XOMA Announces Results From Phase 3 EYEGUARD(TM)-B Study

Company to Host Conference Call and Webcast Today at 8:30am EDT

BERKELEY, Calif., July 22, 2015 (GLOBE NEWSWIRE) -- XOMA Corporation (Nasdaq:XOMA), a leader in the discovery and development of therapeutic antibodies, today announced the Phase 3 EYEGUARD-B study of gevokizumab in patients with Behçet's disease uveitis, run by its partner Servier, an independent French pharmaceutical research company driven by the pursuit of innovative drugs, did not meet the primary endpoint of time to first acute ocular exacerbation.

"Although the study did not achieve its main objective, we did see signals of drug activity such as preserved visual acuity, less severe ocular exacerbations and a reduced incidence of reported macular edema in patients treated with gevokizumab," said Paul Rubin MD, Senior Vice President Research and Development and Chief Medical Officer. "We will continue to work closely with our partner, Servier, and uveitis experts to conduct a thorough analysis of the data to fully understand gevokizumab's impact on several clinically relevant endpoints."

"The initial observations seen in the secondary endpoints are clinically important and meaningful to both clinicians and Behçet's disease uveitis patients," stated Dr. Ilknur Tugal-Tutkun, international coordinator for the EYEGUARD-B study and Professor of Ophthalmology, Head, Ocular Immunology and Uveitis Service at Istanbul University, Istanbul Faculty of Medicine, Department of Ophthalmology. "We look forward to learning more."

"In recent years, our public focus has been on gevokizumab. However, during that time, we have significantly advanced other assets in our pipeline including XOMA 358, for which we completed a positive Phase 1 study showing it is active in down-regulating the insulin receptor and shows potential in treating patients who experience endogenous over-production of insulin, and XOMA 089, our late preclinical anti-TGFβ monoclonal antibody with potential in immuno-oncology and fibrosis," said John Varian, Chief Executive Officer of XOMA. "We will focus our efforts on creating value with these pipeline assets and reduce expenses where appropriate. While we continue to evaluate the data from EYEGUARD-B, the EYEGUARD-A and C studies, in the broader range of non-infectious uveitis, are still recruiting."

Gevokizumab appeared to be well tolerated in the trial. Adverse events were comparable between gevokizumab and placebo treated groups.

Investor Conference Call and Webcast

XOMA will host a conference call and webcast today, July 22, 2015, at 8:30am EDT. The webcast can be accessed via the Investors and Media section of XOMA's website at http://investors.xoma.com/events.cfm and will be available for replay until close of business on August 10, 2015. Telephone numbers for the live audiocast are 877-369-6589 (U.S./Canada) and 408-337-0122 (international).

EYEGUARD-B Study Design

The objective of the Phase 3 EYEGUARD-B study (A randomisEd, double-masked, placebo-controlled studY of the Efficacy of GevokizUmAb in the tReatment of patients with Behçet's Disease uveitis) was to demonstrate the superiority of gevokizumab, compared with placebo, on top of the current standard of care in reducing the risk of Behçet's disease uveitis exacerbations and to assess the safety of gevokizumab. The study was designed to enroll patients with a history of Behçet's disease uveitis with ocular involvement of the posterior segment who had experienced a recent ocular exacerbation that was treated successfully with high doses of corticosteroids.

The trial enrolled a total of 83 patients in the core part of the study (40 on gevokizumab and 43 on placebo). Patients were randomized to either a 60 mg dose of gevokizumab or placebo administered subcutaneously once monthly on top of their current immunosuppressive and corticosteroid therapies. They were randomized when they reached the step of 20 mg/day equivalent oral prednisone and continued a standardized tapering regimen until they reached 5 mg/day during double-masked treatment.

The primary endpoint was the time to first acute ocular exacerbation. Secondary endpoints included total number of exacerbations, best corrected visual acuity, vitreous haze, retinal lesions, fundus assessments and macular edema.

About Behçet's Disease and Behçet's Uveitis

Behçet's (pronounced beh-CHETS) disease is an orphan disease that causes chronic inflammation of the blood vessels (vasculitis). Major symptoms can affect the neurological, pulmonary, gastrointestinal and cardiovascular systems. Painful ulcers in the mouth and on the genitals are hallmarks of the disease. In the United States, an estimated 15,000 individuals have Behçet's disease.

