VEGF Inhibitors: Real or Imagined Cancer Treatments?
Monoclonal antibodies (MAbs) directed against vascular endothelial growth factor (VEGF) receptors on cancer cells, have been found to slow the growth of a variety of cancers including colorectal, breast and lung. While a number of blockbuster biotechnology products( based on these MAbs (Avastin by Genentech/Roche and Eribitux by Bristol-Myers Squibb/ImClone/Merck KGA) have been approved to treat a variety of different cancers their effectiveness as cancer treatments has been the subject of intense debate since their approvals.
Although numerous human clinical trials have shown that VEGF inhibitors slow the growth and development of tumors, they, as a class, don’t seem to significantly increase the survival time for most cancer patients. Further, Avastin and Erbitux are generally not used as stand alone treatments but are used in combination with more tradition anti-cancer chemotherapies. The high costs of these drugs, (Avastin’s worldwide sales hit $ 3.5 billion last year) and their variable effectiveness have caused many to question the usefulness of this class of drugs to treat cancer patients.
The well-publicized use of these drugs as cancer treatments coupled with anecdotal evidence about their effectiveness has put practicing oncologists between a rock and a hard place when it comes to treating patietns with cancer. In an article in Sunday’s New York Times one prominent oncologist said that depsite the controversy, “I still use Avastin routinely. It’s not a slam dunk and, in fact, the incremental benefit may be more modest than we want to admit.” Others are more sanguine about VEGF inhibitors as cancer treatments “Even when these drugs ‘work,’ what kind of impact are you talking about?” said Fran Visco, president of the National Breast Cancer Coalition. But we market them and give them to everybody.”
Nevertheless, most oncologists find it difficult to withhold Avastin or Erbitux from cancer patients seeking hope. As one oncologist put it “ When I am not sitting in front of a patient, I think about whether drugs like Avastin are worth it to society. But when facing a seriously ill patient, who, based on clinical trial results, might benefit — even if only a little — from Avastin, I think about the patient’s needs.”
Regardless of their therapeutic value, the main issue with this class of anti-cancer drugs is cost. Avastin treatment costs patients about $4000-$9000 per month— Eribitux treatment is even more costly! While Medicare and most private insurers cover 80% of the cost, patients can be responsible for 20% or more of treatmetn costs. As posited in the Times article “If Avastin were inexpensive or if it cured cancer or even held it at bay, as the drug Gleevec does for blood cancer, few might care.”
Are anti-VEGF drugs real cancer treatments or expensive red herrings? Clearly, the jury is still out on that one. That said, I think that only cancer patients can truly provide an accurate response to that question!
Until next time…
Good Luck and Good Job Hunting!!!!!!!
