Tag: Genentech

Categories
My Opinion Treatments

Avastin Does Not Cause Infection

One of the most feared complications of eye injections is blindness.  This infection is called endophthalmitis.  Last week the FDA issued an alert the 12 cases of endophthalmitis were caused by the injections.

The cause of the infections is NOT Avastin.  There is nothing wrong with the drug itself.

Avastin Must Be RePackaged

Upon further investigation, a common denominator was a single pharmacy and, possibly, a single lot of tainted syringes.

Avastin is not FDA approved for injection into the eye, but it is standard of care.  Also, Genentech manufactures Avastin and its close cousin, Lucentis.  Lucentis is FDA approved for the treatment of wet macular degeneration.

Thus, in order for physicians like me, to get Avastin, a larger dose of Avastin is ordered.  Once received the “repackaging” of the ARMD drug involves breaking up the larger dose (usually used for chemotherapy) into many more smaller doses for the eye.  The doses are commonly broken up and placed in small syringes ready for injection.

“Repackaging” sounds kind of haphazard, but it’s not.  A licensed pharmacist will distribute the Avastin in smaller allotments under strict sterile conditions.  There are specific protocols for such “repackaging.”

Compounding Pharmacies Routinely Divide Drugs

Apparently, in one particular pharmacy, either the protocol was breached and/or the sterile laboratory conditions were not maintained and they shipped out a few contaminated syringes.  Unfortunately, this caused 12 individuals loss of vision or blindness.

Fortunately, there was a plausible explanation and widespread panic was avoided.

Avastin, itself, is safe.  The mechanisms used to deliver the drug to your doctor’s office are proven safe, too.  Realize that over 2 million injections have been given.

What Does this Mean? Normally, informed consent is obtained prior to the delivery of an injection.  We inform the patient that there is a risk of infection that could lead to blindness.  That risk is estimated to be about 1:1000 to 1:2000 (approximates the risk of cataract surgery).

The source of the infection is thought to be the bacteria that reside on your eyelashes and the surface of the eye, not the actual substance injected nor the container in which it was shipped.

In the end, this was a very rare and unfortunate event for the 12 patients, their families and their doctors.  The culprit; however, was not Avastin.

 

Enhanced by Zemanta
Categories
Macular Degeneration Treatments

FDA Upholds Denial of Avastin

Avastin is no longer FDA approved for breast cancer.  This decision was upheld at a hearing last week.  Eye patients, however, need not worry.

The Food and Drug Administration had removed its approval for Avastin for the treatment of breast cancer last December.  A hearing last week (June, 2011) allowed Genentech and the drugs’ supporters, to voice their concerns about the removal of the drug.

  • While the FDA has removed its approval for one type of cancer, the drug is not being removed from the market.

The FDA argues that bevacizumab (generic name) is not effective in treating breast cancer patients and, so,  reversed its original decision.  The counter argument claims that Avastin is effective, though in a minority of patients.

This anti-VEGF drug has become effective treatment for wet macular degeneration.  Avastin, used for the treatment of a variety of cancers, has become the standard of care and is used my most retinal specialists for their patients.

Avastin Not Effective for Breast Cancer

The initial data indicated that bevacizumab, when given along with another drug, stymied the progression of the disease for 5-6 months compared to the other drug alone.  Avastin was given quick approval for breast cancer.

Since then, re-investigation could not duplicate the results, yet the incidence of GI bleeding complications were notable.  There was no evidence showing improved lifespan either.

The FDA upheld the decision.

What Does This Mean?

Removing an FDA approval only means that insurance companies are likely not to reimburse doctors and hospitals for the treatment.  While treatment can theoretically still be performed, it would require that patients pay for it out-of-pocket.  Thus, it is cost prohibitive in most cases.

Regardless of the FDA hearing, eye patients do not need to worry.  Though the drug may no longer be available for patients with breast cancer, the drug will still be on the market for other treatments.

We should be able to continue using it as a first line treatment for wet macular degeneration.  Avastin may have lost its FDA approval for the treatment of breast cancer, but this is different than a drug being removed from the market.

(By the way, I have wondered why the FDA could not have compromised, in that, as long as existing patients accept the risks, treatment could continue.  Why not remove the FDA approval from this point forward?)

Enhanced by Zemanta
Categories
Macular Degeneration Treatments

Avastin Versus Lucentis; And the Winner Is…

Both Avastin and Lucentis are anti-VEGF treatments for wet macular degeneration. Both are manufactured by Genentech (Roche). A small study just (February 2010, Ophthalmology) published found no clinical difference between the two drugs, that is, one worked as well as the other.

