Core Viewpoint - PROTAC drugs target and degrade pathogenic proteins, offering significant clinical value and potential as oral small molecule drugs, with ER PROTAC and AR PROTAC being the most advanced targets in clinical development [1][2]. Group 1: PROTAC Overview - PROTAC utilizes E3 ubiquitin ligase to ubiquitinate target proteins, leading to their degradation by the proteasome, which allows it to tackle "undruggable" targets and proteins that develop resistance mutations [2]. - PROTACs have high selectivity for targets and catalytic properties, enabling low-dose and low-frequency administration [2]. Group 2: ER PROTAC - The fastest progressing ER PROTAC is Arvinas' ARV-471, which has been licensed to Pfizer for over $2 billion and is expected to read out phase 3 clinical data in Q1 2025 [3]. - ARV-471 has shown excellent efficacy in phase 2 trials among patients who have previously used fulvestrant and chemotherapy, with further phase 3 trials planned in 2025 in combination with CDK4/6 inhibitors [3]. Group 3: AR PROTAC - BMS's BMS-986365 is the fastest progressing AR PROTAC, currently in phase 3 clinical trials, addressing issues of resistance and short survival in prostate cancer patients [4]. - Phase 2 clinical data for BMS-986365 showed clinical benefits in mCRPC patients with both AR LBD wild-type and mutant, with PSA50 rates of 27% and 55% respectively [4]. - Arvinas' ARV-766 has been licensed to Novartis for $1.16 billion, achieving a PSA50 of 43% in phase 2 trials among AR LBD mutant patients [4]. Group 4: Investment Focus - PROTAC drugs possess unique advantages and have been validated over 20 years of exploration, with the upcoming phase 3 data for ARV-471 expected to lead to significant breakthroughs in the field [6]. - Domestic pharmaceutical companies are actively engaging in PROTAC development, demonstrating international competitiveness and first-mover advantages [6].