Neoadjuvant Imlunestrant Plus Abemaciclib Treatment Guided by Ki67 Index After 2 Weeks for ER-Positive HER2-Negative Breast Cancer: A Randomized Phase 2 Trial (IMPATIENS)

This is a prospective, open-label, single-center, randomized controlled Phase II clinical study aimed at evaluating the efficacy and safety of neoadjuvant imlunestrant combined with abemaciclib guided by the Ki67 index after 2 weeks in patients with ER+/HER2- breast cancer.

Start Date01 Jul 2026

Sponsor / Collaborator

Fudan University

NCT07441369

/ Enrolling by invitationPhase 2IIT

Abemaciclib Combined With FOLFOX/FOLFIRI Regimen in Patients With Advanced Colorectal Liver Metastases Cancer Who Failed Standard Two or Three-line Therapy

This is a single-center, single-arm, open-label clinical study, to explore the efficacy and safety of abemaciclib combined with FOLFOX/FOLFIRI regimen in patients with advanced colorectal liver metastases cancer who failed standard two or three-line therapy.

Start Date01 May 2026

Sponsor / Collaborator

Fudan University

NCT07428018

/ Not yet recruitingPhase 2IIT

The VIOLET Trial: A Pragmatic Phase II Study to Optimize Neoadjuvant Treatment and Surgical De-escalation in HR+/HER2- Early Breast Cancer Using Oncotype DX and Abemaciclib

This is a pragmatic phase 2 study to determine the proportion of patients with ER+ (≥10%)/HER2- EBC in whom neoadjuvant chemotherapy can be replaced by NET plus abemaciclib based on the results of the ODX RS obtained in the initial diagnostic biopsy and according to the MDT decision and to evaluate the proportion of patients undergoing breast conservative surgery and/or sentinel node biopsy

Start Date30 Apr 2026

Sponsor / Collaborator

Istituto di Ricerche Farmacologiche Mario Negri

[+2]

100 Clinical Results associated with Abemaciclib

100 Translational Medicine associated with Abemaciclib

100 Patents (Medical) associated with Abemaciclib

1,520

Literatures (Medical) associated with Abemaciclib

31 Dec 2026·Journal of Pharmaceutical Policy and Practice

Economic evaluation of cyclin-dependent kinases 4 and 6 inhibitors in advanced hormonal receptor-positive and human epidermal growth factor receptor 2 negative breast cancer: a nationwide budget impact analysis

Article

Author: Hamad, Anas ; Shafei, Laila ; Hisham Al-Ziftawi, Nour ; Bojassoum, Salha ; Mohamed Ibrahim, Mohamed Izham ; Elazzazy, Shereen

Background:

Several trials demonstrated improvements in clinical outcomes associated with cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors in breast cancer patients. The challenge remains regarding their high costs. Ribociclib and Abemaciclib are cost-effective in Qatar. Yet, their affordability was not studied. This budget impact analysis (BIA) is to assess the affordability of adopting CDK4/6 inhibitors in Qatar over five years duration (2024-2028).

Methods:

We ran a BIA to evaluate two scenarios: (1) Increasing abemaciclib's market share from 20% to 60%, replacing both palbociclib and ribociclib. (2) Assuming equal market share for both ribociclib and abemaciclib up to 80%, reducing palbociclib's share. The analysis considered treatment costs, patient population, and disease prevalence. All data were retrieved from the National Center for Cancer Care and Research, and costs were presented in Qatari Riyals (QAR). Sensitivity analyses were run to ensure the robustness of the conclusion. All results were compared to Qatar's budget threshold, which is QAR 453,822.

Results:

Based on a total of 173 patients using CDK4/6 inhibitors, increasing abemaciclib's market share to 60% yielded cumulative savings of QAR 14 million over five years, which is around QAR 14,613 per patient per year. However, equally increasing ribociclib's and abemaciclib's market share to 80% resulted in a modest budget increase, remaining within acceptable thresholds. Sensitivity analyses confirmed the robustness of these findings, showing that cost reductions and higher uptake rates further enhanced savings.

Conclusion:

Abemaciclib is a budget-saving option for HR+/HER2- breast cancer in Qatar, should it replace the market share by up to 60% over five years. In addition, ribociclib and abemaciclib are affordable treatment options if they equally contributes to up to 80% of the market share for the eligible advanced breast cancer patients. The results supported the concept of allocating CDK4/6 inhibitors as they were found to be affordable to the Qatari healthcare system.

01 Apr 2026·BREAST CANCER RESEARCH AND TREATMENT

Comparative effectiveness of CDK4/6 inhibitors in metastatic breast cancer: using the target trial emulation framework to investigate overall survival in routine care

Article

Author: Davies, Jessica ; Long, Gráinne H ; Nur, Ula ; Finn, Richard S ; Brufsky, Adam M ; Huang-Bartlett, Cynthia ; Metzger, Otto ; Sreenivasan, Sameet ; Goncalves, Rodrigo ; Grigorenko, Alex

PURPOSE:

Cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) plus aromatase inhibitor (AI) is the recommended first-line treatment for hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer (mBC). CDK4/6i head-to-head trials have not been conducted, and randomized controlled trials (RCTs) report inconsistent overall survival (OS) results despite similar effects on the primary endpoint of progression-free survival. Real-world evidence can complement RCTs but selection biases and confounders can challenge interpretation. Target trial emulation applies the principles of RCTs to observational data to overcome such challenges. We emulated a hypothetical target trial to investigate whether causal differences in OS between patients receiving first-line CDK4/6i plus AI exist in the real-world clinical setting.

