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.

Richard Scheller, head of research and early development for Roche’s Genentech unit, which has produced most of the company’s top-selling cancer medicines, said, “you can cut a couple of years out of the clinical trial process by basically doing your pivotal trial straight from Phase I.”

Drugmakers who have benefited from the expedited approval process declined to discuss how much money was saved from the industry average for drug development.

FDA’S NEW “BREAKTHROUGH” DESIGNATION

With impressive enough early results, health regulators are more willing than ever to accept early or midstage trials as adequate proof of safety and effectiveness, rather than insisting on larger, more expensive and time-consuming pivotal Phase III studies that have been a standard requirement.

“The drugs are simply better,” Dr. Richard Pazdur, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, said of the new targeted cancer medicines.

With older highly toxic chemotherapy drugs, he said, “many of the discussions we had at the agency dealt with whether we should approve the drug or not. With some of these newer drugs, the issue is how fast we can approve them, not whether they should be approved,” Pazdur said.

The FDA has come up with a new breakthrough designation for drugs it views as a substantial improvement over existing therapies. With the designation - five have been awarded so far with 12 more drugs currently under consideration - the agency works more closely with drugmakers to identify approval requirements and work out commercial manufacturing issues.