Regeneron Pharmaceuticals dropped more than 11% on Monday, wiping $77.25 off its share price to close at $621, as a combination of pipeline setbacks and ongoing profitability concerns continued to unsettle investors. The move extended a difficult stretch for the biotech company, which has now fallen roughly 19% since the start of the year and sits more than 22% below its 52-week high of $812.27.
The selling pressure reflects concerns that have been building since the company’s first-quarter 2026 earnings report, which showed earnings per share declining to $6.99 from $7.58 a year earlier despite revenue growing 19% to $3.61 billion. Net income fell 10% to $727 million, and the profit margin contracted from 27% to 20%, driven by a significant increase in operating expenses. Markets can live with investment in growth, but the pace of margin compression has made some investors uncomfortable.
A more immediate catalyst for Monday’s decline was investor reassessment of the pipeline situation following recent conference commentary. Management at the Bank of America Healthcare Conference revealed that fianlimab, a LAG-3 inhibitor being developed in combination with cemiplimab for first-line melanoma, had its Phase 3 protocol amended in late 2025 after progression-free survival event accumulation ran slower than expected.
Management confirmed the trial had passed its first interim analysis and that regulators globally had approved the amendment, but the timeline extension has introduced uncertainty around when a readout will arrive. “We were beginning to get concerned about when exactly the readout would occur,” the company said, explaining the decision to expand the patient population while keeping the required event threshold unchanged.
A key positive that analysts continue to highlight is the expected clearance of the Sanofi development balance around the third quarter of 2026. Once that profit-sharing obligation clears, Regeneron receives its full share of Dupixent profits without dilution, which should drive a meaningful step-up in reported earnings. Forward estimates show 2026 normalised earnings per share of around $46.50 accelerating to approximately $53.86 in 2027, a jump of 16%.
Dupixent remains the commercial engine of the business, with 1.4 million patients on therapy worldwide across nine approved US indications. Four of those indications individually generate blockbuster-scale revenues, which gives the company a degree of stability that pure pipeline plays cannot match.
Analysts maintain an average price target around $875, implying substantial upside from current levels. Whether the stock can recover toward that range depends heavily on the fianlimab melanoma readout and whether management can stabilise margins while continuing to invest in the broader pipeline.
