APR-1051 / Aprea - LARVOL DELTA

Aprea Therapeutics…announced that an abstract featuring updated interim results from the ongoing Phase 1 ACESOT-1051 study of its WEE1 inhibitor APR-1051 in patients with advanced solid tumors has been accepted for oral presentation at the 38th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics (ENA 2026) (GlobeNewswire)

P1 data • Solid Tumor

Interim results from the first-in-human phase 1 study of WEE1 inhibitor APR-1051 in patients with advanced solid tumors (ACESOT-1051) (EORTC-NCI-AACR 2026) - "Abstract will be available on the day of the presentation"

Clinical • First-in-human • Metastases • P1 data • Oncology • Solid Tumor

APR1051, a Next-Generation WEE1 Inhibitor, Overcomes Cisplatin Resistance and Suppresses Tumor Progression in KEAP1/NRF2 Hyperactivated Head and Neck Squamous Cell Carcinoma (AHNS 2026) - "APR-1051 effectively overcomes cisplatin resistance in HNSCC. Our findings suggest that combining APR-1051 with cisplatin may offer a promising therapeutic strategy for patients with head and neck tumors exhibiting dysregulation of the KEAP1/NRF2 pathway."

Head and Neck Cancer • Oncology • Oral Cancer • Solid Tumor • Squamous Cell Carcinoma • Squamous Cell Carcinoma of Head and Neck • ANXA5 • CDK1 • CDK2 • KEAP1 • STING

APR-1051, a Next-Generation WEE1 Inhibitor, Enhances the Efficacy of Immunotherapy in Head and Neck Squamous Cell Carcinoma (AHNS 2026) - "APR-1051 promotes antitumor immunity by reducing immunosuppression and enhancing T-cell activity. Its strong synergy with anti-PD-1, particularly in HPV-positive HNSCC models, supports further investigation of APR-1051 in combination immunotherapy trials."

Clinical • IO biomarker • Head and Neck Cancer • Oncology • Solid Tumor • Squamous Cell Carcinoma • Squamous Cell Carcinoma of Head and Neck • ANXA5 • CDK1 • CDK2

Aprea Therapeutics Presents Updated Phase 1 Data on WEE1 Inhibitor APR-1051 at ASCO 2026, Demonstrating Early Monotherapy Activity and Manageable Tolerability in Advanced Solid Tumors (GlobeNewswire) - "Clinical activity: Two patients with endometrial cancers have achieved partial responses ('PR'). Six additional patients achieved stable disease, including those with colorectal cancer, HPV+ head and neck squamous cell carcinoma, and endometrial cancer.... APR-1051 has been well tolerated across all dose levels. Treatment-related adverse events were reported in 54% of patients, with nausea (36%) and fatigue (14%) the most common, nearly all Grade 1 or 2....Aprea is expanding enrollment to include at least 50 patients with uterine serous carcinoma as well as patients with cyclin E-overexpressing, platinum-resistant ovarian cancer. Completion of dose escalation and backfill expansion is anticipated in the second quarter of 2027."

P1 data • Platinum resistant • Trial status • Colorectal Cancer • Endometrial Cancer • Ovarian Cancer • Squamous Cell Carcinoma of Head and Neck • Uterine Cancer

Early results from the first-in-human phase 1 study of WEE1 inhibitor APR-1051 in patients with advanced solid tumors (ACESOT-1051). (ASCO 2026) - P1 | "In the ongoing trial, continuous, oral APR-1051 QD has a manageable safety profile with preliminary signals of antitumor activity in patients with pretreated advanced solid tumors."

Clinical • First-in-human • Metastases • P1 data • Castration-Resistant Prostate Cancer • Colon Cancer • Colorectal Cancer • Endometrial Serous Adenocarcinoma • Head and Neck Cancer • Oncology • Oropharyngeal Cancer • Otorhinolaryngology • Prostate Cancer • Solid Tumor • Uterine Cancer • ABCB1 • CYP3A4 • MUC16 • PLK1 • PLK2

The novel WEE1i, APR-1051, is a potentially well tolerated and effective treatment for cyclin E-overexpressing cancers (AACR 2024) - "One challenge for two of the leading WEE1i, AZD1775 and ZN-c3, has been the observed off-targeting of PLK family members, namely, PLK1, PLK2 and PLK3. APR-1051 is now progressing through IND-enabling studies. Together, these findings underscore the potential of APR-1051 as a novel WEE1i for the treatment of Cyclin E-overexpressing cancers."

