Miravant, Xillix Collaborate to Diagnose and Treat Early Stage Cancer; Miravant Gains Exclusive Access to Proven Diagnostic Technology.

SANTA BARBARA, Calif. and RICHMOND, B.C.--(BW HealthWire)--June 3, 1998--Miravant Medical Technologies (Nasdaq:MRVT) today announced that it has signed an exclusive agreement with Xillix Technologies Corporation (Toronto:XLX) to co-develop proprietary systems for diagnosing and treating early stage cancer and pre-malignant tissues. Under the agreement, Miravant will evaluate the integration of its PhotoPoint(tm) drugs and devices with Xillix's fluorescence imaging systems to detect and destroy abnormal lesions. The initially targeted indication will be early stage lung cancer. Miravant is planning a comprehensive clinical strategy for lung cancer with Xillix and Chiron Diagnostics, a business unit of Chiron Corp., (Nasdaq:CHIR), with which Miravant signed a letter of intent in November 1997. Future applications will target other cancers for which Miravant and Xillix currently have development programs underway.

Xillix develops the LIFE-Lung Fluorescence Endoscopy System(tm) for fluorescenceimaging, and markets its systems through Olympus Optical Co. Ltd., of Tokyo, Japan, the world's leading supplier of endoscopic equipment. The Xillix LIFE systems use a blue light source to activate the natural fluorescence of tissue, employing the principle that healthy tissue fluoresces differently than cancerous or pre-cancerous tissues. Xillix gained U.S. FDA approval in September 1996 for its first product, the Xillix LIFE-Lung Fluorescence Endoscopy System. This system is clinically proven to improve detection and localization of lung cancer by 171% over conventional endoscopy. Miravant is developing PhotoPoint light-activated drugs to treat serious diseases, including cancer. PhotoPoint therapy can potentially be used to destroy abnormal lesions that are detected and localized by Xillix fluorescence endoscopy.

The agreement provides that both companies will own co-developed products and will share the research and development costs associated with the development program. Xillix will receive drug royalty payments from Miravant based on the drug sales generated by the co-developed technology. Miravant will make a $5 million (U.S.) equity investment in Xillix for approximately 9% ownership of the company ($3 million in cash and $2 million in restricted Miravant stock at a premium price to current market). Xillix will work exclusively with Miravant in photodynamic therapy, and Miravant will work exclusively with Xillix in fluorescence detection.

Strategy links early cancer detection with minimally invasive treatment

"This agreement gives Miravant valuable, exclusive access to Xillix's clinically proven fluorescence technology. Linking early cancer detection with minimally invasive cancer treatment is a powerful development strategy for PhotoPoint," said Gary S. Kledzik, Ph.D., Miravant chairman and chief executive officer. "Miravant has preclinical studies underway now for early stage lung cancer. By working together with Xillix and Chiron, we will be targeting a new group of lung cancer patients with early stage disease, who potentially have the best opportunity for good outcome results."

Pierre Leduc, president and chief executive officer of Xillix, stated, "This agreement with Miravant provides a comprehensive strategy for the early detection, localization and treatment of cancer. The three links of survival for cancer includes first, a screening method; second, a method to detect and localize the cancer; and thirdly, a treatment method. We have achieved the best possible arrangement: Miravant has a collaborative relationship with Chiron Corporation who is working toward an assay to screen high-risk patients for lung cancer; Xillix has the fluorescence imaging capabilities that are clinically proven to detect and localize cancer at its earliest stages; and finally, Miravant is developing PhotoPoint therapy to potentially provide a minimally invasive treatment option for these patients."

Miravant plan for early stage lung cancer includes Xillix and Chiron Diagnostics

The first targeted indication is lung cancer, for which Miravant is currently conducting PhotoPoint preclinical studies. There are 178,000 new cases of lung cancer each year in the United States, accounting for nearly a third of all cancer deaths, with an estimated 16 million high risk patients. The worldwide incidence of lung cancer is increasing by 0.5% per year. Early detection is difficult because symptoms often do not appear until the cancer is advanced, and current treatment for early stage disease is open-chest surgery, a traumatic and costly procedure. Chiron Diagnostics is working toward an assay to screen high-risk patients, such as smokers, for abnormal cellular changes suggestive of early stage lung cancer. Under Miravant's clinical development strategy, patients who test positive with the Chiron screening assay may be referred to undergo a Xillix LIFE-Lung Fluorescence Endoscopy System procedure to detect and localize abnormal lesions. Then, certain of these patients will be treated with minimally invasive PhotoPoint therapy.

Xillix Technologies Corp. is a leader in the development and commercialization of proprietary medical imaging technology that helps physicians diagnose early-stage cancer. When tissue containing abnormal cells is exposed to light from Xillix's fluorescence imaging devices, physicians are able to locate pre-cancerous and cancerous cells. The company's lead product, called the Xillix LIFE-Lung Fluorescence Endoscopy System, has been approved for sale in the United States, Canada, Europe and Japan. Worldwide marketing has been granted to Olympus Optical Co. Ltd., of Tokyo, the international endoscopy market leader.

The Xillix LIFE-GI Fluorescence Endoscopy System for gastrointestinal cancer is currently in development and, if approved, will be distributed by Olympus Optical.

Miravant is a leader in developing both pharmaceuticals and devices for photoselective medicine. The Company is pursuing PhotoPoint applications in a number of medical specialties, including oncology, urology, dermatology, ophthalmology, cardiology and gynecology. Over the last several years, Miravant has established strategic collaborative relationships with select corporations, including Boston Scientific Corporation, Chiron Corporation, Cordis, a Johnson & Johnson company, Iris Medical Instruments, Medicis Pharmaceutical Corporation, Pharmacia & Upjohn and Ramus Medical Technologies.

Except for the historical information contained herein, the matters discussed in this news release are deemed forward-looking statements under federal securities laws that involve risks and uncertainties. Actual results may differ materially from those in the forward-looking statements depending on a number of factors including, among other things, the ability to maintain long-term relationships with corporate partners, the ability to bring products to market through the regulatory approval process, uncertainty of future profitability, financing requirements and other factors detailed from time to time in the Company's SEC reports, including its report on Form 10-K filed under Miravant Medical Technologies for the fiscal year ended December 31, 1997. Clinical trials must be completed and FDA approval must be obtained before any of the Company's products may be made commercially available to the public.

For more information please visit our web page at: www.miravant.com

    CONTACT:  Miravant Medical Technologies
               Laurens Lichty, 805/685-9880
                        or
               Xillix Technologies Corp.
               Laurie McMichael, 604/278-5000