Astex Pharmaceuticals announced that it has initiated an open label, randomized, controlled, multi-center, Phase 2 clinical trial, evaluating HSP90 inhibitor AT13387 in anaplastic lymphoma kinase positive non-small cell lung cancer patients or other potentially crizotinib-sensitive NSCLC patients who have been receiving crizotinib. The trial will evaluate AT13387 as both single agent and in combination with crizotinib in these patients. The AT13387 study will consist of three parts. Part A is a lead-in, single arm, dose escalation segment of the trial in patients with NSCLC who have already been receiving crizotinib, to establish the Maximum Tolerated Dose, or MTD, of the combination. Once the MTD is defined in Part A, and depending on the patient's response to crizotinib, Parts B and C will ensue in which patients will be randomized to continue to receive crizotinib alone, AT13387 alone, or the combination of AT13387 with crizotinib.