CHICAGO, June 5 (Reuters) - Roche Holding AG's Alecensa halted the spread of lung cancer for a median of 15 months longer than treatment with rival Pfizer Inc's Xalkori with fewer side effects, according to trial results presented on Monday.
Both drugs are designed to treat advanced non-small cell lung cancer in patients with a mutation of the ALK gene, which is found in about 5 percent of all NSCLC patients.
About 12,500 Americans are diagnosed with ALK-positive NSCLC each year, according to the American Society of Clinical Oncology, which featured the study results at its annual meeting in Chicago.
Alecensa, or alectinib, is currently approved only for people with advanced ALK-positive NSCLC that worsens despite treatment with Xalkori, or crizotinib, which is approved as an initial treatment.
Sales of the Roche drug totaled 182 million Swiss francs last year ($189 million), while Pfizer's Xalkori sales were $145 million.
The 303-patient trial found that Alecensa reduced the risk of cancer progression or death by 53 percent compared with Xalkori. Patients on the Roche drug lived for a median of 25.7 months before their cancer worsened, compared with 10.4 months with Xalkori.
Researchers said cancer spread to the brain for just 9 percent of Alecensa patients, compared with 41 percent of the Xalkori group.
The study "establishes alectinib as the new standard of care for initial treatment in this setting," according to lead study author Dr. Alice Shaw, director of thoracic oncology at Massachusetts General Hospital in Boston.
Severe side effects, including fatigue, constipation and muscle aches were seen in 41 percent of Alecensa patients and 50 percent of Xalkori patients.
Pfizer said it is continuing "to build on the success of Xalkori" by investigating numerous biomarker-driven therapies and immuno-oncology agents, including late-stage trials of an experimental ALK/ROSI inhibitor called lorlatinib. (Reporting by Deena Beasley; Editing by James Dalgleish)