METHODS:

We used de-identified data (Flatiron Health mBC Enhanced Data Mart) from patients ≥ 18 years old at primary diagnosis who were treated with first-line palbociclib/ribociclib/abemaciclib plus AI for mBC between 2018 and 2024. Statistical adjustments included stabilized inverse-probability weighting (sIPTW), investigation of missing data mechanisms, and analyses for unmeasured confounders.

RESULTS:

2626 patients were included (palbociclib n = 1686; ribociclib n = 537; abemaciclib n = 403). After sIPTW, baseline characteristics were balanced between groups and there was no observable difference in real-world OS (ribociclib vs palbociclib, adjusted hazard ratio 1.00, 95% CI: 0.81-1.24; abemaciclib v palbociclib: 0.91, 95% CI: 0.74-1.14). Results were consistent after sensitivity analyses.

CONCLUSION:

Using target trial emulation, real-world OS is similar with palbociclib/ribociclib/abemaciclib plus AI. These findings may contribute to the development of combination strategies to improve clinical outcomes and to guide clinical decision-making.

01 Apr 2026·BREAST

Effectiveness comparison of first-line CDK4/6 inhibitors in patients with hormone-positive HER2-negative advanced breast cancer according to tumor histology: a sub-analysis of the real-world, multicenter, Italian study PALMARES-2

Article

Author: Zurlo, Christian ; Mariani, Luigi ; Chiappe, Edoardo ; Sartori, Donata ; Pedersini, Rebecca ; Jacobs, Flavia ; Gennari, Alessandra ; De Angelis, Carmine ; Armani, Giovanna ; Criscitiello, Carmen ; Giordano, Monica ; Vernieri, Claudio ; Griguolo, Gaia ; Menichetti, Alice ; Sirico, Marianna ; Schianca, Ambra Carnevale ; Toss, Angela ; Rizzo, Gianpiero ; Ligorio, Francesca ; Marra, Antonio ; Capasso, Camilla ; Tagliaferri, Barbara ; Provenzano, Leonardo ; Scagnoli, Simone ; Guarneri, Valentina ; Curigliano, Giuseppe ; Dieci, Maria Vittoria ; Arpino, Grazia ; Faso, Valeria ; Piras, Marta ; Botticelli, Andrea ; Munzone, Elisabetta ; Generali, Daniele ; Fotia, Giuseppe ; La Verde, Nicla ; Pisegna, Simona ; Giuliano, Mario ; De Monte, Matteo ; Mazzoli, Giacomo ; Pruneri, Giancarlo ; Lambertini, Matteo ; Zambelli, Alberto

INTRODUCTION:

Invasive lobular breast cancer (ILC) is the second most common breast cancer subtype, with distinctive biological and epidemiologic features. Although phase III trials of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) in hormone receptor-positive, HER2-negative advanced breast cancer (HR+/HER2-aBC) included patients with ILC, their real-world effectiveness in this population remains poorly characterized.

MATERIAL AND METHODS:

In this sub-analysis of the multicenter, real-world PALMARES-2 study (NCT06805812), we assessed the predictive and prognostic value of lobular histology in HR+/HER2-aBC treated with first-line endocrine therapy (ET) plus CDK4/6i. The primary endpoint was real-world progression-free survival (rwPFS). Associations between histology and outcomes were adjusted for 15 covariates using multivariable Cox-regression and inverse probability of treatment weighting.

RESULTS:

Among 1982 patients, 367 (18.5 %) had ILC and 1481 (74.7 %) non-special type (NST). Median follow-up was 29.8 and 31.2 months, respectively. ILC was associated with shorter rwPFS versus NST (adjusted hazard ratio [aHR]: 1.24, 95 %CI:1.04-1.47, P=0.017). Palbociclib efficacy was not affected by lobular histology (P for interaction = 0.553) while abemaciclib was less effective in ILC (P = 0.009). All three CDK4/6i achieved similar rwPFS in ILC (ribociclib vs palbociclib: aHR: 1.01, 95 %CI: 0.67-1.45, P = 0.949; abemaciclib vs palbociclib: aHR: 1.13, 95 %CI: 0.75-1.71, P = 0.551; abemaciclib vs ribociclib: aHR: 1.15, 95 %CI: 0.73-1.80, P = 0.549).

CONCLUSIONS:

Tumor histology affects the real-world effectiveness of first line ET plus CDK4/6i. In ILC, all three CDK4/6i performed similarly; therefore, treatment selection should prioritize tolerability, manageability, drug-drug interactions, and patient preferences.

434

News (Medical) associated with Abemaciclib

24 Apr 2026

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LeonaBio to Host Virtual Key Opinion Leader Event Highlighting Potential of Lasofoxifene in Treatment-Resistant ER+/HER2-, ESR1-Mutated Metastatic Breast Cancer

