On March 17, 2026 Zentalis Pharmaceuticals, Inc. (Nasdaq: ZNTL), a clinical oncology innovator advancing late-stage development of investigational first-in-class WEE1 inhibitor azenosertib as a biomarker-driven treatment approach for ovarian cancer, reported two poster presentations at the 2026 American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting, taking place April 17-22, 2026, in San Diego, CA.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

"We are excited to highlight the potential to expand the opportunity for azenosertib as a combination therapy with cytotoxic agents, including antibody drug conjugates (ADC) and chemotherapy, for Triple-Negative Breast Cancer, a subtype of breast cancer with elevated Cyclin E1 expression. These data support clinical study of azenosertib in tumor types beyond ovarian cancer," said Julie Eastland, Chief Executive Officer. "In addition, the Cyclin E1 biomarker findings in ovarian cancer based on real world data reinforce the high unmet need for this biomarker-selected patient population with poor prognosis. Our biomarker-driven strategy for azenosertib monotherapy in Cyclin E1-positive platinum-resistant ovarian cancer has potential to address this unmet need."

AACR poster presentation details are below:

Title: "WEE1 Inhibition as a Therapeutic Strategy in Triple-Negative Breast Cancer: Evaluating Single Agent and Combination Activity of Azenosertib in Preclinical Models"
Abstract Number: 2012
Date/Time: Monday, April 20, 2026, 2:00 p.m. – 5:00 p.m. PDT
Presenting Author: Alexandra Levy, MS

Title: "Real-World Treatment Patterns and Outcomes Reveal Distinct Clinical Trajectories of Patients with Cyclin E1-Positive Ovarian Cancer"
Abstract Number: 1708
Date/Time: Sunday, April 19, 2026, 2:00 p.m. – 5:00 p.m. PDT
Presenting Author: Jinkil Jeong, PhD

The posters can be accessed on the Supporting Publications page of the Zentalis website at the time of each presentation’s session.

About Azenosertib
Azenosertib is an investigational, potentially first-in-class, selective, and orally bioavailable inhibitor of WEE1 currently being evaluated in clinical studies in ovarian cancer and additional tumor types. WEE1 acts as a master regulator of the G1-S and G2-M cell cycle checkpoints, through negative regulation of both CDK1 and CDK2, to prevent replication of cells with damaged DNA. By inhibiting WEE1, azenosertib enables cell cycle progression, despite high levels of DNA damage, thereby resulting in the accumulation of DNA damage and leading to mitotic catastrophe and cancer cell death.

Azenosertib is in late-stage development as a potential treatment for Cyclin E1-positive platinum-resistant ovarian cancer (PROC). There is currently no approved treatment option specifically for this biomarker-selected population which comprises approximately 50% of PROC patients. Cyclin E1 protein overexpression has been established as a sensitive and specific predictive biomarker for identifying patients who could potentially derive benefit from azenosertib treatment.

(Press release, Zentalis Pharmaceuticals, MAR 17, 2026, View Source [SID1234663673])

On March 17, 2026 Enara Bio, a pioneer in Dark Antigen discovery and bispecific T cell engager innovation, reported new data to be presented at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026, highlighting its lead clinical candidate, ENA101, a first-in-class bispecific T cell engager (TCE) targeting DARKFOX, a novel cancer-specific Dark Antigen discovered with Enara’s EDAPT platform.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

ENA101 was engineered using Enara’s proprietary EnTiCE T cell engager platform, enabling potent redirection of T cells to destroy cancer cells while maintaining exquisite specificity and robust manufacturability. In multiple preclinical studies, ENA101 demonstrated:

Picomolar binding affinity to the DARKFOX-A3 peptide-HLA complex using an optimized TCR mimic.
Robust cancer cell killing across a range of DARKFOX-A3⁺ solid tumor models with low pM EC50 values.
Compelling in vivo anti-tumor activity, achieving deep tumor regression in xenograft models while maintaining a large preclinical safety window.
A New Class of Cancer Targets: DARKFOX and the Power of the Dark Proteome in Cancer

DARKFOX, encoded by a previously unknown alternative open reading frame (alt-ORF) of FOXM1, is one of the most advanced antigens emerging from Enara’s transformational EDAPT discovery engine.

It is highly prevalent, tumor-specific, and homogeneously expressed, addressing longstanding limitations in solid‑tumor target specificity.
Its HLA-A*03:01–presented peptide (DARKFOX-A3) has a robust cell surface copy number providing a clinically targetable and therapeutically attractive interface for T cell engager design.
Enara’s EDAPT platform applies genomic, proteomic, and machine learning-driven strategies to uncover and validate noncanonical antigens (Dark Antigens), creating a new horizon of targets for immunotherapy development.