Oncology • Ovarian Cancer • Solid Tumor • CCNE1 • PLK2

Aprea Therapeutics…announced the acceptance of an abstract 'Early results from the first-in-human phase 1 study of WEE1 inhibitor APR-1051 in patients with advanced solid tumors (ACESOT-1051)' at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting (GlobeNewswire)

P1 data • Solid Tumor

First-in-human phase 1 study of WEE1 inhibitor APR-1051 in patients with advanced solid tumors harboring cancer-associated gene alterations (AACR 2024) - "Key exclusion criteria are cancer therapy within 3 weeks or at least 5 half-lives, prior radiation therapy at the target lesion except if evidence of disease progression, unresolved therapy-related AEs, investigational agent within 5 half-lives or 30 days of study drug, prior WEE1 inhibitor, CNS metastases or unstable involvement, secondary malignancies that are active and/or require therapy, and concomitant moderate/strong inhibitors/inducers of CYP3A4/5, MDR1, or BCRP. Up to 79 patients will be enrolled at 3 to 5 sites in the United States."

Clinical • First-in-human • Metastases • P1 data • Oncology • Solid Tumor • ABCB1 • CCNE1 • CCNE2 • CDK1 • CYP3A4 • FBXW7 • PPP2R1A

Aprea Therapeutics…announced the confirmation of a partial response (PR) in its ongoing ACESOT-1051 trial evaluating APR-1051, a potent and selective WEE1 kinase inhibitor (GlobeNewswire) - "The confirmed PR was observed in a patient with PPP2R1A-mutated endometrial cancer who is currently being treated at the 220 mg once daily dose level....A total of 24 patients have been treated to date, at doses ranging from 10 mg to 220 mg once daily. Two patients have achieved partial responses, both with endometrial cancers harboring PPP2R1A mutations....Dose escalation is ongoing, with plans to advance to Dose Level 9 (300 mg once daily) in the second quarter of 2026."

P1 data • Trial status • Endometrial Cancer

Key Business Updates and Potential Upcoming Key Milestones: ACESOT-1051… (GlobeNewswire) - "Dose escalation is ongoing, with patients currently being treated at Dose Level 8 (220 mg once daily) as the study continues to evaluate doses intendent to optimize therapeutic benefit while maintaining an acceptable safety profile. The company also plans to enroll additional patients to enrich for endometrial, colorectal and HPV+ tumors. A further update from ACESOT-1051 is expected in the second quarter of 2026."

P1 data • Trial status • Colorectal Cancer • Endometrial Cancer

Aprea Therapeutics Announces Additional Positive Clinical Activity for WEE1 Inhibitor, APR-1051, Including Second Partial Response in Ongoing ACESOT-1051 Trial (GlobeNewswire) - "The Company reported a second unconfirmed partial response at first on-treatment scan in a patient with advanced endometrial cancer being treated at the 220 mg dose level (Cohort 8). At the first on-treatment imaging assessment of single dose daily APR-1051, the responding patient achieved a 50% reduction from baseline in target lesion measurements, consistent with partial response per RECIST v1.1 criteria. In addition, there was a notable decline in the tumor biomarker CA-125, with levels dropping from 362 U/mL at baseline to 47 U/mL (-87%), further supporting the anti-tumor activity of APR-1051....A further update from the trial is expected in the second quarter of 2026."

P1 data • Endometrial Cancer

Aprea Therapeutics Announces Early Clinical Proof-Of-Concept in the Ongoing ACESOT-1051 Dose-Escalation Trial Evaluating WEE1 Inhibitor APR-1051, Including Partial Response Observed on First Scan (Aprea Press Release) - "This early clinical activity was observed in a patient with PPP2R1A-mutated uterine serous carcinoma, a form of endometrial cancer, treated at the 150 mg dose level of APR-1051, with dose escalation continuing into higher dose cohorts to establish the recommended Phase 2 dose (RP2D)...In earlier cohorts of ACESOT-1051 study, multiple patients achieved stable disease with reductions in tumor burden, including a 5% reduction at the 70 mg dose in a patient with HPV-positive head and neck squamous cell carcinoma (HNSCC) and a 15% reduction in a patient with FBXW7-mutated colon cancer treated at the 100 mg dose."