Management to be Joined by Two Clinical Leaders in the Breast Cancer Field Expected to Complete Enrollment in Ongoing ELAINE-3 Phase 3 Registrational Study of Lasofoxifene in Metastatic Breast Cancer in 4Q26 with Data Expected in 2H27 Webinar Event on Wednesday, April 29, 2026, at 12:00 p.m. ET BOTHELL, Wash., April 23, 2026 (GLOBE NEWSWIRE) -- LeonaBio, Inc. (NASDAQ: LONA), a clinical-stage biopharmaceutical company dedicated to the development of novel therapeutics for diseases with high unmet medical needs, today announced that it will host a virtual Key Opinion Leader event with two leading physician experts in the breast cancer field to discuss the current and evolving treatment landscape in metastatic breast cancer and the potential for lasofoxifene to transform the standard of care for patients with treatment-resistant estrogen receptor-positive (ER+), HER2-negative, ESR1-mutated metastatic breast cancer. The event titled, “Modulation and Combination: the Potential for Lasofoxifene to Transform the Standard-of-Care in Metastatic Breast Cancer,” will take place on Wednesday, April 29, 2026, beginning at 12:00 p.m. ET. To participate in the event, register here . “As we look toward completing enrollment in ELAINE-3 later this year, with data expected in the second half of 2027, we are pleased to be joined by two leading voices in the breast cancer field to discuss the evolving treatment landscape in metastatic disease,” said Mark Litton, Ph.D., President and Chief Executive Officer of LeonaBio. “This conversation will highlight the persistent gaps in care, particularly for genetically defined populations, and the potential for lasofoxifene to address a critical unmet need in patients with treatment-resistant ER+, HER2-, ESR1-mutated metastatic breast cancer.” The webcast event will feature a discussion with David Portman , M.D ., Chief Executive Officer of Sermonix Pharmaceuticals and an oncology consultant to LeonaBio, along with two physician experts in the breast cancer field: Matthew P. Goetz, M.D. , Erivan K. Haub Family Professor of Cancer Research Honoring Richard F. Emslander, M.D, Mayo Clinic, Principal investigator and director, Breast Cancer Specialized Program of Research Excellence (SPORE), Mayo Clinic Comprehensive Cancer Center and Enterprise Deputy Director, Translational Research, Mayo Clinic Comprehensive Cancer Center. Seth Wander, M.D., Ph.D. , Director of Precision Medicine, Termeer Center for Targeted Therapies, Director of Translational Research, Breast Oncology Program, Mass General Brigham Cancer Institute, Assistant Professor of Medicine, Harvard Medical School. In addition to the live webinar, the event will be archived on the LeonaBio website under Events in the Investor Relations here . About Metastatic Breast Cancer Metastatic breast cancer (MBC) occurs when cancer spreads from the breast to other parts of the body—such as bones, lungs, liver, or brain. While approximately two-thirds of breast cancers are diagnosed at a localized stage, a notable proportion either present as metastatic at diagnosis or progress to that stage over time. From 2001 to 2021, approximately 4.65 million new cases of female breast cancer were reported in the United States, with approximately 260,000 (5.6%) diagnosed as distant (metastatic) stage at initial diagnosis. The metastatic breast cancer treatment market represents a sizable and rapidly expanding global opportunity with a global market of $17.1 billion in 2021, expected to expand to $41.7 billion by 2030, with a compound annual growth rate (CAGR) of approximately 10.4%. These projections reflect a market rich with innovation—from chemotherapy and hormone therapies to biologics, targeted agents and emerging personalized medicine. Growth is driven by the persistent incidence of metastatic disease, regulatory and clinical advances and evolving treatment landscapes. About Lasofoxifene Lasofoxifene is a novel, nonsteroidal selective estrogen receptor modulator (SERM) with a unique binding profile, designed to confer potent activity against both wild-type and mutant estrogen receptors, including the clinically significant ESR1 mutations commonly associated with resistance to endocrine therapy in metastatic breast cancer. Two Phase 2 studies—ELAINE-1 and ELAINE-2—have demonstrated its potential to address a critical unmet need in this patient population. ELAINE-1, a randomized trial comparing lasofoxifene to fulvestrant, showed improved outcomes for lasofoxifene, including longer median progression-free survival (5.6 vs. 3.7 months), higher objective response rates (13.3% vs. 2.9%), and a durable complete response lasting more than 2.5 years. Patients also reported quality-of-life benefits and the treatment was well tolerated. ELAINE-2, an open-label study evaluating lasofoxifene in combination with abemaciclib, demonstrated clinical benefits in heavily pretreated patients, with a median progression-free survival of approximately 13 months, an objective response rate of 56%, and a clinical benefit rate of 65.5%. The combination was generally well tolerated, with most adverse events being low grade. Lasofoxifene is being advanced in a Phase 3 clinical trial as a targeted therapy for estrogen receptor-positive (ER+), HER2-negative, ESR1-mutated metastatic breast cancer, a population with limited treatment options following progression on aromatase inhibitors and CDK4/6 inhibitors. The ongoing ELAINE-3 trial ( NCT05696626 ) is evaluating lasofoxifene in combination with the CDK4/6 inhibitor, abemaciclib, and is aiming to establish a new standard of care for this genetically defined patient group. About LeonaBio LeonaBio, headquartered in the Seattle, Washington area, is a clinical-stage biopharmaceutical company dedicated to the development of novel therapeutics for diseases with high unmet medical needs, including treatment-resistant metastatic breast cancer and amyotrophic lateral sclerosis (ALS), with the goal of improving patients’ lives. Our lead drug candidates, lasofoxifene and ATH-1105, are novel, small molecule therapies with the potential to address devastating diseases where current treatment options are limited or ineffective. With a strong commitment to scientific excellence and patient-centered innovation, we are dedicated to developing meaningful new therapies for those who need them most. For more information, visit . Forward-Looking Statements This communication contains “forward-looking statements” within the meaning of Section 27A of the Securities Act, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995. These forward-looking statements are not based on historical fact and include statements regarding: the beneficial characteristics, safety and efficacy of LeonaBio’s drug candidates; the potential of any subsequent clinical trials to show the beneficial characteristics, safety and efficacy of LeonaBio’s drug candidates; LeonaBio’s drug candidates as potential treatments for metastatic breast cancer and other diseases; anticipated development milestone timelines, such as the completion of enrollment of clinical trials and the timing of data releases, and LeonaBio’s ability to meet such timelines; the potential of LeonaBio to complete the Phase 3 ELAINE-3 clinical trial for lasofoxifene and to meet the trial endpoints; LeonaBio’s ability to obtain regulatory approval for any of its product candidates and to successfully commercialize any approved products; the rate and degree of market acceptance of LeonaBio’s drug candidates, if approved for commercial use; the size and growth potential of the markets for LeonaBio’s drug candidates, if approved for commercial use, and LeonaBio’s ability to serve those markets; and the potential for lasofoxifene to be a new standard of care in its target genetically defined patient group. Forward-looking statements generally include statements that are predictive in nature and depend upon or refer to future events or conditions, and include words such as “may,” “will,” “should,” “on track,” “would,” “expect,” “plan,” “believe,” “intend,” “pursue,” “continue,” “suggest,” “potential,” “target” and similar expressions. Any forward-looking statements are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to, risks associated with the possible failure to realize certain anticipated benefits of the license relating to lasofoxifene and the recent private placement financing, including with respect to future financial and operating results; the data from nonclinical and clinical trials may not support the safety, efficacy and tolerability of LeonaBio’s drug candidates; development of drug candidates may cease or be delayed; regulatory authorities could object to protocols, amendments and other submissions; future potential regulatory milestones for drug candidates, including those related to current and planned clinical studies, may be insufficient to support regulatory submissions or approval; whether LeonaBio’s trials are sufficiently powered to meet the planned endpoints; LeonaBio may not be able to recruit sufficient patients for its clinical trials; the outcome of legal proceedings that may in the future be instituted against LeonaBio, its directors and officers; possible negative interactions of LeonaBio’s drug candidates with other treatments; FDA regulatory delays and uncertainty and new policies, including executive orders, changes in the leadership of federal agencies such as the FDA and SEC, staff layoffs, budget cuts to agency programs and research and changes in drug pricing controls; LeonaBio’s assumptions regarding its financial condition and the sufficiency of its cash, cash equivalents and investments to fund its planned operations may be incorrect; adverse conditions in the general domestic and global economic markets, including as a result of tariffs; the impact of competition; the impact of drug candidate development and clinical activities on operating expenses; the impact of new or changing laws and regulations; as well as the other risks detailed in LeonaBio’s filings with the SEC from time to time. These forward-looking statements speak only as of the date hereof and LeonaBio undertakes no obligation to update forward-looking statements. LeonaBio may not actually achieve the plans, intentions or expectations disclosed in its forward-looking statements, and you should not place undue reliance on the forward-looking statements. Investor & Media Contact: Julie Rathbun LeonaBio Julie.rathburn@leonabio.com 206-769-9219

