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: DSMM XI study : dose definition for intravenous cyclophosphamide in combination with bortezomib / dexamethasone for remission induction in patients with newly diagnosed myeloma .
### Output Text:
DSMM XI study : dose definition for intravenous <span class="chemical">cyclophosphamide</span> in combination with <span class="chemical">bortezomib</span> / <span class="chemical">dexamethasone</span> for remission induction in patients with newly diagnosed myeloma . 