Billions of health-care dollars can be saved by aggressively pursuing studies of comparative effectiveness of treatments. Drug therapy of macular degeneration provides a striking example.
Macular degeneration is a common cause of visual loss in older people. In the more severe, "wet" form of the disease, new blood vessels grow beneath the macula, the part of the retina that provides our most sensitive vision. Growth of the new vessels is accompanied by leakage of blood, which distorts the overlying cells of the macula. This leads to progressive blurring and eventual loss of vision. Scientists identified a growth factor that stimulates the growth of the new vessels.
Avastin, an anti-cancer agent already approved by the Food and Drug Administration, works by blocking the growth factor. After extensive research, retina specialists began to use Avastin "off-label" for treating macular degeneration. Once FDA approves a drug, it may be used off-label for conditions for which it was not initially approved.
Results of therapy for macular degeneration were quite good.
In 2006, Genentech, the company that also manufactures Avastin, gained FDA approval for Lucentis, a GF blocker specifically designed to treat MD. Both drugs are given by injection into the eye. In 2007, Genetech sought to block the use of Avastin for treating MD. Protests from retinal specialists led to a reversal of this restriction. The principal difference between the two drugs is cost. A dose of Lucentis costs $2000, while a similar dose of Avastin costs $50.
For patients who must pay a deductible for their medications, the cost differential is substantial.
In May, the New England Journal of Medicine released a study in which the two drugs were compared in similar populations of patients with MD. When given monthly, there was no difference in benefits. Side-effects were higher (24 versus 19 per cent) among the Avastin group. The issue of side-effects needs further study.
This study was sponsored by Federal agencies. When pharmaceutical companies perform research on their new products, they typically compare the effectiveness of a new drug against a placebo, an inactive substance. Generally, if a new drug is safe and more effective than a placebo in addressing a particular condition, FDA approves it. When an advance in drug therapy is presented in a medical journal, most of the authors of the study report compensation of some sort from the drug maker. Aggressive advertising campaigns directed both at care providers and consumers further the idea that newer drugs are always better. As older drugs lose patent protection they are seldom promoted by their manufacturers.
Very little research compares products employed to treat the same condition. Such studies are costly, often requiring years of follow-up. Lobbyists for established products have sought to limit funding for research into comparative efficacy of both drugs and clinical procedures.
Critics of comparative effectiveness research contend that it will lead to rationing. Medicare and other health plans might restrict choice of medications by requiring the prescription of the less expensive among competing drugs with similar benefits. The prerogatives of care providers to choose the drug that they deem best for a particular condition would be blocked.
Currently, Medicare approves both Avastin and Lucentis for treating MD. Surprisingly, some private insurers only pay for Lucentis.
Ideally, the choice among competing medications should be based upon effectiveness, safety, and cost. Research sponsored by independent agencies is the best hope that this information will be available when physicians and other health care providers consider the most appropriate drug and therapy for their patients. The costliest or newest drug may not be superior.
Contact Clif Cleaveland at cleaveland1000@comcast.net.