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

EAST BRUNSWICK, N.J. -- Natural History Study Demonstrates the Need for Improved Strategies to Treat the Severe Morbidity Caused by Treatment-Failure Gout 

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

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

The analysis also demonstrates that at all doses tested the serum uric acid level was maintained in the normal range at least 75% of the time. Laboratory assessment of antibody response to PEG-uricase findings was encouraging. The antibody response was primarily of the IgM type and was found to be present prior to dosing in some patients. Savient believes that it was directed toward the PEG portion of the drug, not to the protein portion. The presence of antibody was not predictive of treatment response in terms of safety or efficacy.

Zeb Horowitz, M.D., Chief Medical Officer of Savient said, ""The efficacy results from the Phase 2 are very promising, especially considering that this patient population is one in which conventional therapy already has failed. Additionally, the immunogenicity results presented at EULAR are encouraging, as are the lack of any clinical manifestations of allergy. Yet, it is important to keep in mind that the Phase 2 sample size is small and treatment duration is only three months. The presence of IgM antibodies identified prior to PEG-uricase exposure and almost certainly directed against PEG, suggests it is a cross-reacting antibody. This outcome is not surprising to us given the ubiquity of PEG in the environment in foods, cosmetics, and medicines. We believe that as long as these antibodies continue to be unassociated with adverse events or loss of drug activity, this observation will not have importance to physicians and patients. That is our hope and expectation for the Phase 3 studies.

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

Savient presented two additional Abstracts highlighting a 12-month longitudinal non-intervention study of disease characteristics in patients 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 of Savient, said, "The abstract presentations at this prestigious scientific conference demonstrate the growing recognition of the prevalence of gout and the need for an effective treatment. Puricase is increasingly being recognized among the Rheumatology community as a potential breakthrough treatment for this orphan gout patient population. We are encouraged by the results of Puricase to date and look forward to moving towards commercialization with our Phase 3 trials."

About the Phase 2 Study Abstracts

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

In the study, 41 patients (mean age of 58.1 years) were randomized to 12 weeks of treatment with intravenous Puricase (PEG-uricase) at one of four dose regimens: 4 mg every two weeks (7 patients); 8 mg every two weeks (8 patients); 8 mg every four weeks (13 patients); or 12 mg every four weeks (13 patients). Plasma uricase activity and urate levels were measured at defined intervals. Pharmacokinetic parameters, mean plasma urate concentration and the percentage of time that plasma urate was less than or equal to 6 mg/dL were derived from analyses of the uricase activities and urate levels.

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

At one clinical investigation site, two patients out of six were asked to be photographed pre- and post PEG-uricase therapy while participating in a randomized, phase 2 open-label, multi center study to determine safety, pharmacokinetics and changes in uric acid (UA) levels with PEG-uricase. Photography was not required by the original protocol because a clinical outcome such as regression of tophi was not anticipated during the relatively brief treatment period of three months. While scientifically intriguing, anecdotal observations are not proof of efficacy.

A total of 27 study patients received all intended doses of Puricase (PEG-uricase). Thirty-eight patients experienced an adverse event that was possibly treatment-related, most commonly gout flare (36 patients). As expected with biological administration, there was a high rate of infusion reaction: 23 patients (150 infusions) experienced 34 events that occurred within 24 hours of infusion; 21 of these events in 18 subjects were considered possible infusion reactions, and 14 of these subjects were withdrawn without repeated administration. During the study, the rate of administration was slowed from 30 minutes to 60 minutes, and the infusion volume diluted from 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 efficacy of Puricase (PEG-uricase) administered by two-hour intravenous infusion every two weeks or every four weeks versus placebo infusion, over a six-month period. The program design consists of two replicate six-month placebo-controlled trials of approximately 100 randomized patients each. Eligible patients must have hyperuricemia and symptomatic gout, and who have been unresponsive to or intolerant of conventional therapy. All patients who complete the placebo-controlled trials will be invited to participate in a long-term open label extension, which the FDA suggested to continue for two years.