23 Apr 2026

·www.prnewswire.com

AACR 2026 | Abbisko Therapeutics Showcases Six Research Advances Highlighting pan-KRAS, 4th Generation EGFR, and Synthetic Lethality Approaches

SAN DIEGO, April 22, 2026 /PRNewswire/ -- Abbisko Therapeutics (HKEX: 02256) announced that the company presented six latest preclinical and translational research findings in poster sessions at the American Association for Cancer Research (AACR) Annual Meeting, held from April 17 to 22, 2026, in San Diego, USA. The presentations span multiple key innovation areas, including the pan-KRAS inhibitor ABSK211, the 4 th generation EGFR inhibitor ABK-EGFR-1, the CDK4 selective inhibitor ABK-CDK4, the MTA-cooperative PRMT5 inhibitor ABSK131, as well as a ctDNA-based study investigating resistance mechanisms to the FGFR2/3 inhibitor ABSK061. pan-KRAS Inhibitor ABSK211 ABSK211 is a potent, highly selective, and orally bioavailable small-molecule pan-KRAS inhibitor developed by Abbisko Therapeutics. It demonstrates broad inhibitory activity against multiple KRAS mutations, addressing significant unmet medical needs in KRAS-driven cancers. At AACR 2026, Abbisko presented preclinical data for both monotherapy and combination strategies of ABSK211. Monotherapy: Broad and Potent Inhibition Across KRAS Mutations KRAS mutations are highly prevalent across multiple cancers, including pancreatic (~90%), colorectal (~35%), and lung cancer (~25%). While several pan-KRAS inhibitors have entered clinical development, there remains a critical need for enhanced potency. In preclinical studies, ABSK211 demonstrated: Robust in vitro activity: ABSK211 significantly reduced cell viability across multiple KRAS alterations (including G12, G13, Q61, and WT amplification) at sub-nanomolar to nanomolar concentrations. Meanwhile ABSK211 displayed marginal inhibition in KRAS wild-type cell line with normal copy. Strong in vivo efficacy: Oral administration induced deep tumor regression in multiple KRAS G12V xenograft models, with robust target engagement. Broad mutation coverage: Consistent and significant antitumor activity was observed in models harboring KRAS G12D/C/S and G13D mutations. These findings support the clinical advancement of ABSK211, which is currently undergoing IND-enabling studies. Poster Information Title: Preclinical characterization of ABSK211: A highly potent, orally bioavailable and selective pan-KRAS inhibitor with broad and robust activity in KRAS-driven tumors Time: April 22, 2026, 9:00 AM – 12:00 PM (PT) Location: Poster Section 13, Board #10 Abstract #: 7090 Combination Therapy: Multi-Mechanistic Synergy Enhances Antitumor Activity Combination therapy is widely considered a key strategy to improve treatment outcomes in KRAS-mutant cancers. ABSK211 demonstrated synergistic antitumor activity with multiple therapeutic agents: In vitro synergy: Significant anti-proliferative synergy with PRMT5 inhibitors across KRAS mutations; strong synergy observed with EGFR monoclonal antibodies and chemotherapy in KRAS G12D/G12V models. Enhanced in vivo efficacy: Combination regimens with PRMT5 inhibitors, cetuximab, immunotherapies, and chemotherapy showed superior tumor growth inhibition and improved durability compared to monotherapy. These results demonstrate that ABSK211 can significantly enhance antitumor efficacy through multi-mechanistic synergy, supporting its further development in combination strategies. Poster Information Title: ABSK211, a highly potent and orally available pan-KRAS inhibitor, demonstrates robust antitumor efficacy in combination with multiple agents Time: April 22, 2026, 9:00 AM – 12:00 PM (PT) Location: Poster Section 13, Board #3 Abstract #: 7083 4 th Generation EGFR Inhibitor ABK-EGFR-1 ABK-EGFR-1 is a novel 4th generation EGFR inhibitor developed by Abbisko Therapeutics, specifically designed to target the EGFR C797S resistance mutation. It combines high selectivity with central nervous system (CNS) penetration to address key clinical challenges following resistance to 3rd generation EGFR TKIs. Targeting C797S-Mediated Resistance The EGFR C797S mutation is a clinically validated mechanism of resistance to third-generation EGFR TKIs, with an estimated 51,000–146,000 cases annually worldwide. Currently, no approved therapies specifically target this mutation, representing a significant unmet clinical need. Preclinical studies showed that ABK-EGFR-1: Exhibits high selectivity over wild-type EGFR and other kinases. Demonstrates significant in vivo antitumor activity in multiple EGFR C797S-driven xenograft models, effectively inhibiting tumor growth. Possesses excellent blood-brain barrier penetration and favorable drug-like properties. These findings support further development of ABK-EGFR-1 as a next-generation targeted therapy for EGFR-resistant cancers, particularly for patients with brain metastases. Poster Information Title: Discovery and characterization of ABK-EGFR-1, a 4th generation EGFR C797S Inhibitor with excellent selectivity and brain penetration Time: April 21, 2026, 2:00 PM – 5:00 PM (PT) Location: Poster Section 53, Board #7 Abstract #: LB350 CDK4 Selective Inhibitor ABK-CDK4 ABK-CDK4 is a highly