Upcoming AACR (Free AACR Whitepaper) Oral Presentation

Enara’s Chief Scientific Officer, Dr. Joe Dukes, will deliver an oral presentation titled:

"ENA101: A first-in-class bispecific T cell engager targeting a DARKFOX peptide presented by solid tumors."

Session: Advances in Therapeutic Antibodies
Date/Time: Monday, April 20, 2026, 2:30–4:30 p.m. PST
Abstract Presentation Number: 4052
The presentation will highlight the clinical opportunity associated with DARKFOX, the engineering of ENA101, and the comprehensive preclinical dataset supporting its advancement into clinical development.

Abstracts are available on the AACR (Free AACR Whitepaper) website.

(Press release, Enara Bio, MAR 17, 2026, View Source [SID1234663672])

On March 17, 2026 SELLAS Life Sciences Group, Inc. (NASDAQ: SLS) ("SELLAS’’ or the "Company"), a late-stage clinical biopharmaceutical company focused on the development of novel therapies for a broad range of cancer indications, reported that preclinical data on SLS009 (tambiciclib), a potent, selective CDK9 inhibitor, will be presented in a poster session at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) taking place April 17-22 at San Diego Convention Center in San Diego, CA. The abstracts will be published in the online Proceedings of the AACR (Free AACR Whitepaper).

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

Exposure of acute myeloid leukemia (AML) cell lines to increasing concentrations of SLS009 for 6 hours resulted in increased active caspase-3 levels and decreased MCL-1 expression. When cells were treated repeatedly for 8 hours up to 3 doses, the IC50 decreased from 50 nM to about 20 nM, demonstrating enhanced potency with repeated exposure. Changes in caspase-3 and MCL-1 were observed as early as 6 hours after completion of treatment and became more pronounced at 24 hours. Lower levels of MCL-1 and survivin were strongly correlated with increased apoptosis.

"These new data show tambiciclib’s promise in using optimized, clinically actionable schedules at patient-relevant concentrations," said Dr. Philip Amrein, clinician investigator at Mass General Brigham Cancer Institute and Assistant Professor of Medicine, Harvard Medical School, who designed and conducted experiments.

Notably, SLS009 demonstrated activity even in AML models harboring ASXL1 and TP53 mutations, which are typically associated with high resistance and poor clinical outcomes.

"These data demonstrate that SLS009 effectively targets AML cell survival mechanisms and induces apoptosis across diverse molecular subtypes, including high-risk genetic backgrounds," said Dr. Dragan Cicic, Senior Vice President and Chief Development Officer of SELLAS. "The ability to lower apoptotic threshold in AML cells by suppressing key survival pathways and enhancing potency with repeated exposure further supports the development of SLS009, including in combination regimens. We look forward to sharing the findings at this year’s AACR (Free AACR Whitepaper) conference."

Poster presentation details:

Title: Tambiciclib (SLS009), a CDK9 inhibitor, promotes apoptosis and suppresses MCL-1 levels in AML cell lines

Session Title: Cell Death Pathways and Treatment

Session Date and Time: 4/21/2026 2:00:00 PM

Location: Poster Section 11

Abstract Presentation Number: 5666

(Press release, Sellas Life Sciences, MAR 17, 2026, View Source [SID1234663671])

On March 17, 2026 BlossomHill Therapeutics, Inc., a privately-held, clinical-stage biopharmaceutical company focused on the design and development of next-generation medicines for cancer, reported it will introduce its next-generation KRAS pipeline at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting 2026. These two non-covalent pan-KRAS inhibitors leverage a differentiated chemical scaffold to address limitations of contemporary molecules – achieving sub-nanomolar potency and a prolonged off-rate, combined with oral bioavailability. In addition, the company will present new preclinical data supporting the continued advancement of its clinical programs BH-30643, a first-in-class, mutant-selective, macrocyclic OMNI-EGFRTM inhibitor, and BH-30236, an oral CLK inhibitor for hematologic malignancies. The AACR (Free AACR Whitepaper) Annual Meeting 2026 will be held April 17-22, 2026, in San Diego.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

"We are excited to share new data from across our pipeline at AACR (Free AACR Whitepaper), including new preclinical data supporting the continued advancement of our lead clinical programs BH-30643 and BH-30236, and the introduction of our novel switch II-targeting KRAS programs, one of which will be highlighted during a minisymposium," said Jean Cui, Ph.D., Founder and Chief Executive Officer of BlossomHill Therapeutics. "KRAS remains one of the most important and historically difficult targets in oncology. Our next-generation pan-KRAS inhibitors are intentionally designed using a differentiated chemical scaffold to deliver pseudo-irreversible target engagement and improved drug-like properties we believe will translate to clinical impact. We look forward to engaging with the scientific community at the upcoming AACR (Free AACR Whitepaper) meeting."

