EXHIBIT 1

          PROCTER & GAMBLE  PHARMACEUTICALS,  INC.  ("Seller")  hereby agrees to
sell to [BUYER'S NAME] ("Buyer"),  and Buyer agrees to buy from Seller,  [number
of  shares]  shares of Common  Stock of  REGENERON  PHARMACEUTICALS,  INC.  (the
"Issuer") at $20 per share, or [dollar  amount] in the aggregate.  Seller agrees
that on March 16, 2001, Seller will deliver or cause to be delivered to Buyer at
[Buyer's Address],  a certificate or certificates for such shares, duly endorsed
for transfer to Buyer or with an accompanying stock power or powers in customary
form,  against  payment by Buyer of the purchase price therefor by wire transfer
in  immediately  available  funds to Seller at [bank account] for the account of
The Procter & Gamble Company on March 16, 2001.

          Seller  represents  that  Seller is not,  and has not been  during the
preceding three months, an "affiliate" of the Issuer, as such term is defined in
Rule 144 under the  Securities  Act of 1933, and that such shares may be sold at
this time by Seller  under  such Rule 144  without  limitation  on the amount of
securities sold or the manner of sale.

          IN WITNESS  WHEREOF,  Buyer and Seller have signed this  Agreement  on
March 9, 2001.


                                          PROCTER & GAMBLE PHARMACEUTICALS, INC.



                                          By_________________________

                                          [BUYER]



                                          By_________________________