In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: A combination of 5 d of nelarabine ( AraG ) with 5 d of etoposide ( VP ) and cyclophosphamide ( CPM ) and prophylactic intrathecal chemotherapy was used as salvage therapy in seven children with refractory or relapsed T - cell leukaemia or lymphoma .
### Output Text:
A combination of 5 d of <span class="chemical">nelarabine</span> ( <span class="chemical">AraG</span> ) with 5 d of <span class="chemical">etoposide</span> ( <span class="chemical">VP</span> ) and <span class="chemical">cyclophosphamide</span> ( <span class="chemical">CPM</span> ) and prophylactic intrathecal chemotherapy was used as salvage therapy in seven children with refractory or relapsed T - cell leukaemia or lymphoma . 