Acquisition adds navtemadlin, a late-stage rare blood cancer asset in Phase III. This hemato-oncology program in myelofibrosis expands Ipsen’s growing Oncology portfolio

此次收购增加了navtemadlin，这是一种处于III期临床阶段的晚期罕见血液癌症资产。该针对骨髓纤维化的血液肿瘤项目扩大了Ipsen不断增长的肿瘤产品组合。

Navtemadlin, an oral MDM2 inhibitor, has the potential, through disease modifying activity, to transform suboptimal responses to standard of care ruxolitinib into clinically meaningful responses in patients with myelofibrosis

Navtemadlin 是一种口服 MDM2 抑制剂，凭借其疾病修饰活性，有望将骨髓纤维化患者对标准治疗药物鲁索替尼的欠佳反应转化为具有临床意义的反应。

Top-line data from the ongoing Phase III registrational trial POIESIS is expected in 2027

正在进行中的III期注册临床试验POIESIS的顶线数据预计将于2027年公布

PARIS, FRANCE AND REDWOOD CITY, U.S.

法国巴黎和美国红木城

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29 JUNE 2026

2026年6月29日

– Ipsen (Euronext: IPN; ADR: IPSEY) and Kartos Therapeutics, announced today they have entered into a definitive merger agreement under which Ipsen has agreed to acquire Kartos Therapeutics. The acquisition adds navtemadlin, an investigational MDM2 inhibitor designed to restore the natural tumor-suppressing function of p53, a critical tumor-suppressor in myelofibrosis.

– 益普生（Euronext: IPN；ADR: IPSEY）与 Kartos Therapeutics 今日宣布，双方已签订最终合并协议，根据该协议，益普生同意收购 Kartos Therapeutics。此次收购将 navtemadlin 纳入旗下，这是一种在研的 MDM2 抑制剂，旨在恢复 p53 的自然肿瘤抑制功能，而 p53 是骨髓纤维化中的一种关键肿瘤抑制因子。

Data show strong therapeutic potential of navtemadlin for intermediate and high-risk TP53 wild-type (wt) myelofibrosis as an add-on treatment for patients with a suboptimal response to standard of care ruxolitinib. .

数据显示，作为对标准治疗药物鲁索替尼反应不佳患者的附加治疗，navtemadlin 在中高危 TP53 野生型（wt）骨髓纤维化患者中展现出强大的治疗潜力。

“This acquisition further strengthens our late-stage oncology pipeline and reflects our continued focus on bringing transformational treatments to people living with cancer,” said David Loew, CEO, Ipsen. “We are excited by the potential of navtemadlin to define a new treatment paradigm for patients with myelofibrosis who have a suboptimal response to current standard of care, addressing a critical care gap and offering the potential for a new therapeutic option as early as 2028.”.

益普生首席执行官David Loew表示：“此次收购进一步强化了我们在肿瘤后期研发管线的布局，也体现了我们持续致力于为癌症患者带来变革性治疗方案的承诺。我们对navtemadlin的潜力感到振奋，它有望为对现有标准疗法反应不佳的骨髓纤维化患者确立全新的治疗范式，填补关键的治疗空白，并最早在2028年提供一种新的治疗选择。”

Current standard of care ruxolitinib improves splenomegaly and myelofibrosis-related symptoms. However, a significant proportion of patients experience a suboptimal response to ruxolitinib, resulting in treatment discontinuation. Patient outcomes after ruxolitinib discontinuation are dismal, with a median overall survival of approximately 1-2 years.

目前的标准治疗药物鲁索替尼可改善脾肿大和骨髓纤维化相关症状。然而，相当比例的患者对鲁索替尼的反应不佳，导致治疗中断。患者在停用鲁索替尼后的预后极差，中位总生存期约为1至2年。

Navtemadlin is currently being evaluated in the global Phase III trial POIESIS designed to enroll >600 patients across >250 sites, as an add-on therapy to standard of care ruxolitinib in patients with intermediate and high-risk TP53.

