UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR
15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of ~~May~~ June

Commission File Number 1-15096

Serono S.A. (Translation of registrant’s name into English)

~~(Translation~~15 ofbis, Chemin ~~registrant’s~~des ~~name~~Mines Case ~~into~~Postale ~~English~~54 CH-1211 Geneva 20 Switzerland (Address of principal executive office)

15Indicate ~~bis,~~by ~~Chemin~~check ~~des~~mark ~~Mines Case~~whether ~~Postale~~the 54registrant files or ~~CH-1211~~will ~~Geneva~~file annual reports under cover of Form 20 ~~Switzerland~~-F or Form 40-F.

~~(Address of principal executive office)~~Form 20-F x Form 40-F o

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 ý Form 40-F o

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): o

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): o

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 o No ý x

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


Media Release

FOR IMMEDIATE RELEASE

~~PHASE~~COMPELLING EVIDENCE ~~III~~OF RAPTIVAÒ 12-WEEK CLEAR TRIAL OFDATA IN ~~ORAL~~PATIENTS ~~CLADRIBINE, A~~WITH ~~NOVEL~~MODERATE-TO-SEVERE ~~INVESTIGATIONAL THERAPY~~PLAQUE ~~FOR MULTIPLE~~PSORIASIS ~~SCLEROSIS, BEGINS~~PUBLISHED IN BRITISH ~~THE~~JOURNAL ~~UNITED~~OF ~~STATES~~DERMATOLOGY

~~Nationwide~~The ~~Recruitment~~efficacy ~~Begins~~and atsafety ~~Sites~~of ~~Across~~RaptivaÒ were comparable between refractory patients and the ~~U.S.~~more general moderate-to-severe plaque psoriasis patients

~~Rockland, Massachusetts, and~~ Geneva, Switzerland~~, May~~—June 422, 2006 - —Serono (virt-x: SEO and NYSE: SRA) announced today that ~~recruitment in~~ the ~~U.S. is~~12-week ~~beginning~~data ~~for~~from the ~~Phase~~clinical ~~III CLARITY~~ study CLEAR (~~CLAdRIbine~~CLinical Experience ~~Tablets~~Acquired inwith ~~Treating MS OrallY Study~~RaptivaÒ), demonstrating ofthat ~~oral cladribine for the~~RaptivaÒ produced ~~treatment~~significant ofclinical ~~patients~~improvements ~~with~~and ~~relapsing~~was ~~forms~~generally ofwell ~~multiple~~tolerated ~~sclerosis (MS). This~~among ~~multi-national~~patients ~~study was successfully initiated outside the U.S. in 2005~~refractory, ~~and will~~intolerant ~~now~~or ~~expand~~contraindicated to ~~include~~systemic 17therapies ~~clinical~~as well ~~trial~~as ~~sites~~ in the ~~U.S.~~total ~~The~~population ~~study is one~~ of ~~the~~patients ~~largest~~with MSmoderate-to-severe ~~trials~~plaque psoriasis, ~~ever~~was ~~conducted,~~published ~~and~~in ~~enrollment~~this ismonth’s onedition ~~track~~of tothe ~~be completed~~British inJournal ~~2006~~of Dermatology.(1)

~~CLARITY~~“Data isfrom athe ~~two-year, double-blind,~~CLEAR ~~placebo-controlled~~study ~~Phase~~show ~~III~~compelling ~~study~~evidence of ~~more~~the benefit ~~than~~of ~~1,200~~RaptivaÒ not ~~patients. It~~only isin ~~designed~~the general moderate-to-severe ~~assess~~psoriasis patient population, but also in patients’ ~~clinical~~in ~~relapses,~~which ~~disability~~previous ~~progression~~treatments ~~and~~have ~~MRI~~failed ~~(magnetic~~due ~~resonance imaging)~~to ~~brain~~efficacy, ~~activity. Previous~~or in ~~clinical~~whom ~~trials~~existing ~~using~~therapies ~~cladribine~~cannot ~~administered~~be byprescribed ~~injection~~due into ~~patients~~contraindications ~~with~~or MSsafety ~~showed~~concerns”, ~~positive~~said ~~effects~~Franck inLatrille, ~~reduction~~Senior ofExecutive ~~new~~Vice ~~lesion~~President, ~~development~~Corporate Global inProduct ~~the~~Development ~~brain~~of ~~as seen~~Serono. on“This ~~MRI~~creates ~~scans;~~a ~~reductions~~significant inunmet ~~relapses~~medical need ~~were~~that ~~also~~RaptivaÒ is ~~observed~~able to address.”

