other strategic transactions relating to the Company’s development programs or a merger, reverse merger, acquisition, or other business combination involving the Company. While this strategic exploration is ongoing, the Company will discontinue all product development activities and will take other steps to reduce costs, including a reduction in its workforce to preserve cash resources. “The early results during dose escalation in the Phase 1/2 studies of ONCT-534 in heavily pretreated patients are disappointing, as the study was supported by extensive preclinical data and was designed to address important unmet medical needs for patients with advanced prostate cancer,” said James Breitmeyer, M.D., Ph.D., Oncternal’s President and CEO. “In light of these data and the challenging financing environment, we intend to explore strategic options with the hope of advancing and realizing value from our pipeline including ONCT-534, ONCT-808, zilovertamab and ONCT-216.” About Oncternal TherapeuticsOncternal Therapeutics is a clinical-stage biopharmaceutical company focused on the development of novel oncology therapies for the treatment of patients with cancers that have critical unmet medical need. Oncternal pursues drug development targeting promising, yet untapped biological pathways implicated in cancer generation or progression, focusing on hematological malignancies and prostate cancer. More information on our company and programs is available at https://oncternal.com/. About ONCT-534 ONCT-534 is an investigational dual-action androgen receptor inhibitor (DAARI) with demonstrated preclinical activity in prostate cancer models against both unmutated androgen receptor (AR), and against multiple forms of AR mutation and aberration. It is a potential treatment for patients with mCRPC with unmet medical need because of resistance to androgen receptor pathway inhibitors, including those with AR amplification, mutations in the AR ligand binding domain (LBD), or splice variants with loss of the AR LBD. It is being investigated in Study ONCT-534-101 (NCT05917470) for the treatment of patients with mCRPC who are resistant to current AR pathway inhibitors. About ONCT-808ONCT-808 is an investigational autologous chimeric antigen receptor T (CAR T) cell therapy that targets Receptor Tyrosine Kinase-Like Orphan Receptor 1 (ROR1) using the binding domain from zilovertamab. ONCT-808 has demonstrated activity in preclinical models against multiple hematological malignancies and solid tumors and has been shown to be specific for cancer cells expressing ROR1. Oncternal has developed a robust and reproducible manufacturing process that has the potential to reduce the time patients must wait for their individual CAR T therapy to be produced compared with currently approved CAR T products. Oncternal has dosed patients under Study ONCT-808-101 (NCT05588440) with relapsed or refractory aggressive B-cell lymphoma, including patients who have failed previous CD19 CAR T treatment. About zilovertamabZilovertamab (previously called cirmtuzumab and UC-961) is an investigational monoclonal antibody designed to inhibit the function of ROR1. Zilovertamab has been evaluated in Phase 1/2 Study CIRM-0001 (NCT03088878) in combination with ibrutinib for the treatment of patients with mantle cell lymphoma (MCL), chronic lymphocytic leukemia (CLL) and marginal zone lymphoma (MZL), which resulted in 100% progression free survival (PFS) at 48 months in CLL patients whose tumors harbored p53 mutation/del(17p), a population underserved by current treatment options. The U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation to zilovertamab for the treatment of CLL and MCL. The results of an investigator-sponsored, Phase 1b clinical trial of zilovertamab in combination with paclitaxel for the treatment of women with HER2-negative metastatic or locally advanced, unresectable breast cancer were recently published (Shatsky 2023). Zilovertamab is being evaluated in an investigator-initiated Phase 1b study of zilovertamab in combination with docetaxel in patients with metastatic castration-resistant prostate cancer (NCT05156905), and an investigator-initiated Phase 2 clinical trial of zilovertamab in combination with venetoclax, a Bcl-2 inhibitor, in patients with relapsed/refractory (R/R) CLL (NCT04501939). About ONCT-216ONCT-216 (previously called TK216) is an investigational targeted small-molecule inhibitor of the E26 transformation-specific (ETS) family of oncoproteins including fusion proteins. Tumorigenic fusion proteins involving the EWS protein and an ETS protein can be found in most cases of Ewing sarcoma. ETS-related translocations or overexpression are also found in many other tumors such as acute myeloid leukemia (AML), diffuse large B cell lymphoma (DLBCL), and prostate cancer. In preclinical models, ONCT-216 was observed to bind to EWS-FLI1, blocking the interaction between this fusion protein and other transcriptome proteins such as RNA helicase A, leading to tumor cell apoptosis and inhibiting tumor growth in animal models. The U.S. Food and Drug Administration (FDA) has granted Rare Pediatric Disease Designation, Orphan Drug Designation and Fast Track Status to ONCT-216 for the treatment of Ewing sarcoma. The results of a Phase 1/ 2 clinical trial of ONCT-216 in patients with Ewing sarcoma (NCT02657005) were recently published (Myers 2024). Forward-Looking Information Oncternal cautions you that statements included in this press release that are not a description of historical facts are forward-looking statements. