Savient's Puricase(R) (PEG-uricase) Phase 2 Results Show Powerful Anti-hyperuricemic Activity in Treatment-Failure Gout Patients

Savient Pharmaceuticals, Inc. (NASDAQ:SVNT) today presentedadditional Phase 2 results for its Phase 3 compound Puricase(R)(PEG-uricase) at the European League Against Rheumatism (EULAR) 2006Annual Congress in Amsterdam. The new data extended upon the abstractsshown at the American College of Rheumatology (ACR) meeting inNovember 2005. Puricase (PEG-uricase) is being developed for thecontrol of hyperurecemia in treatment-failure gout.

The first of four Savient posters presented at the meetingreported on anecdotal findings of gout tophus eradication after 12weeks of PEG-uricase treatment, and includes both photographic andradiological results. A second abstract on efficacy and safetyresults, including responder analysis, time to uric acid normalizationand immunogenicity findings was also presented. The response rate,defined as the proportion of patients that had a mean serum uric acidlevel below 6 mg/dL, was over 50% for all dose groups, with the 8 mg/2week dose group showing over 80% response rate.

The analysis also demonstrates that at all doses tested the serumuric acid level was maintained in the normal range at least 75% of thetime. Laboratory assessment of antibody response to PEG-uricasefindings was encouraging. The antibody response was primarily of theIgM type and was found to be present prior to dosing in some patients.Savient believes that it was directed toward the PEG portion of thedrug, not to the protein portion. The presence of antibody was notpredictive of treatment response in terms of safety or efficacy.

Zeb Horowitz, M.D., Chief Medical Officer of Savient said, ""Theefficacy results from the Phase 2 are very promising, especiallyconsidering that this patient population is one in which conventionaltherapy already has failed. Additionally, the immunogenicity resultspresented at EULAR are encouraging, as are the lack of any clinicalmanifestations of allergy. Yet, it is important to keep in mind thatthe Phase 2 sample size is small and treatment duration is only threemonths. The presence of IgM antibodies identified prior to PEG-uricaseexposure and almost certainly directed against PEG, suggests it is across-reacting antibody. This outcome is not surprising to us giventhe ubiquity of PEG in the environment in foods, cosmetics, andmedicines. We believe that as long as these antibodies continue to beunassociated with adverse events or loss of drug activity, thisobservation will not have importance to physicians and patients. Thatis our hope and expectation for the Phase 3 studies.

"We have implemented rigorous assessments for immune response inthe ongoing Phase 3 studies to more fully explore this phenomenon. Atthis time, the emerging immunogenicity picture for PEG-uricase appearsto be quite benign, as would be expected for a pegylated product. But,a more complete understanding of the potential for immunogenicity mustawait the results of the Phase 3 clinical program."

Savient presented two additional Abstracts highlighting a 12-monthlongitudinal non-intervention study of disease characteristics inpatients with treatment-failure gout. These findings reveal that:

-- Despite specialist treatment, some patients with gout are inadequately responsive to therapy as currently provided and develop severe disease.

-- These patients have significant disease-related morbidities despite modest, but persistent hyperurecemia.

-- Most of the patients in the study had chronically tender and swollen joints and significant functional impairment that persisted through 12 months of follow-up while under the care of rheumatologists.

Christopher Clement, President and Chief Executive Officer ofSavient, said, "The abstract presentations at this prestigiousscientific conference demonstrate the growing recognition of theprevalence of gout and the need for an effective treatment. Puricaseis increasingly being recognized among the Rheumatology community as apotential breakthrough treatment for this orphan gout patientpopulation. We are encouraged by the results of Puricase to date andlook forward to moving towards commercialization with our Phase 3trials."

About the Phase 2 Study Abstracts

This Phase 2 study, a randomized, open-label, multi-center,parallel group trial assessed the urate response, and pharmacokineticand safety profiles of Puricase (PEG-uricase) in patients withhyperurecemia and severe gout who are unresponsive to or intolerant ofconventional therapy. The mean duration of disease was 14 years and 70percent of the study population had one or more tophi.

In the study, 41 patients (mean age of 58.1 years) were randomizedto 12 weeks of treatment with intravenous Puricase (PEG-uricase) atone of four dose regimens: 4 mg every two weeks (7 patients); 8 mgevery two weeks (8 patients); 8 mg every four weeks (13 patients); or12 mg every four weeks (13 patients). Plasma uricase activity andurate levels were measured at defined intervals. Pharmacokineticparameters, mean plasma urate concentration and the percentage of timethat plasma urate was less than or equal to 6 mg/dL were derived fromanalyses of the uricase activities and urate levels.

Patients who received 8 mg of PEG-uricase every two weeks had thegreatest reduction in plasma urate with levels below 6mg/dL 92 percentof the treatment time (pre-treatment plasma urate of 9.1mg/dL vs. meanplasma urate of 1.4mg/dL over 12 weeks).

At one clinical investigation site, two patients out of six wereasked to be photographed pre- and post PEG-uricase therapy whileparticipating in a randomized, phase 2 open-label, multi center studyto determine safety, pharmacokinetics and changes in uric acid (UA)levels with PEG-uricase. Photography was not required by the originalprotocol because a clinical outcome such as regression of tophi wasnot anticipated during the relatively brief treatment period of threemonths. While scientifically intriguing, anecdotal observations arenot proof of efficacy.

A total of 27 study patients received all intended doses ofPuricase (PEG-uricase). Thirty-eight patients experienced an adverseevent that was possibly treatment-related, most commonly gout flare(36 patients). As expected with biological administration, there was ahigh rate of infusion reaction: 23 patients (150 infusions)experienced 34 events that occurred within 24 hours of infusion; 21 ofthese events in 18 subjects were considered possible infusionreactions, and 14 of these subjects were withdrawn without repeatedadministration. During the study, the rate of administration wasslowed from 30 minutes to 60 minutes, and the infusion volume dilutedfrom 100 mL to 200 mL. Infusion reactions subsequently abated.

