Anti-VEGF Therapy Presents New Challenges
Specialists discuss how they're using
pegaptanib in light of the clinical trial protocol and a possible increase in
patient visits.
Dr.
Slakter: In December 2004, the FDA approved the anti-VEGF drug pegaptanib sodium
(Macugen) for the treatment of neovascular (wet) age-related macular degeneration
(AMD). What does that mean to you?
Dr. Johnson: I regard pegaptanib
as one of my options for treating AMD, and I include it in my discussions with patients.
I don't treat indolent lesions with pegaptanib, and I don't use it for lesions so
far advanced that vision isn't likely to decline much further. Pegaptanib is a treatment
option for most other CNV lesions.
I find that after discussing
risks, benefits, mode and frequency of delivery, most patients who are eligible
for verteporfin PDT choose it with or without intravitreal triamcinolone. I tend
to follow the Centers for Medicare and Medicaid Services' (CMS) guidelines for determining
PDT eligibility.
In
my practice, most patients who receive pegaptanib are those we expect won't respond
to PDT, usually patients with large, minimally classic or occult lesions.
Even in that subgroup, I question
pegaptanib's efficacy because, to my knowledge, the data on that specific subgroup
have not been released.
There is some indication that
pegaptanib is most effective for small lesions. If we were to tease out the particular
subgroup of large, minimally classic or occult lesions, pegaptanib may or may not
be effective. Nevertheless, it's an approved treatment, and I usually recommend
it to those patients with large lesions.
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 "I
find that after discussing risks, benefits, mode and frequency of delivery, most
patients who are eligible for verteporfin PDT choose it with or without intravitreal
triamcinolone."
—
Mark W. Johnson, MD
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ALL LESIONS ARE NOT THE SAME
Dr. Slakter: What about extrafoveal
and juxtafoveal lesions?
Dr. Johnson: I use laser photocoagulation
for extrafoveal lesions. For juxtafoveal lesions that are too close to the foveal
center for laser therapy, I steer toward PDT with triamcinolone because I have the
most experience with this therapy, and I consider it the most powerful treatment.
I don't use pegaptanib for lesions threatening the foveal center because I'm not
impressed with the immediacy of its action.
Dr. Reichel: I had a case that
underscores the challenges of deciding on an appropriate treatment. I treated an
extrafoveal lesion with the laser, and the patient did fine for a couple of months.
After that, the lesion recurred and became juxtafoveal, so I performed PDT. The
lesion dried up, but in 2 or 3 months was leaking again, and vision declined. I
decided to treat with PDT
and
triamcinolone, which failed. At this point, I didn't feel the PDT effect was strong
enough to warrant another treatment, so I moved on to pegaptanib. When I used
pegaptanib,
the lesion dried up and the patient's vision improved four lines.
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 "We should avoid switching from
one treatment to another too quickly. We should wait to see how patients respond
before trying a new course."
—
Richard F. Spaide, MD |
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Dr. Brucker: These situations
will be challenging now that we have another treatment available. When do we switch
from PDT to something else? Is there any one treatment now available that will be
effective for all forms of AMD disease?
Dr.
Fine: We have to remember we're dealing with a disease for which there is no cure.
When we treat acute strep infection for example, we expect one course of penicillin
to take care of it. But chronic diseases require ongoing intervention. We may never
have a "magic bullet" for AMD.
Dr. Spaide: We can make another
analogy: Warren Buffett got rich by buying stocks and sticking with them. Other
people who traded a lot didn't do so well. Dr. Reichel's decision to switch to pegaptanib
worked for one
patient. He got better vision, and that's our goal, but usually, we should avoid
switching from one treatment to another too quickly. We should wait to see how patients
respond before trying a new course.
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 "We
now have the option of using an anti-VEGF treatment, but we don't have clear guidelines."
—
Jason S. Slakter, MD
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YOUR JUDGMENT VS. LABEL PROTOCOL
Dr. Williams: Much of this discussion
revolves around the breadth of the pegaptanib label. If the label were restrictive,
it would tell us exactly how we may or may not use the drug, and these decisions
would be out of our control.
I'm
glad to see a broad label because it lets us take a more active role in managing
AMD. It's unrealistic to think we can design one trial to cover all patients, because
AMD is so complex.
Dr. Slakter: We now have the
option of using an anti-VEGF treatment, but we don't have clear
guidelines. How will we manage patients in light of this?
For
example, if you want to treat a patient with pegaptanib, will you just bring him
in every 6 weeks for an injection? Will you assess something more than
just a clinical exam?
Retinal Physician, Issue: July 2005