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: Phase 2 trial of liposomal doxorubicin ( 40 mg / m ( 2 ) ) in platinum / paclitaxel - refractory ovarian and fallopian tube cancers and primary carcinoma of the peritoneum .
### Output Text:
Phase 2 trial of liposomal <span class="chemical">doxorubicin</span> ( 40 mg / m ( 2 ) ) in <span class="chemical">platinum</span> / <span class="chemical">paclitaxel</span> - refractory ovarian and fallopian tube cancers and primary carcinoma of the peritoneum . 