Regeneron Pharmaceuticals, Inc.
CorpDigest
Regeneron Pharmaceuticals, Inc.
Company History
Founded 1988 in Tarrytown, New York
Last reviewed: 2025-07-15 · By Swet Parvadiya
Leonard Schleifer rented a single room in a Tarrytown, New York office building in 1988 and wrote the founding documents of Regeneron Pharmaceuticals at a time when the biotechnology industry consisted largely of companies promising to cure everything and delivering very little. Schleifer, a neurologist, had a specific scientific thesis: that understanding the growth factor biology of neurons would yield treatments for neurological diseases. He recruited George Yancopoulos, a Columbia University researcher who had published work on antibody genetics, to lead the science.
The 1991 NASDAQ IPO raised money at a moment when the company had no approved products and no clear path to them — a standard condition for biotech at the time, but one that required convincing investors to fund a decade or more of research before any commercial return. The FDA approval of Arcalyst for a rare inflammatory condition called CAPS in 2008 was Regeneron's first commercial product, twenty years after founding. The real scale came with EYLEA in 2011, an anti-VEGF drug for wet age-related macular degeneration that became the highest-selling ophthalmology drug in history.
The 2015 FDA approval of Praluent for hypercholesterolemia was followed by a patent dispute with Amgen over PCSK9 antibodies that ran for years — a litigation that demonstrated how intensely competitive the antibody drug space had become and how valuable IP protection was for a company whose entire business model depended on years of development investment preceding any commercial return. Decibel Therapeutics, 2seventy bio platforms, and Checkmate Pharmaceuticals were acquired in 2022 through 2024, extending the pipeline into hearing loss, oncology, and tumor immunology.
Leonard S. Schleifer has served as Regeneron's Chief Executive Officer since the company's founding in 1988 and became board co-chair alongside George Yancopoulos in 2023 following the retirement of P. Roy Vagelos. Under his leadership, Regeneron has grown from a two-person startup in a converted Tarrytown industrial space to a $66 billion market-cap biotechnology company with 15 approved medicines and over 15,400 employees. Schleifer's strategic decisions include the 2003 Bayer partnership for EYLEA development, the 2007 Sanofi collaboration that eventually produced Dupixent, and the 2011 IPO that raised capital for commercial infrastructure. He has consistently prioritized R&D investment over short-term margin expansion, with the company's research budget growing from $50 million in the early 1990s to $5.9 billion in 2025. Schleifer is known for maintaining direct involvement in scientific review meetings and pipeline prioritization discussions, a hands-on approach that reflects his medical training and his belief that biotechnology companies fail when commercial executives override scientific judgment. His compensation in 2024 included a base salary of $1.5 million and total compensation of approximately $18 million, with equity awards tied to long-term revenue and pipeline milestones.
George D. Yancopoulos has served as Regeneron's Chief Scientific Officer since 1989 and became board co-chair in 2023, making him one of the longest-serving scientific leaders in the biotechnology industry. Yancopoulos has personally led the development of the VelocImmune, VelociGene, and Veloci-8i2 platforms, which have produced 15 approved medicines and nearly 50 clinical candidates. He has published over 350 scientific papers and holds more than 100 patents covering antibody engineering, trap technologies, and genetic medicine approaches. Yancopoulos played the central scientific role in the discovery of EYLEA, Dupixent, Libtayo, Praluent, and Evkeeza, and he continues to oversee the Regeneron Genetics Center, which has sequenced over 3 million exomes. His 2024 compensation included a base salary of $1.3 million and total compensation of approximately $16 million, with significant equity awards tied to scientific milestones. Yancopoulos is known for attending late-night lab meetings and reviewing primary experimental data personally, maintaining a scientific presence that reinforces the company's culture of rigorous peer review.
Leonard S. Schleifer and George D. Yancopoulos established Regeneron Pharmaceuticals in a converted industrial laboratory in Tarrytown, New York, with initial venture capital funding and the scientific mission of developing neurotrophic factors for neurodegenerative diseases.
Regeneron completed its IPO on the NASDAQ exchange, raising $32 million to fund drug discovery platform development and establishing the financial foundation for three decades of scientific investment.
The FDA approved Arcalyst (rilonacept), Regeneron's first medicine, for Cryopyrin-Associated Periodic Syndromes, validating the company's trap technology and providing the first commercial proof of its platform approach.
The FDA approved EYLEA (aflibercept) for wet age-related macular degeneration, a decision that transformed Regeneron from a development-stage company into a profitable commercial biotechnology firm with a product that would eventually generate $9.6 billion in global annual sales.
The FDA approved Praluent (alirocumab), the first PCSK9 inhibitor developed in collaboration with Sanofi, for heterozygous familial hypercholesterolemia and clinical atherosclerotic cardiovascular disease, entering a new therapeutic market.
