Showing posts with label drusen. Show all posts
Showing posts with label drusen. Show all posts

Sunday, January 9, 2011

Novartis gains new indication for Lucentis in EU for vision loss due to Diabetic Macular Edema

By:Financial

The European Commission has granted Novartis a new indication for Lucentis (ranibizumab) to treat patients with visual impairment due to diabetic macular edema (DME), a leading cause of blindness in the working-age population in most developed countries.

Laser therapy, the current standard of care, has provided stabilization of vision in many patients, but generally does not improve vision. Lucentis is the first licensed therapy to significantly improve both vision and vision-related quality of life in patients with visual impairment due to DME.

"Similarly to wet age related macular degeneration, diabetic macular edema can cause disabling vision loss. While vision loss as a consequence of diabetes affects only a very small proportion of people with the disease, it is one of the most feared complications," said Don Curran, Chair, AMD Alliance International. "Visual impairment impacts everything from managing social interactions to the ability to work - thus, for most people it means a loss of independence."

The approval of Lucentis was based on data from two Novartis-sponsored clinical trials, RESTORE and RESOLVE, which showed that Lucentis was superior in providing rapid and sustained visual acuity gain versus sham (dummy) therapy or laser therapy, the current standard of care.

"In the clinical trials, Lucentis-treated patients began to recover their vision as early as eight days after the first injection on average, and vision improvement was maintained at one year," said Gabriele E. Lang, Professor, University Eye Hospital, University of Ulm, Germany. "The vision improvement for many of these patients was clinically significant, meaning that they regained the ability to carry out day-to-day activities such as driving."

The RESTORE study showed patients treated with Lucentis alone or with Lucentis plus laser therapy gained an average of 6.8 letters and 6.4 letters, respectively, in visual acuity at 12 months compared to baseline, while laser-treated patients gained an average of 0.9 letters as measured on a standard ETDRS eye chart.

The RESOLVE study showed that Lucentis-treated patients gained an average of 10.3 letters in visual acuity at 12 months compared to baseline while sham-treated patients, some of whom also received laser treatment, lost an average of 1.4 letters.

"Since its first launch in the EU in 2007, Lucentis has become the gold standard treatment of wet AMD and its use has stimulated research into other ocular conditions," said David Epstein, Division Head of Novartis Pharmaceuticals. "Our continued investment in the clinical development of Lucentis means that another group of patients who are at risk of losing their eyesight will have the option of a licensed therapy that could help save their vision."

"The pivotal data from RESTORE and RESOLVE studies are further supported by results of an independent US study examining Lucentis for the treatment of DME compared to standard of care. Conducted by the Diabetic Retinopathy Clinical Research Network (DRCR.net), this study showed that at 12 months patients treated with Lucentis plus laser gained an average of nine letters in visual acuity compared to baseline while patients treated with laser therapy alone gained an average of three to four letters. In addition, the study demonstrated superior gains in visual acuity among Lucentis-treated patients up to two years, with a reduced number of Lucentis injections required the second year compared to the first. Specifically, there was a median of only two to three injections required in the second year of treatment compared to a median of eight to nine injections required in the first year," Novartis said.

Diabetic macular edema (DME) is a consequence of diabetic retinopathy, the most common diabetic eye complication. DME is characterized by changes in the blood vessels of the retina, which is the light-sensitive layer at the back of the eye. In patients with DME, leakage from these abnormal blood vessels occurs in the central portion of the retina, called the macula. Because this part of the eye is responsible for sharp central vision, DME can lead to significant visual impairment. Visual impairment due to DME affects approximately 1-3% of patients with diabetes, and DME is a leading cause of blindness in the working-age population in most developed countries.

Lucentis offers an entirely new pharmacological approach to treatment for visual impairment due to DME compared to the current standard of care, which involves the use of laser burns to stop capillary leakage and reduce swelling. Lucentis is an antibody fragment that is injected into the eye and neutralizes vascular endothelial growth factor (VEGF), a protein that is known to increase vascular permeability, resulting in capillary leakage and macular edema in patients with diabetes.