~~“The~~Following ~~Phase~~the ~~III~~12-week ~~CLARITY~~treatment, ~~trial~~RaptivaÒ demonstrated ~~is enrolling at~~ a ~~strong~~favorable ~~pace,~~safety profile and ~~the~~was ~~addition~~clinically ofsuperior USto ~~sites~~placebo ~~will~~in ~~accelerate~~showing ~~this pace and bring~~a usstatistically ~~one~~significantly ~~step~~higher ~~closer~~PASI(2) 75 torate, ~~our~~the ~~goal~~primary efficacy endpoint of ~~making~~ the ~~first~~study. ~~oral~~793 patients MSwere ~~therapy~~enrolled ~~available for~~in ~~people living with~~ this ~~debilitating~~clinical ~~condition~~trial, ~~underscoring our~~ ~~fundamental~~of ~~and~~which ~~long-term~~526 ~~commitment~~comprised to the MSrefractory ~~community,” said Dr~~group. ~~Paul Lammers,~~ ~~Chief~~In ~~Medical~~the ~~Officer~~overall atpatient ~~Serono~~population, ~~Inc~~ 31. ~~“The~~4% ~~formulation~~ of ~~oral~~those ~~cladribine,~~treated ~~combined~~ with ~~the~~RaptivaÒ reached ~~proposed~~a ~~short~~³ 75% PASI ~~dosing regimen~~improvement, ~~should~~compared ~~help~~to ~~patients~~4.2% toof bepatients ~~more compliant~~treated with ~~their~~placebo MS(P ~~therapy~~< 0.0001); ~~and~~in ~~lighten~~ the refractory patient’s ~~treatment~~population, ~~burden~~29.5% versus 2.7% reached a PASI ~~associated~~75 ~~with~~rate ~~chronic~~(P MS< 0.”0001).

“WeBiological ~~all~~therapies are ~~looking~~ ~~forward~~a tomajor ~~the~~progress ~~day~~in ~~when~~the ~~there~~treatment isof anpsoriasis, ~~FDA~~a ~~approved~~frequent ~~oral~~and ~~therapy~~disabling ~~that~~skin disease. ~~can~~RaptivaÒ is ~~affect~~ the ~~underlying~~only ~~disease~~EU ~~process~~approved inbiological ~~MS,”~~molecule ~~said~~to specifically Drtarget T cells. ~~John~~ ~~Richert~~The ~~vice~~CLEAR ~~president~~study ~~research and~~is ~~clinical~~of ~~programs~~major atimportance as it prospectively demonstrates the ~~National~~efficacy MSand ~~Society. “Clinical~~safety ~~studies,~~of ~~such~~RaptivaÒ in moderate-to-severe patients as ~~CLARITY,~~well ~~are~~as ~~an important~~in ~~part~~patients ofwho ~~the~~have ~~process~~little ~~leading~~or no treatment options left available to them. The CLEAR study confirms the ~~development~~hope offered ofto ~~these~~our ~~new~~patients ~~medications. Those~~by ~~interested~~this inoriginal ~~determining~~therapeutic ~~whether~~approach”, ~~they~~said Louis ~~are~~Dubertret, ~~eligible~~professor toand ~~participate~~chairman inof one of the leading global centers for ~~clinical~~Dermatology ~~trial~~at ~~should~~the ~~speak~~Hospital ~~with~~Saint ~~their~~Louis, ~~healthcare~~Paris, ~~provider~~and first author of this publication.”

