* Trial studied Tarceva, Zactima, Nexavar, Targretin
* Nexavar helped 61 percent of patients with KRAS mutation
* New trial design may be way to test new cancer drugs
* Progress at two months predicted if patients would live (Updates throughout with details from news conference; changes dateline and byline)
By Maggie Fox, Health and Science Editor
WASHINGTON, April 18 (Reuters) - Researchers said they helped advanced lung cancer patients fare better by matching their tumors to targeted drugs, in what they said is the first significant trial to show it is possible to choose the best drug for an individual patient.
They tested four so-called targeted therapies in patients with specific biomarkers -- mutations that the drugs were designed to counteract.
After eight weeks, 46 percent of the patients on the trial had their tumors grow more slowly or shrink, compared with about 30 percent of usual lung cancer patients.
The best results were seen with Nexavar, known generically as sorafenib, sold by Onyx Pharmaceuticals Inc ONXX.O and Bayer AG BAYGn.DE, the researchers told a meeting of the American Association for Cancer Research on Sunday.
“Sorafenib performed very well regardless of marker status,” Dr. Edwin Kim of M.D. Anderson told a news conference. Nexavar is designed to target a mutation in a gene called KRAS that is seen in lung and other cancers.
More than half -- 56 percent -- of the patients with no mutations in KRAS were helped by Nexavar and 61 percent of those with the mutation were helped, Kim told the meeting, compared with 32 percent for the other three drugs.
“It overall had very impressive activity,” Kim said.
Nexavar is approved for liver and kidney cancer. It has the “potential to blaze a trail in lung cancer as well,” Kim said.
The trial, called BATTLE for Biomarker-integrated Approaches of Targeted Therapy for Lung Cancer Elimination, was designed to be different from other cancer trials. The researchers looked for some kind of effects after two months of treatment -- either limited growth of the tumor or a sign it had shrunk.
As they learned from the trial, they adapted. The first 97 patients were randomly treated and as the study progressed, information on individual mutations and on the early results were used to fine-tune who got what treatment.
“If a patient was able to achieve disease control at eight weeks their survival was 11.3 months,” Kim said. Patients who did not see any effects of the drugs by two months only lived on average for seven months.
This means doctors will be able to assess treatments much sooner, saving time, money and anguish for patients and their families.
Another difference -- they got nice, big samples of patients’ tumors up front, so they could continue to test the tissue as new drugs are designed or as new discoveries are made about them. The researchers want to encourage doctors and patients to do this as a matter of course with lung cancer.
Tarceva, a pill, helped 71 percent of the lung cancer patients with EGFR mutations and 34 percent of those without them.
Erwin Lobo, a 37-year-old patient with stage 3 lung cancer, is one. “I still do not have my hair and ... I used to have really nice skin but this is one of the side-effects,” Lobo told the news conference. “But hey, I am here, I am sharing my story with you all and I am very happy I am alive.”
Lobo’s cancer had spread to his brain and he should have only lived 30 days after that happened, but he was at the news conference more than four months later.
Other drugs in the study were AstraZeneca PLC's AZN.L Zactima, or vandetanib, designed to act against VEGF, a gene used by tumors to grow vessels to supply blood; and bexarotene, sold under the brand name Targretin by Eisai Pharmaceuticals to treat a type of lymphoma, which targets a gene called cyclin D1.
The study, funded by the U.S. Army, included 255 patients with advanced lung cancer who had previously been treated with chemotherapy.
The drugs had few side-effects, with 11.5 percent having a collapsed lung, or pneumothorax, and 6.5 percent suffering high-grade toxicities -- both much lower-than-usual rates.
The researchers are already designing BATTLE 2 and BATTLE 3 trials to test more patients, new biomarkers and new drugs. (Additional reporting by Deena Beasley in Los Angeles; Editing by Maureen Bavdek)