Navtemadlin 目前正在全球 III 期临床试验 POIESIS 中进行评估，该试验计划在超过 250 个中心入组超过 600 名患者，作为标准治疗药物鲁索替尼的附加疗法，用于中危和高危 TP53 突变患者。

wt

wt

myelofibrosis who have a suboptimal response to ruxolitinib. The trial builds on earlier clinical evidence, including a Phase Ib/II trial (KRT-232-109) in which add-on navtemadlin demonstrated clinically meaningful and disease-modifying activity in myelofibrosis patients who had a suboptimal response to standard of care ruxolitinib.

对鲁索替尼反应不佳的骨髓纤维化患者。该试验建立在早期临床证据的基础上，包括一项 Ib/II 期试验（KRT-232-109），其中在标准治疗鲁索替尼反应不佳的骨髓纤维化患者中，附加使用 navtemadlin 显示出具有临床意义且能改变疾病进程的作用。

Data presented at the European Hematology Association Congress in 2023 showed that at Week 24, in patients with a suboptimal response to ruxolitinib (n=19), 42% achieved at least a 25% reduction in spleen volume, 32% achieved at least a 35% reduction in spleen volume, and 32% achieved a total symptom score improvement of at least 50%.

2023年欧洲血液学协会大会公布的数据显示，在第24周时，在对鲁索替尼反应不佳的患者（n=19）中，42%的患者脾脏体积减少至少25%，32%的患者脾脏体积减少至少35%，32%患者的总症状评分改善至少50%。

These data also showed potential disease modification activity of navtemadlin, as evidenced by 71% of evaluable patients (n=7) achieving a ≥20% reduction of driver variant allele frequency and 57% showing an improvement in bone marrow fibrosis by Central Review of ≥1 Grade by Week 24..

这些数据还显示了navtemadlin潜在的疾病修饰活性，表现为71%的可评估患者（n=7）实现了驱动基因变异等位基因频率降低≥20%，并且57%的患者在第24周时通过中心审评显示骨髓纤维化改善≥1级。

Srdan Verstovsek, MD, PhD, Chief Medical Officer of Kartos Therapeutics, commented, “As a treating clinician who cared for more than a thousand patients with myelofibrosis, I have seen first-hand the significant care gap for patients with myelofibrosis who remain symptomatic or have persistent splenomegaly despite ruxolitinib treatment.

Kartos Therapeutics 首席医学官 Srdan Verstovsek 医学博士、哲学博士评论道：“作为一名诊治过一千多名骨髓纤维化患者的临床医生，我亲眼目睹了那些尽管接受鲁索替尼治疗但仍存在症状或持续性脾肿大的骨髓纤维化患者所面临的巨大诊疗缺口。

Navtemadlin has the potential to enhance the existing standard of care through an add-on approach designed to move patients with a suboptimal response into a clinical responder group by optimizing their care. We believe this innovative treatment paradigm could meaningfully improve outcomes for patients while avoiding unnecessary over-treatment of those already responding well.”.

Navtemadlin 有望通过一种附加治疗策略，优化现有标准治疗方案，使对当前治疗反应不佳的患者转变为临床应答者，从而提升整体疗效。我们相信，这种创新的治疗模式能够在避免对已良好应答患者进行不必要过度治疗的同时，显著改善患者的临床结局。

“Myelofibrosis remains a serious and rare blood cancer associated with a substantial symptom burden and progressive splenomegaly that significantly impact quality of life,” said John Mascarenhas, Professor of Medicine at the Icahn School of Medicine at Mount Sinai and Director of the Center of Excellence for Blood Cancers and Myeloid Disorders.

“骨髓纤维化仍然是一种严重且罕见的血液癌症，伴有严重的症状负担和进行性脾肿大，对生活质量产生重大影响。”西奈山伊坎医学院医学教授、血液癌症和髓系疾病卓越中心主任约翰·马斯卡雷尼亚斯说。

“The clinical rationale for combining navtemadlin with ruxolitinib is very compelling, and the emerging data suggest the synergistic potential to deepen responses and address the underlying biology of the disease.” .