Lucentis was generally well tolerated in DME clinical studies, either when given as monotherapy or when combined with laser treatment. Its safety profile was consistent with the well established profile in patients with wet age-related macular degeneration (wet AMD). There was an incidence of arterial thromboembolic events (<=3.5%) observed in the DME clinical trials, consistent with what was seen in the wet AMD clinical trials, with no significant difference between the groups treated with Lucentis compared to sham or laser therapy. Ocular adverse events were similar to those seen in the wet AMD trials, with an incidence of 1.4% endophthalmitis in the pooled pivotal studies.

Lucentis is currently licensed in more than 85 countries for the treatment of wet AMD. It receives continuous safety monitoring via a systematic pharmacovigilance system and there is more than 750,000 patient-treatment years of exposure to date for Lucentis.

Lucentis was developed by Genentech and Novartis. Genentech has the commercial rights to Lucentis in the United States, where Lucentis is also approved for the treatment of macular edema following retinal vein occlusion (RVO). In addition, Genentech is conducting two Phase III studies, RISE and RIDE, in patients with diabetic macular edema with results expected in 2011. Novartis has exclusive rights in the rest of the world and has filed in the European Union for approval of Lucentis for the treatment of visual impairment due to macular edema secondary to RVO.

Sunday, January 2, 2011

Macular Degeneration Treatments

by:Akler Eye Center

Macular degeneration, or Age-Related Macular Degeneration (ARMD) is a condition related to aging of the eye that causes loss of the central vision. It is the commonest cause of blindness in Americans over 55 years old. Approximately 10 million people in the United States are affected. Smoking, high blood pressure, family history of ARMD, and poor diet are all risk factors for the development of ARMD.

The macula is the center most part of the retina, and is responsible for the sharp vision that allows us to read and drive. In some people, as the eye ages, deposits develop in the retina (dry ARMD). This can cause the macula to function imperfectly, which leads to blurry vision. Only 10% of patients develop the wet form of ARMD. In this more devastating form, abnormal blood vessels grow in the macula, and when they leak or bleed, severe loss of the central vision often results.

The symptoms of macular degeneration are blurring of the vision, which causes difficulty with reading or driving. Macular degeneration does not cause total blindness because the side vision is not affected.

At Akler Eye Center in Dearborn MI, a complete eye examination including dilation of the pupil will allow Dr. Akler to detect both mild and severe forms of macular degeneration. If ARMD is found, further testing may include a fluorescein angiogram and optical coherence tomography (OCT). Fluorescein angiography involves injecting dye into the arm and photographing it as it circulates in the retina. Abnormal blood vessel growth and leakage may be detected. OCT is a computerized picture of the macula that shows if it is swollen with fluid. Both of these tests are performed onsite.

Treatments for macular degeneration are primarily targeted at keeping the retina as healthy as possible and screening for early signs of the wet form of ARMD. A study performed by the National Eye Institute demonstrated that taking special vitamins for the eye that contain anti-oxidants (A, C, E and beta-carotene with zinc) reduces the risk of developing severe vision loss. A home screening tool known as an Amsler Grid allows the patient to check the vision with one eye at a time. If the grid paper lines are wavy or faded, an eye examination is needed urgently.

If the wet form of ARMD is present, the current treatment involves injection of medication into the eye. The medication is targeted at reducing the growth of abnormal blood vessels in the macula.

Dr. Michelle Akler recommends regular eye examinations to screen for macular degeneration, especially in older patients and those with a family history of ARMD. Early detection and treatment allows for the best visual outcome in this difficult condition.

Monday, December 27, 2010

Treatment For Wet Macular Degeneration in Seniors

by: Admin
The National Eye Institute (NEI) had published their facts about Age-Related Macular Degeneration (ARMD) to help patients and their family members to search for general information about the disease.

