Roche (Genentech) announced on June 6, 2017 at the 2017 ASCO conference that the have results from their first line Phase 3 Global Trial that Alectinib had a median PFS of 25.7 months vs 10.4 months for Crizotinib (over a year longer). The trial also found that Alectinib reduced the risk of cancer progression or death by 53% vs. Crizotinib. Furthermore, at 12 months the incidence of brain metastases was 9% for Alectinib and 41% for Crizotinib. Serious side effects were marginally better with Alectinib.
These results compliment earlier results from a Japan only trial and are likely to be the basis of FDA Application to move Alectinib to the first line setting.
I strongly recommend reading the New England Journal of Medicine (NEJM) article. The charts on page 6 are particularly persuasive.