Jiangsu Hengrui Pharmaceuticals' independently developed CDK4/6 inhibitor hydroxyethyl sulfonate dalsalic tablets has received approval for new indications by the National Medical Products Administration.

Jiangsu Hengrui Pharmaceuticals (01276) announced that, recently, Jiangsu Hengrui Pharmaceuticals Co., Ltd. ("the Company") received a notification from the National Medical Products Administration ("NMPA") approving the Company's independently developed CDK4/6 inhibitor hydroxyethanesulfonic acid darzel side tablets for a new indication. Darzel side was first approved for marketing in China in 2021 and currently has two approved indications: 1. This product is suitable for patients with hormone receptor (HR) positive, human epidermal growth factor receptor 2 (HER2) negative locally advanced or metastatic breast cancer: used in combination with aromatase inhibitors as initial endocrine therapy; 2. Used in combination with fulvestrant for patients whose disease has progressed after previous endocrine therapy. Breast cancer ranks among the leading cancers in terms of incidence and mortality rates among women globally, posing a serious threat to women's health. The 2024 Chinese Malignant Tumor Incidence and Mortality Data Analysis Report shows that there are 376,000 new cases of breast cancer in Chinese women each year. HR+/HER2- breast cancer is the most common molecular subtype in clinical practice, accounting for about 70% of all cases. Studies have shown that even after receiving standard adjuvant endocrine therapy, some HR+/HER2- early breast cancer patients still face a continuous risk of recurrence for up to 20 years. Previously available CDK4/6 inhibitors in China for adjuvant therapy in HR+/HER2- early breast cancer mainly relied on evidence from Western populations. However, Chinese breast cancer patients have genetic backgrounds, biological characteristics, and clinical diagnoses and treatments that differ somewhat from those abroad, such as a relatively younger age of onset, with a median age of diagnosis of about 45-49 years, a higher risk of recurrence, and 62.9% of women being diagnosed before menopause, making it relatively more difficult to treat. There is an urgent need to explore treatment options that are more closely aligned with the diagnosis and treatment status of Chinese HR+/HER2- early breast cancer patients. Hydroxyethanesulfonic acid darzel side tablets are orally administered, highly effective, selective small molecule CDK4/6 inhibitors developed independently by the Company. The approval of this new indication is based on a large Phase III clinical trial (study code: DAWNA-A) with a positive outcome, which was multicenter, randomized, double-blind, and placebo-controlled. The DAWNA-A study is the first Phase III clinical study of adjuvant therapy for early breast cancer in high-risk patients based on a 100% Chinese population and achieving positive results. The study included 5,274 Chinese patients with stage II-III HR+/HER2- early high-risk breast cancer, with approximately 60% being premenopausal/perimenopausal, closely matching the characteristics of the Chinese breast cancer population. The first interim analysis results showed that at a median follow-up of 20.3 months, the darzel side combined with endocrine therapy group significantly improved invasive disease-free survival (IDFS) compared to the placebo group, with an absolute benefit rate of 4.5% at 2 years (94.7% vs. 90.2%), reducing the risk of disease progression or death by 44.5% (HR=0.56, 95% CI: 0.43-0.71, P<0.0001). Updated second interim analysis results showed that at a median follow-up of 27.0 months, the IDFS benefit of darzel side combined with endocrine therapy continued, with a 3-year absolute benefit rate of 3.2% (90.6% vs. 87.4%), significantly reducing the risk of disease recurrence or death by 40.0% (HR=0.60, 95% CI: 0.49-0.74). The IDFS benefit was consistent across all subgroups. Disease-free survival (DFS) and distant disease-free survival (DDFS) also showed significant improvements. The approval of this indication for darzel side signifies the expansion of its clinical layout in breast cancer from late-stage to adjuvant therapy in early-stage, filling the gap in the field of early adjuvant therapy for HR+/HER2- breast cancer with Chinese-developed CDK4/6 inhibitors. Currently, the use of darzel side in combination with endocrine adjuvant therapy for HR+/HER2- early high-risk breast cancer has officially been included in the 2026 version of the Chinese Society of Clinical Oncology (CSCO) Breast Cancer Diagnosis and Treatment Guidelines and the 2026 version of the Chinese Anti-Cancer Association Breast Cancer Diagnosis and Treatment Guidelines and Standards. There are various similar products approved for marketing domestically and internationally, such as Pfizer's Palbociclib (brand name Ibrance), Novartis's Ribociclib (brand name Kisqali), and Eli Lilly's Abemaciclib (brand name Verzenio). Among them, there are only two products approved domestically for the early adjuvant treatment indication of breast cancer, which are Ribociclib and Abemaciclib. According to the EvaluatePharma database, the total global sales of the above similar products in 2025 were approximately $14.637 billion. As of now, the cumulative research and development investment in hydroxyethanesulfonic acid darzel side tablets projects is approximately 128,702,000 yuan (unaudited).