Age Related Wet Macular Degeneration

In its attempt to ensure better public understanding of the disease, it had detailed the ARMD by starting on its definition. The NEI defined ARMD as “a disease associated with aging that gradually destroys sharp, central vision.” It is then explained that central vision is important to see fine details and helps common daily tasks such as reading and driving. It has to be noted that ARMD causes no physical pain to the patients.

There are two types of ARMD, which is the dry and the wet ARMD. In most cases, elderly adults develop the dry ARMD and it is the most common form of the disease, with some of them progressing into wet ARMD when abnormal blood vessels start developing and ruptures within. Wet ARMD can be treated, but not fully cured, by laser surgery, photodynamic therapy and injections into the eye. These treatments may actually just delay the process of being legally blind, but patients need to be aware that conditions will continue to worsen over time.

Treating wet ARMD with Laser surgery is a procedure which utilizes the laser technology to destroy fragile, leaky blood vessels that had formed abnormally. A high energy light beam is directly focused on the new blood vessels, and it destroys them to prevent further loss of vision. The negative side of this treatment is that it potentially destroys other healthy cells surrounding the treatment area.

Only a small percentage of patients may use laser to treat wet ARMD. The procedure is performed at the doctor’s office or an eye clinic, and laser is more effective if the abnormal, leaky blood vessels are developed away from the middle of the macula, which is called the fovea. It does not mean that the abnormal blood vessels will automatically stop developing after laser surgery, in fact repeated treatments are necessary as the risk of developing new abnormal blood vessels post surgery is high. In some cases, the patient may still suffer vision loss progressively despite repeated treatments.

Another treatment, called the photodynamic therapy, involves the injection of a drug called verteporfin into the patient’s arm, and it travels throughout the body including the new blood vessels in the eye. The drug will attach itself to the surface of new blood vessels. After this, the doctor shines a light into the patients eye for about 90 seconds to activate the drug. The drug, once activated, will destroy the new blood vessels and helps slower down the rate of vision decline. It is topical and aims only at the new blood vessels, so it does not destroy surrounding healthy tissues and cells like the laser surgery.

However, caution has to be taken with the use of this drug. As it gets activated by lights, patient has to avoid going outdoors, or exposing skin or eye to direct sunlight or bright indoor lights for five days after treatment. Remember that the drug is administered through injection on the patient’s arm, and the fact that it travels throughout the body instead of being contained within the eye.

This treatment is basically painless, and can be performed at the doctor’s office in about 20 minutes. However, while it slows down the rate of vision loss, it does not stop vision loss, or restore the patient’s vision if it was already damaged by ARMD. Again, this technique will require repeated treatments as necessary, based on the doctor’s prescription and the progress of your condition.

Another treatment is the use of injection, this time with new drugs that are injected directly into the eyes. The anti-VEGF therapy will see these new drugs block the effects of the specific growth factor that triggers the abnormal blood vessels. Multiple injections will be required, and it can be a monthly affair. Before injection, the eyes are numbed. After injection, the patient will be kept at the doctor’s office for a while so that the doctor may monitor the progress of the eyes before declaring that the patient is safe to go home. It is said that this treatment helps slow down vision loss from ARMD and may also help to improve the sight of patients in some cases.

In any of these treatments, the patient should listen to the doctor because the doctor will know the best option available for each individual.

Sunday, November 28, 2010

Retinal Disease Treatments Double Over 10 Years

by:Jen Blackstock


When most people think of diabetes, the first thing to come to mind is rarely blindness, yet blindness is a very real complication of diabetes: Diabetes is actually the number one cause of new blindness in the United States.

Diabetic retinopathy happens when diabetes damages the tiny blood vessels inside the retina, which therefore stop feeding the retina properly, according to the American Foundation for the Blind. Symptoms can include blurry or double vision; rings, flashing lights or blank spots; dark or floating spots; pain or pressure in one or both of your eyes; and trouble seeing things out of the corners of your eyes. Forty percent of people with diabetes have some form of diabetic retinopathy.

