DNA Testing Spurring New Breed of Cancer Drugs
For some of his leukemia patients, Dr. Jean-Pierre Issa sends off a snippet of their D.N.A. for testing to help him deduce the best possible treatment.
Certain gene mutations might signal the need for chemotherapy, chemotherapy followed by a transplant or experimental drugs.
While the DNA test is very expensive, such “personalized” care is poised to take off — and along with it the number of niche cancer drugs.
“What we are going to see is a remarkable array of these things come along,” says Dr. Issa, an oncologist at University of Texas MD Anderson Cancer Center. “In five to ten years doctors will be able to send a patient’s DNA for analysis and have a menu of 50 to 100 different medicines to choose from. I don’t think this is science fiction.”
More targeted drugs and a wider range of options may make it tougher for pharmaceutical giants to come up with broad-selling blockbusters that typically drive profits, but they still have plenty of potential to rack up gains with a new, more specialized line of drugs.
While some of those drugs might only treat patients numbered in the thousands instead of millions, their profitability can get a boost from their much higher success rates and longer periods of use that might last years instead of the usual six-month course for traditional chemotherapy.
The drugs can also save the healthcare industry billions by enabling doctors to prescribe them only for patients likely to benefit and avoid blanketing those who aren’t likely to respond.
One particularly promising new personalized drug is vemurafenib, a melanoma treatment from Roche’s Genentech and Daiichi Sankyo’sPlexxikondivision that is among more than 4,000 clinical studies that will be discussed at the American Society of Clinical Oncology, ASCO, annual meeting in Chicago from June 4-8.
The drug blocks a genetic mutation known as BRAF that is present in some patients with melanoma, an aggressive and deadly skin cancer that has been all but untreatable in most late-stage cases.
Developing new drugs “is easier now because we understand biology to a far more extensive degree than we did even five years ago,” says Dr. George W. Sledge Jr., president of ASCO and a pioneer in the development of novel therapies for breast cancer. “We’re really able to fingerprint the criminal in fine detail, to identify what’s causing a normal cell to go bad.”
At the same time, it’s also gotten tougher because the picture doctors and researchers have of cancer is far more complicated than it was ten or 15 years ago, he adds.
2010 Global Oncologics Rank by Product
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“We used to think of colon or lung or breast cancer as “a” disease, but they each harbor many sub-diseases,” he says. “We’re often asked, 'When will we cure cancer?' We will never cure cancer. We will cure cancers. Cures for hundreds, if not thousands of cancers will be needed.”
Crizotnib, an experimental lung-cancer drug from Pfizer highlights the potential for niche treatments.
The drug has been shown to aid patients whose tumors express the ALK gene, a culprit in less than 5 percent of non-small cell lung cancers.
Even with that limited potential pool for the drug, its annual sales could reach $2.5-billion, according to aMorningstarestimate.
Its approval is eagerly anticipated by Pfizer, which is scrambling for new bestsellers as its cholesterol pill Lipitor, the No. 1 selling prescription medicine around the globe, loses its U.S. patent protection later this year.
Global oncology drug sales surged to $54.9 billion in 2010, up from $11.5 billion in 2000, according to the IMS Institute for Healthcare Informatics. But growth has slowed since 2006, in part because generic drug makers are stealing market share as patents expire.
By proving extremely effective or by expanding beyond their original intended use, new niche cancer drugs have the potential to wind up becoming significant blockbusters, which could help fill the gap for big pharma, says Michael Kleinrock, director of research development with IMS.
He points toGenentech’s Avastin, which targets the mechanism that builds blood vessels around a tumor, as an example.
Since its approval for use in 2004 to treat metastatic colorectal cancer, the drug has racked up nearly $7 billion in sales as its treatment uses have expanded. The anti-cancer drug also is showing strong results in clinical trials to treat macular degeneration, a leading cause of blindness.
“There’s so much in science that surprises us,” says Kleinrock. “Viagra used to be a heart medicine.”
While cancer medicines already are the biggest-selling drug category in the world, they also remain the biggest opportunity for drug makers.
“There is such a massive unmeant need because we basically have yet to find a cure for most of these cancers,” says Michael Yee, an analyst for RBC Capital Markets. “It’s a fantastic time for the biotech industry.”