SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                    --------

                                    FORM 6-K

                        REPORT OF FOREIGN PRIVATE ISSUER
                      PURSUANT TO RULE 13A-16 OR 15D-16 OF
                       THE SECURITIES EXCHANGE ACT OF 1934

                         For the month of November, 2002

                                  Serono S.A.
                     ---------------------------------------
                              (Registrant's Name)

                            15 bis, Chemin des Mines
                                Case Postale 54
                                CH-1211 Geneva 20
                                  Switzerland
                     ---------------------------------------
                    (Address of Principal Executive Offices)

                                    1-15096
                     ---------------------------------------
                              (Commission File No.)

     (Indicate by check mark whether the registrant files or will file annual
reports under cover of Form 20-F or Form 40-F.)

     Form 20-  X    FForm 40-F
             -----            -----

     (Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101 (b)(1).)
                                                        -----

     (Indicate by check mark if the registrant is submitting the Form 6-K in
paper as permitted by Regulation S-T Rule 101 (b)(7).)
                                                        -----

     (Indicate by check mark whether the registrant by furnishing the
information contained in this form is also thereby furnishing the information to
the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of
1934.)

     Yes        No   X
         -----     -----

     (If "Yes" is marked, indicate below the file number assigned to the
registrant in connection with Rule 12g3-2(b): 82-     )
                                                 -----



SERONO                                                                    PFIZER
[GRAPHIC OMITTED]

FOR IMMEDIATE RELEASE
---------------------


MULTIPLE SCLEROSIS PATIENTS ON REBIF(R) MORE LIKELY TO REMAIN RELAPSE FREE THAN
                        PATIENTS ON AVONEX(R) AT 48 WEEKS

   HEAD-TO-HEAD STUDY OF INTERFERON BETA-1A TREATMENTS PUBLISHED IN NEUROLOGY


GENEVA,  SWITZERLAND,  ROCKLAND, MA, AND NEW YORK, NY, NOVEMBER 25, 2002-SERONO,
S.A.  (VIRT-X:  SEO  AND  NYSE:  SRA)  AND  PFIZER  INC  (NYSE:  PFE)
Serono's multiple sclerosis therapy, Rebif(R) (interferon beta-1a), was shown to
be  more  effective than Avonex(R) (interferon beta-1a) in reducing relapses and
active  brain  lesions  in  patients  with relapsing remitting MS over 24 and 48
weeks,  according  to  data  published  in  the  current  edition of the journal
Neurology.(1).

"Now  that  there  are a variety of MS therapies available, it is important that
patients and their physicians have data from a comparative study to help them in
making  informed  choices,"  said  Hillel Panitch, M.D., a University of Vermont
College of Medicine researcher for the EVIDENCE Study Group. "The publication of
the  48-week study results will enable the MS community to examine in detail the
scientific  data  supporting the clinical superiority of Rebif(R) over Avonex(R)
at  reducing  frequency  of  relapses."

Multiple  sclerosis  is  a chronic, inflammatory condition of the nervous system
and is the most common, non-traumatic, neurological disease in young adults.  MS
may  affect  up  to  two million people worldwide.  While symptoms can vary, the
most  common  symptoms of MS include blurred vision, numbness or tingling in the
limbs  and  problems  with strength and coordination.  The relapsing forms of MS
are  the  most  common.

The EVIDENCE study, which involved 677 patients with relapsing remitting MS, was
designed  to  compare the proportion of MS patients treated with either Rebif(R)
or Avonex(R) who were relapse-free after 24 (primary endpoint) and 48 weeks. The
data  show  that  75%  of  patients  who  received Rebif(R) (44 mcg administered
subcutaneously,  three  times  weekly)  did not have a relapse after 24 weeks of
treatment  compared  to  63%  of  patients  treated  with  Avonex(R)  (30  mcg
administered  intramuscularly,  once  weekly)  (p<0.001).

                                     -more-


---------------
(1) Panitch H, Goodin DS, Francis G, et al.  Randomized, comparative study of
interferon beta-1a treatment regimens in MS:  The EVIDENCE Trial.  Neurology
2002; 59: 1496-1506.