P1 data • Colon Cancer • Endometrial Cancer • Squamous Cell Carcinoma of Head and Neck

Aprea Therapeutics Provides Clinical Update from ACESOT-1051 Trial Showing Early Signals of Activity for WEE1 Kinase Inhibitor APR-1051 (GlobeNewswire) - "Updated data from ACESOT-1051 Phase 1 trial will be presented today at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics....Results from Dose Level 6 (100 mg), show 3 out of 4 patients achieved stable disease, per RECIST v1.1 in heavily pretreated gastrointestinal and gynecologic malignancies. Disease stabilization was observed in patients with FBXW7, CCNE1, and KRASG12V + TP53 alterations....Following successful clearance of the 100 mg cohort, dose escalation has progressed to Dose Level 7 (150 mg)."

P1 data • Trial status • Colon Cancer • Endometrial Cancer • Rectal Cancer

Early safety and efficacy of APR-1051, a novel WEE1 inhibitor, in patients with cancer-associated gene alterations: Updated data from ACESOT-1051 phase 1 trial (AACR-NCI-EORTC 2025) - P1 | "Continuous once-daily oral APR-1051 shows a manageable safety profile with preliminary signals of antitumor activity in this ongoing trial. Study progress will be updated at the congress."

Clinical • P1 data • Castration-Resistant Prostate Cancer • Colon Cancer • Colorectal Cancer • Head and Neck Cancer • Oncology • Oropharyngeal Cancer • Pancreatic Cancer • Prostate Cancer • Solid Tumor • ABCB1 • CYP3A4

Aprea Therapeutics…announced that two abstracts on its clinical programs, APR-1051 amd ATRN-119, have been accepted for poster presentation at the EORTC-NCI-AACR International Conference on Molecular Targets and Cancer Therapeutics… (GlobeNewswire)

Clinical data • Solid Tumor

Key Business Updates and Potential Upcoming Key Milestones (GlobeNewswire) - "Additional safety and efficacy data from the ACESOT-1051 study are anticipated in the second half of 2025, with completion of the dose-escalation phase expected in the first half of 2026. Aprea intends to submit an abstract to a major oncology conference."

P1 data • Trial status • Solid Tumor

Aprea Reports…Promising Early-Stage Clinical Data for Next-Generation WEE1 Inhibitor, APR-1051, in HPV+ Head and Neck Squamous Cell Carcinoma (HNSCC) in Collaboration with MD Anderson Cancer Center (GlobeNewswire) - P1| N=79 | ACESOT-1051 (NCT06260514) | Sponsor: Aprea Therapeutics | "In a 62-year-old male with advanced HPV-positive oropharyngeal squamous cell carcinoma who had progressed after three prior lines of platinum-based therapy, once-daily administration of a subtherapeutic 70 mg oral dose of APR-1051 resulted in stable disease with a 5% tumor reduction at the first radiographic assessment. The patient tolerated therapy well, with no dose-limiting toxicities reported."

P1 data • Oropharyngeal Cancer • Squamous Cell Carcinoma

Targeting WEE1 Kinase for Breast Cancer Therapeutics: An Update. (PubMed, Int J Mol Sci) - "Adavosertib's clinical promise was challenged by inter-individual variations in response and side effects. Because of these promising preclinical outcomes, other WEE1 kinase inhibitors (Azenosertib, SC0191, IMP7068, PD0407824, PD0166285, WEE1-IN-5, Zedoresertib, WEE1-IN-8, and ATRN-1051) are being developed, with several currently being evaluated in clinical trials or as an adjuvant to chemotherapies...Reliable predictors of clinical responses based on mechanistic insights remain an important unmet need. Herein, we review the role of WEE1 inhibition therapy in breast cancer."

