Sentence: The sensitivity of human neuroblastoma-derived cell lines , cell line-derived , and patient-derived xenograft ( PDX ) models with varying ALK statuses to crizotinib combined with topotecan and cyclophosphamide ( topo/cyclo ) was examined .
Drug combination annotation:
[{'class': 'POS', 'spans': ['crizotinib', 'topotecan', 'cyclophosphamide'], 'is_context_needed': True}]