With the rise in the number of people with diabetes and the aging American population, it is no surprise that the number of older Americans undergoing treatment for retinal conditions such as age-related macular degeneration (AMD) and diabetic retinopathy increased 192 percent between 1997 and 2007. Additionally, there has been a significant shift in the types of procedures being performed, a new study has found.

Age-related macular degeneration is a progressive disease of the retina that causes the loss of central vision. Both age-related macular degeneration and diabetic retinopathy can cause vision loss and blindness.

The study analyzed Medicare data from 1997 to 2007 and found that the number of retinal procedures increased 192 percent during that period. The largest year-to-year increase (20 percent) occurred between 2006 and 2007, according to the study published in the October issue of the journal Archives of Ophthalmology.

In terms of actual procedures performed, the largest increase was in treatments for neovascular, or "wet," AMD. New treatments for this condition include intravitreal therapy, or drug injections directly into the eye, of antibodies that block the formation of new blood vessels. From 1997 to 2001, only 5,000 of these procedures were performed each year. By 2007, the number had jumped to 812,413. Also increasing is the use of vitrectomy, a surgery to remove the gel inside the eye in order to treat retinal detachment -- increased 72 percent between 1997 and 2007.

"Retinal disease is highly prevalent among older individuals, and both age-related macular degeneration and diabetic retinopathy account for more than half the irreversible blindness in older Americans. The prevalence of both macular degeneration and diabetic retinopathy increases with age, and the number of Americans affected by these conditions is expected to increase substantially as the number of Americans older than 65 years doubles from 2010 to 2040," says study author Dr. Pradeep Ramulu, of Wilmer Eye Institute at Johns Hopkins University in Baltimore.

With the rise of cases of diabetes and the aging of the baby boomer population in the United States, eye care and blindness prevention is becoming increasingly important within the medical community.

Monday, November 22, 2010

New Techology Detects Retinal Disease

by Martha L. Hernández


McALLEN — For years, the only way for doctors into the back of the eye for a retina inspection involved special eye drops, which dilated the patient’s pupils and required the wearing of dark glasses for hours after the exam.

Now, scientists have developed the Optomap Retinal Exam, which eliminates the need for drop. Patients only see a quick, green flash of light.

“This test is a non-invasive way of doing it. We don’t put drops in your eyes, we just take a picture of the back of your eye and under 25 seconds (later), it gives us a 3D image. We can review the image with you on the computer (immediately after),” said Dr. Fiona Kolia, a therapeutic optometrist at Astoria Vision Source.

“We can look at it with different filters. This test is very important because it allows us to tell you about the health not only of your eye — where we can detect (diseases like) glaucoma (or) macular degeneration, any holes or tears, anything that is in the eye that shouldn’t be there — it also tells us about the health of your body,” Kolia said.

The new technology has detected other medical conditions in people seeking glasses or contacts.

“For example, a young person, healthy, walked in and he had a hemorrhage in his eye that is caused by high blood pressure, and high blood pressure is a silent killer, you refer them (to their family doctor) and they can start to get treated and take care of themselves,” Kolia said. Undetected high blood pressure can lead to strokes and other serious complications, Kolia noted.

“Sometimes we are the first to detect if the people have signs of high blood pressure, diabetes, high cholesterol, any arteriosclerosis in the eye and we refer them to their family physician” Kolia said.

Kolia is the only optometrist south of Corpus Christi that has an Optomap.

“Sometimes people just don’t see well and they might think it’s just their glasses” Kolia said. “There was a gentleman that had a macular degeneration that needed to be treated … but sometime in younger people (that) kind of problem happens due to high stress and the macular area (center of the eye) can become swollen and you can lose your central vision (if you do not treat it),” Kolia said.

“What we hope to do is be able to screen a lot of people, I think that in this area it is very important for diabetics. We want to it as a tool and make people aware that an eye exam not only involves getting you a better pair of glasses, it involves looking at the interior structures of the eye and behind the eye,” which can aid in the detection of numerous health issues, Kolia said.