selective, brain-penetrant small-molecule CDK4 inhibitor developed by Abbisko Therapeutics. It is designed to selectively target CDK4, reduce CDK6-related toxicity, and expand treatment potential for patients with brain metastases. Differentiation Through Selectivity and CNS Penetration 1st generation CDK4/6 inhibitors (e.g., palbociclib, ribociclib, and abemaciclib) have demonstrated clinical benefit in breast cancer, but CDK6 inhibition is associated with dose-limiting hematologic toxicities. In addition, 20–40% of breast cancer patients develop brain metastases, while current therapies have limited CNS exposure. Preclinical studies showed that ABK-CDK4: High selectivity: Over 50-fold selectivity for CDK4 versus CDK6, potentially reducing CDK6-related toxicity. CNS penetration: Favorable CNS exposure (Kpuu > 0.5) and drug-like properties. Antitumor activity: Effective inhibition of Rb phosphorylation and tumor growth in HR+/HER2− breast cancer models These results suggest that ABK-CDK4 may overcome key limitations of current CDK4/6 inhibitors and provide a differentiated therapeutic option. Poster Information Title: Discovery of ABK-CDK4, a selective and brain-penetrant CDK4 inhibitor Time: April 20, 2026, 9:00 AM - 12:00 PM (PT) Location: Poster Section 20, Board #13 Abstract #: 1905 MTA-cooperative PRMT5 inhibitor ABSK131 ABSK131 is a potent and selective small-molecule MTA-cooperative PRMT5 inhibitor developed by Abbisko Therapeutics, targeting MTAP-deleted tumors, and is currently in clinical development. Broad Synergy Across Multiple Therapeutic Modalities MTAP homozygous deletion occurs in approximately 10–15% of solid tumors and frequently co-exists with oncogenic drivers such as KRAS and EGFR. In addition, MTAP abnormities are associated with poor prognosis following standard-of-care therapies across multiple cancer types. Therefore, there remains a significant unmet need for novel and effective combination therapies centered on MTA-cooperative PRMT5 inhibitor for MTAP-deleted tumors, with the potential to enable precision patient stratification and deliver synergistic therapeutic benefits. Preclinical studies demonstrated that ABSK131 exhibits strong synergistic activity with multiple therapies: KRAS inhibitors: Enhanced tumor growth inhibition in KRAS-mutant, MTAP-deleted models when combined with AMG 510 or ABSK141. EGFR inhibitors: Improved anti-proliferative and in vivo antitumor activity in EGFR-mutant, MTAP-deleted NSCLC models when combined with osimertinib. MAT2A inhibitors: Consistent synergistic effects across multiple tumor models when combined with IDE397. Chemotherapy: Synergistic activity observed both in vitro and in vivo when combined with carboplatin in NSCLC models. These findings support ABSK131 as a potential backbone therapy for combination strategies in MTAP-deleted tumors. Poster Information Title: Synergistic antitumor activity of the MTA-cooperative PRMT5 inhibitor ABSK131 in combination with multiple therapeutic agents in diverse cancer models Time: April 21, 2026, 9:00 AM - 12:00 PM (PT) Location: Poster Section 14, Board #23 Abstract #: 4504 FGFR2/3 Inhibitor ABSK061 ABSK061 is a highly potent and selective small-molecule FGFR2/3 inhibitor developed by Abbisko Therapeutics. It has demonstrated encouraging efficacy and safety in Phase I studies and is currently being evaluated in a Phase II trial for gastric cancer. ctDNA Analysis Reveals Resistance Mechanisms Acquired resistance remains a major challenge limiting the long-term benefit of targeted therapies. Using ctDNA-based next-generation sequencing (NGS), Abbisko conducted longitudinal genomic analyses comparing baseline and progression samples to elucidate resistance mechanisms to ABSK061: On-target resistance: Polyclonal acquired FGFR2 mutations in the FGFR2 kinase domain were commonly observed in gastric cancer and cholangiocarcinoma. Off-target resistance: FGFR2-Atered NSCLC was prone to develop acquired alterations in genes involved in RTK/RAS pathways. These findings provide important molecular insights into resistance mechanisms and inform the design of future combination and sequential treatment strategies. Poster Information Title: Circulating tumor DNA (ctDNA)-based profiling of acquired resistance to the fibroblast growth factor receptor (FGFR)2/3 inhibitor lavengratinib(ABSK061) in patient(pt)s with advanced solid tumors Time: April 21, 2026, 9:00 AM - 12:00 PM (PT) Location: Poster Section 45, Board #14 Abstract #: 5319 At AACR 2026, Abbisko Therapeutics showcased the latest preclinical and translational research advances across multiple pipeline programs, demonstrating its strong capabilities in drug discovery and development. As these programs continue to advance into clinical stages, the company is further strengthening its globally competitive R&D platform. Looking ahead, Abbisko Therapeutics will continue to focus on addressing unmet medical needs and accelerating the translation of innovative discoveries into clinical applications, with the goal of delivering more first-in-class and best-in-class therapies to patients worldwide. SOURCE Abbisko Therapeutics 21% more press release views with Request a Demo

