Regeneron Pharmaceuticals: Dupixent-Driven Growth Offset by Patent Uncertainty, Supporting a Hold Rating

Morgan Stanley analyst Terence Flynn has maintained their neutral stance on REGN stock, giving a Hold rating on January 14.

Terence Flynn has given his Hold rating due to a combination of factors tied primarily to Regeneron’s key products and intellectual property profile. Dupixent is the central growth driver with substantial projected 2025 sales, and its current composition-of-matter patent life extends into the early-to-mid 2030s across major regions, offering a solid base of exclusivity. However, investors are focused on whether the broader Dupixent patent estate can meaningfully stretch protection beyond these dates, similar to the way Humira benefited from an extended patent shield, and upcoming European opposition decisions will be an important test of that strength. The firm’s analysis suggests that Regeneron has pursued a more thoughtful and structured patenting strategy for Dupixent than it did for Eylea, which could translate into stronger follow-on protections, but this still needs to be validated by legal outcomes.

At the same time, the recent experience with Eylea’s patent disputes underscores the risk that secondary patents (such as formulation and dosing claims) may not reliably block competition, as seen when courts declined to uphold key protections and did not grant injunctive relief against a biosimilar launch. While Regeneron’s choice to fully litigate Eylea delayed biosimilar entry by several months versus a negotiated settlement, the ultimate window extension was modest and fell well short of the exceptional case achieved by Humira. These legal precedents create uncertainty around how much incremental exclusivity Dupixent’s secondary patents can ultimately secure, even if they are higher quality than Eylea’s. Taken together—strong near- to medium-term fundamentals anchored by Dupixent, balanced against legal and duration-of-exclusivity risks—support a neutral risk‑reward view and, therefore, a Hold rating on Regeneron’s shares.

In another report released on January 14, Scotiabank also maintained a Hold rating on the stock with a $770.00 price target.