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: Treatment , given every 21 days for a maximum of three cycles , consisted of paclitaxel by 3 - hour infusion followed the next day by a fixed dose of cisplatin ( 75 mg / m2 ) .
### Output Text:
Treatment , given every 21 days for a maximum of three cycles , consisted of <span class="chemical">paclitaxel</span> by 3 - hour infusion followed the next day by a fixed dose of <span class="chemical">cisplatin</span> ( 75 mg / m2 ) . 