I came across this press release on Yahoo for Chiron. It may have some relevance to QLT.
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Friday February 20, 12:28 pm Eastern Time
Company Press Release
Phase I/II Trial Shows PhotoPoint Improves Vision in Patients With an Advanced Stage of Macular Degeneration
Results Encouraging for Short-Term Treatment of Debilitating Eye Condition
BOCA RATON, Fla.--(BW HealthWire)--Feb. 20, 1998--Results of a Phase I/II trial presented today at the 21st Annual Meeting of The Macula Society suggest that PhotoPoint(tm) may help to increase visual acuity in patients diagnosed with exudative (''wet'') macular degeneration, the vision threatening form of the disease. Patients treated at optimal doses were able to read up to an additional 4 1/2 lines on a standard eye chart, a significant improvement in vision.
''Historically, the majority of patients with age-related macular degeneration have had very little recourse,'' said Robert P. Murphy, M.D., co-director of The Glaser Murphy Retina Treatment Center in Baltimore, Maryland, and an investigator for the study. ''Although these results are from early trials and more study needs to be done, the vision improvements seen in some PhotoPoint patients were nothing short of astonishing.''
The ''wet'' form of age-related macular degeneration (AMD) is the leading cause of vision loss in older adults, affecting over one million people. AMD is a degenerative disease that affects the macula, a vital portion of the retina or light-sensing tissue that lines the inside of the eye. In ''wet'' AMD, abnormal blood vessels grow under the retina resulting in scarring and distortion or loss of central vision. This makes it difficult for patients to read, distinguish detail, recognize faces, or drive. PhotoPoint is an office procedure that combines a light-activated drug with a non-thermal light that destroys abnormal blood vessels with minimal damage to the overlying retina.
Until Now, Few Options
While a small percentage of patients with wet AMD are eligible for high-power laser surgery, heat generated by the treatment always damages the overlying retina, often leading to loss of central vision. In contrast, the PhotoPoint procedure uses low-power red light to selectively destroy the target vessels while leaving normal blood vessels and tissues much less affected. The PhotoPoint procedure is performed in an office setting and requires no anesthesia. During the procedure, the patient is given an infusion of the light-activated compound Purlytin(tm) (tin ethyl etiopurpurin, SnET2) that collects in the abnormal blood vessels in the macula. Approximately fifteen minutes later, a low-power red light is aimed at the macula through the pupil of the eye. This activates the drug and selectively destroys the abnormal vessels. In these trials, the treatment was comfortable and painless for the patient.
Patients Experienced Visual Improvement
The Phase I/II trial was an open-label, multicenter, dose escalation study that examined the safety and efficacy of Purlytin- based PhotoPoint for the treatment of wet AMD. Patients in the study received one of four drug doses tested, followed by varying exposures of non-thermal light from a 664 nm diode laser. Visual acuity, using a standard eye chart, was measured at day one following treatment and at weeks one, three, six and 12, and compared to the baseline (pre-treatment) measurements.
Results of the first 28 patients treated showed that eyes receiving the shorter duration of light exposure did better in both higher and lower drug dosage groups. At optimal doses patients experienced improvement in visual acuity at day one, with continued improvement through week 12, gaining up to an impressive +4 1/2 lines of text on a standard eye chart. The most common side effect was a mild sensitivity to sunlight for one to two weeks after the procedure.
''The results for patients in select dosage groups were striking for an early clinical trial,'' said Dr. Murphy. ''If they can be confirmed in more patients for a longer duration in Phase II/III studies, patients suffering from wet AMD may have access to a treatment option that not only stabilizes degeneration but potentially restores vision.''
A Phase II/III investigational study is planned to begin this spring at select medical centers nationwide to determine long-term visual acuity in patients treated with PhotoPoint for wet AMD.
Miravant (NASDAQ:MRVT - news) 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, ophthalmology, urology, dermatology, cardiology, and gynecology. Over the last several years, Miravant has established strategic collaborative relationships with select corporations, including Boston Scientific Corporation [NYSE:BSX - news], Chiron Corporation [Nasdaq:CHIR - news], Cordis, a Johnson & Johnson company, Iris Medical Instruments, Inc., Medicis Pharmaceutical Corporation [Nasdaq:MDRX - news], Pharmacia & Upjohn, and Ramus Medical Technologies. For more information on Miravant, consult the company's Internet site: www.miravant.com.
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, results from further clinical studies, 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 (formerly known as PDT, Inc.) for the fiscal year ended December 31, 1996. 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.
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Contact:
Miravant
Laurens Lichty, 805/685-9880 |
