QLT and Ciba Vision: Visudyne clinical results
QLT PhotoTherapeutics Inc QLT
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Tue 28 Mar 2000 News Release
Dr. Julia Levy reports
Ciba Vision, the eye care unit of Novartis, and QLT PhotoTherapeutics Inc.
achieved positive top-line results from the pivotal phase III study
confirming that the benefit and safety of Visudyne (verteporfin) therapy in
treatng the predominantly classic form of age-related macular degeneration
(AMD) is sustained over a two-year period.
In addition, one-year results from a separate and ongoing Phase IIIb study
showed that Visudyne therapy benefits patients with a similar but distinct
condition referred to as choroidal neovascularization (CNV) due to
pathologic myopia.
"These results are significant," said Dr. Neil Bressler, chair of the
Visudyne Study Advisory Group, and retinal specialist and professor of
Ophthalmology at the Wilmer Eye Institute of the Johns Hopkins University
School of Medicine in Baltimore, Md. "Visudyne therapy showed a sustained
benefit over two years with no additional safety issues and fewer
treatments required in the second year."
A complete analysis of the results is currently under way. Further details
will be submitted for publication in a peer-reviewed medical journal and
presented at the annual association of research in vision and ophthalmology
(ARVO) meeting in Fort Lauderdale, Fla., scheduled for April 30-May 5,
2000. The U.S. Food and Drug Administration (FDA) has not received this
data, nor do they need it to complete their review of the Visudyne new drug
application (NDA) filed in August 1999.
"This is a significant development for patients suffering from wet AMD --
they can now look forward to even more prolonged benefits from Visudyne
therapy," said Luzi von Bidder, president of Ciba Vision's worldwide
Ophthalmic business unit. "We are pleased to see Visudyne has a durable
effect based on the 24-month follow up data."
"We are equally encouraged with the results in the pathologic myopic
patients," said Dr. Julia Levy, president and chief executive officer of
QLT. "Until now this group of younger patients have had very little hope
once diagnosed with the condition -- a devastating proposition given that
the vast majority of them are still in the workforce. We intend to discuss
this potential new indication with the FDA to determine the viability of a
supplemental NDA for Visudyne."
Visudyne therapy is currently under review by the FDA as a treatment for
AMD in patients with predominantly classic CNV. Visudyne therapy received
its first regulatory approval in Switzerland in December 1999, and
additional submissions remain pending in the European Union, Canada,
Australia, New Zealand, Norway, Iceland, Brazil, Argentina and India.
Outside of Switzerland, in many countries, the treatment is available
through early access programs. In North America, a treatment
investigational new drug program, in which approximately 3,300 patients
have been treated to date, is ongoing.
Study Data:
Phase III TAP Investigation-Wet AMD
The study results show that the beneficial effect of Visudyne therapy
observed at the 12-month time period has been fully maintained out to two
years. These findings are based on 24-month follow-up data from 609
patients with wet AMD who participated in two phase III multi-centre
randomized placebo- controlled trials known as the TAP (Treatment of AMD
with Photodynamic therapy) Investigation.
In the 242 patients with predominantly classic CNV (those cases for which
the therapy is currently under review by the FDA), 59.1 per cent of
patients treated with Visudyne therapy lost less than three lines of
vision, or 15 letters, on a standard eye chart, compared with 31.3 per cent
of patients administered placebo (p less than 0.001) at 24 months. Visudyne
patients also exhibited statistically significant positive results in a
number of additional areas including slower lesion growth, reduced leakage,
and stable contrast sensitivity -- which may be important for activities
such as reading and recognizing faces. Further, the percentage of
Visudyne-treated patients that experienced an improvement in vision
remained at 13 per cent over the 24 months.
The results confirm that Visudyne therapy is safe and well-tolerated in the
longer-term.
The average number of treatments required in the second year decreased from
3.4 to 2.1 for a total of 5.5 treatments over the 24-month period.
