I. To evaluate the efficacy of the combination of crizotinib and pemetrexed (pemetrexed disodium) compared to pemetrexed monotherapy as measured by progression-free survival (PFS) in anaplastic lymphoma kinase (ALK)+ non-squamous non-small cell lung cancer (NSCLC) patients who achieved clinical benefit with crizotinib monotherapy and subsequently progressed systemically.