Insurance companies do not typically cover treatment with an Optomap. If there is a definite medical diagnosis it may be billed as a retinal photo in some instances with some insurance plans. Patients without insurance pay $37 for the test.

“In a lot of people who are nearsighted, the eyeball elongates, so it is important to look behind the eye because they can develop a retinal detachment,” Kolia said.

Kolia said the Optomap likely would be added to the regular battery of tests conducted by optometrists and ophthalmologists during routine eye exams as the technology comes into more widespread use.

Saturday, October 30, 2010

Telescope Implant Improves Vision in Macular Degeneration

by Kathleen Louden
(Chicago, Illinois) — People with end-stage age-related macular degeneration (AMD) have improved visual acuity and quality of life after receiving an intraocular implant containing a tiny telescope in 1 eye, new research shows. An ophthalmologist who participated in the clinical trials presented the unpublished results here at the American Academy of Ophthalmology and Middle East Africa Council of Ophthalmology 2010 Joint Meeting.

The telescope implant improves vision in "a disease in which the patient is legally blind and has no surgical or medical alternatives," the presenter, Stephen Lane, MD, told Medscape Medical News. He was a medical monitor for the pivotal trials and is an adjunct professor of ophthalmology at the University of Minnesota, Minneapolis.

In July, the US Food and Drug Administration approved the telescope implant, also called the implantable miniature telescope (VisionCare Ophthalmic Technologies), to improve vision in some patients with end-stage AMD.

Telescope Magnifies Images More Than 2 Times

"The reason why this [device] works is a magnification effect, so the central scotoma can be overcome," Dr. Lane told meeting attendees.

This pea-sized implant, which replaces the natural lens, magnifies images greater than 2 times and projects the images onto a healthy part of the retina, according to the device manufacturer. It is available in 2 models: 1 that provides 2.2 times the magnification and another that gives 2.7 times magnification. Patients use the eye that received the implant for central vision and use the untreated fellow eye for peripheral vision.

To be eligible for this class 3 medical device, patients must have bilateral geographic atrophy or "post-wet" AMD disciform scars and must not yet have had cataract surgery, although they can have cataract, Dr. Lane said. Other eligibility criteria, according to the US Food and Drug Administration, include age 75 years or older and "stable severe to profound vision impairment" resulting from bilateral central scotoma.

In a multicenter clinical trial of more than 200 patients who received the implant, the mean best corrected visual acuity before implantation was worse than 20/300, Dr. Lane said. More than 80% of patients had at least a 2-line improvement in visual acuity on the Snellen chart 1 year after surgery, and 46% of patients improved 4 lines or more at 1 year, he reported. Most of those patients, according to Dr. Lane, maintained their improved visual acuity 2 years postoperatively (75% with 2 lines or better and 43% with 4 or more lines of improvement).

"Quality of life gains also are clinically meaningful," Dr. Lane said. "Patients were less dependent, better able to recognize people, and better able to...do activities of daily living."

Endothelial Cell Loss Possible

A possible complication of the implant is the loss of corneal endothelial cells. In the study, there was a 20% loss of epithelial cells, which Dr. Lane called "a little high." He said ophthalmologists should inform their patients that substantial endothelial cell loss can lead to corneal decompensation and the need for a corneal transplant.

A Michigan ophthalmologist who did not participate in the studies, George Williams, MD, said in an interview that study investigators told him that most patients in the studies tolerated the implant well and found it very helpful.

However, the device is for "a select group of patients with end-stage AMD," said Dr. Williams, chairman of the Department of Ophthalmology at Oakland University William Beaumont School of Medicine, Royal Oak, Michigan.

He mentioned, as did Dr. Lane, that patients need to undergo an evaluation to determine whether they can benefit from this device, which involves a trial with an external telescope.