Details of the presentations are as follows:

Title: Discovery and characterization of BH-501284: A non-covalent, pan-KRAS inhibitor for treatment of diverse KRAS-mutant tumors (#6736)
Date & Time: April 21, 2026; 2:30-4:30 p.m. PT
Session Title: Targeted Therapies
Session Type: Minisymposium
Location: San Diego Convention Center
Key Findings: BH-501284 is a potent, selective, orally available non-covalent pan-KRAS inhibitor that demonstrates picomolar binding affinity, broad activity across KRAS mutations, and durable tumor regression in non-small cell lung cancer (NSCLC), colorectal cancer (CRC) and pancreatic ductal adenocarcinoma (PDAC models). By preferentially targeting inactive KRAS and maintaining activity under growth factor-driven resistance conditions, BH-501284 may overcome key limitations of existing KRAS inhibitors.

Title: Design and discovery of BH-501242, a novel pan-KRAS on/off inhibitor targeting KRAS switch II pocket (#5120)
Date & Time: April 21, 2026; 9:00 a.m.-12:00 p.m. PT
Session Title: New Ligands and Inhibitors
Location: San Diego Convention Center, Poster Section 38
Key Findings: Preclinical data demonstrate that BH-501242, a novel pan-KRAS inhibitor targeting the switch II pocket, potently inhibits a broad range of KRAS mutations, including G12D, G12V, and G12C, with sub-nanomolar cellular activity and robust tumor regression in multiple xenograft models. Its ability to bind both active and inactive KRAS and achieve strong oral exposure supports further development as a differentiated, mutation-agnostic KRAS therapy.

Title: CLK inhibitor BH-30236 synergizes with venetoclax in anti-leukemia activity via splicing modulation in preclinical AML and CLL models (#5872)
Date & Time: April 21, 2026; 2:00-5:00 p.m. PT
Session Title: Tyrosine Kinase, Phosphatase, and Other Inhibitors
Location: San Diego Convention Center, Poster Section 18
Key Findings: BH-30236, a novel oral CLK1/2/4 inhibitor, modulates alternative splicing to induce apoptosis and suppress leukemia stem cell–associated pathways, demonstrating robust anti-leukemia activity in acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL) models. In combination with venetoclax, BH-30236 produced synergistic tumor regression, including durable, complete responses in resistant xenograft models.

Title: BH-30643, a novel macrocyclic non-covalent, mutant-selective EGFR inhibitor, addresses the resistance and potency limitations of contemporary EGFR TKIs (#5877)
Date & Time: April 21, 2026; 2:00-5:00 p.m. PT
Session Title: Tyrosine Kinase, Phosphatase, and Other Inhibitors
Location: San Diego Convention Center, Poster Section 18
Key Findings: BH-30643 is a macrocyclic, non-covalent, mutant-selective OMNI-EGFR inhibitor that uniquely overcomes T790M and C797S resistance mutations while maintaining potent activity against classical EGFR drivers and sparing wildtype EGFR. In preclinical studies, BH-30643 demonstrated prolonged suppression of tumor cell proliferation compared to osimertinib, including under growth factor-mediated resistance conditions.

(Press release, BlossomHill Therapeutics, MAR 17, 2026, View Source [SID1234663669])

On March 17, 2026 Olema Pharmaceuticals, Inc. ("Olema" or "Olema Oncology", Nasdaq: OLMA), a clinical-stage biopharmaceutical company focused on the discovery, development, and commercialization of targeted therapies for breast cancer and beyond, reported it will present two preclinical posters at the American Association for Cancer Research (AACR) (Free AACR Whitepaper) Annual Meeting taking place April 17-22 in San Diego, California.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

Poster Presentation Details
Title: Palazestrant directly recruits the corepressor protein NCoR1 in vitro leading to complete antagonism of estrogen receptor alpha
Poster/Abstract: 2950
Session: Experimental and Molecular Therapeutics: Cellular Responses to Anticancer Drugs
Date/Time: April 20, 2026, from 2:00-5:00pm PT / 5:00pm-8:00pm ET

Title: Palazestrant, a CERAN, in combination with OP-3136, a KAT6 inhibitor, synergistically downregulates cell proliferation and metastasis related gene signatures
Poster/Abstract: 2949
Session: Experimental and Molecular Therapeutics: Cellular Responses to Anticancer Drugs
Date/Time: April 20, 2026, from 2:00pm-5:00pm PT / 5:00pm-8:00pm ET

Additional information can be found on the AACR (Free AACR Whitepaper) Annual Meeting website.

(Press release, Olema Oncology, MAR 17, 2026, View Source [SID1234663668])