Leonard Schleifer

$2.79 B

Ranked #1470 in World

About Leonard Schleifer

Leonard S. Schleifer, born in 1953 in Queens, New York, has notably advanced the biopharmaceutical sector as the co-founder of Regeneron Pharmaceuticals since 1988 alongside George Yancopoulos. Despite initial setbacks with drugs for Lou Gehrig's disease and obesity, Schleifer's strategic pivot—to focus on well-understood biology and prioritize human testing under the guidance of former Merck & Co. CEO Roy Vagelos—yielded the breakthrough drug, Eylea, in 2011 for macular degeneration. Also noteworthy is Regeneron's significant contribution to COVID-19 research, developing therapeutic solutions amidst ethical debates. With a background rooted in a family with deep academic and patriotic contributions, Schleifer's journey from a Cornell University graduate to a key figure in medical innovation mirrors his impactful role in addressing global health crises.

Born

July 07, 1952

Age

73 years

Source Of Wealth

Pharmaceuticals

Industries

Healthcare

Citizenship

United States

Residence

Tarrytown, New York

Education

Bachelor of Arts/Science, Cornell University; Medical Doctor, University of Virginia; Ph.D, University of Virginia

Spouse

Harriet Partel Schleifer

Parent

Florence Schacht Schleifer, Charles Baker Schleifer

Leonard S. Schleifer was born in 1953 in Queens, New York, into a Jewish family. His parents were Florence and Charles Baker Schleifer, with his father being a sweater manufacturer and a World War II codebreaker. Schleifer graduated with a B.S. from Cornell University and went on to earn an MD-PhD from the University of Virginia. During his studies, he had the privilege of learning under the guidance of future Nobel Laureate, Alfred G. Gilman. After completing his education, Schleifer received training as a neurologist and served as a junior faculty member at New York Hospital.

Leonard Schleifer: Family

Leonard S. Schleifer is married to Harriet (née Partel) Schleifer, and together they have two children, Adam and David. Harriet holds an undergraduate degree from Cornell University, two graduate degrees in education from the University of Virginia, and a J.D. degree from St. John's University School of Law. She actively serves on the Board of Governors of the American Jewish Committee and holds the position of president at her synagogue.

Leonard Schleifer: Career Highlights

In 1988, Leonard S. Schleifer co-founded Regeneron Pharmaceuticals alongside George Yancopoulos. Initially, they faced challenges in recruiting research doctors. Their first attempt at drug development was for Lou Gehrig's disease, but unfortunately, it did not succeed. A subsequent drug they developed for obesity also failed to meet expectations. To overcome these setbacks, Schleifer invited former Merck & Co. CEO Roy Vagelos to become the chairman of Regeneron. This strategic move led to significant changes in the company's approach, with a focus on drugs that had well-understood biology and an emphasis on human testing.

Leonard Schleifer: Companies

Leonard S. Schleifer is closely associated with the following companies:

Regeneron Pharmaceuticals
Aventis
Sanofi

Leonard Schleifer: Major Achievements

One of Schleifer's major achievements was the development of Eylea, Regeneron's first successful drug. Approved in 2011, Eylea is used to treat age-related macular degeneration, a condition that can lead to blindness due to leaky blood vessels in the eye.

Initially licensed to Aventis and later acquired by Sanofi, Eylea became a blockbuster drug, generating substantial revenue for Regeneron after Sanofi paid $50 million and ceded the rights back to the company.

Leonard Schleifer: Awards & Achievements

Leonard S. Schleifer has received numerous awards and recognition for his contributions to the field of medicine and biotechnology. Some notable honors include:

2015: Ernst & Young Entrepreneur of the Year Award in the New York Metro region
2016: Scrip Awards "Deal of the Year" for the Regeneron-Sanofi collaboration
2017: Biotechnology Heritage Award from the Biotechnology Innovation Organization (BIO)
2018: Albany Medical Center Prize in Medicine and Biomedical Research

Leonard Schleifer: Personal Life & Legacy

Beyond his professional achievements, Leonard S. Schleifer is known for his personal interests and contributions. He is acquainted with U.S. President Donald Trump through their shared membership at a golf club in Westchester County, New York. Additionally, Schleifer's son, Adam, ran as a candidate in the 2020 Democratic Primary for New York's 17th congressional district.

Leonard Schleifer: Trivia

One notable aspect of Leonard S. Schleifer's career is the privileged access that he and his company, Regeneron, provided to experimental COVID-19 therapeutics for Donald Trump and his administration. This raised ethical concerns and sparked discussions about the potential influence of wealth and power in healthcare.

Wealth History

Timeline

1953

Leonard S. Schleifer was born in Queens, New York, to a Jewish family.

Graduated with a B.S. from Cornell University.

