EXHIBIT 99(a)

FOR IMMEDIATE RELEASE

                   REGENERON COMPLETES 12-MONTH EFFICACY PHASE
       OF AXOKINE(R) PHASE III PIVOTAL TRIAL FOR THE TREATMENT OF OBESITY

Tarrytown, NY (January 7, 2003) - Regeneron Pharmaceuticals, Inc. (Nasdaq: REGN)
announced today at the JP Morgan Healthcare Conference that the last study
participant has completed the 12-month placebo-controlled portion of its Phase
III pivotal trial designed to assess the efficacy and safety of AXOKINE(R) for
weight loss in overweight and obese subjects. This pivotal trial included nearly
2,000 people at 65 study sites across the United States.

"This is an important milestone in the AXOKINE pivotal trial and overall in the
Phase III development program," noted Steven P. Weinstein, M.D., Ph.D.,
Regeneron's Executive Director of Endocrinology. "We note that approximately 65
percent of all study subjects completed the 12-month placebo-controlled phase
of the trial, and the average treatment period for participants in this trial is
now more than 14 months."

THE AXOKINE PHASE III PROGRAM

The Company initiated its Phase III AXOKINE program in July 2001 and began
treating people in the pivotal trial in September 2001. This pivotal trial
includes two phases. The recently completed first phase was designed to measure
weight change in a 12-month double-blind treatment period, in which participants
gave themselves daily subcutaneous injections of placebo or AXOKINE. This phase
was overseen by an independent Data Safety Monitoring Board, which reviewed the
safety data. The co-primary end-points of the study are change in body weight
and proportion of subjects who lose 5 percent or more of their body weight over
the 12-month treatment period. Data collection for this first phase of the
pivotal study and finalization of the database for statistical analysis are
currently underway. The double-blind, placebo-controlled treatment period is
being followed by a 12-month open-label safety extension phase, during which all
trial participants receive AXOKINE.

To be included in the study, patients must not have been diabetic and must have
had a body mass index (BMI) of 30 to 55 if they had no obesity-related risk
factors or 27 to 55 if they had obesity-related risk factors, such as elevated
blood pressure or increased blood lipids. People are classified

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as overweight if they have a BMI between 25 and 30, and obese if they have a BMI
of 30 or greater. BMI is a medical measure of obesity. It measures weight in
relation to height and is calculated as weight in kilograms divided by height
measured in meters, squared. For example, a person 5'8" tall weighing 174 pounds
would have a BMI of 27 and be considered overweight. The same 5'8" adult
weighing 258 pounds would have a BMI of 40 and be considered extremely obese.

The entire AXOKINE program has been designed to include approximately 4,000
participants. As part of the overall Phase III program, Regeneron has initiated
4 clinical studies that are currently underway and has planned additional
confirmatory and ancillary studies of AXOKINE(R) in obese and obese diabetic
subjects.

ABOUT REGENERON

Regeneron is a biopharmaceutical company that discovers, develops, and intends
to commercialize therapeutic medicines for the treatment of serious medical
conditions. Regeneron has therapeutic candidates for the potential treatment of
obesity, rheumatoid arthritis, cancer, and asthma and has preclinical programs
in other diseases and disorders.

This news release discusses historical information and includes forward-looking
statements about Regeneron and its products, programs, finances, and business,
all of which involve a number of risks and uncertainties, such as risks
associated with preclinical and clinical development of drugs and biologics,
determinations by regulatory and administrative governmental authorities,
competitive factors, technological developments, the availability and cost of
capital, the costs of developing, producing, and selling products, the potential
for any collaboration agreement to be canceled or to terminate without any
product success, and other material risks. A more complete description of these
risks can be found in Regeneron's filings with the United States Securities and
Exchange Commission, including its Form 10-K for the year ended December 31,
2001 and the Form 10-Q for the quarter ended September 30, 2002. Regeneron does
not undertake any obligation to update publicly any forward-looking statement,
whether as a result of new information, future events, or otherwise, unless
required by law.

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