AACRPhase 1Phase 2Clinical Result

21 Apr 2026

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Independent Nonclinical Research on Lasofoxifene Presented at American Association for Cancer Research Annual Meeting 2026 Consistent with LeonaBio’s Data

Results showed lasofoxifene protected against hormone withdrawal-induced bone loss and maintained a robust anti-tumor response in primary and metastatic animal models of ER+ breast cancer BOTHELL, Wash., April 21, 2026 (GLOBE NEWSWIRE) -- LeonaBio, Inc. (NASDAQ: LONA), a clinical-stage biopharmaceutical company dedicated to the development of novel therapeutics for diseases with high unmet medical needs, attended the American Association for Cancer Research Annual Meeting 2026 (AACR26), where independent researchers at Virginia Commonwealth University’s Massey Comprehensive Cancer Center presented nonclinical data on lasofoxifene, including its potential for a bone protective role in metastatic breast cancer. 1 “We are delighted to learn the findings of this independent research at AACR26, attended by an audience of the world’s leading oncology researchers. We believe these data add to the body of evidence in support of lasofoxifene as a therapeutic candidate and align with the scientific rationale for LeonaBio’s ongoing ELAINE-3 Phase 3 evaluation of lasofoxifene in metastatic estrogen receptor (ER)-positive breast cancer in patients with ESR1 mutations. The potential ability to combine robust anti-tumor activity with beneficial estrogenic activity in bone tissue has been a core tenant of lasofoxifene’s development in breast cancer,” said David Portman, M.D., a consultant to LeonaBio. The presentation titled, “Lasofoxifene Acts as a Selective Estrogen Receptor Agonist in the Bone Microenvironment,” highlights results reported by independent researchers at the Virginia Commonwealth University, who investigated the physiological relevance of lasofoxifene’s selective estrogen receptor- agonist activity and its impact on metastatic progress in animal models. “Our findings demonstrate that lasofoxifene exhibits unique, context-dependent estrogen receptor activity that both suppresses ER-driven tumor growth and preserves bone integrity in nonclinical models of ER-positive breast cancer,” stated Emily K. Zboril, Department of Cellular, Molecular, and Genetic Medicine, Virginia Commonwealth University, Richmond, Virgina. “Notably, in models of ESR1-mutant disease, lasofoxifene significantly reduced metastatic tumor burden in bone while maintaining favorable effects on the bone microenvironment, supporting its potential to address two critical challenges faced by patients with metastatic breast cancer.” The complete poster can be accessed via the AACR26 website at About Lasofoxifene Lasofoxifene is a novel, nonsteroidal selective estrogen receptor modulator (SERM) with a unique binding profile, designed to confer potent activity against both wild-type and mutant estrogen receptors, including the clinically significant ESR1 mutations commonly associated with resistance to endocrine therapy in metastatic breast cancer. Two Phase 2 studies—ELAINE-1 and ELAINE-2—have demonstrated its potential to address a critical unmet need in this patient population. ELAINE-1, a randomized trial comparing lasofoxifene to fulvestrant, showed improved outcomes for lasofoxifene, including longer median progression-free survival (5.6 vs. 3.7 months), higher objective response rates (13.3% vs. 2.9%), and a durable complete response lasting more than 2.5 years. Patients also reported quality-of-life benefits and the treatment was well tolerated. ELAINE-2, an open-label study evaluating lasofoxifene in combination with abemaciclib, demonstrated clinical benefits in heavily pretreated patients, with a median progression-free survival of approximately 13 months, an objective response rate of 56%, and a clinical benefit rate of 65.5%. The combination was generally well tolerated, with most adverse events being low grade. Lasofoxifene is being advanced in a Phase 3 clinical trial as a targeted therapy for estrogen receptor-positive (ER+), HER2-negative, ESR1-mutated metastatic breast cancer, a population with limited treatment options following progression on aromatase inhibitors and CDK4/6 inhibitors. The ongoing ELAINE-3 trial ( NCT05696626) is evaluating lasofoxifene in combination with the CDK4/6 inhibitor, abemaciclib, and is aiming to establish a new standard of care for this genetically defined patient group. About LeonaBio LeonaBio, headquartered in the Seattle, Washington area, is a clinical-stage biopharmaceutical company dedicated to the development of novel therapeutics for diseases with high unmet medical needs, including treatment-resistant metastatic breast cancer and amyotrophic lateral sclerosis (ALS), with the goal of improving patients’ lives. Our lead drug candidates, lasofoxifene and ATH-1105, are novel, small molecule therapies with the potential to address devastating diseases where current treatment options are limited or ineffective. With a strong commitment to scientific excellence and patient-centered innovation, we are dedicated to developing meaningful new therapies for those who need them most. For more information, visit . Forward-Looking Statements This communication contains “forward-looking statements” within the meaning of Section 27A of the Securities Act, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995. These forward-looking statements are not based on historical fact and include statements regarding: the beneficial characteristics, safety and efficacy of LeonaBio’s drug candidates; the potential of any subsequent clinical trials to show the beneficial characteristics, safety and efficacy of LeonaBio’s drug candidates; the potential of LeonaBio to complete the Phase 3 ELAINE-3 clinical trial for lasofoxifene and to meet the trial endpoints; the potential learnings from nonclinical studies and other nonclinical data and their ability to inform and improve future clinical development plans; and LeonaBio’s ability to obtain regulatory approval for any of its product candidates and to successfully commercialize any approved products. Forward-looking statements generally include statements that are predictive in nature and depend upon or refer to future events or conditions, and include words such as “may,” “will,” “should,” “on track,” “would,” “expect,” “plan,” “believe,” “intend,” “pursue,” “continue,” “suggest,” “potential,” “target” and similar expressions. Any forward-looking statements are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to, risks associated with the possible failure to realize certain anticipated benefits of the license relating to lasofoxifene and the recent private placement financing, including with respect to future financial and operating results; the data from nonclinical and clinical trials may not support the safety, efficacy and tolerability of LeonaBio’s drug candidates; development of drug candidates may cease or be delayed; regulatory authorities could object to protocols, amendments and other submissions; future potential regulatory milestones for drug candidates, including those related to current and planned clinical studies, may be insufficient to support regulatory submissions or approval; whether LeonaBio’s trials are sufficiently powered to meet the planned endpoints; LeonaBio may not be able to recruit sufficient patients for its clinical trials; the outcome of legal proceedings that may in the future be instituted against LeonaBio, its directors and officers; possible negative interactions of LeonaBio’s drug candidates with other treatments; FDA regulatory delays and uncertainty and new policies, including executive orders, changes in the leadership of federal agencies such as the FDA and SEC, staff layoffs, budget cuts to agency programs and research and changes in drug pricing controls; LeonaBio’s assumptions regarding its financial condition and the sufficiency of its cash, cash equivalents and investments to fund its planned operations may be incorrect; adverse conditions in the general domestic and global economic markets, including as a result of tariffs; the impact of competition; the impact of drug candidate development and clinical activities on operating expenses; the impact of new or changing laws and regulations; as well as the other risks detailed in LeonaBio’s filings with the SEC from time to time. These forward-looking statements speak only as of the date hereof and LeonaBio undertakes no obligation to update forward-looking statements. LeonaBio may not actually achieve the plans, intentions or expectations disclosed in its forward-looking statements, and you should not place undue reliance on the forward-looking statements. Investor & Media Contact: Julie Rathbun LeonaBio Julie.rathbun@leonabio.com 206-769-9219 1 LeonaBio does not have any financial relationships with the researchers at Virginia Commonwealth University and did not contribute to their research. The lasofoxifene studied by the researchers was obtained from an independent source for research use only. LeonaBio’s clinical study of lasofoxifene is not related to the research conducted at Virginia Commonwealth University.