Therefore, patients who are randomized to the placebo arms will be eligible to receive Puricase (PEG-uricase) treatment in an open label extension trial following completion of the six-month controlled registration trial.

Each of the two trials is independently powered for the primary efficacy (or key registration) endpoint, a responder analysis assessing the proportion of patients who have normalized plasma uric acid at month 3 and month 6. Secondary efficacy endpoints will be assessed in a population pooled from the two trials. These endpoints will include an assessment of the reduction in burden of gout tophi using digital photography, reduction in the frequency of gout flares, improvement in the count of swollen and tender joints, and improvements 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 technologies related to Puricase (PEG-uricase) from Duke University ("Duke") of North Carolina and Mountain View Pharmaceuticals, Inc. ("MVP"), a California corporation. Duke developed the recombinant porcine uricase enzyme and MVP developed the PEGylation technology. MVP and Duke were granted 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 in developing, manufacturing and marketing pharmaceutical products that address unmet medical needs in both niche and broader markets. The Company's Phase 3 product, Puricase(R) (PEG-uricase), for treatment-failure gout has reported positive Phase 1 and 2 clinical data. Savient's experienced management team is committed to advancing its pipeline and expanding its product portfolio by in-licensing late stage compounds and exploring co-promotion and co-development opportunities that fit the Company's expertise in specialty pharmaceuticals and initial focus in rheumatology. Savient markets its product Oxandrin(R) (oxandrolone, USP) in the United States. The Company's subsidiary, Rosemont Pharmaceuticals Ltd., develops, manufactures, and markets through its own sales force oral liquid formulations of prescription products for the UK pharmaceutical market. Rosemont's product portfolio includes over 100 liquid formulations primarily targeting the geriatric population. Puricase is a registered trademark of Mountain View Pharmaceuticals, Inc. Further information on the Company can be accessed by visiting: www.savientpharma.com

FORWARD LOOKING LANGUAGE

This news release contains forward-looking statements within the meaning of Section 21E of the Securities Exchange Act of 1934. All statements, other than statements of historical facts, included in this report regarding the Company's strategy, expected future financial position, results of operations, cash flows, financing plans, discovery and development of products, strategic alliances, competitive position, plans and objectives of management are forward-looking statements. Words such as "anticipate," "believe," "estimate," "expect," "intend," "plan," "will" and other similar expressions help identify forward-looking statements, although not all forward-looking statements contain these identifying words. In particular, the statements regarding the clinical development of Puricase (PEG-uricase), commencement of the Phase 3 clinical trial for Puricase (PEG-uricase), time for completion of patient recruitment and timing for the filing of an NDA for Puricase (PEG-uricase) are forward-looking statements. These forward-looking statements involve substantial risks and uncertainties and are based on current expectations, assumptions, estimates and projections about the Company's business and the biopharmaceutical and specialty pharmaceutical industries in which the Company operates. Such risks and uncertainties include, but are not limited to, the Company's ability to find a buyer for Rosemont Pharmaceuticals and to negotiate and consummate a sale of Rosemont at an attractive price; delay or failure in developing Puricase and other product candidates; difficulties of expanding the Company's product portfolio through in-licensing; introduction of generic competition for Oxandrin; fluctuations in buying patterns of wholesalers; potential future returns of Oxandrin or other products; the Company's continuing to incur substantial net losses for the foreseeable future; difficulties in obtaining financing; potential development of alternative technologies or more effective products by competitors; reliance on third-parties to manufacture, market and distribute many of the Company's products; economic, political and other risks associated with foreign operations; risks of maintaining protection for the Company's intellectual property; risks of an adverse determination in on-going or future intellectual property litigation; and risks associated with stringent government regulation of the biopharmaceutical and specialty pharmaceutical industries. The Company may not actually achieve the plans, intentions or expectations disclosed in its forward-looking statements, and you should not place undue reliance on the Company's forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements that the Company makes. The Company's forward-looking statements do not reflect the 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 any forward-looking statements.

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