2CLEAR is the first and currently only multinational, randomized, double-blind, placebo-controlled, parallel-group trial demonstrating the efficacy of a biological therapy in an international patient population, where patients have previously failed to respond to other systemic therapies, or where these were inappropriate due to contraindications or intolerance. CLEAR prospectively and uniquely demonstrates that RaptivaÒ is an effective therapy in moderate-to-severe plaque psoriasis patients regardless of previous systemic treatments.

~~Trial~~(1) Dubertret ~~Recruitment~~L, ~~Taking~~Sterry ~~Place~~W, Bos JD, Chimenti S, Shumack S, Larsen CG, Shear NH, Papp KA, CLEAR Multinational Study Group. Clinical experience acquired with the efalizumab (RaptivaÒ) (CLEAR) trial in 15patients ~~States~~with moderate-to-severe plaque psoriasis: results from a phase III international randomized, placebo-controlled trial. Br J Dermatol 155:170–181.

~~Currently,~~(2) Psoriasis Area ~~there~~and ~~are~~Severity ~~17 clinics,~~Index; ~~medical~~most ~~centers,~~commonly ~~universities~~used ~~and~~clinical ~~hospitals~~scoring ~~recruiting~~system ~~patients~~ to assess ~~participate~~disease inseverity ~~the study~~ in 15clinical ~~major cities across the country, including:~~trials

• Medford, OR • Ann Arbor, MI • Newark, NJ • Oklahoma City, OK • Boulder, CO • Charleston, SC • Las Vegas, NV • Columbus, OH • Fort Wayne, IN • Chicago, IL • Durham, NC • Edmonds, WA • Baltimore, MD • Atlanta, GA • Charleston, WV1

~~Further~~Psoriasis ~~clinical~~is ~~trail~~a ~~site~~debilitating ~~information~~chronic inflammatory skin disease for which there is currently no permanent cure, and patients require ~~available~~long-term attreatment ~~www~~to control the disease.~~TheCLARITYStudy.com~~ While various systemic therapies and phototherapies are available, treatment options are limited for many orpatients as these treatments potentially have serious side effects in the long-term Umanagement of the disease.S. ~~National~~In ~~Institutes~~responding patients, the biological agent RaptivaÒ offers a new treatment paradigm for the continuous management of ~~Health~~the disease, increasing their quality of life(3). Globally, more than 30,000 patients have received Raptiva®, both during clinical trials and post ~~trial~~registration. ~~information~~This ~~website~~represents atmore ~~www~~than 17,500 patient years of exposure, creating one of the largest existing databases of patients taking a biological therapy for psoriasis.~~ClinicalTrials.gov.~~

“We are excited to further evaluate oral cladribine for the treatment of MS,” said Dr. Dusan Stefoski, M.D., associate professor of the Rush Multiple Sclerosis Center and a clinical investigator for the CLARITY trial. “From my clinical experience, the addition of an oral therapy for MS could improve compliance among patients and potentially change the MS treatment paradigm.”###

ItAbout is estimated that approximately 400,000 Americans are affected with MS, a chronic, progressive autoimmune disease of the centralCLEAR nervous system (CNS). Relapsing forms of MS are the most common. While symptoms of MS are unpredictable and can vary, the most common symptoms of MS include blurred vision, numbness or tingling in the limbs and problems with strength and coordination.Study

~~About~~CLEAR ~~Oral~~(CLinical ~~Cladribine~~Experience Acquired with RaptivaÒ) is the first multinational, randomized, double blind, placebo-controlled, parallel-group trial designed to evaluate the safety and efficacy of RaptivaÒ compared to placebo. Patients with moderate-to-severe plaque psoriasis, including refractory patients, defined as those for whom at least two systemic therapies were unsuitable because of lack of efficacy, intolerance or contraindication, were randomized in a 2:1 ratio to receive either once weekly for 12 weeks 1mg/kg RaptivaÒ or placebo.