About Puricase (PEG-uricase) Phase 3 Clinical Studies:

The Phase 3 program is designed to compare the safety and efficacyof Puricase (PEG-uricase) administered by two-hour intravenousinfusion every two weeks or every four weeks versus placebo infusion,over a six-month period. The program design consists of two replicatesix-month placebo-controlled trials of approximately 100 randomizedpatients each. Eligible patients must have hyperuricemia andsymptomatic gout, and who have been unresponsive to or intolerant ofconventional therapy. All patients who complete the placebo-controlledtrials will be invited to participate in a long-term open labelextension, which the FDA suggested to continue for two years.

Therefore, patients who are randomized to the placebo arms will beeligible to receive Puricase (PEG-uricase) treatment in an open labelextension trial following completion of the six-month controlledregistration trial.

Each of the two trials is independently powered for the primaryefficacy (or key registration) endpoint, a responder analysisassessing the proportion of patients who have normalized plasma uricacid at month 3 and month 6. Secondary efficacy endpoints will beassessed in a population pooled from the two trials. These endpointswill include an assessment of the reduction in burden of gout tophiusing digital photography, reduction in the frequency of gout flares,improvement in the count of swollen and tender joints, andimprovements in patient reported outcomes using the Short Form 36(SF-36) and the Health Assessment Questionnaire-Disability Index(HAQ-DI).

Savient licensed exclusive, worldwide rights to the technologiesrelated to Puricase (PEG-uricase) from Duke University ("Duke") ofNorth Carolina and Mountain View Pharmaceuticals, Inc. ("MVP"), aCalifornia corporation. Duke developed the recombinant porcine uricaseenzyme and MVP developed the PEGylation technology. MVP and Duke weregranted U.S. and foreign patents covering the licensed technology.Puricase is a registered trademark of Mountain View Pharmaceuticals,Inc.

ABOUT SAVIENT

Based in East Brunswick, New Jersey, Savient Pharmaceuticals,Inc., is a specialty pharmaceuticals company and is engaged indeveloping, manufacturing and marketing pharmaceutical products thataddress unmet medical needs in both niche and broader markets. TheCompany's Phase 3 product, Puricase(R) (PEG-uricase), fortreatment-failure gout has reported positive Phase 1 and 2 clinicaldata. Savient's experienced management team is committed to advancingits pipeline and expanding its product portfolio by in-licensing latestage compounds and exploring co-promotion and co-developmentopportunities that fit the Company's expertise in specialtypharmaceuticals and initial focus in rheumatology. Savient markets itsproduct Oxandrin(R) (oxandrolone, USP) in the United States. TheCompany's subsidiary, Rosemont Pharmaceuticals Ltd., develops,manufactures, and markets through its own sales force oral liquidformulations of prescription products for the UK pharmaceuticalmarket. Rosemont's product portfolio includes over 100 liquidformulations primarily targeting the geriatric population. Puricase isa registered trademark of Mountain View Pharmaceuticals, Inc. Furtherinformation on the Company can be accessed by visiting:www.savientpharma.com

FORWARD LOOKING LANGUAGE

This news release contains forward-looking statements within themeaning of Section 21E of the Securities Exchange Act of 1934. Allstatements, other than statements of historical facts, included inthis report regarding the Company's strategy, expected futurefinancial position, results of operations, cash flows, financingplans, discovery and development of products, strategic alliances,competitive position, plans and objectives of management areforward-looking statements. Words such as "anticipate," "believe,""estimate," "expect," "intend," "plan," "will" and other similarexpressions help identify forward-looking statements, although not allforward-looking statements contain these identifying words. Inparticular, the statements regarding the clinical development ofPuricase (PEG-uricase), commencement of the Phase 3 clinical trial forPuricase (PEG-uricase), time for completion of patient recruitment andtiming for the filing of an NDA for Puricase (PEG-uricase) areforward-looking statements. These forward-looking statements involvesubstantial risks and uncertainties and are based on currentexpectations, assumptions, estimates and projections about theCompany's business and the biopharmaceutical and specialtypharmaceutical industries in which the Company operates. Such risksand uncertainties include, but are not limited to, the Company'sability to find a buyer for Rosemont Pharmaceuticals and to negotiateand consummate a sale of Rosemont at an attractive price; delay orfailure in developing Puricase and other product candidates;difficulties of expanding the Company's product portfolio throughin-licensing; introduction of generic competition for Oxandrin;fluctuations in buying patterns of wholesalers; potential futurereturns of Oxandrin or other products; the Company's continuing toincur substantial net losses for the foreseeable future; difficultiesin obtaining financing; potential development of alternativetechnologies or more effective products by competitors; reliance onthird-parties to manufacture, market and distribute many of theCompany's products; economic, political and other risks associatedwith foreign operations; risks of maintaining protection for theCompany's intellectual property; risks of an adverse determination inon-going or future intellectual property litigation; and risksassociated with stringent government regulation of thebiopharmaceutical and specialty pharmaceutical industries. The Companymay not actually achieve the plans, intentions or expectationsdisclosed in its forward-looking statements, and you should not placeundue reliance on the Company's forward-looking statements. Actualresults or events could differ materially from the plans, intentionsand expectations disclosed in the forward-looking statements that theCompany makes. The Company's forward-looking statements do not reflectthe potential impact of any future acquisitions, mergers,dispositions, joint ventures or investments that the Company may make.The Company does not assume any obligation to update anyforward-looking statements.

(SVNT-G)