"Only 1 in 5 patients who are screened actually end up getting the device," Dr. Williams told Medscape Medical News.

After the surgery, patients must receive training with a low-vision specialist. "It's hard to walk around with a telescope in your eye," Dr. Williams said.

Patients who did not tolerate the implant were those who could not adjust to using 1 eye for near-vision tasks and the other eye for distance vision, Dr. Lane said during the meeting.

Friday, July 16, 2010

Gene Therapy for Eye Diseases

The pharmaceutical giant Genzyme has started a clinical trial to see whether a drug to treat macular generation could be delivered via long-lasting gene therapy rather than monthly injections.



Eye colors: Drusen, the yellow flecks in this image of the retina, are common in people with age-related macular degeneration. These flecks are made up of proteins involved in the part of the immune system called the complement system, which has also been implicated in the disease by genetic studies.


A drug called Lucentis, made by Genetech, has proved effective at treating the wet form of age-related macular degeneration, which can lead to blindness. Some 200,000 Americans a year are diagnosed with the disease. But Lucentis has to be injected into the eye every month or two, a burden for patients and doctors.
Lucentis binds to and neutralizes a wound-healing growth factor known as VEGF. This binding action stalls the excess growth of blood vessels in the eye that characterizes age-related macular degeneration. Genzyme's gene therapy drug, officially called AAV2-sFLT01, would insinuate itself into the patient's retinal cell to produce the same VEGF-binding protein as Lucentis over far longer periods--up to several years.


A phase 1 clinical trial of Genzyme's gene therapy treatment began at the end of May. Three patients received the treatment, according to Sam Wadsworth, a Genzyme group vice president in charge of gene and cell therapy. Preliminary results should be available in about a year.


The trial is one of a handful worldwide seeking to prove the effectiveness of gene therapy for eye diseases. The Genzyme trial also involves using new type of virus as the delivery mechanism. Early results of a federally funded trial to deliver normal-functioning genes to patients with a rare retinal disease known as type 2 leber congenital amaurosis, or LCA, have confirmed that this "viral vector" has merit for eye treatments, several researchers say.


The LCA trials "demonstrated success both in terms of safety and ability to introduce the gene and have efficacy and success," said Jeffrey S. Heier, an assistant professor at Tufts University School of Medicine and director of retinal research at Ophthalmic Consultants of Boston, a private practice group, who is involved in the Genzyme research. "This study is taking the virus vector that they used, and [Genzyme has] taken what has really been the success of the anti-VEGF story and they've packaged the two together."


Eyes have been an early target for gene therapy because they are small--meaning they require relatively little active dose, they are self-contained, and because the tools of eye surgery have advanced enough to make the treatments possible. The drug has to be delivered to the retina, a thin film lining the inner wall of the eye. Instrumentation has improved in recent years to allow injections through the retina without piercing it, said Shalesh Kaushal, chairman of ophthalmology at University of Massachusetts Memorial Medical Center and UMass Medical School.


To Kaushal, who is involved in the Genzyme study as well as the LCA research, the big challenge will be broadening the use of gene therapy to dozens more diseases, and using that understanding to eventually reach beyond the eye. "If one could understand those fundamental cellular, biochemical events and identify targets, you might have the chance to treat many diseases with a single gene-therapy construct," Kaushal said.


Earlier gene therapy programs used a type of virus called adenovirus to target genes, but both the LCA and Genzyme trials are using adeno-associated virus, which is far less inflammatory and which expresses itself over longer periods than adenovirus, therefore making the treatment last longer, Wadsworth said. Viruses are used to deliver gene therapies because they are adept at getting through cell walls.


VEGF is involved in vascular cell growth throughout the body, and its expression increases in the presence of a wound. Studies have shown that with Lucentis, virtually all the VEGF-binding protein stays within the eye, and does not significantly affect VEGF levels elsewhere in the body, Wadsworth says. Genzyme's drug will provide even lower levels of the VEGF-binding protein, so it's expected that the drug will not have any adverse affects throughout the body, he said.