The effect of Visudyne therapy for the primary endpoint at 24 months also
remained statistically significant in the overall population in the
combined studies. Patients who elected to continue treatment beyond the
24-month follow-up period are being followed for an additional two years in
an open label study called the TAP extension.
Phase 111b VIP Trial--CNV dae to pathologic myopia
The results for patients with CNV due to pathologic myopia are based on a
single study involving 120 patients with the condition who were enrolled in
a Phase IIIb 24-month multicentre randomized placebo-controlled study
called the VIP (Verteporfin in photodynamic therapy) Trial.
At 12 months, patients showed a definite benefit from Visudyne therapy with
respect to visual acuity, contrast sensitivity, lesion size, amount of
leakage and other outcomes. Specifically, 86.4 per cent of patients
receiving Visudyne therapy lost less than three lines of vision, or 15
letters, on a standard eye chart, compared with 66.7 per cent of patients
administered a placebo (p equals 0.01).
Patients in the study received an average of 3.4 treatments during the
12-month period and will continue to be followed for an additional 12
months.
CNV due to pathologic myopia is caused by abnormal blood vessels that grow
under the centre of the retina as a result of an abnormal elongation of the
back of the eye associated with severe near-sightedness or myopia. It
generally occurs among people over 30 years of age and can result in a
progressive loss of vision for which there were no proven treatments. The
worldwide incidence of CNV due to pathologic myopia is estimated to be
50,000 new cases per year.
Phase IIIb VIP Trial -- Wet AMD
One-year results of an additional Phase IIIb multi-centre randomized
placebo-controlled trial involving 339 AMD patients with a different
pattern of CNV, that were not eligible for inclusion in the TAP
Investigation, did not show a statistically significant benefit with
respect to the primary endpoint at 12 months. Forty-nine per cent (49.37
per cent) of patients treated with Visudyne therapy lost less than three
lines of vision, or 15 letters, on a standard eye chart, compared with 45.6
per cent of patients on placebo. These patients will continue to be
followed for an additional 12 months. These findings have no impact on the
recommendation regarding the beneficial effects of Visudyne therapy for
predominantly classic CNV in AMD.
Safety of Visadyne therapy
Both the TAP and VIP studies confirmed the positive safety profile found
with Visudyne therapy. The most frequently reported adverse events
attributed to the treatment include injection site events and visual
disturbances. In over 3,400 treatments, photosensitivity reactions occurred
less than 0.6 percent of the time.
Background information
About AMD
AMD is the leading cause of blindness in people over the age of 50 and is
caused by a growth of abnormal blood vessels (a condition known as
choroidal neovascularization or CNV) across the central part of the retina,
or macula. The vessels leak fluid and cause scar tissue that destroys
central vision, resulting in a deterioration of sight over a period ranging
anywhere from two months to three years. Although the wet form represents
an estimated 15 per cent of all AMD cases, it accounts for approximately 90
per cent of the severe vision loss associated with the disease. Worldwide,
approximately 500,000 new cases of wet AMD occur each year and this
estimate is expected to grow dramatically as the population ages.
About the TAP investigation Results from 12 months of the TAP investigation
-- previously released in January 1999, and subsequently published in the
October 1999, issue of the leading peer-reviewed journal Archives of
Ophthalmology -- showed that Visudyne therapy could significantly and
safely reduce the risk of vision loss associated with wet AMD.
About Visadyne therapy
Visudyne therapy is a two-step procedure that can be performed in a
doctor's office. First Visudyne is injected intravenously into the
patient's arm, then a non-thermal laser light is shone into the patient's
eye activating the drug. Visudyne therapy uses a specially-designed laser
that produces the low level, non-thermal 689nm light required to activate
the drug. These lasers have been developed by two of the world's leading
laser companies, Coherent Inc., based in California, and the Carl Zeiss
Group, based in Germany.
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