This  improvement  was  sustained  at  48  weeks  at which point 62% of Rebif(R)
patients  were  relapse-free as compared to 52% of Avonex(R) patients (p=0.009).
At  24  and 48 weeks, Rebif(R) patients had a 19% relative increase in remaining
relapse  free  as  compared  to  Avonex(R)  patients.

Magnetic  resonance  imaging (MRI) was used to assess brain lesions periodically
throughout  the  48-week study.  Patients treated with Rebif(R) had fewer active
lesions  per  MRI  scan  for  all activity measures with effects seen within 2-3
months  of  starting  treatment.  There  was  an  approximate one-third relative
difference  in  favor  of Rebif(R) and treatment effects were maintained over 48
weeks  for  measures  of  lesion  activity.  The  exact relationship between MRI
findings  and  clinical  outcomes  for  patients  is  unknown.

Adverse  events  reported  more  frequently  with  Rebif(R)  were injection site
reactions  (83%), asymptomatic liver function test changes (18%) and white blood
cell  abnormalities  (11%).  These events were generally mild.  The incidence of
other  events,  including  flu-like  symptoms,  did  not  show  a  statistically
significant  difference  between  the  groups.  Serious  adverse  events  and
discontinuations  of  therapy  were  also  comparable  between  the  groups.

Neutralizing  antibodies  (NAbs)  developed  in  25%  of  the  Rebif(R)  treated
patients.  While  the  effect  of  neutralizing  antibodies  on  the efficacy of
treatment  with  interferon  beta-1a  is  unknown(2), in the EVIDENCE trial, the
development  of  neutralizing  antibodies  did  not have any observable clinical
impact  although  a difference on mean MRI lesion count was seen. Development of
neutralizing  antibodies did not affect Rebif(R)'s superiority over Avonex(R) on
either  the  primary endpoint of preventing relapses or on MRI outcome. Patients
receiving  Rebif(R)  who  were NAb-positive had fewer relapses than NAb-negative
patients  receiving  Avonex(R). The effect of neutralizing antibodies beyond the
48-week  term  of  the  study  remains  to  be  determined.

ADDITIONAL INFORMATION
Rebif(R)  was approved in the US on March 7, 2002, for the treatment of patients
with relapsing forms of multiple sclerosis to decrease the frequency of clinical
exacerbations  and  delay  the  accumulation  of physical disability.  Rebif(R),
which is co-promoted in the United States by Serono and Pfizer Inc, is the first
and  only  drug  to gain exception to the marketing exclusivity provision of the
Orphan Drug Act based on superior efficacy.  The Orphan Drug Act, enacted in the
US  in  1983,  provides  drug makers with commercial incentives to encourage the
development  of  treatments  for  patients  with rare and debilitating diseases.

Rebif(R)  was  approved in Europe in 1998 and is registered for use in more than
70 countries worldwide.  During 2001, Rebif(R) increased its leading position in
these  countries as the treatment of choice for patients with relapsing forms of
MS  with  a  market share of 38% in value terms and sales of $379.6m outside the
US.


                                     -more-

---------------
(2) Goodin DS, Frohman EM, Garmany GP, et al.  Disease Modifying Therapies in
Multiple Sclerosis.  Report of the Therapeutics and Technology Assessment
Subcommittee of the American Academy of Neurology and the MS Council for
Clinical Practice Guidelines. Neurology 2002; 58:  169-178, 175.



The  EVIDENCE  study was cited in a recent assessment in Neurology(3) of disease
modifying  therapies  in  MS.

In  that  article,  the  authors  emphasized  that  EVIDENCE  was  a  randomized
prospective  trial  in  which  both  the  clinical and MRI outcome measures were
assessed in a blinded fashion. As such, the study results qualified as "Class I"
evidence  of  efficacy,  the  highest  classification  rating.  The authors also
reiterated the finding that, at six months, relapse and MRI outcome measures for
patients taking Rebif(R) (44 mcg three times weekly) were statistically superior
to  outcome  measures  for  patients  taking  Avonex(R)  (30  mcg  once weekly).
Further,  they  recognized  that  either  the  dose,  or  the  frequency  of
administration  or  both  significantly  influenced  the  treatment  outcomes in
patients  with  RRMS.

