China’s First and Currently Only Oral Selective Estrogen Receptor Degrader, Zeshuo® (Elacestrant), Approved — Combination Regimen Receives First Global Approval

• It is estimated that approximately 20%-40% of patients with ER+, HER2- metastatic breast cancer develop ESR1 mutations during or after treatment with aromatase inhibitors^[1];
• According to data from the EMBER-3 trial, among patients with ESR1 mutations, imlunestrant monotherapy extended median overall survival (OS) by 11.4 months compared to endocrine therapy (ET)^[2];
• Furthermore, in the ESR1 mutation subgroup, the combination of imlunestrant with abemaciclib achieved a median progression-free survival (PFS) of 11.1 months, reducing the risk of disease progression or death by 51%^[2];
• Imlunestrant has been approved in China, addressing the challenge of endocrine resistance in advanced breast cancer through its innovative mechanism of precisely targeting ESR1 mutations.

ShanghaiJune 23, 2026 /PRNewswire/ — Today, Eli Lilly and Company announced that its product, Zexu^® (imlunestrant), has been approved by the National Medical Products Administration for use as monotherapy or in combination with abemaciclib for the treatment of adult patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-), ESR1-mutated locally advanced or metastatic breast cancer who have previously received endocrine therapy. The approval of imlunestrant in China marks it as the first and currently only approved oral selective estrogen receptor degrader (SERD) in the domestic breast cancer field, successfully filling the clinical gap in treating endocrine-resistant breast cancer caused by ESR1 mutations. Its combination regimen with abemaciclib has achieved a first-in-the-world approval in the Chinese market, ahead of other global markets, enabling more Chinese breast cancer patients with ESR1 mutations to access innovative treatment options.

As a next-generation oral SERD independently developed by Eli Lilly, imlunestrant binds to and blocks the estrogen receptor while promoting its degradation, thereby helping to delay disease progression. The drug is administered once daily, offering patients a new oral treatment option that aligns with the need for chronic disease management in breast cancer, helping to advance China’s breast cancer diagnosis and treatment into a new phase.

Breast cancer is the leading cause of cancer death among women globally and the most common malignancy among Chinese women^[3]; among these, the ER+, HER2- subtype accounts for approximately 70%^[4]. Endocrine therapy is the cornerstone of treatment for this subtype, but about 20%-40% of patients develop ESR1 mutations during or after prior endocrine therapy (particularly aromatase inhibitors)^[1], leading to sustained overactivation of the estrogen receptor and subsequent treatment resistance. There is an urgent clinical need for novel therapeutic strategies that are more specifically targeted against ESR1 mutations.

Dehe Lan, Vice President of Eli Lilly and Company and General Manager of Lilly China, stated: “The approval of imlunestrant in China brings a new precision treatment option for Chinese advanced breast cancer patients with ESR1 mutations and endocrine resistance. This is not only the first and currently only oral SERD in China, but its combination regimen has also achieved a global first approval, highlighting the ‘China speed’ in innovative drug access and serving as a significant testament to Lilly’s 150-year commitment to the principle of ‘health first.’ Moving forward, Lilly will continue to accelerate the introduction of innovative drugs and actively promote their accessibility to benefit more Chinese cancer patients.”

Dr. Wang Li, Senior Vice President of Eli Lilly and Company and Head of Lilly China Drug Development and Medical Affairs Center, stated: “In the oncology field, Lilly has long been dedicated to providing innovative solutions for cancer patients. The approval of imlunestrant in China represents another important milestone for Lilly in the breast cancer arena and further underscores China’s significant role in driving the continuous optimization of the global treatment landscape. The EMBER-3 study showed that in patients with ESR1 mutations, whether as monotherapy or in combination with abemaciclib, imlunestrant reduced the risk of disease progression or death, filling a clinical gap in the relevant treatment area and bringing new hope to Chinese advanced breast cancer patients. In the future, Lilly will continue to deepen global R&D collaboration to bring more life-changing innovative therapies to Chinese cancer patients.”

This approval is based on the global Phase III EMBER-3 study of imlunestrant. The study enrolled 874 patients worldwide with ER+, HER2- advanced breast cancer who experienced disease recurrence or progression during or after treatment with aromatase inhibitors. It evaluated the efficacy and safety of imlunestrant monotherapy compared to standard endocrine therapy (fulvestrant or exemestane), as well as imlunestrant combined with abemaciclib compared to monotherapy. Results showed that in patients with ESR1 mutations, imlunestrant monotherapy significantly prolonged progression-free survival (PFS), with a median PFS of 5.5 months, reducing the risk of disease progression or death by 38%; imlunestrant combined with abemaciclib extended median PFS to 11.1 months, reducing the risk of disease progression or death by 51%^[2].

Professor Zhang Qingyuan, Chief Physician at Harbin Medical University Cancer Hospital and Lead Chinese Investigator of the EMBER-3 clinical trial, emphasized: “The clinical value of the next-generation oral SERD imlunestrant, both as monotherapy and in combination therapy, has been recognized by the academic community and recommended by the Chinese Anti-Cancer Association Guidelines and Standards for Breast Cancer Diagnosis and Treatment (2026 Edition)^[5]. The dual-indication approval in China adds a powerful tool to precision breast cancer treatment domestically. Precision treatment relies on precise patient identification. The updated guidelines place strong emphasis on genetic testing. We advocate for incorporating ESR1 testing into the routine clinical workflow for ER+, HER2- advanced breast cancer. For patients who experience recurrence or progression during endocrine therapy, routine ESR1 mutation testing is recommended to translate guidelines into practice and safeguard patient health.”

Disclaimer: If you wish to learn more about disease-related information, please consult a healthcare professional. This content is supported by Lilly China.

Approval Number: CMAT-34546