Sentence: Recent clinical trials have reported improved survival for two novel agents ; ipilimumab , a humanized , IgG1 monoclonal antibody that blocks cytotoxic T-lymphocyte-associated antigen 4 ( CTLA-4 ) and vemurafenib , a BRAF ( v-raf murine sarcoma viral oncogene homolog B1 ) inhibitor targeting an activating mutation in the serine-threonine-protein kinase BRAF gene .
Drug combination annotation:
[{'class': 'POS', 'spans': ['ipilimumab', 'vemurafenib'], 'is_context_needed': False}]