~~Oral~~This ~~cladribine~~prospective istrial ~~a proprietary~~consisted ~~oral tablet formulation~~ of ~~cladribine~~three periods: ~~that is being studied in~~ an ~~effort~~ toinitial ~~demonstrate~~12-week ~~possible~~double-blind ~~benefits as a~~ treatment ~~for~~period, ~~patients~~an ~~with~~observation ~~relapsing~~period ~~forms~~ of ~~MS.~~up ~~Cladribine~~to is24 weeks and a ~~purine~~12-week ~~nucleoside~~open-label ~~analogue~~re-treatment ~~that~~period. ~~interferes~~The ~~with~~primary ~~the~~efficacy ~~behavior~~endpoint ~~and~~was the ~~proliferation~~proportion of ~~certain~~patients ~~white~~achieving ~~blood~~³ ~~cells,~~75% ~~particularly~~PASI ~~lymphocytes,~~improvement ~~which~~at ~~are~~week 12. ~~involved~~The insecondary ~~the~~endpoints ~~pathological~~included ~~process~~changes ofin ~~MS. Through~~PASI, ~~its~~static ~~differentiated mechanism~~Physician’s ofGlobal ~~action~~Assessment, ~~cladribine~~Physician’s ~~tablets~~Global ~~may~~Assessment ~~offer~~of change anfrom ~~effective~~baseline ~~new~~and ~~option~~percentage ~~to patients~~of ~~with~~body MSsurface area affected.

~~About~~793 patients were ~~Serono~~included ~~Neurology~~in this prospective trial, thereof 529 were randomized to RaptivaÒ and 264 to placebo. Amongst the 793 patients, 526 were refractory patients (342 randomized to RaptivaÒ and 184 to placebo). At week 12, RaptivaÒ achieved significantly higher PASI-75 rates in both, the refractory patients—29.5% for RaptivaÒ compared to 2.7% for placebo; (P< 0.0001)—and the overall study population—31.4% for RaptivaÒ versus 4.2% for placebo; (P < 0.0001). Superiority of RaptivaÒ to placebo was shown in both groups, the overall patient population and the refractory patients, for all secondary endpoints.

~~Currently~~Overall, ~~Serono~~ ~~has two therapies available for~~ the safety ~~treatment~~profile of ~~MS:~~RaptivaÒ in ~~Rebif~~the ~~(interferon beta-1a),~~initial ~~indicated~~12 weeks ~~for relapsing forms~~ of ~~MS,~~the ~~and Novantrone (mitoxantrone for~~CLEAR ~~injection~~study ~~concentrate),~~is ~~the~~consistent ~~only~~with ~~therapy~~that ~~approved~~reported ~~for~~in ~~worsening~~previous ~~forms~~US ofphase III clinical MSstudies. ~~Full~~ ~~prescribing information~~The ~~for~~incidence ~~these~~of ~~products~~serious ~~can~~adverse beevents ~~obtained~~affecting ~~by contacting Serono or visiting~~ the ~~Serono~~skin ~~website~~was ~~at www~~2.~~seronousa.com. Additional therapy options beyond~~5% ~~cladribine~~among ~~tablets~~efalizumab-treated ~~are~~patients ~~currently~~and ~~under~~2.3% ~~development~~among atplacebo-treated ~~Serono,~~patients. ~~including~~The ~~osteopontin,~~frequency anof ~~MMP~~serious arthritis-12related ~~inhibitor,~~adverse aevents ~~JNK~~was ~~inhibitor~~0.9% ~~and~~with ~~interferon beta:Fc, in~~efalizumab ~~early-stage~~compared ~~development~~with ~~for MS~~0.4% ~~Serono~~with ~~also~~placebo. isIn ~~taking~~the afirst ~~leading~~12 ~~role~~weeks ~~in developing an understanding~~ of ~~the~~this ~~role~~study, ofadverse events ~~genetics~~considered inpotentially ~~MS,~~infection-related ~~with~~were areported ~~whole~~28.4% ~~genome~~of ~~scan~~efalizumab-treated ~~currently~~patients ~~underway~~and 20.1% Toof placebo-~~date,~~treated 80patients. ~~genes~~No malignancies ~~associated~~were ~~with~~reported MSand ~~have~~there ~~been identified,~~were ~~based~~no onreports aof ~~40% scan~~thrombocytopenia. The most ~~project~~frequently isreported ~~due~~events toin bethe ~~completed~~CLEAR instudy ~~2006~~were ~~and~~headache, ‘influenza-like ~~will~~illness, ~~improve~~arthralgia, ~~understanding~~rigor, ofpyrexia, ~~the~~nasopharyngitis, ~~causes~~myalgia, ~~of MS~~ and ~~the appropriate therapeutic targets for the disease~~pruritus.