Journal • Review • Breast Cancer • Oncology • Solid Tumor • Triple Negative Breast Cancer • CDC25C • CDK1 • CDK2 • GNRP • PKMYT1 • STING

Aprea Reports Anti-Proliferative Results and Promising Early-Stage Clinical Data for Next-Generation WEE1 Inhibitor, APR-1051, in HPV+ Head and Neck Squamous Cell Carcinoma (HNSCC) in Collaboration with MD Anderson Cancer Center (GlobeNewswire) - "Aprea Therapeutics, Inc...announced new preclinical data and a clinical update on APR-1051, the Company’s next-generation oral WEE1 inhibitor, in human papillomavirus–positive (HPV+) head and neck squamous cell carcinoma (HNSCC)...APR-1051 demonstrated robust antiproliferative effects across a broad panel of human and murine head and neck cancer cell lines, including HPV+ subtypes, with IC₅₀ values ranging from 8.9 to 230 nM."

Preclinical • Squamous Cell Carcinoma of Head and Neck

ACESOT-1051: A Biomarker Focused, Phase 1 Trial of Oral WEE1 inhibitor, APR-1051 (Aprea Press Release) - "Patients are now being enrolled into the 100 mg QD dose level in the ACESOT-1051 (A Multi-Center Evaluation of WEE1 Inhibitor in Patients with Advanced Solid Tumors, APR-1051) Phase 1 clinical trial...we are in a position to accelerate dose escalation and explore higher doses, potentially improving APR-1051 therapeutic impact. Informed by pharmacokinetic (PK) data, the dose escalation in ACESOT-1051 has been revised to get to potential therapeutic levels of drug earlier. After successfully clearing the 100 mg once-daily dose level, patients in the next cohort are expected to be dosed at 150 mg. The first patient at the 70 mg once-daily dose level had HPV+ head and neck squamous cell carcinoma (HNSCC)...Preliminary safety and efficacy data from the ACESOT-1051 study are anticipated in the second half of 2025, with completion of the dose-escalation phase expected in the first half of 2026."

P1 data • Trial status • Squamous Cell Carcinoma of Head and Neck

Aprea Therapeutics Announces Dosing of Patient with HPV+ Head and Neck Squamous Cell Carcinoma (HNSCC) in Ongoing ACESOT-1051 Trial (GlobeNewswire) - "Aprea Therapeutics, Inc...today announced that a patient with HPV+ head and neck squamous cell carcinoma (HNSCC) has been dosed in the ongoing ACESOT-1051 clinical trial evaluating APR-1051. This is the first patient to be dosed in Cohort 5 (70 mg once daily) of the study. Open label data from the study are expected in the second half of 2025....We look forward to continuing the study as we work toward identifying the optimal dose for future studies....The latest patient in ACESOT-1051 was enrolled at MD Anderson Cancer Center."

P1 data • Trial status • Squamous Cell Carcinoma of Head and Neck

Aprea Therapeutics Reports Fourth Quarter and Full Year 2024 Financial Results and Provides a Business Update (GlobeNewswire) - "ACESOT-1051 trial evaluating WEE1 kinase inhibitor APR-1051 now enrolling patients in Cohort 5; open label safety and efficacy data expected H2 2025; Twice daily (BID) dosing regimen in ongoing ABOYA-119 trial expected to maximize clinical benefit of ATR inhibitor ATRN-119; plan to complete dose escalation H2 2025."

P1 data • Trial status • Oncology • Solid Tumor

Select Financial Results for the Year ended December 31, 2024 (GlobeNewswire) - "R&D expenses were $9.4 million for the year ended December 31, 2024, compared to $7.6 million for the year ended December 31, 2023. The increase in R&D expense was primarily related to the ABOYA-119 clinical trial to evaluate ATRN-119, the initiation of the ACESOT-1051 clinical trial to evaluate APR-1051 and an increase in personnel costs primarily related to new hires and severance."

Commercial • Solid Tumor

ACESOT-1051: A Biomarkers Focused, Phase 1 Trial of Oral WEE1 inhibitor, APR-1051 (GlobeNewswire) - "Patients are now being enrolled in Cohort 5 (70 mg dose) of the ACESOT-1051 (A Multi-Center Evaluation of WEE1 Inhibitor in Patients with Advanced Solid Tumors, APR-1051) trial. This Phase 1 clinical trial is evaluating single-agent APR-1051 in advanced solid tumors harboring cancer-associated gene alterations. No hematological toxicities have been observed to date....Preliminary efficacy data from ACESOT-1051 are expected in the second half of 2025."

P1 data • Trial status • Solid Tumor