There has been quite a debate over the difference between the two drugs and their ability to treat wet macular degeneration. There are differences in cost, FDA approval, etc., but this is the first study that has compared the two drugs head to head.

The large difference in cost between the two drugs has led to speculation that the popular use of Avastin among retina specialists is due to price alone. The chemotherapy agent costs less than $50 per injection whereas Lucentis is priced at $2000 per injection. Supporters of Avastin (including yours truly) feel that its use is justified by the excellent results and in many areas of the country has become the standard of care.

Other than price there are differences in the number of isoforms that the molecules block; Avastin blocks more isoforms than Lucentis, but is this significant in the eye? No one knows. It seems not to matter.

What Does this Mean? This study was a retrospective study, that is, the results were determined looking backwards. One weakness of retrospective studies is that there are too many variables between patient groups to allow a true “head to head” comparison. The result, too much bias in the study and it is difficult to make true, concrete conclusions. It doesn’t mean that retrospective studies are worthless, but you must keep in mind there may be flaws in the conclusions.

A prospective, randomized study is really the gold standard. In these studies, similar patients (similar in age, vision, race, etc.) are treated exactly the same and differ only in the treatments they receive. In this case, similar patients would be randomly treated with either Avastin or Lucentis. The patients are treated with the exact same protocol with respect to dosage, frequency of injection, etc. The groups are then followed for a given length of time.

The results of prospective studies have far less bias and results are taken to be more meaningful. An NIH sponsored prospective study is underway comparing Avastin vs. Lucentis and may be completed by 2011.

This “study” also gives both patients and doctors reassurance that the use of Avastin is justified.

For now, there seems to be no advantage to using either drug.

Reblog this post [with Zemanta]
Categories
Macular Degeneration

Lucentis: Another Shot in the Eye, Effective TX for ARMD

Lucentis™ is the second intraocular, anti-VEGF injection FDA approved for the treatment of wet macular degeneration.  It was approved in 2006.  It fast became the mainstay of the treatment for wet macular degeneration.  It is still popular today among retina specialists for treatment of wet macular degeneration.

Facts About Lucentis

  • FDA approved for the treatment of Wet Macular Degeneration
  • Lucentis is a portion of an antibody directed against VEGF
  • Lucentis binds directly to VEGF
  • Lucentis is given as a series of intraocular injections
  • Directed against several forms of VEGF

Lucentis and Diabetic Retinopathy

  • It is not FDA approved for the treatment of diabetic retinopathy
  • May be suitable for diabetic macular edema
  • May be suitable for proliferative diabetic retinopathy

As with all the anti-VEGF intraocular injections, Lucentis is given as a series of injections.  The frequency varies, but it is safe to say that most retina specialists recommend injections every 4-6 weeks.  Originally, Lucentis was recommended for a complete year or more.

For our purposes, Lucentis is a portion of an antibody (specifically the Fab Fragment) directed against several forms of VEGF.  It does not block all isoforms (types) of VEGF.  Practically speaking, the antibody latches on, just as Macugen (an aptamer, but functions the same way as an antibody), to the VEGF molecule.  The binding to VEGF prevents VEGF from “plugging-in” to the receptor.  The receptor never gets activated.  VEGF effects are blocked.

Lucentis is manufactured by Genentech (Roche).  Genentech (Roche) also manufacturers Avastin™ (more tomorrow).  Compared to most drugs in ophthalmology, Lucentis is pretty pricey.  Though Medicare and other insurance companies do cover the cost of the drug, they do not cover the full price of the drug.  The difference is usually paid out of pocket by the patient if there is no “gap” insurance.

What Does This Mean? Lucentis rapidly became popular for the treatment of wet macular degeneration.  There were several reasons; effective marketing, “second generation” phenomenon (ergo, must be better) and the acceptance of intraocular injections overall.  By 2006, more and more doctors were now comfortable with the whole “package” or idea of giving intraocular injections and so, too, were patients.  The results were truly remarkable.  The injections, whether Macugen (approved 2004) or Lucentis………….patients were getting better!

As with all the anti-VEGF drugs, there may be true implications for their use in the treatment of diabetic retinopathy.  Remember that VEGF is implicated in vascular leakage, inflammation and neovascularization.  Vascular leakage and neovascularization can occur in diabetic retinopathy.  Inflammation is thought to be a key component as well.   In theory, anti-VEGF should be a “slam dunk” for the treatment of diabetic retinopathy. Many small studies have already indicated that anti-VEGF is an effective treatment for diabetic retinopathy.

“Randy”

Randall V. Wong, M.D.

Retina Specialist, Ophthalmologist
Fairfax Virginia

Verified by MonsterInsights