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 March, 2004

                                  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-F  X   Form  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                                                                      IVAX



MEDIA  RELEASE


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



                  SERONO AND IVAX ANNOUNCE POSITIVE OUTCOME OF
                   PHARMACOKINETIC TRIALS WITH ORAL CLADRIBINE

     CLADRIBINE TARGETED TO BECOME FIRST ORAL THERAPY FOR MULTIPLE SCLEROSIS



GENEVA,  SWITZERLAND,  AND MIAMI, USA - MARCH 23, 2004 - Serono (virt-x: SEO and
NYSE:  SRA)  and  IVAX  Corporation  (AMEX:  IVX and LSE: IVX.L) announced today
positive  results  from  two  clinical  trials  with  a  new  proprietary  oral
formulation  of  cladribine,  a  potential  new treatment for multiple sclerosis
(MS).  The  study  results  showed that the formulation of oral cladribine which
has  been  developed  by  Serono  and  IVAX  has  met  the targets for an orally
administered  product,  with  blood  levels  of  cladribine  in  the  expected
therapeutic  range.  Efficacy  studies  of  oral  cladribine  in MS patients are
planned  to  start  late  2004.

Previous  Phase  II and Phase III clinical trials have demonstrated the positive
effect  of  injectable  cladribine  in  patients  with  MS.  In  these  trials,
cladribine caused a dramatic reduction in new lesion development in the brain as
seen  on  magnetic  resonance  imaging  (MRI)  scans.  Patients  with  relapsing
remitting  MS  receiving  cladribine  also  experienced  clinical  benefits.

"As  the  originator  of  Rebif(R),  a  current reference treatment for multiple
sclerosis,  Serono  has  a  long-term  commitment  to  patients  with  multiple
sclerosis",  said  Ernesto  Bertarelli, CEO of Serono.  "This is a major step in
the  development  of  the  first  oral  disease modifying treatment for multiple
sclerosis."

Dr.  Phillip  Frost, CEO and Chairman of IVAX commented, "We are very pleased to
report the important progress which has been made with our partner Serono in the
development  of  cladribine as a novel oral therapy for multiple sclerosis. With
the  successful  completion  of  these  clinical trials, another of our products
advances  in  its  clinical  development."

Cladribine  is  being  developed  by Serono and IVAX under a worldwide agreement
signed  in  October  2002.


                                                                             1/3

ABOUT  CLADRIBINE
Cladribine  is  a  purine nucleoside analogue that disrupts the proliferation of
certain  white  blood cells, particularly lymphocytes, which are involved in the
pathological  process  of  multiple  sclerosis.


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

                                       ###

FOR SERONO
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 17, 2003.  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.

FOR IVAX
This press release contains certain forward-looking statements regarding product
development efforts and product performance and other non-historical facts which
are  being  are  made  pursuant  to  the  safe  harbor provisions of the Private
Securities  Litigation  Reform  Act  of 1995. These statements involve risks and
uncertainties  that  cannot  be  predicted  or  quantified and, consequentially,
actual  results  may  differ  materially from those expressed or implied by such
forward-looking  statements. Such risks and uncertainties include, among others,
that  development  efforts for Cladribine may fail, may not achieve the expected
results  or  effectiveness  and/or  may not generate data that would support the
approval  or  marketing of this product for the indications being studied or for
other  indications;  that  IVAX'  patents  pertaining  to  this  product  may be
invalidated or that additional patents may not be issued, and in either case may
not  succeed  in  preventing other products; and that others may develop product
formulations  that  are  superior  to IVAX' formulation. In addition to the risk
factors  set forth above, IVAX' forward looking statements may also be adversely
affected  by  general  market  factors, competitive product development, product
availability,  federal  and  state  regulations  and legislation, the regulatory
process  for  new products and indications, manufacturing issues that may arise,
trade  buying patterns, patent positions and litigation, among other things. For
further  details  and discussion of these and other risks and uncertainties, see
IVAX'  Annual  Report  on  Form  10-K  and other filings with the Securities and
Exchange  Commission.


                                       ###


                                                                             2/3

ABOUT  SERONO

Serono  is  a  global  biotechnology  leader.  The Company has seven recombinant
products,  Rebif(R),  Gonal-F(R),  Luveris(R),  Ovidrel(R)/Ovitrelle(R),
Serostim(R), Saizen(R) and Zorbtive(TM) (Luveris(R) is not approved in the USA).
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 approximately 30 ongoing development
projects.

In  2003,  Serono  achieved  worldwide revenues of US$2,018.6 million, and a net
income  of  US$390.0 million, making it the third largest biotech company in the
world. Its products are sold in over 90 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).


ABOUT  IVAX

IVAX is a multinational pharmaceutical company. The company discovers, develops,
manufactures  and  markets  branded  and  brand-equivalent  (generic)  drugs and
veterinary  products  in  the  U.S. and abroad. Headquartered in Miami, Florida,
IVAX  has operations in over 30 countries and its products are sold in more than
80.  The  company  is  strategically  focused  on  product  diversification  and
geographic  expansion  in  key pharmaceutical markets in North America; Western,
Central  and  Eastern  Europe;  Latin  America; and Asia. IVAX has more than 700
scientists and researchers involved in research and development.


FOR MORE INFORMATION, PLEASE CONTACT:

SERONO IN GENEVA, SWITZERLAND:
MEDIA RELATIONS:                     INVESTOR RELATIONS:
Tel:  +41-22-739 36 00               Tel:  +41-22-739 36 01
Fax:  +41-22-739 30 85               Fax:  +41-22-739 30 22
http://www.serono.com                Reuters:  SEOZ.VX / SRA.N
---------------------                Bloomberg:  SEO VX / SRA US

SERONO, INC., ROCKLAND, MA
MEDIA  RELATIONS:                    INVESTOR  RELATIONS:
Tel.  +1 781 681 2340                Tel.  +1 781 681 2552
Fax:  +1 781 681 2935                Fax:  +1 781 681 2912
http://www.seronousa.com
------------------------



IVAX INVESTOR RELATIONS
Tel:  +1 305-575-6043


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                                   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)



March 23, 2004                      By:   /s/  Allan Shaw
                                          ---------------------------
                                          Name:  Allan Shaw
                                          Title: Chief Financial Officer