Behçet's disease uveitis is one of the most severe forms of non-infectious uveitis and affects approximately 50 percent of those with Behçet's disease. Behçet's disease uveitis is characterized by recurrent unpredictable acute attacks or exacerbations. Without immediate treatment, major exacerbations of Behçet's uveitis may lead to retinal detachment, vitreous hemorrhage, glaucoma and eventual blindness. Symptoms, which most often include acute retinal lesions and the accumulation of vitreous haze that can block eyesight or the loss of visual acuity, can manifest differently from patient to patient. Available treatments for Behçet's disease uveitis are limited to corticosteroids and off-label use of immunosuppressive drugs and biologics, all of which can have significant side effects when used on a chronic basis.

About Gevokizumab

Gevokizumab is a potent monoclonal antibody with unique allosteric modulating properties. It has the potential to treat patients with a wide variety of inflammatory and other diseases. Gevokizumab binds strongly to interleukin-1 beta (IL-1 beta), a pro-inflammatory cytokine, and modulates the cellular signaling events that produce inflammation. IL-1 beta has been shown to be involved in a diverse array of disease states, including non-infectious and Behçet's disease uveitis, cardiometabolic diseases and other auto-inflammatory diseases.

Gevokizumab currently is being studied in multiple indications. Global Phase 3 clinical programs are underway in Behçet's disease uveitis, non-infectious uveitis and pyoderma gangrenosum. Information about gevokizumab clinical studies can be found at www.clinicaltrials.gov and www.clinicaltrialsregister.eu.

About XOMA Corporation

XOMA Corporation is a leader in the discovery and development of therapeutic antibodies. The Company's innovative product candidates are the result of its expertise in developing ground-breaking monoclonal antibodies, including allosteric modulating antibodies, which have created new opportunities to potentially treat a wide range of human diseases. XOMA is developing its lead product gevokizumab (IL-1 beta modulating antibody) with Servier through a global Phase 3 program for Behçet's disease uveitis and non-infectious uveitis. XOMA also has an ongoing Phase 3 study of gevokizumab in pyoderma gangrenosum. Additionally, XOMA's scientific research has produced the XMet platform, which consists of three classes of Selective Insulin Receptor Modulators (SIRMs) antibodies. XOMA 358, the lead antibody in the XMetD program, is an allosteric modulating monoclonal antibody that reduces both the binding of insulin to its receptor and down-regulates insulin signaling and could have a major effect on the treatment of abnormal metabolic states. XOMA 358 recently completed Phase 1 testing. For more information, visit www.xoma.com.

About Servier

Servier is an independent French pharmaceutical research company with a strong international presence in 146 countries that employs more than 21,400 people worldwide. Its development is based on the continuous pursuit of innovation in the therapeutic areas of cardiovascular, metabolic, neurologic, psychiatric, bone and joint diseases, as well as cancer. In 2014, the company recorded revenue of 4 billion euros, 92 percent of which was generated from sales outside of France, and reinvested 28 percent of the revenue in Research and Development activities. More information is available at: www.servier.com.

Forward-Looking Statements

Certain statements contained in this press release including, but not limited to, statements related to, or statements that otherwise relate to future periods are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. These statements are based on assumptions that may not prove accurate, and actual results could differ materially from those anticipated due to certain risks inherent in the biotechnology industry and for companies engaged in the development of new products in a regulated market. Potential risks to XOMA meeting these expectations are described in more detail in XOMA's most recent filing on Form 10-K and in other SEC filings. Consider such risks carefully when considering XOMA's prospects. Any forward-looking statement in this press release represents XOMA's views only as of the date of this press release and should not be relied upon as representing its views as of any subsequent date. XOMA disclaims any obligation to update any forward-looking statement, except as required by applicable law.

CONTACT: Company and Investor Contact:
         Ashleigh Barreto
         +1 510-204-7482
         barreto@xoma.com

         Juliane Snowden
         The Oratorium Group, LLC
         jsnowden@oratoriumgroup.com

         Media Contact:
         Ryan Flinn
         W2O Group
         +1 415-946-1059
         rflinn@w2ogroup.com

         Servier Communications Department
         +33 1-5572-6037
         presse@servier.fr

Released July 22, 2015