Guoxin Securities·2025-08-07 15:20Investment Rating - The report maintains an "Outperform" rating for the industry [1] Core Insights - There is an unmet clinical need in HR+/HER2- breast cancer (BC), which accounts for approximately 60-70% of all breast cancer cases globally [2][8] - New mechanism drugs are expected to extend chemotherapy-free survival for HR+/HER2- BC patients, with a focus on overcoming resistance to endocrine therapy (ET) and enhancing the efficacy of CDK4/6 inhibitors [2][40] - The report highlights the potential of various new target molecules and mechanisms to improve patient outcomes and expand market size [2][40] Summary by Sections 1. Unmet Clinical Needs in HR+/HER2- BC - HR+/HER2- BC is the most common subtype of breast cancer, with significant unmet clinical needs, especially for patients with specific mutations [2][8] - Current treatment options, including ET and CDK4/6 inhibitors, are limited for patients who progress after first-line therapy [2][40] 2. Endocrine Therapy: New Mechanism Molecules to Overcome Resistance - New generation oral SERDs and ER PROTACs are promising in overcoming resistance caused by ESR1 mutations [2][40] - The estrogen signaling pathway plays a critical role in breast cancer, and targeting this pathway is essential for effective treatment [13][48] 3. CDK Inhibitors: Partners in ET to Extend Treatment Duration - CDK4/6 inhibitors significantly improve progression-free survival (PFS) when combined with ET in first-line treatment [14][25] - There is a need for new mechanism molecules targeting the CDK-cyclin pathway to address resistance after first-line therapy [2][40] 4. Other New Target Molecules: Potential to Extend Chemotherapy-Free Survival - Activation of the PI3K/AKT/mTOR pathway is a common resistance mechanism in HR+/HER2- BC, with several products already approved for treatment [2][40] - New targets such as KAT6i and ADCs are expected to show advantages over chemotherapy and occupy significant positions in treatment sequences [2][40] 5. Company Analysis - Companies leading in the development of new mechanism drugs include BeiGene, Hansoh Pharmaceutical, Kelun-Botai Biopharmaceutical, and China National Pharmaceutical Group [2][40]