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: Thirty patients were treated with three 21 - day cycles of bortezomib 1 . 3 mg / m ( 2 ) on days 1 , 4 , 8 , and 11 plus dexamethasone 40 mg on the day of bortezomib injection and the day after plus cyclophosphamide at 900 , 1 , 200 , or 1 , 500 mg / m ( 2 ) on day 1 .
### Output Text:
Thirty patients were treated with three 21 - day cycles of <span class="chemical">bortezomib</span> 1 . 3 mg / m ( 2 ) on days 1 , 4 , 8 , and 11 plus <span class="chemical">dexamethasone</span> 40 mg on the day of <span class="chemical">bortezomib</span> injection and the day after plus <span class="chemical">cyclophosphamide</span> at 900 , 1 , 200 , or 1 , 500 mg / m ( 2 ) on day 1 . 