REGENERON PHARMACEUTICALS INC

We conduct our research, development, manufacturing, and administrative activities at our owned and leased facilities. A summary of our significant owned and leased properties is provided below.

Tarrytown, New York

At our Tarrytown, New York location, we lease approximately 1,467,000 square feet of laboratory and office space. Refer to Part II, Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations - Liquidity and Capital Resources -Tarrytown, New York Leases" for further details. We also own an approximate 100-acre parcel of land adjacent to our Tarrytown, New York location, which we are in the process of developing, primarily in connection with expanding our research and support facilities to accommodate our growth.

Rensselaer, New York

We own facilities in Rensselaer, New York totaling approximately 1,260,000 square feet of manufacturing, research, office, and warehouse space. In addition, we have constructed an approximately 341,000 square foot fill/finish facility in Rensselaer, New York that is undergoing process validation as required by regulatory authorities.

Limerick, Ireland

We own a facility in Limerick, Ireland totaling approximately 555,000 square feet of manufacturing, warehouse, laboratory, and office space.