Clinical ResultPhase 3Phase 2AACR

100 Deals associated with Abemaciclib

External Link

KEGG	Wiki	ATC	Drug Bank
D10688	Abemaciclib	L01XE50	DB12001

R&D Status

Approved

10 top approved records.

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Indication	Country/Location	Organization	Date
Advanced breast cancer	Canada	Eli Lilly Canada, Inc.	08 Apr 2019
Metastatic breast cancer	Canada	Eli Lilly Canada, Inc.	08 Apr 2019
HR Positive/HER2 Negative/Node positive breast cancer	European Union	Eli Lilly Nederland BV	26 Sep 2018
HR Positive/HER2 Negative/Node positive breast cancer	Iceland	Eli Lilly Nederland BV	26 Sep 2018
HR Positive/HER2 Negative/Node positive breast cancer	Liechtenstein	Eli Lilly Nederland BV	26 Sep 2018
HR Positive/HER2 Negative/Node positive breast cancer	Norway	Eli Lilly Nederland BV	26 Sep 2018
Hormone receptor positive HER2 negative breast cancer	United States	Eli Lilly & Co.	28 Sep 2017

Developing

10 top R&D records.

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Indication	Highest Phase	Country/Location	Organization	Date
Castration-sensitive prostate cancer	Phase 3	United States	Eli Lilly & Co.	14 Apr 2022
Castration-sensitive prostate cancer	Phase 3	China	Eli Lilly & Co.	14 Apr 2022
Castration-sensitive prostate cancer	Phase 3	Japan	Eli Lilly & Co.	14 Apr 2022
Castration-sensitive prostate cancer	Phase 3	Argentina	Eli Lilly & Co.	14 Apr 2022
Castration-sensitive prostate cancer	Phase 3	Australia	Eli Lilly & Co.	14 Apr 2022
Castration-sensitive prostate cancer	Phase 3	Belgium	Eli Lilly & Co.	14 Apr 2022
Castration-sensitive prostate cancer	Phase 3	Brazil	Eli Lilly & Co.	14 Apr 2022
Castration-sensitive prostate cancer	Phase 3	Canada	Eli Lilly & Co.	14 Apr 2022
Castration-sensitive prostate cancer	Phase 3	Czechia	Eli Lilly & Co.	14 Apr 2022
Castration-sensitive prostate cancer	Phase 3	France	Eli Lilly & Co.	14 Apr 2022