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplates,” “believes,” “estimates,” “predicts,” “potential” or “continue” or the negatives of these terms or other similar expressions. These statements are based on Oncternal’s current beliefs and expectations. Forward-looking statements include statements regarding: Oncternal’s ability to complete a strategic transaction or continue as a going concern even if a strategic transaction is completed; anticipated benefits of strategic transactions; and Oncternal’s ability to preserve cash during the strategic alternatives process. Forward-looking statements are subject to risks and uncertainties inherent in Oncternal’s business, including: Oncternal may not realize the benefits expected from the workforce reduction and discontinuation of product development activities, including its ability to conserve cash; Oncternal’s ability to retain remaining key personnel; whether Oncternal will be able to secure and complete or achieve the anticipated benefits from any potential strategic transactions on acceptable terms or at all; Oncternal may use its capital resources sooner than it anticipates, resulting in a liquidation and dissolution of the Company; Oncternal’s common stock may be delisted from Nasdaq; and other risks described in Oncternal’s filings with the U.S. Securities and Exchange Commission. All forward-looking statements in this press release are current only as of the date hereof and, except as required by applicable law, Oncternal 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. All forward-looking statements are qualified in their entirety by this cautionary statement. This caution is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Contact Information: InvestorsRichard Vincent 858-434-1113rvincent@oncternal.com Business DevelopmentPablo Urbaneja 415-316-8276 purbaneja@oncternal.com

Robert A. Copeland, Chief Scientific Officer, to provide major symposium presentation on inhibition of key RNA-modifying enzymes as precision cancer therapeutics Preclinical data validate DHX9 as a new target in breast cancer and other solid tumors with loss-of-function mutations in the DNA damage repair genes BRCA1 or BRCA2 Accent shares data on KIF18A, an exciting target in chromosomally instable tumors, showing their novel inhibitors display selective dose-dependent tumor growth inhibition Preclinical data validate circBRIP1 as a minimally-invasive, pharmacodynamic biomarker of DHX9 inhibition LEXINGTON, Mass., April 8, 2024 /PRNewswire/ -- Accent Therapeutics, a biopharmaceutical company pioneering a novel class of small molecule precision cancer therapeutics presents advances in cancer targeting, including data on DHX9 and KIF18A inhibitor activity in multiple tumor types, at the 2024 American Association for Cancer Research (AACR) Annual Meeting, taking place April 5-10 in San Diego, California. "Accent has expanded the potential of our two lead programs in preclinical investigations, and we are excited for the promise they hold for addressing cancers with high unmet clinical need," said Robert A. Copeland, Ph.D., President, Founder, and Chief Scientific Officer of Accent Therapeutics. "Our results reveal that DHX9 and KIF18A inhibition are potent therapeutic strategies that stand to benefit large patient populations. These findings validate our systematic approach to tapping the rich therapeutic potential of our target space." In the presentation entitled "RNA-Modifying Enzyme Inhibitors as Precision Cancer Therapeutics," Dr. Copeland delineates the promise of RNA-modifying enzyme (RME) inhibitors as precision cancer therapeutics that confer cancer-selective growth inhibition in vitro and in vivo. The potential of RME inhibitors is exemplified by inhibitors of the novel cancer target, DHX9, which display great promise as a novel treatment modality in BRCA1 and/or BRCA2 loss-of-function (LOF) cancers across multiple tumor types, including breast cancers. Studies in breast cancer models demonstrate the potential impact of DHX9 inhibitor treatment for patients with defective DNA repair. These data are highlighted in