Regeneron Stock Plunges 22.6% YTD: Should You Buy, Sell or Hold?

Core Viewpoint - Regeneron Pharmaceuticals, Inc. (REGN) has underperformed the medical sector and S&P 500 Index, with shares down 22.6% year to date, while the industry has grown by 0.6% [1][2]. Sales Performance - The decline in sales of the lead drug Eylea has significantly impacted the company's top-line growth, as Eylea accounts for a majority of REGN's sales [1][5]. - Eylea's sales have faced pressure due to competition from Roche's Vabysmo, which has seen strong uptake, and the emergence of biosimilars [4][9]. Pipeline Developments - Regeneron is attempting to diversify its revenue and develop its oncology franchise, but recent pipeline setbacks have negatively affected investor sentiment [3][9]. - The FDA accepted a supplemental biologics license application (sBLA) for Eylea HD, with a target action date of August 19, 2025, but a complete response letter (CRL) was issued for the pre-filled syringe of Eylea HD due to issues with a third-party supplier [6][7]. Dupixent and Oncology Focus - Dupixent has been a strong contributor to REGN's top line, with ongoing label expansions and solid sales trends [12][14]. - The oncology franchise includes Libtayo and odronextamab, with recent approvals and ongoing efforts to strengthen this segment, although there have been setbacks in the U.S. approval process for odronextamab [15][18][17]. New Ventures - Regeneron is exploring the obesity market through a licensing agreement for an obesity drug with Hansoh Pharmaceuticals, aiming to expand its clinical-stage obesity portfolio [19][20]. Valuation and Estimates - REGN shares are currently trading at a price/earnings ratio of 18.27X forward earnings, slightly below its historical mean but above the large-cap pharma industry's average of 15.04X [21]. - The bottom-line estimate for 2025 has decreased by $0.57 to $36.15 over the past 60 days, indicating a downward trend in earnings expectations [23].