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: Among the patients with 1 year of follow - up , NVP therapy was significantly associated with developing rash and d4T therapy with developing peripheral neuropathy ( p < 0 . 05 ) .
### Output Text:
Among the patients with 1 year of follow - up , <span class="chemical">NVP</span> therapy was significantly associated with developing rash and <span class="chemical">d4T</span> therapy with developing peripheral neuropathy ( p < 0 . 05 ) . 