The trick will be getting the cells to produce enough VEGF-binding protein to help patients, said Peter Campochiaro, a professor at the Wilmer Eye Institute at Johns Hopkins Medicine, who is involved in the research. In addition to establishing safety, the current phase 1 trial will explore four different doses of the study

Thursday, June 10, 2010

Wider access to drug to prevent and reverse eye damage

By: Staff Writer

Manitobans now have wider access to a drug to prevent and reverse eye damage, Health Minister Theresa Oswald said Wednesday.

The drug Lucentis is now available through doctors' offices to treat wet macular degeneration.

Last March the province said Manitoba Health would cover Lucentis treatment though the Misericordia Eye Centre of Excellence as of June 1.

At that time the province said it wanted to expand patient access to Lucentis through other retinal specialists' offices.

Oswald said Lucentis is now accessible through doctors' offices ahead of schedule.

Wet macular degeneration is a disease that can impair vision and cause blindness.

Lucentis has been available at no cost to Manitobans with wet macular degeneration since June 1 through the Misericordia and Manitoba retinal specialists.

Manitoba Health says up to 1,000 patients could benefit from this new program annually.

Saturday, June 6, 2009

Exploiting Cortistatins' Essence

Simple analogs of a complex natural product may protect against loss of vision
Carmen Drahl

By making simplified versions of cortistatins, marine natural products that halt new blood vessel growth, researchers can treat excessive vessel growth in mice with macular degeneration. The analogs may inspire a new class of medications for the disease, which is a leading cause of vision loss.

Cortistatins A and J are potent blockers of angiogenesis, or new blood vessel growth, but the natural supply is scarce and chemical syntheses of the cortistatins haven't produced enough material for animal testing. Chemists Barbara Czakó, László Kürti, and E. J. Corey at Harvard University decided to study analogs instead.

"What distinguishes cortistatins are two basic groups at opposite ends of a steroidlike scaffold that are important for bioactivity," Corey says. His team incorporated those essential groups, a dimethylamino and an isoquinoline group, on opposite ends of an easy-to-build steroid and made refinements to optimize anti-angiogenic activity in cells. In collaboration with vascular biologists Akiko Mammoto and Donald E. Ingber of Harvard Medical School, they found that some of their compounds blocked angiogenesis in a mouse model of macular degeneration but did not show signs of toxicity in cellular assays (J. Am. Chem. Soc., DOI: 10.1021/ja902601e).

The most effective pharmaceutical treatment for macular degeneration is administered by injection into the eye, Corey notes. All of his team’s most potent analogs are water soluble and could lead to an eye-drop-based treatment, he says.

Chemist Samuel J. Danishefsky of Memorial Sloan-Kettering Cancer Center and Columbia University praised the work, saying that Corey's team “has increased the scope of the cortistatins by weaving them into a steroid setting which provided a doable terrain for chemical synthesis.”

"In terms of an exercise in blending intuition and rational discovery, this paper could emerge as a classic," Danishefsky adds.

Studies from other groups suggest that inhibitors of the particular angiogenesis pathway that the cortistatin analogs target may lead to side effects, cautions David A. Cheresh, who studies tumor angiogenesis at the University of California, San Diego. Nonetheless, the analogs "represent exciting new leads in the search for the next class of anti-angiogenic agents" and should be studied further, he adds.

Corey tells C&EN that the cortistatin analogs are effective in mice at very low doses of less than 1 mg and would also be locally administered. Therefore, the amount of drug that the rest of the body would see is likely to be essentially zero, vastly reducing the potential for side effects, he says.

In related work, independent teams led by Hiromasa Kiyota at Tohoku University in Japan and Phil S. Baran at Scripps Research Institute have tested simplified cortistatins in cells, but neither team has reported animal studies (Biosci. Biotechnol. Biochem. 2008, 72, 2992; Angew. Chem. Int. Ed., DOI: 10.1002/anie.200901116).