The FDA approved Dupixent (dupilumab) for moderate-to-severe atopic dermatitis, marking the beginning of what would become a $17.8 billion global immunology franchise and the first biologic approved for this indication.
The FDA approved Libtayo (cemiplimab) as the first PD-1 inhibitor for metastatic or locally advanced cutaneous squamous cell carcinoma, establishing Regeneron's presence in oncology immunotherapy.
The Regeneron Genetics Center sequenced its 500,000th exome, creating a foundational dataset that would eventually grow to over 3 million exomes and enable the discovery of multiple therapeutic targets including ANGPTL3 and GPR75.
The FDA approved Evkeeza (evinacumab) for homozygous familial hypercholesterolemia, a medicine derived directly from Regeneron Genetics Center discoveries of protective ANGPTL3 loss-of-function variants in less than 1% of sequenced individuals.
Regeneron exercised its option to take full worldwide development, commercialization, and manufacturing rights for Libtayo from Sanofi, ending the profit-sharing arrangement and giving Regeneron direct control over the PD-1 inhibitor's future expansion.
The FDA approved EYLEA HD (aflibercept 8mg) for neovascular age-related macular degeneration and diabetic macular edema, extending the dosing interval to 12-16 weeks and launching the next-generation ophthalmology franchise.
Regeneron completed its acquisition of Decibel Therapeutics for approximately $109 million, adding three gene therapy programs for congenital hearing loss including DB-OTO, which would become the first FDA-approved gene therapy for otoferlin-related deafness.
The European Commission approved Dupixent as the first-ever biologic therapy for uncontrolled chronic obstructive pulmonary disease characterized by raised blood eosinophils, expanding the addressable population by millions of patients.
Regeneron acquired 2seventy bio's preclinical and clinical cell therapy programs for a $5 million upfront payment, forming Regeneron Cell Medicines with approximately 150 transferred employees to advance CAR-T and TCR therapies.
The FDA approved DB-OTO as the first gene therapy for profound congenital hearing loss caused by mutations of the otoferlin gene, marking Regeneron's entry into commercial genetic medicines and validating the Decibel acquisition strategy.
Regeneron acquired Decibel to strengthen its genetic medicines portfolio and gain access to three gene therapy programs for congenital monogenic hearing loss, including the lead candidate DB-OTO. The acquisition built on a six-year collaboration that began in 2017 and was extended in 2021, reflecting Regeneron's strategic decision to expand beyond antibodies into AAV-based therapies for rare diseases where genetic validation provides clear therapeutic targets.
Regeneron acquired 2seventy bio's preclinical and clinical cell therapy programs, including CAR-T and TCR therapies, to form Regeneron Cell Medicines. The transaction complemented Regeneron's antibody and bispecific expertise with cell-based immuno-oncology approaches, enabling combination therapies that pair engineered immune cells with Regeneron's proprietary antibodies.
Regeneron acquired Checkmate Pharmaceuticals to deepen its immuno-oncology portfolio with a novel TLR9 agonist approach designed to activate innate immunity and enhance responses to checkpoint inhibitors like Libtayo.
Regeneron Pharmaceuticals was founded in 1988 by Leonard Schleifer, a 35-year-old neurologist with research training, and George Yancopoulos, a 28-year-old molecular biologist who joined as the founding chief scientific officer, with the original mission of developing therapeutic proteins for neurological diseases. Schleifer had completed his medical training and neurology fellowship before deciding that biotechnology offered a more promising path to treat neurological diseases than academic clinical practice, and he recruited Yancopoulos from Columbia University where Yancopoulos had been a rising molecular biologist exploring growth factor signaling. The founding team established Regeneron in Tarrytown, New York, with venture funding led by Merrill Lynch Ventures and a research focus on neurotrophic factors — proteins that support neuronal survival and growth and that early 1980s research had suggested could treat amyotrophic lateral sclerosis (ALS), Parkinson's disease, and other neurodegenerative conditions. The initial neurological-disease focus did not produce approved therapies despite multiple clinical programs through the 1990s, and the company faced multiple difficult moments before pivoting its scientific platform and discovering the antibody and trap-protein technologies that produced its eventual commercial success. The founding team's unique characteristic was the partnership between a physician-CEO (Schleifer) and a scientist-CSO (Yancopoulos) that has persisted for thirty-five years — one of the longest founder partnerships in pharmaceutical history.