“将navtemadlin与ruxolitinib联合使用的临床依据非常有力，初步数据表明其具有协同作用潜力，可加深治疗反应并针对疾病的根本生物学机制。”

“The Phase III POIESIS trial has the potential to redefine how we treat patients with myelofibrosis,” said Dr Pankit Vachhani, Associate Professor of Medicine and Director of Clinical Research Unit at the University of Alabama at Birmingham, and Global Principal Investigator of POIESIS. “It is the largest trial conducted in this disease and uniquely designed to reflect real-world clinical practice.

“III期POIESIS试验有可能重新定义我们治疗骨髓纤维化患者的方式，”阿拉巴马大学伯明翰分校医学副教授、临床研究单元主任兼POIESIS全球主要研究者Pankit Vachhani博士表示。“这是在该疾病领域开展的最大规模试验，其设计独特，旨在反映真实世界的临床实践。”

The trial evaluates how adding navtemadlin can deliver more clinically meaningful and durable responses, thereby addressing a critical unmet need. I am excited by the prospect of navtemadlin delivering disease modifying benefits, ushering an era of rational combination therapies for those with suboptimal response to standard therapy, and targeting complementary disease pathways beyond JAK inhibition alone in myelofibrosis.”.

该试验评估了加入navtemadlin如何能够带来更具临床意义且更持久的缓解，从而解决一个关键的未满足需求。我对navtemadlin可能带来的疾病修饰益处感到兴奋，它为对标准治疗反应不佳的患者开启了合理联合治疗的新时代，并在骨髓纤维化中针对除JAK抑制之外的互补疾病通路。”

Transaction details

交易详情

Under the terms of the agreement and plan of merger, Ipsen through a fully-owned subsidiary, will pay $450 million upfront at closing. Kartos Therapeutics shareholders are also eligible to receive additional milestone payments of up to $1.3 billion including a significant regulatory approval milestone and sales-based milestones..

根据合并协议和计划的条款，益普生（Ipsen）将通过一家全资子公司在交易完成时支付4.5亿美元的预付款。Kartos Therapeutics的股东还有资格获得高达13亿美元的额外里程碑付款，其中包括一项重大的监管批准里程碑以及基于销售的里程碑付款。

This late-stage transaction is expected to be accretive to Ipsen’s core operating income from 2029, with limited dilution to 2026 full-year guidance. The transaction is anticipated to close by the end of Q3 2026, subject to fulfilment of customary closing conditions including the expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act..

这笔后期交易预计将从2029年起对益普生（Ipsen）的核心营业利润产生增厚效应，而对2026年全年业绩指引的稀释影响有限。该交易预计将在2026年第三季度末前完成，前提是满足惯例交割条件，包括《哈特-斯科特-罗迪诺反托拉斯改进法》规定的等待期届满。

Advisors

顾问

Orrick Herrington & Sutcliffe LLP (DC office) is acting as legal counsel to Ipsen. Goldman Sachs & Co. LLC and PJT Partners (UK) Ltd are serving as financial advisors to KARTOS THERAPEUTICS. DLA Piper LLP (NY office) is serving as legal counsel to KARTOS THERAPEUTICS.

Orrick Herrington & Sutcliffe LLP（华盛顿特区办公室）担任益普生的法律顾问。高盛有限责任公司和PJT Partners（英国）有限公司担任KARTOS THERAPEUTICS的财务顾问。DLA Piper LLP（纽约办公室）担任KARTOS THERAPEUTICS的法律顾问。

About navtemadlin

关于 navtemadlin

Navtemadlin is an investigational oral MDM2 inhibitor being developed as an add-on therapy to ruxolitinib for patients with myelofibrosis who have a suboptimal response to ruxolitinib. The Phase III POIESIS study is evaluating whether the addition of navtemadlin could improve clinical outcomes compared with ruxolitinib alone in this patient population.

Navtemadlin 是一种在研的口服 MDM2 抑制剂，正在开发作为鲁索替尼的附加疗法，用于对鲁索替尼反应不佳的骨髓纤维化患者。III 期 POIESIS 研究正在评估在此类患者人群中，与单用鲁索替尼相比，加用 navtemadlin 是否能改善临床结局。

Early clinical data demonstrate navtemadlin has the potential to transform suboptimal responses to standard of care ruxolitinib into clinically meaningful responses in patients with intermediate and high risk TP53wt myelofibrosis, to provide both enhanced clinical outcomes and potential disease-modifying benefit.

