Dupixent's Q4 Growth Reinforces Earnings Backstop, But EYLEA Transition Remains Key to Regeneron's Thesis

What happened

Regeneron Pharmaceuticals' Q4 2025 performance highlighted strong Dupixent sales growth of 22.8% year-over-year, as reported in a recent article, underscoring its role in the company's revenue mix. This aligns with the DeepValue report's emphasis on Dupixent as a critical earnings backstop, providing stability amid the uncertain transition from EYLEA 2mg to EYLEA HD. However, the report cautions that Regeneron's investment thesis centers on EYLEA HD's ability to offset legacy declines, with near-term catalysts like FDA approval of the pre-filled syringe in Q2 2026 being pivotal. Despite Dupixent's strength, risks persist from biosimilar competition, manufacturing delays, and concentration in Sanofi collaboration revenue, which accounted for 41% of total revenues in 2025. Thus, while Dupixent offers a buffer, the stock's upside depends on successful execution in the retina franchise over the next 6-12 months.

Implication

The robust Dupixent sales growth reinforces Sanofi collaboration revenue as a reliable buffer, mitigating near-term downside risk and supporting Regeneron's heavy R&D and capex investments. This stability allows the company to navigate the EYLEA transition without immediate financial distress, but it also highlights concentration risk that could amplify volatility if Sanofi's execution falters. For the stock to achieve the base-case implied value of $830, EYLEA HD must demonstrate sustained share gains and the pre-filled syringe must gain FDA approval on schedule to reduce commercial friction. Investors should remain vigilant for early warning signs, such as sequential declines in total EYLEA franchise dollars or delays in manufacturing remediation, which could break the thesis. Ultimately, Dupixent provides a floor, but the investment case hinges on resolving EYLEA uncertainties, making the next two quarters critical for validation.

Thesis delta

The new article does not shift the core investment thesis but strengthens confidence in Dupixent as an earnings backstop, confirming its role in cushioning near-term volatility. However, the thesis remains unchanged: REGN's potential hinges on EYLEA HD demand trends and the Q2 2026 FDA decision, with Dupixent growth merely supporting the existing narrative rather than altering the risk-reward dynamics.