US  residents  can  find more information about Rebif(R) in the full prescribing
information,  on  line  at  www.rebif.com  or  by  calling  MS  LifeLines  at
                            -------------
1-877-44REBIF.  Patients  should  be  instructed  to  read  the Medication Guide
accompanying  the  product.

                                       ###
Some  of  the  statements  in  this  press  release  are  forward  looking. Such
statements  are inherently subject to known and unknown risks, uncertainties and
other  factors  that  may  cause  actual results, performance or achievements of
Serono  S.A.  and  affiliates  to be materially different from those expected or
anticipated  in  the  forward-looking statements. Forward-looking statements are
based on Serono's current expectations and assumptions, which may be affected by
a  number  of  factors, including those discussed in this press release and more
fully  described  in  Serono's  Annual  Report  on Form 20-F filed with the U.S.
Securities and Exchange Commission on April 22, 2002.  These factors include any
failure  or  delay  in  Serono's ability to develop new products, any failure to
receive  anticipated  regulatory  approvals,  any  problems  in  commercializing
current  products  as  a  result of competition or other factors, our ability to
obtain  reimbursement  coverage  for  our  products,  and government regulations
limiting  our  ability  to  sell  our  products. Serono has no responsibility to
update the forward-looking statements contained in this press release to reflect
events  or  circumstances  occurring  after  the  date  of  this  press release.
                                       ###


ABOUT  SERONO
Serono,  Inc.,  located  in Rockland, MA, is the US affiliate of Serono, S.A., a
global  biotechnology  leader, headquartered in Geneva, Switzerland. The Company
has  six  recombinant  products  on the market, Gonal-F(R) (follitropin alfa for
injection),  Luveris(R)  (lutropin  alfa),  Ovidrel(R)/Ovitrelle(R)
(choriogonadotropin  alfa  for  injection),  Rebif(R)  (interferon  beta-1a),
Serostim(R) [somatropin  (rDNA origin) for injection] and Saizen(R) [somatropin
(rDNA  origin)  for injection].  (Luveris(R)  is not approved in the USA).(4) In
addition  to  being  the  world leader in reproductive health, Serono has strong
market  positions  in  neurology,  metabolism and growth. The Company's research
programs  are  focused  on  growing  these  businesses  and  on establishing new
therapeutic  areas. Currently, there are seventeen new molecules in development.

In 2001, Serono achieved worldwide revenues of US$1.38 billion, and a net income
of  US$317  million,  making  it  the third largest biotech company in the world
based  on  revenues.  The Company operates in 45 countries, and its products are
sold  in  over 100 countries. Bearer shares of Serono S.A., the holding company,
are  traded on the virt-x (SEO) and its American Depositary Shares are traded on
the  New  York  Stock  Exchange  (SRA).

                                     -more-

---------------
(3) Ibid.
(4) Package inserts for Serono's US products are available at
    www.seronousa.com or by calling 1-888-275-7376.
    -----------------



ABOUT PFIZER
Pfizer  Inc  discovers,  develops, manufactures and markets leading prescription
medicines  for  humans  and  animals and many of the world's best-known consumer
brands.



FOR MORE INFORMATION, PLEASE CONTACT:

MEDIA RELATIONS           MEDIA RELATIONS
SERONO, INC.              SERONO
ROCKLAND,  MA             GENEVA, SWITZERLAND:
Tel:  +1 781 681 2340     Tel: +41-22 739 36 00
Fax:  +1 781 681 2935     Fax  +41-22-739 30 85
www.seronousa.com         www.serono.com
-----------------         --------------


INVESTOR RELATIONS
SERONO
GENEVA, SWITZERLAND:
Tel:  +41-22 739 36 01
Fax:  +41-22 739 30 22
www.serono.com
--------------


MEDIA RELATIONS
PFIZER
NEW YORK, NY
Tel : 212 733 5260
Fax : 212 808 8799
www.pfizer.com
--------------



                                      -end-



                                   SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.



                                       SERONO S.A.
                                       a Swiss corporation
                                       (Registrant)



November 26, 2002                      By:   /s/ Jacques Theurillat
                                           ---------------------------------
                                       Name:  Jacques Theurillat
                                       Title: Deputy Chief Executive Officer