早期临床数据表明，navtemadlin 有望将中间和高危 TP53 野生型骨髓纤维化患者对标准治疗药物 ruxolitinib 的欠佳反应转化为具有临床意义的反应，从而提供更优的临床结局并带来潜在的疾病修饰获益。

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About myelofibrosis

关于骨髓纤维化

Myelofibrosis is a myeloproliferative neoplasm, frequently linked to alterations in the JAK/STAT pathway, in which patients develop bone marrow fibrosis due to the abnormal proliferation of hematopoietic stem cells and secretion of fibrogenic cytokines. As marrow function declines, blood production shifts to other organs, most often the spleen, leading to splenomegaly.

骨髓纤维化是一种骨髓增殖性肿瘤，常与JAK/STAT通路的改变相关。患者因造血干细胞异常增殖及致纤维化细胞因子的分泌，导致骨髓纤维化。随着骨髓功能衰退，造血活动转移至其他器官（最常见为脾脏），从而引起脾肿大。

Myelofibrosis is characterized by bone marrow failure, fibrosis, splenomegaly and a high symptom burden that can significantly affect quality of life, including fatigue, night sweats and other progressive symptoms. It also carries a risk of transformation to acute myeloid leukemia. The median age at diagnosis is approximately 67–69 years and the condition affects around 1.5 per 100,000 people in the U.S.

骨髓纤维化的特征为骨髓衰竭、纤维化、脾肿大以及高症状负担，包括疲劳、盗汗和其他进行性症状，这些可显著影响生活质量。该病还存在转化为急性髓系白血病的风险。诊断时的中位年龄约为67至69岁，在美国，该病的患病率约为每10万人中1.5例。

and Europe. Approximately 75–89% of patients are intermediate- or high-risk at diagnosis and more than 95% are TP53wt. Ruxolitinib, a JAK inhibitor, is the first-line standard of care; however, it is estimated that a significant proportion of patients have an initial suboptimal response and approximately 50%-75% discontinue treatment after three years.

以及欧洲。约75–89%的患者在诊断时属于中危或高危，超过95%的患者为TP53野生型。芦可替尼是一种JAK抑制剂，为一线标准治疗方案；然而，据估计，相当比例的患者初始反应不佳，且约50%-75%的患者在三年后停止治疗。

Median overall survival is typically one to two years after treatment discontinuation, underscoring the need for new strategies that can increase the number of patients that can achieve optimal clinical outcomes..

中位总生存期通常在治疗中止后的一到两年，这凸显了需要新的策略来增加能够实现最佳临床结果的患者数量。

About Ipsen

关于益普生

We are a global biopharmaceutical company with a focus on bringing transformative medicines to patients in three therapeutic areas: Oncology, Rare Disease and Neuroscience. Our pipeline is fueled by internal and external innovation and supported by nearly 100 years of development experience and global hubs in the U.S., France and the U.K.

我们是一家全球性生物制药公司，专注于在肿瘤学、罕见病和神经科学三大治疗领域为患者带来变革性药物。我们的研发管线由内部和外部创新共同驱动，并依托近百年开发经验以及位于美国、法国和英国的全球研发中心提供支持。

Our teams in more than 40 countries and our partnerships around the world enable us to bring medicines to patients in more than 100 countries..

我们在40多个国家的团队以及遍布全球的合作伙伴关系，使我们能够将药品提供给100多个国家的患者。

Ipsen is listed in Paris (Euronext: IPN) and in the U.S. through a Sponsored Level I American Depositary Receipt program (ADR: IPSEY). For more information, visit

益普生（Ipsen）在巴黎证券交易所上市（泛欧交易所代码：IPN），并通过赞助一级美国存托凭证计划在美国上市（ADR代码：IPSEY）。更多信息，请访问

ipsen.com

ipsen.com

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About Kartos Therapeutics

关于 Kartos Therapeutics

Kartos Therapeutics is a clinical-stage biopharmaceutical company developing navtemadlin, a potential best-in-class MDM2 inhibitor. The company is focused on harnessing the therapeutic potential of p53 pathway activation to develop innovative treatments for patients with myeloproliferative neoplasms, including myelofibrosis, where substantial unmet medical need persists..