3Data on the 24-week observation and 12-week re-treatment period were presented at the European Academy of Dermatology and Venerology in London, UK, in October 2005.(4)

~~Some of the statements in this press release are forward looking. Such~~(3) Impact ~~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.~~efalizumab ~~and~~on ~~affiliates~~patient-reported tooutcomes ~~be materially different from those expected or anticipated~~ in ~~the forward~~high-~~looking~~need ~~statements.~~psoriasis ~~Forward-looking~~patients: ~~statements are~~results ~~based~~of onthe ~~Serono’s current expectations and assumptions~~international, ~~which may be affected by a number of factors~~randomized, ~~including~~placebo-controlled ~~those~~Phase ~~discussed~~III ~~in this press release and~~Clinical ~~more~~Experience ~~fully~~Acquired ~~described~~with inRaptiva ~~Serono’s~~(CLEAR) ~~Annual~~trial, ~~Report~~Ortonne ~~on Form 20~~J-FP ~~filed with the U.S. Securities and Exchange Commission on February~~et ~~28, 2006~~al.; ~~These factors include any failure or~~BMC ~~delay~~Dermatology ~~in Serono’s ability to develop new products~~2005, 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, the outcome of government investigations and litigation 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.5:13

~~###~~(4) The safety of efalizumab in patients with moderate-to-severe plaque psoriasis: results from the CLEAR study beyond 12 weeks, J. Ring, L. Dubertret, T. May, S. Chimenti & W. Sterry, JEADV (2005) 19 (Suppl. 2), 1–412 poster P06.87

~~About Serono~~2

~~Serono~~About is a global biotechnology leader. The Company has seven biotechnology products in the U.S., Rebif® (interferon beta-1a), Gonal-f® (follitropin alfa for injection), Luveris® (lutropin alfa), Ovidrel PreFilled Syringe®/Ovitrelle® (choriogonadotropin alfa injection), Serostim® [somatropin (rDNA origin) for injection], Saizen® [somatropin (rDNA origin) for injection] and Zorbtiveä [somatropin (rDNA origin) for injection].(1) 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, including oncology and autoimmune diseases. Currently, there are more than 25 on-going development projects.RaptivaÒ

InRaptiva® (efalizumab) ~~2005,~~is ~~Serono,~~a ~~whose~~humanized ~~products~~therapeutic ~~are~~antibody ~~sold~~designed into ~~over~~selectively 90and ~~countries,~~reversibly ~~achieved~~block ~~worldwide~~the ~~revenues of US$2~~activation,~~586.4~~ ~~million.~~reactivation ~~Reported~~and ~~net~~trafficking ~~loss in 2005 was US$106.1 million, reflecting a charge~~ of ~~US$725~~ ~~million~~T-cells ~~taken~~that ~~relating~~lead to the ~~settlement~~development of ~~the US Attorney’s Office~~ ~~investigation~~psoriasis ~~of Serostim~~symptoms. ~~Excluding~~Raptiva® is ~~this~~designed ~~charge as well as other non-recurring items, adjusted net income grew 28.4%~~ to ~~US$565.3~~be ~~million~~administered inonce ~~2005.~~weekly ~~Bearer~~via ~~shares~~subcutaneous ofinjection ~~Serono~~and ~~S.A.,~~can ~~the~~be ~~holding company, are traded on the virt~~self-xadministered ~~(SEO)~~by ~~and its~~patients ~~American~~at ~~Depositary Shares are traded on the New York Stock Exchange (SRA)~~home.