Clinical Result

Indication

Phase

Evaluation

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Study	Phase	Population	Analyzed Enrollment	Group	Results	Evaluation	Publication Date


NCT06630325 (CTgov)	Phase 2	Ovarian Cancer \| Advanced Malignant Solid Neoplasm \| Pancreatic Cancer ... View more	6	Survey Administration+Abemaciclib+Gemcitabine (Arm I (Abemaciclib, Gemcitabine))	iukwxqldms(ydyzfszsiz) = hzclkkaduj qjqtzwzeav (erzrmssobe, jbxqqjdqod - xdnmbpphov) View more	-	28 Apr 2026
				Survey Administration+abemaciclib+Pemetrexed (Arm II (Abemaciclib, Pemetrexed))	iukwxqldms(ydyzfszsiz) = lviqodovpg qjqtzwzeav (erzrmssobe, phfmnevssk - fseggftssw) View more
NCT05714072 (AACR2026)	Phase 1	Myelofibrosis	11	Ruxolitinib + Abemaciclib	hktstosyyn(wfwgcybwol) = anemia (n=2) and neutropenia (n=1) lwkstamrro (bvwveabxkc ) View more	Positive	21 Apr 2026
AACR2026	Phase 2/3	Hormone receptor positive HER2 negative breast cancer HR Positive \| HER2 Negative	16	Imlunestrant alone	dggrvokezk(agsdpffalv) = mgnoevzwbv htbknlzumu (coeajdooby ) View more	Positive	21 Apr 2026
				Camizestrant 75mg	dggrvokezk(ijffuxnjre) = jsofieuwbo ctbzclevxh (kwzuxjrvot ) View more
NCT04293393 (CARABELA, CTgov)	Phase 2	HR Positive/HER2 Negative/Node positive breast cancer \| Early Stage Breast Carcinoma	200	Taxane+Cyclophosphamide+Doxorubicin (Arm A: Doxorubicin Plus Cyclophosphamide and Taxane)	zvqnuzdhme = coznjxqonj cwevmbrncv (vuknwdbfkg, ohxhpydksy - qiirhzoqnd) View more	-	12 Mar 2026
				LHRH Analogue+Letrozole+abemaciclib (Arm B: Letrozole Plus Abemaciclib +/- LHRH)	zvqnuzdhme = svncqwavvx cwevmbrncv (vuknwdbfkg, asibzmjkxs - wsmhkfybau) View more
NCT05440786 (CTgov)	Phase 2	Neoplasm Metastasis \| Recurrent Ewing Sarcoma	46	Temozolomide+abemaciclib+Irinotecan (Abemaciclib + Irinotecan +Temozolomide)	rrgcrkmjjv(xolayxekjf) = mqrzzstwhn xajnbdcnof (cuhmkoaykp, yzvwkrlkyg - nyflwheqsj) View more	-	12 Mar 2026
				Temozolomide+Irinotecan (Irinotecan +Temozolomide)	rrgcrkmjjv(xolayxekjf) = hcqczicwsq xajnbdcnof (cuhmkoaykp, futmllanke - omsxowhjqv) View more
ESGO2026	Phase 1/2	Ovarian Serous Adenocarcinoma	70	Ribociclib + letrozole	dpfdczazsq(xzykozoivz) = hqxhojqltf yiedrbgzog (kujffqjwtd ) View more	Positive	28 Feb 2026
				Ribociclib + letrozole	dpfdczazsq(xzykozoivz) = kwhauwzkbu yiedrbgzog (kujffqjwtd )
SABCS2025	Not Applicable	HR Positive/HER2 Negative/Node positive breast cancer Adjuvant HR+ \| HER2-	1,063	Abemaciclib 150 mg BID	jjnibwerad(fmfzuxpkhw) = onxferyvui unqveztjab (nonxesoswr ) View more	Positive	12 Dec 2025
				Abemaciclib 150 mg BID (No Dose reductions)	jjnibwerad(fmfzuxpkhw) = esbiruhjyb unqveztjab (nonxesoswr ) View more
SABCS2025	Not Applicable	Hormone receptor positive HER2 negative breast cancer HR+/HER2−	199	Abemaciclib + Fulvestrant or Aromatase Inhibitor (Endocrine resistant (ER))	uwahnsksaf(ywckvxacza) = tkqqixfpwc tybtwgjmbz (hvagwspbpx ) View more	Positive	12 Dec 2025
				Abemaciclib + Fulvestrant or Aromatase Inhibitor (Endocrine-sensitive (ES))	uwahnsksaf(ywckvxacza) = regffddkko tybtwgjmbz (hvagwspbpx ) View more
NCT04158362 (AMBRE, SABCS2025)	Phase 3	First line HR+ \| HER2-	180	Abemaciclib + ET (letrozole or fulvestrant ± OFS)	tbbkwzqufx(ngpodkhbnk) = olrekzcdsu bkoqvvbtli (ngkmiwrjmy ) View more	Positive	11 Dec 2025
				CT (weekly paclitaxel or capecitabine)	tbbkwzqufx(ngpodkhbnk) = safpoyinjc bkoqvvbtli (ngkmiwrjmy )
SABCS2025	Not Applicable	Hormone receptor positive HER2 negative breast cancer Adjuvant	714	Abemaciclib combined with an aromatase inhibitor	cpljfchxlt(mkbzjoplrv) = ewcqhnphwc zsduxaaomx (lqkexkoytj ) View more	Positive	11 Dec 2025

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