Kartos Therapeutics 是一家临床阶段的生物制药公司，正在开发 navtemadlin，这是一种潜在的同类最佳 MDM2 抑制剂。该公司专注于利用 p53 通路激活的治疗潜力，为骨髓增殖性肿瘤（包括骨髓纤维化）患者开发创新疗法，这些领域仍存在巨大的未满足医疗需求。

Ipsen Contacts

Ipsen 联系方式

Investors

投资者

Henry Wheeler

亨利·惠勒

henry.wheeler@ipsen.com

henry.wheeler@ipsen.com

+33 7 66 47 11 49

+33 7 66 47 11 49

Khalid Deojee

哈立德·德奥吉

khalid.deojee@ipsen.com

khalid.deojee@ipsen.com

+33 6 66 01 95 26

+33 6 66 01 95 26

Media

媒体

Sally Bain

萨莉·贝恩

sally.bain@ipsen.com

sally.bain@ipsen.com

+1 857 320 0517

+1 857 320 0517

Anne Liontas

安妮·利昂塔斯

anne.liontas.ext@ipsen.com

anne.liontas.ext@ipsen.com

+33 7 67 34 72 96

+33 7 67 34 72 96

Disclaimers and/or forward-looking statements

免责声明和/或前瞻性陈述

The forward-looking statements, objectives and targets contained herein are based on Ipsen’s management strategy, current views and assumptions. Such statements involve known and unknown risks and uncertainties that may cause actual results, performance or events to differ materially from those anticipated herein.

本文所载的前瞻性陈述、目标和指标基于益普生（Ipsen）的管理层战略、当前观点及假设。此类陈述涉及已知和未知的风险与不确定性，可能导致实际结果、业绩或事件与本文预期存在重大差异。

All of the above risks could affect Ipsen’s future ability to achieve its financial targets, which were set assuming reasonable macroeconomic conditions based on the information available today. Use of the words ‘believes’, ‘anticipates’ and ‘expects’ and similar expressions are intended to identify forward-looking statements, including Ipsen’s expectations regarding future events, including regulatory filings and determinations.

上述所有风险均可能影响益普生未来实现其财务目标的能力，这些财务目标是在基于当前可用信息假设合理的宏观经济条件下设定的。使用“相信”、“预计”和“预期”等词语及类似表述旨在识别前瞻性陈述，包括益普生对未来事件（含监管申报和决定）的预期。

Moreover, the targets described in this document were prepared without taking into account external-growth assumptions and potential future acquisitions, which may alter these parameters. These objectives are based on data and assumptions regarded as reasonable by Ipsen. These targets depend on conditions or facts likely to happen in the future, and not exclusively on historical data.

此外，本文所述目标在编制时未考虑外部增长假设及潜在的未来收购事项，而这些因素可能会改变相关参数。这些目标基于益普生（Ipsen）认为合理的数据和假设。这些目标的实现取决于未来可能发生的情况或事实，而不仅仅依赖于历史数据。

Actual results may depart significantly from these targets given the occurrence of certain risks and uncertainties, notably the fact that a promising medicine in early development phase or clinical trial may end up never being launched on the market or reaching its commercial targets, notably for regulatory or competition reasons.

鉴于某些风险和不确定性的存在，实际结果可能与这些目标存在显著差异，尤其是处于早期开发阶段或临床试验阶段的有前景药物可能最终无法上市或实现其商业目标，这主要可能是由于监管或竞争原因所致。

Ipsen must face or might face competition from generic medicine that might translate into a loss of market share. Furthermore, the research and development process involves several stages each of which involves the substantial risk that Ipsen may fail to achieve its objectives and be forced to abandon its efforts with regards t.

伊普森必须面对或可能面临来自仿制药的竞争，这可能导致其市场份额流失。此外，研发过程包含多个阶段，每个阶段都存在伊普森未能实现目标并被迫放弃相关努力的重大风险。

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Attachment

附件

Ipsen PR_Ipsen to acquire Kartos Therapeutics_29062025

益普生公关_益普生将收购Kartos Therapeutics_2025年6月29日