a presentation entitled "DHX9 inhibition as a novel therapeutic for cancer with loss-of-function mutations in DNA damage repair genes BRCA1 and BRCA2." Additional key takeaways from this talk are: DHX9 inhibition shows selective growth inhibition in breast cancer cell lines that exhibit BRCA LOF DHX9 inhibition results in DNA damage and catastrophic increase in replication stress in BRCA LOF cell lines, causing cell cycle arrest prior to onset of apoptosis In vivo, DHX9 inhibitors were well tolerated and demonstrate robust tumor growth inhibition in multiple BRCA LOF cell line xenograft models Accent scientists further reinforce KIF18A – a kinesin that plays a critical role in facilitating mitosis – as a compelling therapeutic target in chromosomally instable tumors. In a poster entitled "Inhibition of KIF18A leads to mitotic arrest and robust anti-tumor activity in chromosomally instable tumors," they show data that Accent's novel, potent and selective small molecule inhibitors of KIF18A: Upregulate biomarker proteins, indicating specific induction of mitotic arrest, DNA damage, and apoptosis Exhibit robust anti-proliferative activity, and result in fragmented nuclei and malformed mitotic spindles in chromosomally instable ovarian cancer cell lines Induce cell cycle arrest in G2/M for sensitive cell lines, consistent with the role of KIF18A in facilitating mitosis Lead to dose-dependent tumor growth inhibition in an OVCAR-3 cancer cell line-derived xenograft model, while sparing tumors that are insensitive to KIF18A loss Data describing a DHX9-specific pharmacodynamic biomarker of inhibition are presented in a poster entitled "circBRIP1 RNA as a non-invasive target engagement pharmacodynamic biomarker for DHX9 inhibition." Key takeaways include: Positive correlation of circBRIP1 induction with DHX9 biochemical activity, dose, and exposure for DHX9 inhibitors Similar potency of dose-dependent induction of circBRIP1 across cell lines that are sensitive or insensitive to DHX9 inhibition, indicating that circBRIP1 is a unique target engagement PD biomarker, but not a predictor of DHX9 sensitivity circBRIP1 induction correlates with DHX9 inhibitor concentration within individual tumors in mouse xenografts, providing strong evidence of a predictable PK/PD relationship Select posters and presentations will be shared on Accent's website following the meeting. About DHX9 Accent's lead program is a first-in-class DHX9 inhibitor with the potential to address high unmet need indications not adequately served by existing therapies, including tumors with BRCA loss of function (breast, ovarian, and others), mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H) cancers (colorectal, endometrial, gastric) and additional undisclosed cancer types representing large patient populations. DHX9 is a DNA/RNA helicase that has been reported to play important roles in replication, transcription, translation, RNA splicing, RNA processing, and maintenance of genomic stability. Hence, this enzyme represents a compelling novel oncology target as inhibition of DHX9 exploits key tumor vulnerabilities, resulting in cancer-specific death. Accent is currently conducting IND-enabling studies for this program. About KIF18A Accent's second lead program is a potential best-in-class inhibitor for KIF18A which may address a large patient population across several cancer indications, including ovarian and triple negative breast cancer (TNBC). KIF18A is a mitotic kinesin motor protein critical for cell division in select tumors with chromosomal instability. A subset of tumor cells with an abnormal number of chromosomes (aneuploid) are reliant on KIF18A and show rapid cell killing in vitro and in vivo upon KIF18A inhibitor treatment, while cells with normal numbers of chromosomes (euploid) are unaffected. Accent is planning to initiate IND-enabling studies for KIF18A in the first half of 2024. About Accent Therapeutics Accent Therapeutics is pioneering a new class of small molecule precision cancer therapies targeting critical intracellular dependencies that span multiple types of cancer. Building upon industry-leading expertise in RNA-modifying proteins (RMPs) and the systematic mapping of both the RMP space and adjacent high-value areas for drug discovery, the company is building a flexible model that allows for a diversity of approaches to developing potentially transformative biomarker-driven cancer medicines. Accent's therapies are designed for both novel and known, but suboptimally-addressed, high-impact oncology targets with the potential to benefit large patient populations with significant unmet need. For more information on Accent's mission to translate extraordinary science into life-changing therapeutics for patients living with cancer, visit or follow us on LinkedIn. SOURCE Accent Therapeutics, Inc.