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: INTERVENTION : Each patient received either intravenous docetaxel 30 mg / m2 / week for 3 consecutive weeks , followed by 1 week off , or the combination of continuous oral thalidomide 200 mg every evening plus the same docetaxel regimen .
### Output Text:
INTERVENTION : Each patient received either intravenous <span class="chemical">docetaxel</span> 30 mg / m2 / week for 3 consecutive weeks , followed by 1 week off , or the combination of continuous oral <span class="chemical">thalidomide</span> 200 mg every evening plus the same <span class="chemical">docetaxel</span> regimen . 