Cancer drugs proving worth earlier in testing

Michael Weitz was out of options. The Californian had endured chemotherapy, radiation and surgery but his lung cancer still spread to his bones and brain.

With time running out, the emergency room physician entered a Phase I study - the earliest stage of human testing for a new medicine - of crizotinib. The drug works for about 4 percent of advanced lung cancer patients with a mutated form of a protein called ALK.

"Once I knew that I had that mutation, I knew that I had an exciting new chance," said Weitz, now 55, who is cancer-free after three years of taking the drug now sold by Pfizer as Xalkori after an unusually swift development process.

It typically has taken a decade and $1 billion to bring a new treatment to market. But in the last two years a handful of cancer drugs - including Onyx Pharmaceutical Inc's Kyprolis for multiple myeloma, Roche's Zelboraf for melanoma, and Pfizer's Xalkori - were approved in about half that time because of improved genetic screening, more definitive Phase I trials and the dire need for new, effective treatments.

"We hope to be able to shave years off the time it takes to get final approval and save hundreds of millions of dollars per drug," said Robert Schneider, director of translational cancer research at New York University Cancer Institute. "We're going to see this as a sea change over the next five years."

Weitz's story is a dramatic example of how personalized medicine is advancing 10 years after researchers sequenced the human genome, enabling drugs to target specific genetic variations. The emerging trend is likely to bring more effective treatments to desperate patients faster, increase the number of annual drug approvals and cut research costs through earlier and more reliable data. It will also help drugmakers identify ineffective therapies sooner, although it may not necessarily lead to lower priced medicines.

There are some concerns about the faster approval process but most agree that the benefits of a potentially life-saving drug outweigh the risks. "The accelerated development of new drugs can be a double-edged sword," said Mace Rothenberg, head of oncology for Pfizer. "As you move more quickly some questions may be unanswered."

He said those answers can come from trials conducted after drugs are approved, and the Food and Drug Administration often requires post-marketing studies following expedited approvals

Historically, Phase I trials did little more than reveal the dose of an experimental drug that could safely be tolerated before larger studies determined clinically meaningful benefit. But advances in genetic screening and an improved understanding of the biology of cancer are enabling researchers to identify patients most likely to benefit from specific cancer treatments.

"You can see positive signals much more quickly, and clinically you can spare patients for whom the drug is not likely to work," said Dr. Michael Davies, assistant professor in the department of melanoma medical oncology at MD Anderson Cancer Center in Houston.