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 January, 2005

                                  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 TO INITIATE PHASE III CLINICAL TRIAL
                       OF MYLINAX(R) IN MULTIPLE SCLEROSIS

     MYLINAX(R) TARGETED TO BECOME FIRST ORAL THERAPY FOR MULTIPLE SCLEROSIS


GENEVA, SWITZERLAND, AND MIAMI, USA - JANUARY 11, 2005 -
Serono  (virt-x:  SEO  and  NYSE:  SRA) and IVAX Corporation (AMEX: IVX and LSE:
IVX.L) announced today that they will initiate a Phase III study with Mylinax(R)
(a  proprietary  oral  formulation  of cladribine) in the first quarter of 2005.
This  multi-center, multi-national study is designed to assess the effectiveness
of Mylinax(R) in patients with relapsing forms of multiple sclerosis.  Endpoints
will  include  assessments  of clinical relapses, disability progression and MRI
(magnetic  resonance imaging) brain scans.  It will be a two-year, double-blind,
placebo-controlled  study  involving  over  1,200  patients.

"As  a leader in multiple sclerosis, we are committed to providing new treatment
options  that  can  further  improve  the  quality  of  the lives of people with
multiple  sclerosis,"  said  Ernesto  Bertarelli,  CEO  of  Serono.  "With  the
initiation  of  the  Phase  III  program of Mylinax(R), we are getting closer to
realizing  our  objective to bring the first oral disease-modifying treatment to
people  with  multiple  sclerosis."

"We are very pleased to have reached this important milestone in the development
of  Mylinax(R)  as  a  novel  therapy  for multiple sclerosis," said Dr. Phillip
Frost,  Chairman and CEO of IVAX Corporation.  "The initiation of this Phase III
study  supports  our  belief in Mylinax(R) and our choice of Serono as a partner
that  could  help  maximize  its  potential."

Previous  clinical  trials  using a parenteral formulation demonstrated positive
effects  of  cladribine  administered  via  injection  in patients with multiple
sclerosis.  In these trials, reduction in new lesion development in the brain as
seen  on  MRI  scans  and  clinical  benefits  were  observed.

Mylinax(R)  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 interferes with the behavior and
the  proliferation of certain white blood cells, particularly lymphocytes, which
are  involved  in  the  pathological process of multiple sclerosis.  Through its
differentiated  mechanism  of action, Mylinax(R) may offer an alternative option
to  patients  with  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 March 25, 2004. 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  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, consequently, actual
results  may  differ  materially  from  those  expressed  or  implied  by  such
forward-looking  statements. Such risks and uncertainties include, among others,
that  indications  from previous clinical trials may not be indicative of future
results; that others may develop product formulations that are superior to IVAX'
formulations, that Phase III clinical trials for Mylinax(R) may not be commenced
or completed on a timely basis or at all, may fail, may not achieve the expected
results  or  effectiveness  and/or  may not generate data that would support the
continued development, approval or marketing of this product for the indications
being studied or other indications; and that Mylinax(R) may not become the first
oral  therapy  for multiple sclerosis. 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 eight biotechnology
products,  Rebif(R),  Gonal-F(R),  Luveris(R),  Ovidrel(R)/Ovitrelle(R),
Serostim(R),  Saizen(R),  Zorbtive(TM)  and Raptiva(R). In addition to being the
world  leader  in  reproductive  health,  Serono  has strong market positions in
neurology,  metabolism  and  growth and has recently entered the psoriasis area.
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  Corporation,  headquartered  in  Miami,  Florida,  discovers,  develops,
manufactures, and markets branded and brand equivalent (generic) pharmaceuticals
and  veterinary  products  in  the  U.S.  and  internationally.

In 2003, IVAX had worldwide net revenues of $1.4 billion and net income of $121
million. During the first nine months of 2004, IVAX' worldwide net revenues have
been $1.33 billion and net income, $135 million. IVAX has direct operations in
over 36 countries and its products are sold in more than 80. IVAX is listed on
the American, London and Warsaw stock exchanges.

Copies of this and other news releases may be obtained free of charge from IVAX'
website  at  www.ivax.com.
             ------------


FOR MORE INFORMATION, PLEASE CONTACT:

SERONO
CORPORATE MEDIA RELATIONS:   CORPORATE 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: SEO.VX / SRA.N
 ---------------------       Bloomberg: SEO VX / SRA US


MEDIA RELATIONS, USA:        INVESTOR RELATIONS, USA:
 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 CORPORATION
David Malina
Director/Investor Relations & Corporate Communications
305.575.6043


                                                                             3/3

                                   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)



January 11, 2005                         By:    /s/ Stuart Grant
                                                -------------------
                                         Name:  Stuart Grant
                                         Title: Chief Financial Officer