Regeneron's transition from its founding neurology focus to its modern multi-platform pharmaceutical business occurred gradually through the 1990s and 2000s as several research programs failed clinically and the company developed broader technological platforms that opened new therapeutic areas. The neurotrophic factor programs targeted at ALS and other neurodegenerative diseases produced multiple late-stage clinical failures, illustrating the difficulty of translating in vitro protein activity into clinical efficacy in human neurological disease. The pivotal scientific developments that redirected the company included the development of the trap technology — engineered fusion proteins that capture and neutralize circulating signaling molecules — which produced the company's first major commercial product, Eylea (aflibercept), an angiogenesis-trap protein launched in 2011 for wet age-related macular degeneration. Concurrently, the VelocImmune platform, an engineered mouse system that produces fully human antibodies, became the company's most strategically valuable technology asset and the foundation for subsequent product successes including Dupixent (dupilumab, partnered with Sanofi), the COVID-19 antibody cocktail REGEN-COV, and multiple oncology and inflammatory disease antibodies. The strategic transformation from neurology specialist to diversified protein therapeutic company took roughly two decades and required sustained capital investment through multiple commercial setbacks, with the founders' continued partnership providing the strategic continuity necessary for the platform development.
Regeneron completed its initial public offering on Nasdaq in April 1991, just three years after founding, raising approximately $90 million at an IPO valuation that was high for a clinical-stage biotech of the era. The 1991 IPO occurred during a period of significant biotech enthusiasm following the early successes of Amgen (with Epogen and Neupogen) and Genentech, and Regeneron benefited from investor appetite for promising early-stage drug discovery companies with strong scientific founders. The IPO provided the capital that funded the company's subsequent decade of research investment despite multiple clinical setbacks, and the early funding combined with disciplined burn-rate management allowed Regeneron to survive through the late-1990s biotech downturn that bankrupted many of its peers. The strategic lesson from the early IPO history is the value of public-market access during favorable capital cycles for companies with multi-decade product development timelines — Regeneron raised $90 million in 1991, then additional capital in subsequent secondary offerings and through the Eylea launch in 2011 onward, with the cumulative public-market capital deployment supporting the platform development that has produced the modern $66 billion-market-cap company. The 1991 IPO is also notable as an early example of a biotech founded around a unique founder partnership — Schleifer as CEO and Yancopoulos as scientific leader — that has remained intact for thirty-five years.
Eylea (aflibercept), launched in November 2011, was the transformative product launch that established Regeneron as a major pharmaceutical company and produced the scale that funded subsequent platform development. Eylea is a fusion protein that captures vascular endothelial growth factor (VEGF), the signaling molecule that drives abnormal blood vessel growth in wet age-related macular degeneration (AMD), diabetic macular edema, and several other retinal diseases. The drug was the second VEGF-trap therapy to reach market after Roche/Genentech's Lucentis, but Eylea's advantages — longer dosing intervals, more complete VEGF inhibition, and broader retinal-disease indication coverage — drove rapid market-share gains. The product reached $1 billion of US sales within its first full year on market and grew to peak global sales above $9 billion across both Regeneron's US franchise and Bayer's ex-US franchise (the two companies share Eylea revenue and profits under a 2006 collaboration agreement, with Regeneron retaining US rights and Bayer holding ex-US rights). Eylea has produced cumulative revenue exceeding $50 billion since launch and has funded the research investment that produced the company's subsequent products. The drug's franchise has come under pressure since 2022 from Roche's Vabysmo (faricimab), a competing bispecific antibody, and from biosimilar Eylea launches in the US and Europe, prompting Regeneron's defense through the higher-dose Eylea HD launched in 2024.
Regeneron's COVID-19 monoclonal antibody cocktail, branded REGEN-COV in the United States and Ronapreve internationally, was a one-time but historically significant commercial event in the company's history. The product was developed using Regeneron's VelocImmune platform within months of the SARS-CoV-2 pandemic emergence, combining two monoclonal antibodies (casirivimab and imdevimab) that neutralize the SARS-CoV-2 virus by binding to non-overlapping sites on the viral spike protein. The drug received emergency use authorization in November 2020 and gained significant public attention when then-President Donald Trump received it as treatment during his October 2020 COVID-19 infection, with Trump publicly endorsing it after his recovery. The US government purchased the drug at scale through Operation Warp Speed, with Regeneron recording approximately $2.6 billion of US REGEN-COV revenue in 2021 alone. The Roche collaboration on the ex-US Ronapreve franchise added additional revenue. The product effectively lost efficacy against the Omicron variant in late 2021 and was de-authorized by the FDA in January 2022, ending the commercial franchise. Despite the short commercial duration, REGEN-COV demonstrated the speed and capability of Regeneron's antibody discovery platform and provided several billion dollars of one-time revenue and earnings that supported continued investment in the platform. The episode also raised Regeneron's public profile materially beyond the ophthalmology specialist audience that had defined the Eylea-era franchise.