Received an MD-PhD from the University of Virginia.

Studied under future Nobel Laureate, Alfred G. Gilman.

Trained as a neurologist and served as a junior faculty member at New York Hospital.

1988

Co-founded Regeneron Pharmaceuticals with George Yancopoulos.

Initially faced challenges in recruiting research doctors.

Developed their first drug to treat Lou Gehrig's disease, but it failed.

Second drug for obesity also failed.

Invited former Merck & Co. CEO Roy Vagelos to be the chairman and implemented strategic changes.

Focused on drugs with well-understood biology and emphasized human testing.

2011

Regeneron's first successful drug, Eylea, was approved for age-related macular degeneration.

Eylea prevented leaky blood vessels in the eye from causing blindness.

Eylea was licensed to Aventis, then acquired by Sanofi, which had no interest in the drug.

Sanofi paid Regeneron $50 million and ceded the rights back.

Eylea became a blockbuster drug, generating significant revenue.

Currently working on a Phase 2/3 trial with Sanofi to evaluate the antibody agent Kevzara(TM) for hospitalized COVID-19 patients.

Developing a novel, multi-antibody cocktail for prevention and treatment of SARS-CoV-2.

Privileged access of experimental COVID-19 therapeutic to Donald Trump and his administration raised ethical concerns.

Married to Harriet (née Partel) Schleifer, with two children, Adam and David.

Harriet has an undergraduate degree from Cornell University, two graduate degrees in education from the University of Virginia, and a J.D. degree from St. John's University School of Law.

Serves on the Board of Governors of American Jewish Committee and as president of her synagogue.

Knows U.S. President Donald Trump from their membership at a golf club in Westchester County, New York.

Son Adam ran as a candidate in the 2020 Democratic Primary for New York's 17th congressional district.

Leonard Schleifer : FAQs

What is Leonard Schleifer's current net worth?

Leonard Schleifer's current net worth is $2.79 billion.

What is Leonard Schleifer's current global rank among billionaires?

Leonard Schleifer holds the 1470th position globally among billionaires.

What is Leonard Schleifer's current ranking within the United States?

Leonard Schleifer holds the 520th position in United States.

What was the change in Leonard Schleifer's net worth compared to the previous year?

Leonard Schleifer's net worth increased by 21.31 million dollars compared to the previous year 2025, when his net worth was 2.77 billion dollars.

What is the recent change in Leonard Schleifer's net worth?

Leonard Schleifer's net worth increased by 3.46 million dollars recently, a 0.12% increase, with his net worth standing at 2.79 billion dollars.

What are Leonard Schleifer's main sources of wealth?

Leonard Schleifer's main source of income comes from Pharmaceuticals.

In which industry does Leonard Schleifer primarily operate?

Leonard Schleifer is primarily involved in the Healthcare industry.

What is Leonard Schleifer educational background?

Leonard Schleifer holds a Bachelor of Arts/Science from Cornell University, a Medical Doctor from the University of Virginia and a Ph.D from the University of Virginia.

How old is Leonard Schleifer?

Leonard Schleifer is 73 years old.

How many children does Leonard Schleifer have?

Leonard Schleifer has 3 children.

Who is Leonard S. Schleifer and what is his connection to Regeneron Pharmaceuticals?

Leonard S. Schleifer co-founded Regeneron Pharmaceuticals in 1988, overcoming initial challenges to lead the company to develop significant drugs, including Eylea, a treatment for age-related macular degeneration.

What were Leonard S. Schleifer's contributions to medical science before founding Regeneron?

Before founding Regeneron, Leonard S. Schleifer studied under future Nobel Laureate Alfred G. Gilman, earned an MD-PhD from the University of Virginia, and worked as a trained neurologist and junior faculty member at New York Hospital.

How did Leonard S. Schleifer's strategic decisions impact Regeneron's success?

Leonard S. Schleifer's strategic decision to invite former Merck & Co. CEO Roy Vagelos as chairman and focus on drugs with well-understood biology and human testing was pivotal in overcoming early setbacks and leading Regeneron to success, notably with the blockbuster drug Eylea.

What is Eylea and why is it significant for Regeneron Pharmaceuticals?

Eylea, Regeneron's first successful drug approved in 2011, treats age-related macular degeneration by preventing leaky blood vessels in the eye from causing blindness. It became a blockbuster drug, generating significant revenue for the company.

How has Leonard S. Schleifer's Regeneron contributed to COVID-19 treatment efforts?

Under Leonard S. Schleifer's leadership, Regeneron is working on a COVID-19 treatment, including a multi-antibody cocktail for prevention and treatment of SARS-CoV-2, and has conducted trials to evaluate the efficacy of the antibody agent Kevzara(TM) for hospitalized COVID-19 patients.