~~For~~Raptiva® received ~~more~~EU ~~information~~approval for the ‘Treatment of adult patients with moderate to severe chronic plaque psoriasis who have failed to respond to, or ~~please~~who ~~contact:~~have a contraindication to, or are intolerant to other systemic therapies including cyclosporine, methotrexate and PUVA’.

Media Relations, USA:		Investor Relations, USA:
Tel:	1 781 681 2719	Tel:	+1 781 681 2552
Fax:	1 781 681 2928	Fax:	+1 781 681 2912
http://www.seronousa.com

Adverse events observed with Raptiva® include headache, non-specific infection (e.g., common colds), chills, pain, nausea, asthenia (weakness), and fever, all of which diminished after the first 1-2 doses. There is no evidence of accumulation or cumulative toxicity to date.

~~(1) Package~~Serono ~~inserts~~has ~~for~~the rights to develop and market ~~Serono’s~~Raptiva® worldwide USoutside ~~marketed~~of ~~products~~the ~~are~~United States and Japan. To date, RaptivaÒ is available atin ~~www~~over 50 countries, amongst them many countries in Europe, Latin America, Asia as well as Australia.~~seronousa.com~~ Development orand bymarketing ~~calling~~rights in the United States, where RaptivaÒ has been available since November 2003, ~~1-888-275-7376~~remain with Genentech Inc. (NYSE:DNA) and its U.S. partner XOMA (Nasdaq: XOMA).

4About Psoriasis

~~SIGNATURE~~Psoriasis is a T-cell mediated disease, which occurs when skin cells grow abnormally, resulting in thick, red, scaly, inflamed patches. Plaque psoriasis, the most common form of the disease is characterized by inflamed patches of skin (“lesions”) topped with silvery white scales. Psoriasis can be limited to a few spots or involve extensive areas of the body, appearing most commonly on the knees, elbows, trunk, and scalp. Although it is highly visible, psoriasis is not a contagious disease. While there are a number of medications that may help control the symptoms of psoriasis, there currently is no known permanent cure.

~~Pursuant to the requirements of~~Background ~~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.~~material

		SERONO S.A.,
		a Swiss corporation
		(Registrant)
Date	May 4, 2006	By: /s/ Stuart Grant
		Name: Stuart Grant
		Title: Chief Financial Officer

For free B-roll, video and other content for Serono and its products, please visit the Serono Media Center www.thenewsmarket.com/Serono. You can download print-quality images and receive broadcast-standard video digitally or by tape from this site. Registration and video is free to the media.

5About Serono

Serono is a global biotechnology leader. The Company has eight biotechnology products, Rebif®, Gonal-f®, Luveris®, Ovidrel®/Ovitrelle®, Serostim®, Saizen®, Zorbtive™ and Raptiva®. 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, including oncology and autoimmune diseases. Currently, there are more than 25 on-going development projects.

In 2005, Serono, whose products are sold in over 90 countries, achieved worldwide revenues of US$2,586.4 million. Reported net loss in 2005 was US$106.1 million, reflecting a charge of US$725 million taken relating to the settlement of the US Attorney’s Office investigation of Serostim. Excluding this charge as well as other non-recurring items, adjusted net income grew 28.4% to US$565.3 million in 2005. 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).

###

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 February 28, 2006. 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, the outcome of government investigations and litigation 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 more information, please contact:

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

	Investor Relations, USA:
	Tel:	+1 781 681 2552
	Fax:	+1 781 681 2912

SIGNATURE

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)


Date	June 22, 2006	By:	/s/ Stuart Grant
		Name:	Stuart Grant
		Title:	Chief Financial Officer

Filing Compare · MERCK SERONO S.A.